# Fruit and vegetables. Opportunities and challenges for small-scale sustainable farming

Fenton Beed, Makiko Taguchi, Bruno Telemans, Remi Kahane, Fabrice Le Bellec, Jean-Michel Sourisseau, Eric Malézieux, Magalie Lesueur-Jannoyer, Peninna Deberdt, Jean-Philippe Deguine, et al.

► To cite this version:

Fenton Beed, Makiko Taguchi, Bruno Telemans, Remi Kahane, Fabrice Le Bellec, et al. Fruit and vegetables. Opportunities and challenges for small-scale sustainable farming. FAO; CIRAD, 196 p., 2021, 978-92-5-134238-1. 10.4060/cb4173en. hal-04708335

HAL Id: hal-04708335

https://hal.science/hal-04708335v1

Submitted on 31 Jul 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>
<figure><img src="image_2.png" /></figure>

Food and Agriculture
Organization of the
United Nations

<figure><img src="image_3.png" /></figure>

cirad

AGRICULTURAL RESEARCH
FOR DEVELOPMENT

<figure><img src="image_4.png" /></figure>

# FRUIT AND VEGETABLES

Opportunities and challenges for small-scale sustainable farming
<figure><img src="image_5.png" /></figure>

INTERNATIONAL YEAR OF
FRUITS AND VEGETABLES

2021

The UN designated International Year of Fruit and Vegetables 2021, approved in 2019 and formally launched on 15 December 2020 advocates for the importance of healthy diets and lifestyles through sustainable food systems. It also seeks to strengthen the role of small-scale and family farmers in sustainable farming and production practices, accountable for the livelihoods of millions of rural families, and raises awareness of the nutritional benefits

of fruit and vegetable, and also of the high levels of food loss and waste in fruit and vegetable supply/value chains. This publication was developed to provide further technical information and policy guidance, with a particular focus on opportunities and challenges for small-scale farmers, for further developing the fruit and vegetable sector towards achieving the SDGs.
# FRUIT AND VEGETABLES

## Opportunities and challenges for small-scale sustainable farming

<figure><img src="image_6.png" /></figure>

Published by
the Food and Agriculture Organization of the United Nations (FAO)
and
Agricultural Research Centre for International Development (CIRAD)
Required citation:

FAO and CIRAD. 2021. *Fruit and vegetables – Opportunities and challenges for small-scale sustainable farming*. Rome.
https://doi.org/10.4060/cb4173en

The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO) or the Agricultural Research Centre for International Development (CIRAD) concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or products of manufacturers, whether or not these have been patented, does not imply that these have been endorsed or recommended by FAO or CIRAD in preference to others of a similar nature that are not mentioned.

The views expressed in this information product are those of the author(s) and do not necessarily reflect the views or policies of FAO or CIRAD.

ISBN 978-92-5-134238-1 [FAO]

© FAO, 2021

<figure><img src="image_7.png" /></figure>

Some rights reserved. This work is made available under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 IGO license (CC BY-NC-SA 3.0 IGO; https://creativecommons.org/licenses/by-nc-sa/3.0/igo/legalcode).

Under the terms of this license, this work may be copied, redistributed and adapted for non-commercial purposes, provided that the work is appropriately cited. In any use of this work, there should be no suggestion that FAO endorses any specific organization, products or services. The use of the FAO logo is not permitted. If the work is adapted, then it must be licensed under the same or equivalent Creative Commons license. If a translation of this work is created, it must include the following disclaimer along with the required citation: "This translation was not created by the Food and Agriculture Organization of the United Nations (FAO). FAO is not responsible for the content or accuracy of this translation. The original [Language] edition shall be the authoritative edition."

Disputes arising under the license that cannot be settled amicably will be resolved by mediation and arbitration as described in Article 8 of the license except as otherwise provided herein. The applicable mediation rules will be the mediation rules of the World Intellectual Property Organization http://www.wipo.int/amc/en/mediation/rules and any arbitration will be conducted in accordance with the Arbitration Rules of the United Nations Commission on International Trade Law (UNCITRAL).

**Third-party materials.** Users wishing to reuse material from this work that is attributed to a third party, such as tables, figures or images, are responsible for determining whether permission is needed for that reuse and for obtaining permission from the copyright holder. The risk of claims resulting from infringement of any third-party-owned component in the work rests solely with the user.

**Sales, rights and licensing.** FAO information products are available on the FAO website (www.fao.org/publications) and can be purchased through publications-sales@fao.org. Requests for commercial use should be submitted via: www.fao.org/contact-us/licence-request. Queries regarding rights and licensing should be submitted to: copyright@fao.org.
## ACKNOWLEDGEMENTS

This publication was prepared under the codirection of Fenton Beed, Team Leader for Rural, Urban, Crop and Mechanization Systems (NSPLD), Plant Production and Protection Division (NSP) of the Food and Agriculture Organization of the United Nations (FAO), and Rémi Kahane, Horticulture Leader at *Centre de coopération internationale en recherche agronomique pour le développement* (CIRAD), with continuous support from Makiko Taguchi and Bruno Telemans (NSPLD-FAO).

## THE KEY CONTRIBUTORS

**Writer:** Gordon Ramsay

**FAO:** Fenton Beed, Makiko Taguchi, Bruno Telemans, Mayling Flores Rojas, Melvin Medina Navarro, Guido Santini, Rémi Nono Womdim and Jingyuan Xia

**CIRAD:** Rémi Kahane, Fabrice Le Bellec, Jean-Michel Sourisseau, Eric Malézieux, Magalie Lesueur-Jannoyer, Péninna Deberdt, Jean-Philippe Deguine and Emile Faye

**Special thanks to expert reviewers** (in alphabetical order):

Jane Ambuko, University of Nairobi; Marie-Joséphe Amiot-Carlin, INRAe; Sayed Azam-Ali, Crops for the Future; Baptiste Bert, La Coopération Agricole; Eric Boa; Luigi Damiani; Gilles Delhove; Narinder Dhillon, World Vegetable Center; Thomas Dubois,ICIPE; Andreas Ebert; Arij Everaarts; Marjon Fredrix; Julie Howard, Center for Strategic & International Studies; Lisa Kitinoja, The Postharvest Education Foundation; Ravza Mavlyanova; Sisir Kumar Mitra, ISHS; Srinivasan Ramasamy, World Vegetable Center; Pepijn Schreinemachers, World Vegetable Center; Yüksel Tüzel, ISHS; and Marco Wopereis, World Vegetable Center.

**FAO contributing units and individuals** (in alphabetical order):

NSP: Plant Production and Protection, ESA: Agrifood Economics, ESF: Food Systems and Food Safety, ESN: Food and Nutrition, EST: Markets and Trade, NFO: Forestry, NSL: Land and Water, OCB: Office of Climate Change, Biodiversity and Environment, OER: Office of Emergency and Resilience, OIN: Office of Innovation, and SFS: Subregional Office for Southern Africa.

Sabine Altendorf, Amrouk El Mamoun, Heiko Bammann, Giulia Bottaro, Simone Borelli, Pierre Marie Bosc, Tian Cai, Innocent Chamisa, Sandra Corsi, Sonia Dias, Stefano Diulgheroff, Olivier Dubois, Bonnie Furman, Isaac Guzman, Buyung Hadi, Wilson Hugo, Joanna Ilicic, Luc Ingenbleek, Shangchuan Jiang, Siobhan Kelly, Preetmoninder Lidder, Charlotte Lietaer, Pascal Liu, Chikelu Mba, Shawn McGuire, Joseph Mpagalile, Hafiz Muminjanov, Alexandrova Nevena, Divine Njie, Arshiya Noorani, Zitouni Oulddada, Dafydd Pilling, Moctar Sacande, Dirk Schulz, and Kim Anh Tempelman.

**Editor:** Jeannie Marshall

**Graphic designer:** Delphine Bonnet (www.dbgraph.com)

**Illustrator:** Cyril Girard (www.editions-mediterraneus.fr)

**Proofreader:** WRENmedia

**Printed by:** Pure Impression
CONTENTS

<table><tr><td>Tables - Figures - Boxes</td><td>VI</td></tr><tr><td>Acronyms</td><td>VII</td></tr><tr><td>Forewords (FAO & CIRAD)</td><td>VIII</td></tr><tr><td>Preface</td><td>X</td></tr></table>

CHAPTER 1

Introduction - 1

Defining and classifying fruit and vegetables - 2

Fruit and vegetables statistics - 6

Losses - 11

Making the case for fruit and vegetables; based on the Sustainable

Development Goals - 12

CHAPTER 2

Production systems, practices and technologies - 23

Water management - 24

Rainfed cultivation - 24

Irrigated cultivation - 26

- Water collection - 27

- Low-cost irrigation - 28

- High-cost irrigation systems - 28

- Deficit irrigation - 29

Soil health - 30

- Conservation agriculture - 30

- Minimizing soil disturbance - 31

- Maintaining a protective organic cover over the soil - 31

- Crop rotations and associations - 33

Managing fertilisers - 34

Plant health - 36

Surveillance and detection - 37

Resistant varieties and healthy seeds - 38

Chemical control - 38

Cultural practices - 40

- Integrated production and protection - 40

- Managing the agrobiodiversity - 43

- Grafting - 44

- Netting - 47

- Soil solarization and heat treatments - 48

Biological control - 49

- The sterile insect technique and area-wide integrated pest management - 50

Crops and varieties and access to genetic resources - 52

- Access to seeds and planting materials - 52

- Vegetable crops - 53

- Vegetable seed production - 54

- Formal seed systems - 56

- Fruit crops - 58

- Woody fruit crops - 58

- Herbaceous fruit crops - 59

Breeding - 60

- Vegetables - 60

- Fruit - 63

Conservation - 64

- In situ conservation - 64

- On-farm management - 64

- Ex situ conservation - 65

- Vegetable genetic resource conservation - 66

- Fruit genetic resource conservation - 67

Protected cultivation systems - 67

- Climate management - 70

- Water management - 71

- Soil health - 72

- Plant health - 73

- Crops and varieties - 73

- Pollination - 74

- Adoption constraints - 74
TABLES - FIGURES - BOXES

TABLES

<table><tr><td>TABLE 1. Fruit crops included in FAOSTAT production and trade databases</td><td>4</td></tr><tr><td>TABLE 2. Vegetable crops included in FAOSTAT production and trade databases</td><td>7</td></tr><tr><td>TABLE 3. Most commonly produced fruit and vegetable crops and production of total fruit and vegetables per region and per country (listed in descending order)</td><td>9</td></tr><tr><td>TABLE 4. Policies and incentives for sustainable production and food systems for fruit and vegetables</td><td>138</td></tr></table>

FIGURES

<table><tr><td>FIGURE 1. Types of vegetables</td><td>3</td></tr><tr><td>FIGURE 2. Production of fruit between 1968 and 2018, global total and per region</td><td>10</td></tr><tr><td>FIGURE 3. Production of vegetables between 1968 and 2018, global total and per region</td><td>10</td></tr><tr><td>FIGURE 4. Fruit and vegetable range (median and extremes) of reported food loss and waste percentages by supply chain stage, 2000-2017</td><td>14</td></tr><tr><td>FIGURE 5. Range (median and extremes) of reported food loss and waste percentages at the wholesale and retail stage, 2001-2017</td><td>16</td></tr><tr><td>FIGURE 6. Different types of fruit and vegetable production systems depending on levels of intensification with external inputs (X-axis) and on agrobiodiversity (Y-axis)</td><td>25</td></tr><tr><td>FIGURE 7. Vegetable and fruit diversity of markets</td><td>98</td></tr></table>

BOXES

<table><tr><td>BOX 1. Examples of African and Asian neglected and underutilized species (NUS) fruit and vegetables</td><td>12</td></tr><tr><td>BOX 2. Various stages of the SAFTA transitional agroforestry cropping system, Brazilian Amazon</td><td>33</td></tr><tr><td>BOX 3. Crop rotation to combat bacterial wilt of tomato in the French West Indies</td><td>41</td></tr><tr><td>BOX 4. The control of fruit flies on the French island of Réunion in the Indian Ocean</td><td>42</td></tr><tr><td>BOX 5. Grafting tomato to combat bacterial wilt caused by Ralstonia solanacearum in Viet Nam</td><td>45</td></tr><tr><td>BOX 6. Low-cost anti-insect netting for small-scale vegetable growers in Africa</td><td>46</td></tr><tr><td>BOX 7. The cucurbit breeding programme of the World Vegetable Center and private sector partnerships</td><td>61</td></tr><tr><td>BOX 8. Fruit and vegetables in the International Treaty on Plant Genetic Resources for Food and Agriculture</td><td>62</td></tr><tr><td>BOX 9. Germplasm collection of bananas in the world</td><td>66</td></tr><tr><td>BOX 10. Dimitra Clubs for improved extension services</td><td>113</td></tr><tr><td>BOX 11. Tree tenure</td><td>117</td></tr><tr><td>BOX 12. Quality declared seed and planting material systems</td><td>126</td></tr><tr><td>BOX 13. Green insurance pilot</td><td>131</td></tr><tr><td>BOX 14. Digital Agriculture to meet the needs of small-scale farmers and value chain actors</td><td>134</td></tr></table>
ACRONYMS

**AEAS** Agricultural Extension and Advisory Services

**APSA** Asia and Pacific Seed Association

**CGIAR** Consultative Group on International Agricultural Research

**CIRAD** *Centre de coopération internationale en recherche agronomique pour le développement*
*(Agricultural Research Centre for International Development)*

**CRFS** city region food systems

**CWR** crop wild relatives

**DLT** distributed ledger technologies

**FAO** Food and Agriculture Organization of the United Nations

**FAOSTAT** Free database of food and agriculture data

**FFS** Farmer Field Schools

**GAP** good agricultural practices

**GDIC** Green Delta Insurance Company

**GMP** good manufacturing practices

**ICT** information and communication technologies

**IFAD** International Fund for Agricultural Development

**IFC** International Finance Corporation

**IPM** Integrated Pest Management

**IPP** Integrated production and protection

**ISHS** International Society of Horticultural Science

**MRL** maximum residues levels

**NES** not elsewhere specified

**NGO** non-governmental organization

**NUS** neglected and underutilized species

**PAA** Purchase from Africans for Africa

**PGS** Participatory Guarantee Systems

**QDS** Quality Declared Seed System

**SAFTA** *Sistema Agroflorestal de Tomé-Açu (Agroforestry System of Tomé-Açu)*

**SDG** Sustainable Development Goals

**SOFI** State of Food Insecurity in the World

**UN** United Nations

**WFP** World Food Programme

**WHO** World Health Organization
The delicious flavours of fresh seasonal fruit and vegetables are among life's pleasures. Their vitamin, mineral and fibre content keep us well-nourished and healthy.

However, for too many people the availability, affordability and, therefore, the consumption of fruit and vegetables, does not meet recommended daily dietary requirements. The lack of these foods in diets is resulting in widespread malnutrition and is reducing global wellbeing.

Empowering small-scale farmers in low-middle-income countries to increase their production of fresh fruit and vegetables in environmentally, economically and socially sustainable ways is a priority if we are to achieve the Sustainable Development Goals.

This mission is supported by the incredible diversity of fruit and vegetables that exist locally, nationally and internationally. Farmers have an array of options when it comes to deciding what to grow, when and where. They can select diversified cropping systems adapted to their environment, pests and diseases, seasons, changes in climate and according to market demands.

Some challenges must be addressed, such as the need for an enabling environment to increase consumer demand for fruit and vegetables. Fruit and vegetables are highly perishable and vulnerable to food loss and waste. To meet demand, farmers must be integrated into stable value chains and city region food systems. This is essential to ensure that harvested produce is kept cool, processed carefully and quickly, and delivered to markets without loss of quality. In addition, since fruit and vegetables are often eaten raw, special attention must be paid to assurances that the food is safe by reducing the risks of chemical (pesticides and mycotoxins) and biological (pest, disease and food-borne pathogen) contamination. Such safety is also important to the regulated markets where fruit and vegetables are traded.

Sustainable fruit and vegetable production is labour, input and knowledge intensive and provides a wealth of opportunities for decent employment opportunities such as for specialized farm inputs, post-harvest services and marketing. Furthermore, the logistics involved in crop calendars, cultivation and harvesting, managing post-harvest facilities, coordinating deliveries, and systems to ensure the traceability of produce, require the expanded use of digitalization data services in both rural and urban areas.

This publication has been prepared to support the United Nations International Year of Fruits and Vegetables, which will encourage the increased consumption of nutritious food to promote a healthy global population and increased wellbeing through thriving food systems with sustainable production practices at their core.

Empowering
small-scale
farmers
to sustainably
produce
more fruit
and vegetables
is a priority

<figure><img src="image_8.png" /></figure>

Food and Agriculture
Organization of the
United Nations

**Mrs Beth Bechdol**
Deputy Director-General
Food and Agriculture Organization
of the United Nations

<figure><img src="image_9.png" /></figure>
CIRAD has a long tradition of research for development in the tropical and Mediterranean fruit and vegetable sector. Its scientific teams are committed to working in partnership with all stakeholders to ensure a sense of ownership of the research results while focusing on the main target, which is to benefit family farming. CIRAD provides a direct response to the issues and concerns of populations, especially agricultural households in the south where they are most vulnerable to climate hazards and to health and economic crises.

Beyond a classical sector approach, mobilizing all its scientific disciplines – from agronomic to human sciences – and its stakeholders – in the public and private sectors and in civil society – CIRAD considers horticulture to be a prime target for studying the agroecological transition, the integration into the concept of "One Health", and the territorial approach.

Fruit and vegetables, and traditional horticultural production systems, encompass an enormous range of cultivated biodiversity, made up of rotations and interrelationships between crops, some of which are known only to farmers. They must be understood and recognized, preserved and improved, together with their creators and farming managers, to contribute to the sustainability of agriculture.

Fruit and vegetables are highly nutritious, and this, among their many benefits, makes them essential for human health. Though people everywhere must be encouraged to eat them, any campaign related to increasing production and consumption must go along with efforts to reduce the health and environmental risks from contamination and pollution as well as efforts to change the poor diets and sedentary lifestyles that often accompany the urbanization of populations.

The perishability of fruit and vegetables has long shaped the technical and spatial organization of food systems in relation to distance to markets. Today, conservation, processing, transportation and packaging technologies, as well as information and communication technologies, are redesigning this structure in view of economic and ecological optimization and food sovereignty.

Even though fruit and vegetables account for the largest share of world trade in value, they make up only a small part of the diets of most women and children, especially in sub-Saharan Africa. These sectors represent the lowest budget for public agricultural research. The International Year of Fruits and Vegetables will be an opportunity for CIRAD and the international community to change this situation and remove the obstacles to developing sustainable horticultural systems.

Fruit and vegetables are highly nutritious, and this, among their many benefits, makes them essential for human health

**Mr Michel Eddi**
Chief-Executive Officer
Agricultural Research Centre
for International Development

<figure><img src="image_10.png" /></figure>

<figure><img src="image_11.png" /></figure>

cirad

AGRICULTURAL RESEARCH
FOR DEVELOPMENT
PREFACE

<figure><img src="image_12.png" /></figure>

There are 690 million undernourished people living in the world today, 750 million people suffering food insecurity, 2 billion people lacking access to safe and nutritious foods and 3 billion people unable to afford a healthy diet. The State of Food Insecurity in the World (SOFI) 2020 reports that the burden of malnutrition in all its forms poses a significant challenge to those who suffer it (FAO et al., 2020). According to estimates from 2019, 21.3 percent (144 million) of the world's children under 5 years of age were stunted, 6.9 percent (47 million) were wasted and 5.6 percent (38 million) were overweight. Diets in low-income countries rely more on staple foods and less on fruit, vegetables and animal proteins than in high-income countries. The Food and Agriculture Organization of the United Nations (FAO)/World Health Organization (WHO) recommendation of a minimum of 400 g of fruit and vegetables per person per day is only met in parts of Asia and in upper-middle-income countries where sufficient fruit and vegetables are available for human consumption. The global poverty rate is projected to reach 8.8 percent in 2020, rising for the first time since 1998. The impact of COVID-19 is exacerbating these trends and putting vulnerable people even more at risk, which could cause another 132 million people to be added to the global number of undernourished (Kharas, 2020). Restrictions implemented to combat the spread of COVID-19 have reduced the availability of labour for fruit and vegetable production and have limited transport and marketing activities, which has resulted in increased consumer prices for fruit and vegetables. Put simply, the world is not on track to achieve Zero Hunger by 2030 (FAO et al., 2020)!

In order to achieve the 2030 Agenda for Sustainable Development, all United Nations (UN) Members adopted the 17 Sustainable Development Goals (SDGs) in 2015 (https://www.un.org/sustainabledevelopment/sustainable-development-goals/) as a universal call to action to end poverty, protect the planet and improve the lives and prospects of everyone, everywhere.

Promoting sustainable crop production is a critical part of FAO's work with partners to contribute to global efforts to achieve the SDGs and is central to realizing FAO's strategic objectives. In particular, the sustainable production of fruit and vegetables requires attention because the current supply does not meet global nutrition requirements (SDGs 2 and 3). Fruit and vegetables are highly perishable, making them a "hot spot" in the fight to reduce food loss and waste (SDGs 2 and 12). The vast diversity of fruit and vegetable crops provides small-scale farmers with greater options for adapting to climate shocks and stresses and mitigating climate change (SDG 13) and environmental and market shocks across different production settings (SDGs 1 and 15). Fruit and vegetables are high-value crops that can be grown on small areas of land, creating economic opportunities for small-scale farmers in rural, peri-urban and
urban settings as well as in conflict zones and in fragile contexts (SDGs 1, 3, 11 and 16). Since fruit and vegetables are often eaten fresh or raw, food safety is a critical issue. Promoting good practices in producing, harvesting and post-harvest handling of fresh produce lowers the risk of food contamination (FAO and WHO, 2003) and helps maintain quality, thereby reducing losses (SDGs 2 and 12). Since fruit and vegetable value chains are high value and are labour and knowledge intensive, they can generate on-farm and off-farm employment opportunities and create decent work that is attractive to youth and other vulnerable populations, such as migrants (SDGs 4 and 8). Initiatives to make fruit and vegetable production and supply chains more sustainable can be particularly strategic points of entry for empowering women (SDG 5), since it is traditionally women who produce and handle fruit and vegetables while men focus more on staple crops.

One impetus for the timing of this publication is the designation by the UN of 2021 as the International Year of Fruits and Vegetables. This provides an opportunity to emphasize the important role played by fruit and vegetables in efforts to reduce poverty and malnutrition in all its forms, including: undernutrition (wasting, stunting, underweight), inadequate minerals or vitamins, overweight and obesity resulting in metabolic-related non-communicable diseases. This publication has been prepared as a key contribution to this International Year and in recognition of the critical role played by the sustainable production of fruit and vegetables in achieving the SDGs.

This publication is intended to provide guidance to practitioners and policy makers on sustainable fruit and vegetable production, and value chain management, that is resilient to changes in the climate or in market demand. Such resilience can be achieved by balancing economic, social and environmental objectives to achieve development that meets the needs of the present without compromising the ability of future generations to meet their own needs. FAO's report *Building a Common Vision for Sustainable Food and Agriculture* (FAO, 2014a) describes sustainability in terms of the following five principles:

1. Improving efficiency in the use of resources, including reducing loss and waste, is crucial to sustainable agriculture.

2. Sustainability requires direct action to conserve, protect and enhance natural resources.

3. Agriculture that fails to protect and improve rural livelihoods, equity and social wellbeing is unsustainable.

4. Enhanced resilience of people, livelihoods, communities and ecosystems is key to sustainable agriculture.

5. Sustainable food and agriculture require responsible and effective governance mechanisms.

> This is a key contribution to the International Year of Fruits and Vegetables
Fruit
and vegetable
crops are
different
from staple
crops: they are
highly diverse,
perishable
and nutrient
dense

This publication is an evolution of FAO's Save and Grow series. The first, *Save and Grow: A policymaker's guide to the sustainable intensification of smallholder crop production* (FAO, 2011a), followed by *Save and Grow: Cassava* (FAO, 2013a) and *Save and Grow in practice: maize, rice, wheat* (FAO, 2016). These publications set out an approach for meeting three interconnected challenges:

1. providing options for small-scale farmers and the most vulnerable people dependent on agriculture to increase their incomes, wellbeing and resilience;

2. safeguarding and revitalizing the natural resource base (water, land, soil and genetic resources), which is the foundation for global food and nutrition security, but which is being increasingly threatened and degraded by a number of factors, including disasters, climate change and unsustainable agricultural production systems that both harm the environment and threaten public health; and

3. supplying enough safe and nutritious food to meet the demands of expanding and increasingly urban populations whose dietary patterns are changing.

Many of the practices and principles for the sustainable production of staple crops to 1) generate income, 2) protect the environment, and 3) ensure social equity, are also appropriate to the production of fruit and vegetables. Similarly, many of the farmers and their households are coping with high levels of poverty and food and nutrition insecurity and are particularly vulnerable to the impacts of disasters and climate change, increasing water scarcity, pests and diseases, loss of soil fertility and shortage of productive land (due to unsustainable production methods).

However, fruit and vegetable crops are fundamentally different from staple crops. Fruit and vegetables are highly diverse, perishable and nutrient dense. They can generate significantly higher incomes from small units of land, little water and nutrients. Their sustainable production and post-harvest management are knowledge and labour intensive and require high-quality inputs such as seeds and technologies or practices to appropriately manage water, nutrients, soil, pests and diseases and to manage the perishability of the produce prior to reaching market. The high-value market potential and nutrient density of fruit and vegetables are directly linked to how they are produced and handled, and how fresh they are when delivered to markets. This generates unique opportunities for new on-farm and off-farm enterprises to provide high-quality inputs, post-harvest services and market linkages.

The vast diversity of fruit and vegetable crop species and their available varieties offer numerous opportunities for small-scale farmers to produce highly nutritious and high-value crops in their environment. At the same time, it is unrealistic to prepare a "users guide" that could be useful for all small-scale fruit and vegetable production systems.
The most appropriate pathway available to small-scale farmers will be determined by the type of crop, variety, cropping system, environmental conditions, local capacities, accessibility to, or proximity of, markets and other challenges, as well as the types of shocks and stresses that might be faced and will necessarily involve making trade-offs to find an inclusive approach to meet social, economic and environmental objectives.

For this reason, this document provides an overview of the general challenges and opportunities for small-scale farmers when starting up or expanding fruit and vegetable production or when integrating these crops into their existing production system. It provides guidance on options to ensure sustainable production, stable value chains and dynamic markets. Wherever possible recommendations are made on how policy makers can create an enabling environment to support a thriving fruit and vegetable sector in their country or region, and these are summarized in Table 4.

With these considerations in mind, this document has been divided into five chapters:

**CHAPTER 1**

**Introduction**, provides a working definition for fruit and vegetables and makes the case for supporting

small-scale farmers to sustainably intensify and market their fruit and vegetable production.

**CHAPTER 2**

**Production systems, practices and technologies,**

describes farm management options for small-scale fruit and vegetable farmers to ensure that production is sustainable, and it addresses crop genetic resources, seed systems and the management of water, soil, nutrients, pests and diseases in the context of disasters, climate change, nutrition insecurity and endangered biodiversity.

**CHAPTER 3**

**Value chains,** focuses on options to integrate small-

scale commercial fruit and vegetable farmers into socially-inclusive value chains, including innovative post-harvest handling practices and services, market linkages, maintenance of or increases to nutritional densities, and to reduce food loss and waste.

**CHAPTER 4**

**Enabling environment,** describes actions by practitioners and policy makers in different

governmental, institutional and social settings to promote the sustainable production and consumption of safe, nutritious and affordable fruit and vegetables.

**CHAPTER 5**

**The way forward,** presents key interventions and gaps that innovation could address to facilitate the

sustainable production of fruit and vegetables in most low- and middle-income countries across the world.

<figure><img src="image_13.png" /></figure>
<figure><img src="image_14.png" /></figure>
CHAPTER 1

Introduction

* Defining and classifying fruit and vegetables 2

* Fruit and vegetables statistics 6

* Losses 11

* Making the case for fruit and vegetables 12

<figure><img src="image_15.png" /></figure>
## Defining and classifying fruit and vegetables

The International Year of Fruit and Vegetables defines fruit and vegetables as the "edible parts of plants (e.g. seed-bearing structures, flowers, buds, leaves, stems, shoots and roots), either cultivated or harvested wild, in their raw state or in a minimally processed form" (FAO, 2020f).

Excluded are:

* starchy roots and tubers such as cassava, potato, sweet potato and yams (although the leaves of these plants are consumed as vegetables);

* dry grain legumes (pulses);

* cereals including corn;

* nuts, seeds and oilseeds such as coconuts, walnuts, sunflower seeds;

* medicinal, herbal plants and spices, unless used as vegetables;

* stimulants such as tea, cacao, coffee; and

* processed and ultra-processed products made from fruit and vegetables such as alcoholic beverages (wine, spirits), plant-based meat substitutes, or fruit and vegetable products with added ingredients (packed fruit juices, ketchup).

The precise botanical definition of the word "fruit" is: the seed-bearing structure (or, more accurately, the ripened ovary as not all fruit have seeds) in flowering plants. The word "vegetable" is not a botanical term. For consumers, and for the purposes of this document, fruit and vegetables are distinguished by their culinary uses and their taste: a fruit is commonly the sweet or sour part of a plant, and a vegetable is the savoury part.

The different types of crops in the family Cucurbitaceae (cucurbits) can serve to illustrate how culinary tastes and uses distinguish fruit from vegetables. Cucurbits include squashes, zucchini and pumpkins (Cucurbita spp.), cucumbers and various melons (Cucumis spp.), watermelon (Citrullus lanatus) and gourds (Momordica spp., Lagenaria siceraria, Luffa acutangula, Luffa cylindrica, Benincasa hispida, Trichosanthes spp.). The edible part of all these crops is called the fruit (although zucchini flowers can also be eaten as a vegetable, as can the leaves of some pumpkins and chayote). It is the sweet tasting cucurbits (melons and watermelons) that are commonly considered as fruit, whereas other cucurbits are considered vegetables. Unripe papayas and mangoes can also be consumed as vegetables.

For some important vegetable crops, the edible part of the plant is the botanical fruit, for example tomatoes (Solanum lycopersicum), African
<figure><img src="image_16.png" /><figcaption>**FIGURE 1**
**Types of vegetables**</figcaption></figure>

Adapted from Nichols and Hilmi (2011)

eggplants (*Solanum aethiopicum*) and different species of peppers (*Capsicum spp*.). But many parts of plants, including the leaves, roots, stems, shoots and bulbs are considered vegetables **(Figure 1)**. Different vegetables can be produced even from the same plant. For example, beets (*Beta vulgaris* subsp. *vulgaris* 'Conditiva' Group) are grown both for their root (beetroot) and their leaves (beet greens).

Some familiar foods, such as carrots (Daucus carota), are grown for their roots and are considered vegetables. However, potatoes (Solanum tuberosum), whose starchy tubers are grown as a staple crop, are considered 'root crops', along with cassava (Manihot esculenta), sweet potato (Ipomoea batatas), taro (Colocasia esculenta), yam (Dioscorea spp.) and corms of the Araceae family (Xanthosoma spp.). These crops are categorized separately from vegetables in the FAOSTAT primary production database and are beyond the scope of this document. However, the leaves of sweet potato, taro and cassava, which are a critically important part of many diets, are considered vegetables.
<table><caption>TABLE 1
Fruit crops included in FAOSTAT production and trade databases</caption><thead><tr><th>FAMILY</th><th>SPECIES AND VARIETIES</th></tr></thead><tbody><tr><td>Actinidiaceae</td><td>- kiwi fruit (Actinidia spp.)</td></tr><tr><td>Anacardiaceae<br>Clusiaceae<br>Myrtaceae</td><td>- mangoes, mangosteens, guavas (respectively Mangifera indica; Garcinia spp; Psidium guajava)</td></tr><tr><td>Arecaceae</td><td>- dates or date palm (Phoenix dactylifera)</td></tr><tr><td>Bromeliaceae</td><td>- pineapples (Ananas comosus; A. sativa)</td></tr><tr><td>Caricaceae</td><td>- papayas (Carica papaya)</td></tr><tr><td>Cucurbitaceae</td><td>- melons, cantaloupes (Cucumis melo)<br>- watermelons (Citrullus lanatus)</td></tr><tr><td>Ebenaceae</td><td>- persimmons (Diospyros kaki: D. virginiana)</td></tr><tr><td>Ericaceae</td><td>- blueberries (Vaccinium myrtillus; V. corymbosum)<br>- cranberries (Vaccinium macrocarpon; V. oxycoccus)</td></tr><tr><td>Grossulariaceae</td><td>- currants (Ribes nigrum; R. rubrum)<br>- gooseberries (Ribes grossularia)</td></tr><tr><td>Lauraceae</td><td>- avocados (Persea americana)</td></tr><tr><td>Moraceae</td><td>- figs (Ficus carica)</td></tr><tr><td>Musaceae</td><td>- bananas (Musa sapientum; M. cavendishii; M. nana)<br>- plantains (Musa paradisiaca)</td></tr><tr><td>Rosaceae</td><td>- apples (Malus pumila; M. sylvestris; M. communis; Pyrus malus)<br>- pears (Pyrus communis)<br>- peaches and nectarines (Amygdalus persica; Persica laevis; Prunus persica)<br>- plums and sloes (Prunus domestica; Prunus spinosa)<br>- apricots (Prunus armeniaca)<br>- cherries (Prunus avium; Cerasus avium; var. duracina; var. juliana)<br>- cherries, sour (Prunus cerasus; Cerasus acida)<br>- quinces (Cydonia oblonga; C. vulgaris; C. japonica)<br>- strawberries (Fragaria spp.)<br>- raspberries (Rubus subg. Idaeobatus)</td></tr><tr><td>Rutaceae</td><td>- lemons and limes (Citrus Limon; C. aurantifolia; C. limetta)<br>- grapefruit and pomelos (Citrus maxima; C. grandis; C. paradisi)<br>- oranges (Citrus sinensis; C. aurantium)<br>- tangerines, mandarins (Citrus reticulata), clementines, satsumas (C. unshiu)</td></tr><tr><td>Vitaceae</td><td>- grapes (Vitis vinifera)</td></tr></tbody></table>
<figure><img src="image_17.png" /></figure>

<figure><img src="image_18.png" /><figcaption>Star fruit</figcaption></figure>

<figure><img src="image_19.png" /><figcaption>Pineapple</figcaption></figure>

<figure><img src="image_20.png" /><figcaption>Tamarillo</figcaption></figure>

<figure><img src="image_21.png" /><figcaption>Pitahaya</figcaption></figure>

<figure><img src="image_22.png" /><figcaption>Watermelon</figcaption></figure>

Also, leguminous crops, which are important rotational crops (e.g. in cereal-based cropping systems) provide another example because of their ability to establish symbiosis with bacteria and fix nitrogen in the soil. Leguminous crops are considered as vegetables when eaten fresh (green peas (*Pisum sativum*)), or as sprouts (mungbean (*Vigna radiata*) and soybean (*Glycine max*)), whereas other legumes, which are harvested for their dry seed (pulses), such as lentils (*Lens culinaris*) are not. Finally, field maize (*Zea mays*) is a cereal grain, but some varieties with higher sugar content (*Zea mays* convar. *saccharata* var. *rugosa*) are vegetables because they are grown to be eaten fresh, canned, or frozen. Baby corn or sweet corn, which is harvested very early from the field and eaten fresh, is also considered a vegetable.

The organization of fruit and vegetable crops and the botanical families they belong to, as applied in the FAOSTAT production and trade databases (FAO, 1994a), are shown in **Tables 1 and 2**, respectively. In the FAOSTAT databases, several vegetable and fruit crops are not named individually because they are of relatively minor international importance in terms of trade.
<figure><img src="image_23.png" /><figcaption>Moringa</figcaption></figure>

<figure><img src="image_24.png" /><figcaption>Chinese cabbage</figcaption></figure>

<figure><img src="image_25.png" /><figcaption>African
eygplant</figcaption></figure>

<figure><img src="image_26.png" /><figcaption>Red onion</figcaption></figure>

<figure><img src="image_27.png" /><figcaption>Black-seed squash</figcaption></figure>

Fruit and vegetables statistics

In the FAOSTAT primary production databases, the aggregated list of vegetables, which is used to derive total production figures (area cultivated, yield, production quantity), includes mushrooms and truffles, which are not considered in this publication. In the FAOSTAT trade databases, which provide data on the quantity and value of imports and exports, fruit and vegetables are aggregated together, and the list includes many commodities that fall outside the scope of this publication (nuts, root crops, pulses) as well as derived products (flours, juices and homogenized preparations).

As with vegetables, FAOSTAT production and trade databases group fruit that have relatively minor international importance under a single category: "fruit, fresh, not elsewhere specified (NES)". The NES classification is also used in the subgroups: citrus fruit, tropical fruit, stone fruit, pome fruit and berries. They are grouped together under the single classification "vegetables, fresh, NES".

Information on the area planted and quantity produced must be interpreted with caution. There are a number of factors that make it particularly challenging to establish a methodology that can provide precise statistics on production. For example, vegetables are diverse; they have different growing cycles and cultivation methods, and they are grown on very different types of sizes of land and types of land holdings.
<table><caption>TABLE 2
Vegetable crops included in FAOSTAT production and trade databases</caption><thead><tr><td>FAMILY</td><td>SPECIES AND VARIETIES</td></tr></thead><tbody><tr><td>Alliaceae<br>(genus Allium)</td><td>- onions, dry (Allium cepa): onions at a mature stage<br>- onions, shallots (green) (Allium cepa; A. fistulosum; A. ascalonicum), young onions pulled before the bulb has enlarged; used especially in salads<br>- leeks and other alliaceous vegetables (Allium porrum; A. schoenoprasum; other allium varieties)</td></tr><tr><td>Amaranthaceae</td><td>- spinach (Spinacia oleracea)</td></tr><tr><td>Apiaceae</td><td>- carrots and turnips (Daucus carota)</td></tr><tr><td>Asparagaceae</td><td>- asparagus (Asparagus officinalis)</td></tr><tr><td>Asteraceae</td><td>- lettuce and chicory (Lactuca sativa; Cichorium intybus var. foliosum; C. endivia var. crispa; C. endivia var. latifolia)<br>- artichokes (Cynara scolymus)</td></tr><tr><td>Brassicaceae</td><td>- cabbages and other brassicas (Brassica chinensis; B. oleracea; all varieties except B. oleracea botrytis)<br>- cauliflower and broccoli (Brassica oleracea var. botrytis, subvar. cauliflora and cymosa)</td></tr><tr><td>Cucurbitaceae</td><td>- cucumbers and gherkins (Cucumis sativus)<br>- pumpkins, squash, gourds (Cucurbita spp.)</td></tr><tr><td>Euphorbiaceae</td><td>- cassava leaves (Manihot esculenta; M. utilissima)</td></tr><tr><td>Leguminosae</td><td>- beans, green (Phaseolus and Vigna spp.): for shelling<br>- broad beans, green (Vicia faba): for shelling<br>- peas, green (Pisum sativum): mostly for shelling, but including edible-podded peas or sugar peas<br>- string beans (Phaseolus vulgaris; Vigna spp.): not for shelling</td></tr><tr><td>Malvaceae</td><td>- okra (Abelmoschus esculentus; Hibiscus esculentus)</td></tr><tr><td>Poaceae</td><td>- green corn (maize) Zea mays, particularly Z. mays var. saccharata</td></tr><tr><td>Solanaceae</td><td>- tomatoes (Solanum lycopersicum)<br>- chillies, peppers (green) (Capsicum annuum; C. fructescens)<br>- eggplants (Solanum melongena)</td></tr></tbody></table>
Further complicating matters is the fact that their short growing cycle means that different vegetables can be intercropped, and they can be grown in rotation on the same piece of land during the same growing season (FAO, 2018a) or with staggered production cycles. It is also important to note that much of the fruit and vegetables grown are often not sold at all or are sold at informal markets, and in many countries, the production statistics reported will not capture the complete picture.

Nevertheless, it is worthwhile reviewing the available data in FAOSTAT to appreciate the most commonly reported fruit and vegetable crops and the total production of fruit and vegetables per region and per country, shown in **Table 3**.

FAOSTAT shows clear trends in increases in the global total production of fruit (Figure 2) and vegetables (Figure 3) between 1968 and 2018. While there are differences between different regions, the rapid increases in Asia are remarkable.

The types of fruit and vegetables categorized in FAOSTAT represent only a small fraction of the total fruit and vegetable diversity. Many fruit and vegetables have been categorized as neglected and underutilized species (NUS). This category encompasses thousands of domesticated, semi-domesticated or wild species that are not viewed as significant commodity crops and have received little attention from researchers and breeders in either the public or private sector (FAO, 2018b). The designation "NUS" can be somewhat fluid: a major crop in one country may be considered a neglected minor crop in another, and in some countries, agricultural statistics and research do not differentiate between NUS and other crops (Lin et al., 2009; Padulosi et al., 2013). Further, NUS have different uses in different countries. A few examples for Africa and Asia are shown in **Box 1**. Interested readers are also referred to **Table 3** of the publication from Ulian et al. (2020) that lists 100 NUS, many of which are fruit and vegetables. The publication cites the scientific studies or projects, networks or international agencies that recommend them and defines which parts are edible (leaves, inflorescences/flowers, fruit, seeds, roots/tubers and/or stems/shoots based on Diazgranados et al. (2020) and whether they are wild, cultivated or both.

Many fruit and vegetable crops are ignored by FAO and national statistics. Despite a lack of data on NUS, they are nutritionally important and many such as tropical fruit from the Amazonian basin (passiflora, roselle, jackfruit, dragon fruit) and from Asia (durian) are traded at local, informal markets. Similarly, numerous tropical vegetables are not included in national databases, especially leafy vegetables such as amaranths or spider plants (Cleome spp.), or seed vegetables such as egusi melons (cucurbits) in West Africa.
2018

<table><thead><tr><th>VEGETABLES PER CROP</th><th>Mt</th></tr></thead><tbody><tr><td>Vegetables, fresh (NES)</td><td>298</td></tr><tr><td>Tomatoes</td><td>182</td></tr><tr><td>Onions, dry</td><td>97</td></tr><tr><td>Cucumbers and gherkins</td><td>75</td></tr><tr><td>Cabbages and other brassicas</td><td>69</td></tr><tr><td>Eggplants (aubergines)</td><td>54</td></tr><tr><td>Carrots and turnips</td><td>40</td></tr><tr><td>Chillies and peppers, green</td><td>37</td></tr><tr><td>Garlic</td><td>28</td></tr><tr><td>Pumpkins, squash and gourds</td><td>28</td></tr><tr><td>Lettuce and chicory</td><td>27</td></tr><tr><td>Cauliflowers and broccoli</td><td>27</td></tr><tr><td>Spinach</td><td>26</td></tr><tr><td>Beans, green</td><td>25</td></tr><tr><td>Peas, green</td><td>21</td></tr><tr><td>Maize, green</td><td>12</td></tr></tbody></table>

2017

<table><thead><tr><th>VEGETABLES PER REGION</th><th>Mt</th></tr></thead><tbody><tr><td>Asia</td><td>843</td></tr><tr><td>Europe</td><td>94</td></tr><tr><td>Africa</td><td>79</td></tr><tr><td>Latin America</td><td>46</td></tr><tr><td>North America</td><td>34</td></tr><tr><td>Oceania</td><td>3</td></tr></tbody></table>

2018

<table><thead><tr><th>VEGETABLES PER COUNTRY</th><th>Mt</th></tr></thead><tbody><tr><td>China</td><td>552</td></tr><tr><td>India</td><td>128</td></tr><tr><td>United States of America</td><td>32</td></tr><tr><td>Turkey</td><td>24</td></tr><tr><td>Nigeria</td><td>16</td></tr><tr><td>Viet Nam</td><td>16</td></tr><tr><td>Mexico</td><td>16</td></tr><tr><td>Egypt</td><td>16</td></tr><tr><td>Iran (Islamic Republic of)</td><td>15</td></tr><tr><td>Russian Federation</td><td>14</td></tr><tr><td>Spain</td><td>13</td></tr><tr><td>Italy</td><td>12</td></tr><tr><td>Indonesia</td><td>12</td></tr><tr><td>Republic of Korea</td><td>10</td></tr><tr><td>Japan</td><td>10</td></tr></tbody></table>

2018

<table><thead><tr><th>FRUIT PER CROP</th><th>Mt</th></tr></thead><tbody><tr><td>Bananas</td><td>116</td></tr><tr><td>Watermelons</td><td>104</td></tr><tr><td>Apples</td><td>86</td></tr><tr><td>Grapes</td><td>79</td></tr><tr><td>Oranges</td><td>75</td></tr><tr><td>Mangoes, mangosteens, guavas</td><td>55</td></tr><tr><td>Plantains and others</td><td>39</td></tr><tr><td>Tangerines, mandarins, clementines, satsumas</td><td>34</td></tr><tr><td>Pineapples</td><td>28</td></tr><tr><td>Melons, other (incl cantaloupes)</td><td>27</td></tr><tr><td>Peaches and nectarines</td><td>24</td></tr><tr><td>Pears</td><td>24</td></tr><tr><td>Lemons and limes</td><td>19</td></tr><tr><td>Fruit, citrus (NES)</td><td>14</td></tr><tr><td>Papayas</td><td>13</td></tr><tr><td>Plums and sloes</td><td>13</td></tr></tbody></table>

2017

<table><thead><tr><th>FRUIT PER REGION</th><th>Mt</th></tr></thead><tbody><tr><td>Asia</td><td>490</td></tr><tr><td>Latin America</td><td>133</td></tr><tr><td>Africa</td><td>109</td></tr><tr><td>Europe</td><td>76</td></tr><tr><td>North America</td><td>27</td></tr><tr><td>Oceania</td><td>8</td></tr></tbody></table>

2018

<table><caption>TABLE 3
Most commonly produced fruit and vegetable crops and production of total fruit and vegetables per region and per country (listed in descending order) in million tonnes (Mt)
Source: FAOSTAT (2020)</caption><thead><tr><th>FRUIT PER COUNTRY</th><th>Mt</th></tr></thead><tbody><tr><td>China</td><td>244</td></tr><tr><td>India</td><td>99</td></tr><tr><td>Brazil</td><td>40</td></tr><tr><td>United States of America</td><td>26</td></tr><tr><td>Turkey</td><td>24</td></tr><tr><td>Mexico</td><td>33</td></tr><tr><td>Indonesia</td><td>20</td></tr><tr><td>Spain</td><td>19</td></tr><tr><td>Iran (Islamic Republic of)</td><td>19</td></tr><tr><td>Italy</td><td>18</td></tr><tr><td>Philippines</td><td>17</td></tr><tr><td>Egypt</td><td>15</td></tr><tr><td>Nigeria</td><td>12</td></tr><tr><td>Colombia</td><td>12</td></tr><tr><td>Thailand</td><td>12</td></tr></tbody></table>
<figure><img src="image_28.png" /></figure>

<figure><img src="image_29.png" /></figure>
Still, it is important that the often neglected "traditional" vegetables are also considered for building more nutritious food systems as they are often better adapted and more nutritious than their global cousins (Wopereis and Kuo, 2020). Van Zonneveld et al. (2020) show that the diversity of traditional vegetables is threatened, particularly in Africa, and action must be taken to conserve and use these vegetables.

## Losses

Due to reasons such as labour demand and perishability, fruit and vegetable loss percentages are relatively high worldwide. Losses are highest in sub-Saharan Africa, commonly 15 to 50 percent. Losses are lower in East and South-eastern Asia (with a maximum of 13 percent) and lower still in Central and South Asia (with a maximum of 7 percent).

On-farm losses are, however, highly context-dependent, based on the crop, commodity group and geography. However, the following categories highlight the key factors: i) unsuitable harvest timing – farmers are often forced to harvest prematurely to meet an urgent need for food or cash, or due to insecurity and fear of theft; ii) unexpected harsh climatic conditions and environment – excessive rainfall or a lack of rain causes significant pre-harvest and post-harvest losses. Insect and pest infestations are another important cause of losses; iii) harvest and handling practices – part of a crop may be missed during harvest due to a lack of or inadequate machinery, and due to insufficient or excessive drying of crops; and iv) infrastructure and marketing challenges – farmers may prefer not to market, or even to harvest, their crops if, for instance, the cost of reaching markets due to poor transport is too high relative to the market price. Lack of storage facilities is another significant determinant of loss and compounds other causes of loss (FAO et al., 2020).

The availability of fruit and vegetables worldwide has increased consistently from 1968 to 2017 (see Figures 2 and 3). Production in Asia grew by almost 750 percent in volume terms over the period, mainly driven by an increase of production in China; in Africa, production increased four-fold, from 45 to 180 million tonnes per year (although this volume remains low compared with other regions). The production of fruit and vegetables in Central and South America has increased 317 percent over the past 50 years. Meanwhile, production increased by 117 percent in Europe and by 174 percent in North America.
BOX 1. Examples of African and Asian NUS fruit and vegetables.

Source: Bioversity International (2007)

FRUIT

AFRICA

• Natal plum (Carissa edulis)

• Carob, locust bean (Ceratonia siliqua)

ASIA

• Jackfruit (Artocarpus heterophyllus)

• Lapsi (Choerospondias axillaris)

• Quince (Cydonia oblonga)

• Indian gooseberry (Emblica officinalis)

• Mangosteen (Garcinia mangostana)

• Ndjanssang (Ricinodendron heudelotii)

• Tamarind (Tamarindus indica)

AFRICA and ASIA

• Ber, jujube (Ziziphus spp.)

VEGETABLES

AFRICA

• Baobab (Adansonia digitata)

• Cat's whiskers (Cleome gynandra)

• Leucaena (Leucaena leucocephala)

• Black nightshade (Solanum nigrum)

ASIA

• Estragon (Artemisia dracunculus)

• Chicory (Cichorium intybus)

• Purslane (Portulaca oleracea)

AFRICA and ASIA

• Moringa (Moringa oleifera)

AFRICA, ASIA
and LATIN AMERICA

• Amaranth (Amaranthus spp.)

AFRICA, ASIA and OCEANIA

• Ceylon spinach (Basella rubra)

AFRICA, ASIA and EUROPE

• Jute mallow (Corchorus olitorius)

● Making the case for fruit and vegetables; based on the Sustainable Development Goals

IN BRIEF

1. Increasing the sustainable production of fruit and vegetables is necessary to fulfil global nutrition requirements (SDGs 2 and 3).

2. Fruit and vegetables are highly perishable crops, making them a "hot spot" in the fight to reduce food loss and waste (SDGs 2 and 12).

3. The diversity of fruit and vegetable crops provides small-scale farmers with greater options for adapting to climate shocks and stresses and mitigating climate change, and environmental and market shocks across different production settings (SDGs 1, 13 and 15).

4. Fruit and vegetables are high-value crops that can be grown on small areas of land, creating economic opportunities for small-scale farmers in rural, peri-urban and urban settings as well as in conflicts and fragile contexts (SDGs 1, 3, 11 and 16).

5. Since fruit and vegetables are often eaten fresh, food safety is a critical issue and promoting good practices in the production, harvesting and post-harvest handling of fresh produce lowers the risk of food contamination and helps maintain quality (SDGs 2 and 12).
6. Since fruit and vegetable value chains are labour and knowledge intensive, they can generate on-farm and off-farm employment opportunities, especially for youth and other vulnerable populations such as migrants (SDGs 4 and 8).

7. Initiatives to make fruit and vegetable production and supply chains more sustainable can be particularly strategic entry points for empowering women (SDG 5).

...

## 1. Increasing the sustainable production of fruit and vegetables is necessary because the current supply does not meet global nutrition requirements (SDGs 2 and 3).

To meet target 2 of SDG 2 (Zero Hunger) it is necessary to end malnutrition in all its forms by 2030, and is therefore critical that fruit and vegetable production and also consumption is increased. The World Health Organization (WHO) recommends a daily minimum intake of fruit and vegetables of 400 g per person (adult) per day, and *The State of Food Security and Nutrition in the World* reports that world average per capita availability of fruit and vegetables is only 390 g per day (FAO et al., 2020). Only upper-middle-income countries and parts of Asia are currently meeting the FAO/WHO recommendation for availability as well as daily consumption of fruit and vegetables. In Africa, the per capita availability of fruit and vegetables is only 191 g per day, and in low-income countries as a whole it is only 142 g per day. A simulation to estimate future availability, which explored the interactions between supply and demand in more than 150 countries from 1961 to 2050, concluded that it was not possible to satisfy the minimum WHO intake recommendations given the current amount of loss and waste combined with the threat to production from climate change and water scarcity (Mason-D'Croz et al., 2019). Meeting the WHO recommendation will require improvements along the entire fruit and vegetable value chain, from production to processing to marketing to consumption.

Fruit and vegetables are rich sources of vitamins and minerals such as vitamin A, vitamin C, folate and iron as well as other micronutrients that are essential for a healthy life. They also provide organic acids, which stimulate appetite, help digestion and provide dietary fibres and natural compounds (antioxidants, anti-inflammatory agents) that can protect health. An inadequate intake of micronutrients, which enable the body to produce enzymes, hormones and other substances essential for proper growth and development, has serious health consequences.
<figure><img src="image_30.png" /><figcaption>**FIGURE 4**
Fruit and vegetable range (median and extremes) of reported food loss and waste percentages by supply chain stage, 2000–2017

Source: Adapted from FAO (2019a)</figcaption></figure>

Young women of reproductive age, pregnant women, nursing mothers and infants and children during their first 1 000 days are particularly vulnerable to the adverse health impacts of micronutrient deficiencies.

Micronutrient deficiencies are a form of malnutrition. Undernutrition – the inadequate intake of dietary energy (calories), which is commonly used as an indicator of hunger – is another form. Overweight and obesity is a third form, which can result from an excessive intake of low-nutrient calories, is a risk factor for a number of non-communicable diseases such as type-2 diabetes, high blood pressure, heart attacks and some forms of cancer. Fruit and vegetables are among the few food groups with beneficial outcomes across all three forms of malnutrition (Beaudreault, 2019). Adopting a diet that includes enough fruit and vegetables can help support the maintenance of a healthy weight and prevent associated non-communicable diseases.

More than 690 million people are undernourished (FAO et al., 2020). However, all forms of malnutrition affect a much greater proportion of the global population with one in three people in the world, or around
2.6 billion people, suffering some form of malnutrition (FAO and WHO, 2018). Malnutrition, in all its forms, has a large and detrimental effect on the global economy. In fact, malnutrition has been estimated to cost the global economy USD 3.5 trillion per year, or USD 500 per individual, due to lost labour and medical costs (Global Panel on Agriculture and Food Systems for Nutrition, 2016).

The consumption of fruit and vegetables can be increased through a combination of supply-side interventions and behavioural changes with public communications that emphasize the importance and health benefits that result from regularly eating fruit and vegetables (Schreinemachers et al., 2018). Investments in sustainable small-scale fruit and vegetable production can address all forms of malnutrition by increasing the incomes of farmers so they can purchase more diverse and nutritious foods for their households, and by making available a greater variety of fruit and vegetables to consumers who have been made aware of the health benefits of this essential food category.

## 2. Fruit and vegetables are highly perishable crops, making them a "hot spot" in the fight to reduce food loss and waste (SDGs 2 and 12).

In 2016, around 22 percent of fruit and vegetables were lost globally every year from post-harvest to distribution, which is significantly higher than losses for pulses and cereals (FAO, 2019a). Fruit and vegetables were the food group with the second highest level of loss after roots, tubers and oil-bearing crops, more than 25 percent of which are lost per year. However, there were significant differences depending on the stage of the supply chain, the region under consideration (Figure 4) and considering the absence of statistics on informal markets.

Fruit and vegetables also have higher levels of waste at the retail stage than cereals and pulses. In all regions, up to 15 percent of fruit and vegetables are wasted at the retail level, except in sub-Saharan Africa where the percentage can be as high as 35 percent (Figure 5).

Addressing the high levels of food loss and waste in fruit and vegetable production and supply chains can make a significant contribution towards achieving target 3 of SDG 12 (Responsible Production and Consumption): "By 2030, halve per capita global food waste at the retail and consumer levels and reduce food losses along production and supply chains, including post-harvest losses". It is also essential that production practices change to make production more efficient. There is little point in producing more if one-third of it still goes to waste.
<figure><img src="image_31.png" /></figure>

Adapted from FAO (2019a)

3. The diversity of fruit and vegetable crops provides small-scale farmers with greater options for adapting to climate shocks and stresses and mitigating climate change, and environmental and market shocks across different production settings (SDGs 1, 13 and 15).

There is great genetic diversity among fruit and vegetable species and varieties along with a multiplicity of traits. This allows for planting material to be selected to adapt to cultivation in specific environments where the plants will have to be resistant to prevailing pests and diseases, to tolerate drought and flooding, to withstand high or low temperatures, salinity, and fluctuating weather patterns. Further, such diversity enables farmers to grow crops with certain characteristics that meet the needs of local markets, whether they be the taste, shape or colour, or shelf life, packing and processing qualities.

In open fields, diversified production systems involving crops in associations, sequences and rotations, and using practices that minimize soil disturbance and enhance or maintain a protective organic cover on the soil surface, can increase the organic content of the soil and sequester and store carbon dioxide. Using more organic materials and less chemical fertilizer can also lower nitrous oxide emissions. Integrated Pest Management (IPM) strategies and improved soil health can reduce
the need for chemical inputs, which in turn lowers the carbon dioxide emissions associated with their manufacture and transport. All of these climate-smart practices are fundamental to achieving sustainable crop production and will be discussed further in this publication.

Integrating perennial fruit trees and annual vegetable crops into an agroforestry system, as can be done in family home gardens, can support a number of ecosystem services such as improved water regulation and infiltration, and erosion and flood control that can buffer the impacts of disasters and climate change. The trees can also provide shade and windbreaks and create more favourable microclimates for integrated crop and livestock systems. Crop diversification is also a risk management strategy that provides a safety net in times of economic crisis, when climatic shocks affect one crop more than another and when there are market shifts.

Vegetables can also be produced under protected cultivation systems (greenhouses, netting or mulching) that make efficient use of water and nutrients, and that offer opportunities for alternative methods to control pests and diseases compared with field cultivation, and can enable production regardless of ambient climatic conditions. The World Meteorological Organization has stated that protected cultivation is a necessary approach to build resilient cities (cited in Dubbeling and de Zeeuw, 2011). In rural areas, when the environment and marketplace conditions allow, protected systems enable off-season production with better prices for farmers and more variety for consumers.

4. Fruit and vegetables are high-value crops that can be grown on small areas of land, creating economic opportunities for small-scale farmers in rural, peri-urban and urban settings as well as in conflict and fragile contexts (SDGs 1, 3, 11 and 16).

Flavourful, nutritious, fresh fruit and vegetables deliver higher economic returns to farmers than staple crops. Their high value means that fruit and vegetable crops do not need to be cultivated on the same scale as cereals for farmers to earn an equivalent income, which makes them particularly suitable for small-scale rural, peri-urban and urban farmers (Lumpkin *et al.*, 2005). Even resource-poor farming families, able to make only modest investments, can earn potentially higher incomes from fruit and vegetables if they have the appropriate inputs and knowledge. The global value of fruit and vegetable production exceeds that of all food grains combined (Schreinemachers *et al.*, 2018).
The production of fruit and vegetables has a comparative advantage in areas where farmers have limited access to land, where labour is abundant and where markets, particularly growing urban markets, are accessible (Joosten et al., 2015). These conditions predominate in many areas where there is an insufficient supply of fruit and vegetables. For example, in sub-Saharan Africa, South Asia, East Asia and the Pacific, 85 to 95 percent of farms are smaller than 2 ha; in the Middle East and North Africa, Europe and Central Asia, the percentage is 60 to 70 percent; in Latin America and the Caribbean, it is 35 percent (Lowder et al., 2019). In population dense cities like Cairo, Dhaka, Singapore or Tokyo, rooftop gardening or vertical farming is gaining in popularity. In other cities like Quito or São Paulo, vacant lots are made available to those who are interested in vegetable farming.

As many vegetable crops can be grown in quick rotation, small-scale farmers with insecure land tenure have an incentive to grow these higher-value crops. Fruit trees can often be grown on land less suitable for other crops and still generate an income for the farmer.

5. Since fruit and vegetables are often eaten fresh, food safety is a critical issue and promoting good practices in the production, harvesting and post-harvest handling of fresh produce lowers the risk of food contamination and helps maintain quality (SDGs 2 and 12).

Sustainable fruit and vegetable production includes IPM strategies or good agricultural practices (GAP) that eliminate or reduce the use of chemical pesticides. This reduces the risk of harm to consumers caused by pesticide residues. Farm management practices that maintain soil health and avoid using untreated municipal waste or grey water as fertilizer also reduce the risk of heavy metal contamination.

Good agricultural practices, encouraged by relevant regulations and policies, particularly in urban and peri-urban areas, can ensure that water is clean, and the manure used as fertilizer is properly composted so that the food does not become contaminated by food-borne pathogens. Actions to promote market-oriented sustainable fruit and vegetable production also encourage the use of good hygienic practices by farmers and others who handle the fresh produce in order to lower the transmission risk of food-borne diseases.

Good harvest and post-harvest practices are critical to preventing produce from being contaminated by mycotoxins, among other things. Mycotoxins are naturally occurring poisons produced by certain
soil-borne fungi and have deleterious effects on human and animal health and, consequently, on trade. Moulds grow on different crops and foodstuffs, including chilis and dried fruit, often in hot and humid environments. Mycotoxins develop in the field, during post-harvest and storage and are stringently monitored by international trade standards. A comprehensive review of mycotoxins in fruit and vegetables is available for further reading (Barkai-Golan and Paster, 2008).

The commercial viability of small-scale fruit and vegetable production systems and supply chains depends on consumers having confidence that the food is safe.

## 6. Since fruit and vegetable value chains are labour and knowledge intensive, they can generate on-farm and off-farm employment opportunities, especially for youth and other vulnerable populations such as migrants (SDGs 4 and 8).

Fresh produce, especially vegetables, usually require considerably more labour than other crops for production, harvesting and post-harvest handling. Furthermore, sustainable production requires a broad range of skills and knowledge. In addition, small-scale farmers need to engage with a range of providers including advisory services and those providing production inputs such as seeds or planting materials, trellising, stakes, nettings, IPM inputs, fertilizers, an array of small tools and equipment (including for irrigation), renewable energy systems and for supply and maintenance of protective structures. Fruit and vegetable value chains are capital intensive and benefit from investment in protected cultivation technology, adequate storage facilities (particularly cold storage), processing facilities and smart ways to harmonize production and marketing to reduce losses.

Because perishable fruit and vegetables must be handled with care, it is rather difficult to mechanize many of the production, harvest and post-harvest operations. In rural or peri-urban areas where jobs are scarce, this creates opportunities for employment on farms as well as for post-harvest services to farmers aggregated in formal farmer's organizations to prepare their fruit and vegetable produce for markets (sorting, cleaning, washing, grading, packing, storing, cooling, transporting, distributing and marketing).

Employment opportunities will also be created in information and communication technologies (ICT) to increase the precision of on-farm management, decisions for pest and disease diagnostics, nutrient and water management and off-farm for coordinating the logistics
<figure><img src="image_32.png" /><figcaption>Women preparing traditional meals made of leafy vegetables in a city market</figcaption></figure>

for the timely transportation of fresh fruit and vegetables along the different stages of the supply chain, managing inventories and making sure production is responsive to market requirements and to test that produce is safe. Youth employment through decent work opportunities and training can be facilitated through ICT services, which will help reduce rural migration to cities and provide employment to connect rural and urban areas. The rapid acceleration of ICT adoption during the COVID-19 pandemic has demonstrated significant opportunities for fruit and vegetable value chains (FAO, 2020d).

Fruit and vegetables also create opportunities for small- and medium-sized enterprises to preserve (fermentation, pickling) and to process produce for different markets while reducing food losses. Collaboration among farmers, suppliers, processors and retailers can create new markets for lesser-known fruit and vegetable crops that may be well adapted to local growing conditions and markets. Such collaboration can encompass promotional and social networking techniques that make use of the latest ICTs, which can be an attractive employment option for young women and men and people with disabilities.

Sustainable fruit and vegetable production opens up the possibility of establishing clusters of related businesses underpinned by the high
economic value of these perishable foods. This will require small-scale farmers to work collectively in some type of organization so they can increase their economies of scale, more effectively communicate their needs, and improve their bargaining power. These clusters of farmer groups, small- and medium-sized agro-enterprises and related service providers, which crystalize around the sustainable production of fruit and vegetables, can form a foundation for sustainable industrial and agricultural development within a given territory.

## 7. Initiatives to make fruit and vegetable production and supply chains more sustainable can be particularly strategic points of entry for empowering women (SDG 5).

Women are often responsible for the production of fruit and vegetables in home gardens, although men will also contribute, and gender divisions of labour will vary depending on the context. Women also play a prominent role in the commercial production of fruit and vegetables. In African countries, staple crops (maize, sorghum) and cash crops (cotton, cocoa) are generally viewed as "male" crops, with men responsible for a significantly higher share of production management and allocation of the income. Whereas for vegetables the gender differences in production management and income allocation are less clear-cut, with women receiving more than half the income for some vegetable crops (Fischer et al., 2018). In many countries, women play a prominent role in marketing fresh fruit and vegetables. They also make up a significant part of the labour force for post-harvest operations that prepare the fruit and vegetables for market and in processing industries. Fruit and vegetable production, particularly in urban agriculture, is important to women of low-income households in ways less directly related to monetary gain. Women use urban agriculture in processes of empowerment, to establish social networks, symbolize a sense of security and encourage community development (Slater, 2001). Finally, women are primarily responsible for preparing home meals, thus are directly involved in the nutritional status of the household's diet and the health of its members.

<figure><img src="image_33.png" /></figure>
<figure><img src="image_34.png" /></figure>
CHAPTER 2

Production
systems,
practices
and technologies

• Water management .................................................... 24

• Rainfed cultivation .................................................... 24

• Irrigated cultivation .................................................... 26

• Soil health ................................................................ 30

• Managing fertilizers .................................................... 34

• Plant health ................................................................ 36

• Surveillance and detection ............................................ 37

• Resistant varieties and healthy seeds ............................ 38

• Chemical control ........................................................ 38

• Cultural practices ........................................................ 40

• Biological control ........................................................ 49

• Crops and varieties and access to genetic resources ........ 52

• Breeding .................................................................... 60

• Conservation ................................................................ 64

• Protected cultivation systems ........................................ 67
Fruit and vegetable crops are grown under a wide range of production systems that can be classified according to the nature and quantity of labour involved, the level of investment or knowledge, but also according to the agronomical and technological characteristics of the respective production system. The level of agrobiodiversity in the system is a first important variable. The level of use of technology and external inputs (pesticides, biological control agents, fertilizers) is a second indicator of the type of system, based on the intensification level. Both indicators determine a typology of production systems (Figure 6) in which fruit and vegetables make the best use of the natural resources, available and affordable inputs, in a constrained environment where the most limiting factors are water, soil fertility, and pest and disease management.

* **Water management**

The primary limiting factor for growing fruit and vegetables is water, both in terms of quantity and quality. Water scarcity can be due to the climate, especially in arid areas, or to unpredictable rainfall patterns due to climate change and to competition with other human activities such as domestic or industrial uses in urbanized areas. Non-adapted agricultural practices can also affect the quantity and quality of the available water. The short life cycle of most vegetable species is an advantage for production, and the perennial status of most tropical fruit species is a beneficial trait for withstanding dry periods. Humans have developed fruit and vegetable farming in deserts (such as in Death Valley in California and the Jordan and Nile valleys) using irrigation. Too much water is also a constraint in the tropics and sub-tropics, and protected cropping systems can save a harvest from flood as well as from drought.

When considering watering crops that will be consumed fresh or raw, the sanitary status of the water used is of critical importance, either at a local scale (water polluted by urban waste, heavy metals or chemicals, or sewage containing disease causing microorganisms) or at a watershed level (increasing salinity of deep soil water).

* **Rainfed cultivation**

While many small-scale farmers rely on rainfed vegetable production, supplementary irrigation is commonly applied using watering cans. However, in dry areas of India, many drought tolerant vegetable crops, including varieties of tomato, eggplant, chilli, pumpkin and watermelon, are grown successfully under rainfed conditions. In the Sudan-Sahel
<figure><img src="image_35.png" /><figcaption>FIGURE 6
Different types of fruit and vegetable production systems depending on levels of intensification with external inputs (X-axis) and on agrobiodiversity (Y-axis)</figcaption></figure>

Source: Adapted from Malézieux et al. (2009)

region, exotic vegetables are mainly produced during the dry cool season as irrigated crops to avoid flooding, poor drainage, limited fruit set in many flowering plants and excessive disease pressure during the rainy season. In the inland valleys of Benin, for instance, tomatoes and peppers are grown during the dry season (to avoid high pest and disease incidence during the rainy season), yet increases in production will require supplemental irrigation (Sintondji et al., 2016).

Conversely, many species of fruit trees grow well under rainfed conditions. In Iran, for example, figs have been grown by small-scale farmers on sloping land under rainfed conditions for many generations (Ministry of Jihad-e-Agriculture, 2011). The Central Research Institute for Dryland Agriculture (CRIDA), under the Indian Council of Agricultural Research (ICAR), has identified nine fruit trees that can be commercially cultivated under rainfed conditions: mango, guava, pomegranate, custard apple, jamun (Syzygium cumini), ber or Indian jujube (Ziziphus mauritiana), sapota (Achras zapota), tamarind (Tamarindus indica) and acid lime (Citrus aurantifolia) (Reddy et al., 2019). It should be noted that fruit tree seedlings in general need to be watered when being developed in nurseries and after being transplanted in fields.
In the semi-arid regions of central Mexico, cactus pear (Opuntia ficus-indica) has become the most dependable and even profitable option for using rainfed semi-arid lands. Cactus pear can be cultivated for food – both its fruit and its pads (cladodes) are edible, as well as for fodder and industrial uses. It can grow where no other crops can, and it contributes to the restoration of degraded lands. The cultivation of cactus pear has spread from Mexico to other countries, including Brazil, Ethiopia, India, Italy, Morocco, South Africa and Tunisia (FAO, 2017a).

In dryland forest ecosystems in south-central Africa (Miombo woodlands), many traditional fruit, such as sugar plum or mahobohobo (Uapaca kirkiana), tutu or idofun (Parinari curatellifolia) and monkey orange (Strychnos cocculoides), are harvested from wild or semi-domesticated tree species. These types of fruit are important for household nutrition and may have some commercial value in local markets. A survey from Malawi, Mozambique and Zambia found that 26 to 50 percent of rural households depended on indigenous fruit during the seasonal hunger period. Since the fruit trees ripen at different times, they can cover the nutritional needs of rural households throughout the year (Akinnifesi et al., 2004, 2006).

## Irrigated cultivation

Many small-scale farmers rely on access to water in private or community wells. In densely populated areas, balancing the needs of different water users can be challenging. The options small-scale farmers choose for irrigating their crops will be determined by a number of social and economic factors, particularly the costs associated with inputs and labour. Furthermore, irrigation planning, system design and management entail a complex method comprised of four key components: water balance between water resources and crop water requirements, institutional systems, conveyance and delivered water services (Maher et al., 2019). These factors will be context-dependent making each irrigation scheme and small-scale farmers requirements unique. It is important to keep in mind that using water efficiently is not just about irrigation system management, and that other farm management practices play a role. For example, understanding the soil type and structure, keeping the soil covered with living or organic mulch so that it retains moisture, selecting drought-tolerant crop species and varieties, which also reduces the demand for water, understanding the need of water depending on the seasons and the development cycle of the crops.
Water collection

The most essential point for irrigated fruit and vegetables is to grow them close to a reliable water source: a river, a dam, or any water storage, a well, or a tap in certain urban areas. The volume of the available water source and the trend of water transportation from the source to the crops, will determine the size of the cultivated plot. Therefore, water collection necessitates infrastructures and possibly joined investments, to catch it (borehole, pump such as solar or treadmill pumps), to store it (tank, dam) and to distribute it (cans, pipes). Therefore, growing fruit and vegetables around a water source is often regulated by an agreement among small-scale farmers, often in agreement with non-agricultural use of water (domestic), or with herders.

Sustainable fruit and vegetable production depends on clean and
non-polluted water supplies. For many small-scale growers in low- and
lower-middle-income countries, especially those in peri-urban and
urban settings, untreated wastewater will be the primary source of water
for irrigation. In some countries (e.g. Ghana), the area under informal
irrigation using wastewater in urban and peri-urban settings is greater
than the area under formal irrigation in the whole country (Drechsel
et al., 2006, Obuobie et al., 2003). The use of untreated wastewater for
irrigation in vegetable production presents clear public health risks. The
long-term goal is to create conditions where all farmers have access to
treated wastewater and knowledge of how to ensure that their produce
is safe. For example, studies carried out in Accra, Ghana (Keraita et al.,
2012) recommended four wastewater irrigation practices that reduced
the risk of biological contamination of vegetables:

* sedimentation ponds (or drums) and disturbing the water as little as possible when collecting it;

● filtration techniques (sand filtration or fabric sieves);

* irrigation methods that reduce water contact with the leaves (drip irrigation or hand watering with the spout held low to the ground); and

* stopping irrigation several days before harvest, as most food-borne pathogens are killed by exposure to sunlight.

These wastewater management practices, along with other topics are
described in *On-farm Practices for the Safe Use of Wastewater in Urban
and Peri-urban Horticulture - A training handbook for farmer field schools*
(FAO, 2012a).
## Low-cost irrigation

Transporting water from its source and watering crops by hand is widely practiced by small-scale farmers for vegetable production. The watering can is a simple, low-cost and accessible tool, and for many growers it is the only irrigation option they can afford. Watering vegetable crops by hand is labour intensive and only suitable for relatively small plots. Frequently the burden of collecting water and applying it to crops falls on women. This is the main method of irrigation in the urban and peri-urban vegetable systems of sub-Saharan Africa. Treadmill treadle pumps are a valuable alternative for the more expensive motorized versions and have become popular in some countries in sub-Saharan Africa.

Furrow irrigation, a method of surface irrigation in which water is channelled along slightly sloping furrows between rows of plants, is suitable for fruit and vegetable crops and is the conventional approach for many growers, as it does not require expensive equipment. Furrow irrigation requires accurate land levelling, regular maintenance and a high level of

farmer organization to operate the system. It does not apply water to crops in an efficient manner and can contribute to the spread of soil-borne diseases as well as weeds.

<figure><img src="image_36.png" /></figure>

Example of low-cost irrigation techniques, including bore well and hand watering

## High-cost irrigation systems

Sprinkler systems where water is under pressure, such as those mediated by solar, electric or generator-powered pumps or through gravitational flow from elevated tanks through pipes and sprayed into the air through rotating sprinkler heads, require more financial investment and adequate water availability but require less labour and can be used on sloping and uneven land. Such systems are suitable for some fruit orchards and some vegetables crops, although more fragile crops, such as lettuce, may be damaged by the falling drops. Sprinklers can be used to irrigate a relatively small area, but distribution is affected by winds and evaporation losses are high. Sprinklers also represent high energy and operation costs.
<figure><img src="image_37.png" /><figcaption>Example of high-cost irrigation techniques, including motor pump and drip irrigation</figcaption></figure>

In drip irrigation, water under pressure is supplied to narrow pipes that act to maintain flow rates. It is then released via tiny pores or through emitters, slowly and in small quantities, close to the base of plants. Drip irrigation offers the best results in terms of water use efficiency even compared with hand watering, and it reduces labour needs. However, drip irrigation systems require regular maintenance to prevent blockages in pipes, filters, pores and emitters by soil particles and dust.

Drip irrigation systems can also be used for the precise application of liquid fertilizer (fertigation). In this type of micro-irrigation, the leaves and stems of plants remain dry, which helps control diseases that tend to develop in high humidity. Drip irrigation also reduces soil erosion and pressure from weeds.

The high cost of drip irrigation can be prohibitive for small-scale farmers in low- and middle-income countries. Low-cost solutions have been developed (FAO, 2007) to allow small-scale farmers to have access to this efficient irrigation system.

## Deficit irrigation

In deficit irrigation, water is applied only during drought-sensitive stages of the plant's growth. It has proven to be successful for various crops, particularly fruit trees and vines and in locations where a certain amount of seasonal moisture is guaranteed. In south-eastern Australia, regulated deficit irrigation of fruit trees increased water use efficiency
by 60 percent with no loss in yield (Goodwin and Boland, 2000). However, for most field and vegetable crops, deficit irrigation has limited prospects (Steduto et al., 2012). Deficit irrigation reduces water use but requires knowledge on the development and drought tolerances for different crops, and the needs of different species and varieties (Geerts and Raes, 2009). For guidelines on the crop yield response to water for fruit trees and vines, see Steduto et al. (2012); for a review of responses to deficit irrigation strategies to emerging fruit crops in semi-arid Mediterranean agricultural systems, see Galindo et al. (2018).

## Soil health

Sustainable crop production in open field systems is dependent on soils with good structure to prevent erosion, retain water, nutrients, air and a rich biodiversity for soil formation, nutrient cycling and biological control of pests and diseases (Beeuw et al., 2011, 2017). Soil organic matter – the product of on-site biological decomposition – affects the chemical and physical properties of the soil and its overall health. Its composition and breakdown rate affect the soil structure and porosity, the water infiltration rate and moisture holding capacity of soils, the diversity and biological activity of soil organisms, and plant nutrient availability (FAO, 2005b).

Correct salt and pH levels ensure that nutrients in the soil are made available to crop plants. Worldwide, the area of land that is slightly and moderately saline is increasing every year, which limits the possibilities for growing vegetables and fruit. In this regard, it is necessary to develop and introduce technologies that promote desalinization of lands.

The management of nutrients in fruit and vegetable production requires careful attention. Fruit and vegetable crops have specific nutrient requirements, which may change depending on the species, variety and on the stage of development. It is important for farmers to understand these requirements and to know the amount and type of fertilizer to use and how and when to apply it to provide adequate nutrition for the crops. This keeps production costs to a minimum and prevents runoff and pollution of soils, waterways and the air.

## Conservation agriculture

Conservation agriculture is commonly applied in sustainable cereal-based cropping systems (Shaxson and Barber, 2003) and is also
applicable to commercial fruit and vegetable crops. It is based on three
objectifs:

* minimizing soil disturbance, e.g. no-tillage;

* maintaining a protective organic cover over the soil; and

* cultivating a diverse range of plant species in associations, sequences, or rotations.

Minimizing soil disturbance

Avoiding tillage is important because the more often the land is
ploughed, the more the soil may lose organic matter, structure and
biodiversity as well as resistance to erosion and compaction.

Cultivating fruit trees and vines, because they are perennial crops, requires less tillage. Their deep root systems act to conserve soil, preventing erosion and loss of soil carbon. Cultivating fruit trees can also contribute to long-term efforts to rehabilitate degraded lands. For example, just as some fruit tree species can be cultivated under semi-arid rainfed conditions, some species can tolerate soils that have been degraded through unsustainable agricultural practices. Findings from a study in India (Dagar et al., 2001) showed that seven years after planting (with gypsum as a soil amendment), *Ziziphus mauritiana*, *Syzygium cumini*, *Psidium guajava*, *Emblica officinalis* and *Carissa caranandus* were able to establish themselves and grow in high alkaline soils that had become unsuitable for most agricultural crops. Fruit trees can be grown on slopes to reduce erosion in arid countries (e.g. fig production in Iran) and in tropical highlands (Schreinemachers et al., 2013), additionally contributing to reduce risks of landslides. In mountainous areas in central Asian countries, farmers have conserved and used local fruit tree varieties to increase incomes while restoring agriculture lands (Lapeña et al., 2014).

Maintaining a protective organic cover
over the soil

Many vegetable farmers are aware of the benefits of keeping the soil covered with vegetation. An alternative, to avoid increased evaporation due to the evapotranspiration of these cover crops and to avoid competition with the cover crops for nutrients is to use a protective layer
of material (mulch). Cover crops and mulch help to retain moisture in the soil and reduce the need for irrigation. Cover crops and mulch also contribute to controlling weeds and reduce the need for herbicides and rouging, which is particularly important for empowering women who are commonly responsible for the arduous task of weeding. However, the labour requirement for collecting and spreading organic mulch can also be high and attention must be paid to ensure that mulch does not provide a moist and suitable habitat for crop pests and diseases.

A common problem faced by many farmers is the difficulty of obtaining enough organic material of sufficiently high quality for mulching. The competition for organic material on farms can be strong, particularly on farms where crop residues are used for livestock feed or fuel wood. As a result, the use of plastic mulch has become common in vegetable cultivation especially in conjunction with subsurface and drip irrigation and has played a major role in the increases in production of tomato, pepper, eggplant, melon, watermelon, cucumber and squash. Plastic mulch keeps fruit (e.g. strawberries) off the soil, which reduces contact with soil-borne pathogens that can cause fruit rot and other diseases. It has also been reported that transparent plastic mulch increased the temperature of the soil around the roots of the plants by conserving heat from the sun. This adversely affected the activities of the root knot nematodes in the soil thereby creating a conducive environment for the plants to make maximum use of soil nutrients by the roots (Ogwulumba and Ugwuoke, 2011).

Plastic mulch can cause problems if not managed well. When temperatures are high and watering excessive, heat and steam are released, which damage the plants and can lead to fungal diseases during the first days after transplanting. Problems are aggravated when plastic is improperly installed and becomes loose in the field.

The widespread use of plastic mulch, which is made of polyethylene and is not biodegradable, has led to serious environmental pollution (Teuten et al., 2009; Liu et al., 2014; Steinmetz et al., 2016). The mulch sheets are often contaminated with dirt, pesticides and other materials after the growing season and require cleaning before recycling. Furthermore, collection and recycling options are rarely available. Very thin mulches are quite difficult to collect and are sometimes simply abandoned in the landscape or burned. Thicker plastic sheets are easier to recover and are most often disposed of through landfill and incineration. Some countries have established standards on the thickness of the mulch sheeting and regulations on its recovery and disposal. Other countries have completely banned the use of plastic mulch, which has left farmers struggling to find other materials to cover the soil.
BOX 2. Various stages of the SAFTA transitional agroforestry cropping system, Brazilian Amazon. Source: Bolfe (2010); Junior and da Silva (2014)

<figure><img src="image_38.png" /></figure>

The successional cocoa-based agroforestry system: *Sistema Agroflorestal de Tomé-Açu* (SAFTA) of the Brazilian Amazon, developed by immigrant Japanese family farmers and their descendants over a century, has realized diversification and enrichment in both farm income and the agroecosystem. The farmers

receive continuous income from short (annual) and medium (perennial) term intercrops while growing multistoried orchards with high aggregated productivity. While the farmers wait for the establishment of cocoa (their main crop), annual vegetable crops are intercropped to generate income.

Other perennial crops such as bananas and papaya are grown as shade trees and to diversify income. Finally, intercropped timber trees also provide shade and income. The establishment of a farmer cooperative was key to ensure value addition and market access.

Finding alternatives to plastic mulch is important for vegetable production. Biodegradable plastic and polysaccharide mulch have been developed as an alternative to polyethylene, but their performance and cost has not led to high levels of uptake (Limpus, 2012). In addition, uncertainty remains as to the environmental footprint of biodegradable plastic mulch (Lambert and Wagner, 2017).

## Crop rotations and associations

Fruit trees can be grown with other crops in associations, sequences, intercropping and rotations to maintain healthy soils. Diversified production systems offer different market opportunities and provide insurance against the failure of any one given crop. Which agroforestry system to select depends on local climatic and market conditions. Understory cover crops, such as leguminous "green manure" crops, add nitrogen to the soil. Fodder crops can also be included to create
agroforestry-pastoral systems. Integrated fruit tree and vegetable cultivation is also practiced and is common in many home gardens as well as in commercial systems. Since vegetables are short-cycle crops with shallow roots and relatively low plant height, they are well suited as companion crops for fruit trees with deeper roots as they mine nutrients and water from different depths. Furthermore, fruit trees make use of otherwise unavailable water from deeper depths than the shallow rooting of vegetables, reduce runoff and stabilize the soil by improving water infiltration, which contributes to reducing erosion and risk of landslides in sloping areas. As fruit trees develop and their canopy closes, more shade tolerant vegetable crops are increasingly grown in association such as in the Brazilian cocoa-based agroforestry system (Box 2).

For many farmers, establishing agroforestry systems that integrate fruit trees and vegetable crops require significant investment and a long-term management plan. To facilitate the adoption of these practices, for which farmers may lack resources, access to land, secure tenure and markets, incentives and agronomic skills need to be provided.

For short-cycle vegetables it is common practice to rotate different families of crops on the same unit of land to avoid the depletion of the same nutrient profile and water from the same depth, and to avoid pest and disease build up. A good example is the management of the soil-borne bacterium *Ralstonia solanacearum* that causes wilt disease in crops belonging to the Solanaceae family, which includes sweet and hot peppers, eggplant, tomato, nightshade, tree tomato, as well as potatoes and tobacco (Box 3).

## Managing fertilizers

Even healthy soils require some form of fertilization to replenish nutrients taken up by crops. The nutritional requirements of different fruit and vegetable crops vary and can depend on their stage of development. For example, if leaves are the part that is consumed (e.g. lettuce), little variation in the type of fertilizer is required. However, for fruit such as apples, tomatoes and pumpkins, the timing and balance of nutrients is important to stimulate fruiting. Farmers need to be aware of these requirements. Ideally, farmers would undertake soil analysis to determine the available plant nutrients. The results enable farmers to select crop species and varieties whose nutrient requirements are best suited to their fields and to apply appropriate fertilizer regimes. For many small-scale farmers in low-income countries soil analysis
services are not always available or are prohibitively costly. However, new technologies, such as test strips for assessing key nutrients in soil and water and electronic scanners, can be used by small-scale farmers (Testen et al., 2018; Agriterra, 2018).

Nutrients can be applied as organic inputs such as compost, animal manure or crop residues, which help to maintain or increase soil biodiversity, structure and organic matter. Nutrients can also be applied using inorganic fertilizers (fertilizer produced industrially by chemical processes, mineral extraction or by mechanical grinding). The International Code of Conduct for the Sustainable Use and Management of Fertilizers notes there are many sources of plant nutrients available and they should be considered as complementary rather than exclusive to one another (FAO, 2019b). Organic fertilizers generally have lower nutrient content than inorganic fertilizers and they also make their nutrients available to the plants at a much slower rate. However, they are recognized as helping to maintain healthier soils and to produce food richer in minerals and antioxidants.

For many farmers, it can be difficult to obtain sufficient quantities of organic fertilizers and amendments, especially in arid countries, urban and peri-urban settings and farming areas where there may be high competition for biomass. Raw organic materials such as crop residues, animal manure, food waste and some municipal and industrial waste can be used for compost. Composting is the natural process in which micro-organisms decompose organic matter and kill food-borne pathogens. Vermicomposting has gained popularity over recent years. In this technique, worms of different species are used to accelerate the decomposition process. However, chemical contaminants such as pesticides, antibiotics and heavy metals can remain. In some areas, sewage sludge, such as solid materials removed from the wastewater stream originating from a public sewage system and composted (FAO, 2019a), is used as an organic fertilizer. It is critical that sludge be regularly analysed and treated to ensure that dangerous chemicals and food-borne pathogens do not persist.

Inorganic fertilizers make nutrients immediately available to the plants and can be selected based on their composition to contain key micronutrients such as boron, manganese, calcium, molybdenum and zinc, enabling crop specific supplements. However, because inorganic fertilizers are water soluble, any nutrients not taken up by crops are at risk of leaching into waterways. Although, the solubility of inorganic fertilizers can vary, with some types releasing nutrients more slowly, nutrient pollution is a serious environmental problem. Moreover, the manufacture
of inorganic fertilizers is a source of carbon dioxide emissions and excessive application of nitrogen fertilizers is a significant source of nitrous oxide emissions. Overuse and misuse of fertilizers can also lead to increased soil salinity. Furthermore, the application of inorganic nutrients suppresses the activity and survival of microbes, insects and nematodes that cycle nutrients in soils (Beed et al., 2017).

As already mentioned, fertigation allows for frequent applications of very small amounts of fertilizer, adjusted to the specific requirements of a given crop at a given time. Subsurface and drip irrigation increases nutrient delivery by directing water to the area where crops are growing, thus reducing nutrient runoff and pollution.

## Plant health

Nutrient-rich fruit and vegetables are not just highly attractive to people but also to a vast array of pests and diseases which may render the growth of fruit and vegetables impossible without pesticides, which, as a consequence, entails a higher risk of pesticide overuse and the presence of pesticide residues in case of poor management.

Managing pests and diseases in fruit and vegetable crops is a significant issue for small-scale growers that can be best addressed through IPM strategies. This includes avoiding pests and disease by adopting preventive instead of curative measures (seedling nurseries under protected cultivation, physical barriers, clean water, soil and tools), the use of resistant varieties, the use of trap crops and pheromone traps, biological control agents and the judicious use of chemical pesticides. Traps are usually simple interception devices that capture insects moving through an area. Traps are also used to detect new invasions of insect pests in time and/or space, to reduce infestations and to monitor the populations of established pests (Epsky et al., 2008).

The success of IPM strategies by individual growers increases when their neighbours deploy the same techniques. For example, farmers worked collectively to carry out mass trappings using pheromone traps to reduce the numbers of the tomato leafminer (Tuta absoluta) in the Near East (FAO, 2012b) and eggplant fruit and shoot borer (Leucinodes orbonalis) in South Asia (Alam et al., 2006). Recognizing the importance of collective action, FAO worked with farmers to create community IPM strategies through the Farmer Field School (FFS) approach at the community level and with local institutions (Pontius et al., 2000).
● Surveillance and detection

Growers must be familiar with the enemies and friends of their crops and when attacks are most likely in terms of environmental conditions, season or due to certain agronomic practices. Regular observation or scouting of crops to monitor for pests and diseases is fundamental, especially on vegetable crops due to their rapid production cycles. Regular scouting enables growers to detect problems early, to rapidly deploy appropriate control interventions, before pest and disease damage reaches economic threshold levels, and to evaluate the efficacy of control interventions. When scouting exercises are coordinated across a region, involving several national research and plant protection organizations, and are provided with technical support from laboratory services, efficiencies and knowledge sharing is increased, as was realized, for example, for known and new diseases of banana in the Great Lakes region of Africa (Beed et al., 2013).

In general, for any given crop and location, there are common pests and diseases. As with human medicine, diagnosis of the pest and causal agent of disease in plants is the first and most important critical step towards the deployment of the most appropriate control intervention (Miller et al., 2009). When there is a new pest or disease, invasion growers must be supported by advisory services or research institutions to diagnose the problem and provided with early warnings and advice on control measures. The first step in recognizing symptoms linked to pests and diseases is for growers to know what a healthy crop looks like, to identify differences between crop varieties and to differentiate pest and disease symptoms from those caused by physical stresses such as nutrient deficiencies, drought, flooding, heat, sun, cold or salinity. Symptoms of ill health are evident as deviations from normal crop function and are manifested as changes in appearance. There are a variety of organisms that cause disease symptoms, including insects, bacteria, fungi, viruses, nematodes and phytoplasmas. There are different types of symptoms associated with each such as wilt, spots, cankers, curling, blights, mosaics, galls, profuse flowering, rots, dieback, malformation and discolouration. The most appropriate method of control is dependent on the type of organism causing the disease and their epidemiology (how they are transmitted and what conditions facilitate their infection). For some growers, public and private extension services assist with diagnoses. For growers with access to the Internet, an online search that combines a symptom description with the crop type will reveal the potential disease causal agent and appropriate control measures.

Another general principle of IPM is ensuring proper field sanitation.
The removal of diseased and pest damaged plants or plant parts and crop
residues after harvest will help to reduce pest and disease pressures. Regularly cleaning farm machinery, tools and clothing can also help prevent the spread of diseases. Similarly, ensuring water supplies are free from pests and diseases is important.

* **Resistant varieties and healthy seeds**

Deployment of resistant varieties forms the foundation of any IPM programme. Whenever they are available, fruit and vegetable varieties with known resistance against common pests or diseases in a given locale should be selected and used. Using healthy seeds will reduce the incidence of seed-borne diseases. Seed treatment using biological control agents such as *Trichoderma* spp. or *Pseudomonas* spp. has been shown to reduce the incidence of some seed- and soil-borne pathogens in vegetables (Mancini and Romanazzi, 2013). Managing the plant diversity (within and among varieties and species) is also a strategy to sustain the efficiency of resistance genes. The Hortivar database (http://www.fao.org/hortivar/) is based on a network of scientists who are engaged in collating and disseminating information on the field performance of fruit and vegetable cultivars including their resistance to pests and diseases, to help farmers identify the best-adapted varieties. The important role of resistance traits has been recognized by the private sector and seed companies as a priority (Schreinemachers et al., 2016b). Similarly, research into improving resistance in vegetable varieties has shown returns on investment that are as high as those previously reported for some staple crops (Schreinemachers et al., 2017b).

* **Chemical control**

Even though chemical pesticides should only be applied as a last resort, based on considerations including cost, food safety and human and environmental health, chemical control remains a common method for small-scale fruit and vegetable growers who can afford it. Many feel obliged to use pesticides – and also herbicides – as a precautionary measure to protect their crops since pest and disease outbreaks can lead to total crop failure and substantial economic losses. The impetus to apply pesticides is also exacerbated because the appearance of fruit and vegetables is important for their marketability and even slight blemishes caused by pests and diseases can mean a loss of income.

However, fruit and vegetable growers are often inclined to apply excessive amounts of chemical pesticides and herbicides to their crops and even to use the wrong chemical, combinations of incompatible
chemicals, doses, timing, types of application, storage and disposal (Schreinemachers et al., 2017a), which can all expose farm workers to pesticide poisoning. Further, misuse of pesticides harms the environment and kills organisms that benefit sustainable crop production (Beed et al., 2017) and contributes to pests becoming pesticide-resistant, creating a vicious circle in which more and more pesticides are applied only to achieve less and less protection. Pesticide residues above accepted levels, maximum residues levels (MRL), prohibit trade and therefore directly lead to food loss or, if consumed, to consumers being exposed to increased levels of pesticide residues. Incidents of chemical contamination of foods from pesticides undermine efforts to increase consumption and consequently the demand and supply of fresh and nutritious foods. International export markets are strictly regulated for pesticide MRLs, and, if exceeded, they can significantly harm the reputation of the exporting country and limit future trading opportunities. Conversely, for many local markets, there is no systematic monitoring of pesticide residues.

In many countries, the technical considerations for safely and correctly applying pesticides and herbicides are often neglected, unknown or unregulated. Farmers and small pesticide dealers become ill because they ignore, or are unaware of, the technical principles of their safe application, storage and disposal and don't have access to individual protection equipment. Very often pesticides are sold in small quantities, distributed from larger bottles into smaller ones to allow small-scale farmers to buy the amount they need at affordable prices. Some small pesticide dealers do not comply with regulations, and may even sell prohibited or obsolete, out of date products. Supporting growers to adopt a range of IPM methods and not only rely on pesticides requires knowledge and appropriate policy support (Schreinemachers et al., 2015). It is critical that fruit and vegetable growers are better educated and informed to choose what pesticides suit their needs, how to apply them and to respect interval periods between application and harvest.

In general, the following considerations should be observed with regard to pesticide application as a part of an IPM programme:

* Pesticides are the last resort in an IPM programme, thus other pest management interventions already noted above should be tried before considering the use of pesticides. The decision to use pesticides should be guided by the economics of the action while the selection of the pesticide should be guided by human health (both producers and consumers) as well as environmental concerns. Biopesticides can help reduce the use of chemical pesticides, but should not always be considered as totally harmless for humans or the environment.
* Economic threshold is the most common guide for making the decision for pesticide use, even though it is not yet generally known by vegetable farmers given the diversity of crops, varieties, growing seasons and conditions. The economic threshold represents numerous pest populations or plants showing a certain level of severity/incidence that can trigger a pesticide application decision. Frequent scouting for pests and injured plants is important to gather this information. Determination of economic threshold is highly reliant on the costs of action and the farmgate price of the crops. Additionally, the threshold should also take into account the resistance/tolerance level of a particular variety. Thus, the estimation of thresholds is best done in a specific agroecosystem/socio-economic context. Pesticide application that is not guided by an economic threshold risks wasting resources on pest or disease damages that do not affect yield significantly enough to warrant an action.

* If a decision is made to apply a pesticide based on an economic threshold, it is important to select pesticides with low risks to human health and the environment. Numerous insecticidal active ingredients have been shown to disrupt beneficial insect populations such as natural enemies and pollinators. To avoid this scenario, pesticides must be selected to affect the target pest only and not other organisms.

* Ensure proper use of the selected products for approved applications to reduce risks to producers and consumers, this includes using relevant personal protective equipment, properly storing and disposing of used containers, respecting re-entry and pre-harvest intervals and complying with international standards (FAO, 2010d; FAO and WHO, 2014).

* Rotate the active ingredients among the selected pesticides with different modes of action to avoid developing resistance among pests and pathogens.

## Cultural practices

### Integrated production and protection

Integrated production and protection (IPP) has been advocated as a means to help small-scale farmers adopt non-chemical pest and disease control in support of sustainable intensification. The concept of IPP is to consider not only the pest and disease complex affecting a crop, and identify the best available means of control for each component within that complex, but also to consider commonly used cultural practices that could control pests and diseases (Hanafi, 1999).
BOX 3. Crop rotation to combat bacterial wilt of tomato in the French West Indies. Source: Deberdt et al., 2018

<figure><img src="image_39.png" /></figure>

Bacterial wilt caused by the bacterium *Ralstonia solanacearum* is highly aggressive towards tomato crops all over the tropical world. Emerging strains of *R. solanacearum* have overcome disease resistance traits in most commercial varieties. Faced with the lack of approved protection products against bacterial wilt, a biocontrol strategy based on the use of sanitizing plants in intercropping or in crop rotation was developed and tested in Martinique (French West Indies).

Multisite agronomic trials were carried out on eight species and varieties of potential sanitizing plants belonging to three families (Brassicaceae, Asteraceae and Fabaceae). These plants, selected because of their hardiness, competitiveness with weeds and

high biomass production, were then evaluated for their host status with respect to *R. solanacearum* and for their sanitizing potential. The trials were conducted in a fully-controlled climatic chamber, then under semi-controlled conditions in a greenhouse. The plants selected from earlier stages were finally tested under real conditions on a farm in Martinique.

The lowest bacterial densities in the soil were observed when fodder radish (*Raphanus sativus* cv. Melody), marigold (*Tagetes patula*) and showy rattlepod (*Crotalaria spectabilis*) were grown. In greenhouses, the cultivation of sunn hemp (*Crotalaria juncea*), rattle box, and fodder radish before planting tomatoes was able to significantly reduce the

incidence of bacterial wilt. On-farm field trials showed that, compared with the tomato control, cultivating velvet bean (*Mucuna deeringiana*) before planting tomatoes reduced the incidence of tomato bacterial wilt by 53 percent, showy rattlepod reduced it by 58 percent, and sunn hemp by 71 percent.

This innovative plant protection technique is currently being transferred to small-scale vegetable producers in the French West Indies. The sanitizing properties of showy rattlepod, sunn hemp and fodder radish as rotational cover crops can also help control nematodes, which are also major pests of vegetable crops. Both velvet bean and fodder radish can also be used as fodder for animals.
BOX 4. The control of fruit flies on the French island of Réunion in the Indian Ocean. Source: Deguine et al. (2017)

<figure><img src="image_40.png" /></figure>

In Réunion, fruit fly (Diptera: Tephritidae) species that affect cucurbit crops (Bactrocera cucurbitae, Dacus ciliatus and Dacus demmerezi) are the most damaging pests. Spraying chemical insecticides is ineffective because the flies live in the surrounding vegetation. Regular multiple sprays also lead to a build-up of pesticide-resistant pest populations and it eliminates the natural enemies of fruit flies. In the late 2000s, studies were undertaken to move towards a preventive plant protection programme based on a technical package consisting of five major components:

* monitoring with pheromone traps;

* sanitation measures (removal of infested or infected parts

of the host plant), along with the increased presence of natural predators (augmentorium technique);

* assisted push-pull with trap plants (maize) spot-sprayed with a fruit fly bait containing an organic insecticide, spinosad;

* mass trapping with pheromone traps; and

* biological control, mainly through habitat management to support natural enemies.

The results from 28 conventional farms and four organic farms growing mainly zucchini (Cucurbita pepo) and chayote (Sechium edule) showed no negative effect from eliminating chemical insecticides, and showed that

crop protection costs were reduced.

Although the push-pull component was essential to the protection schemes for zucchini and pumpkins, it was relatively less successful for chayote. This was primarily because the chayote value chain is well organized and chayote growers can benefit from technical support and market demand.

Producers of other cucurbits also tend to be involved in other economic activities and they cultivate cucumber or zucchini on smaller fields to reap any benefits from fluctuating market prices. This appears not to be compatible to investing in such a crop protection strategy.
Managing the agrobiodiversity

Natural ecological systems, undisturbed by the activities of man,
tend to sustain the greatest diversity of living organisms. Agricultural
practices, by their very definition, promote certain species over others
and efforts are required to ensure that agrobiodiversity is not threatened
(FAO, 2019c; FAO, 2020e). The performance of crop species relies on
"associated biodiversity" such as pollinators, biological control agents
and soil-dwelling organisms. Sustainable crop production, particularly
the need for environmental protection and continued income generation,
is dependent on associated biodiversity. This can be promoted through
mixed farming systems and by diversifying the number and type of crops
cultivated and by using companion crops. Crop rotation, for instance, is an
effective technique for reducing weeds, pest populations and diseases,
especially for those that attack only one botanical family or crop variety.
For example, the diamondback moth (Plutella xylostela) only damages
crops in the brassica family (cabbage, cauliflower, broccoli) during its
larval stage. In this case, the rotation planting of brassica crops, both in
space and time, with crops from other botanical families will break the
diamondback moth's life cycle and reduce its numbers. Another example
is water mould (Pseudoperonospora cubensis), which is a pathogen of the
cucurbit family (cantaloupe, cucumber, pumpkin, squash, watermelon).
Rotating cucurbit crops with other crops reduces the prevalence of this
pathogen. Bacterial wilt caused by Ralstonia solanacearum is a serious
problem for vegetable growers in tropical and sub-tropical regions,
particularly for crops in the families Solanaceae (pepper, tomato,
eggplant, potato) and also Cucurbitaceae. This soil-borne disease
is difficult to control because it can survive for long periods under a
wide range of environmental conditions and has a wide range of hosts
(more than 200 species). For this reason, crops of the Solanaceae and
Cucurbitaceae families should not be cultivated in succession (Box 3).
In addition, to control this bacterium, it is critical to keep farm tools and
irrigation systems clean after use.

Intercropping, plant association and planting trap crops and barrier
 (border) crops can also prevent or reduce the incidence of insect pests
on fruit and vegetable crops. Sujayanand et al. (2015) found that when
eyplant was grown with intercrops such as coriander, mint and marigold,
with maize as the border crop, the diversity of the natural enemies of
eyplant pests was significantly higher compared with eggplant grown as
the only crop. Another study (Srinivasan et al., 2013) showed that tropical
soda apple (Solanum viarum), a perennial shrub, was an effective "dead-
end" trap crop to manage tomato fruit worm (Helicoverpa armigera).
Dead-end trap crops do not require any pesticide treatment to prevent
the pest population from moving onto the main crop. They should be
planted in field borders where they can intercept adults of the pest and thereby reduce damage to the main crop (Shelton and Badenes-Pérez, 2006). Sequential trap cropping with Indian mustard (*Brassica juncea*) is an effective way of using crop planning to reduce diamondback moth damage in brassicas.

The push-pull strategy is another method of plant protection based on intercropping. It uses a combination of stimuli to modify the behaviour of insect pests and beneficial insects, which influences their numbers and distribution (Cook et al., 2007). In this strategy, the pests are pushed away from the main crop by using plants that either mask the presence of the potential crop host, or repel the pest. At the same time, the insect pests are pulled to other areas by traps or trap crops using highly obvious and attractive stimuli. Once they are concentrated in a given area, the insect pests can be more easily managed. The source (push) depends on the crop management tactics and can take the form of visual and/or chemical cues. The stimulus is generally a plant-produced compound, but it can also be a synthetic blend (Cook et al., 2007). The push-pull strategy for control of stem borers in maize was described in *Save and Grow in Practice: Maize rice wheat* (FAO, 2016). The push-pull strategy can also be used in vegetable crops, using a maize-tomato system that was developed on the French island of Réunion in the Indian Ocean (**Box 4**).

## Grafting

Grafting, which increases the yield and quality of fruit and vegetable crops, is done by joining the severed part (the bud or scion) of one plant to the stem or branch of another (rootstock) to form a new plant. The commercially important section is the upper part called the scion while the lower stem and roots section is the rootstock. The crop variety selected for the scion is based on desirable market traits and the crop variety selected for the rootstock is based on its resistance to soil-borne diseases or capacity to grow in specific soils. Grafting of fruit trees is an ancient practice and is common because fruit trees grown from seed will not produce fruit with the same genetic traits as the parent tree.

Since the rootstock of some varieties provide resistance to soil-borne diseases (fungi, bacteria, nematodes) affecting root systems, grafting has been used to protect fruit and vegetable crops without the need for pesticides. The most famous example of this occurred in the 1870s when European grape vines were attacked by the insect pest *phylloxera* (or *Daktulosphaira vitifoliae*), which feeds on the roots and leaves
BOX 5. Grafting tomato to combat bacterial wilt caused by Ralstonia solanacearum in Viet Nam. Source: Genova et al. (2013)

<figure><img src="image_41.png" /></figure>

The World Vegetable Center started working on tomato grafting in 1992 as a means of controlling bacterial wilt caused by the bacterium *Ralstonia solanacearum* and demonstrated the technique to Vietnamese scientists in September 1998.

From 2002 to 2006, the technique was introduced to Lam Dong province in southern Viet Nam in collaboration with the Potato, Vegetable and Flower Research Center. In the Red River Delta in northern Viet Nam, the technique was introduced in collaboration with the Fruit and Vegetable Research Institute (FAVRI) in Hanoi. In Lam Dong province, where the problem of bacterial wilt is experienced all year round due to high humidity, the rootstock of a tomato variety that was

resistant to bacterial wilt was used for the grafted plants. In the Red River Delta, where tomatoes are grown in the wet season and flooding is a problem, the rootstock of an eggplant variety that is both resistant to bacterial wilt and tolerates waterlogging was used.

Farmers in Lam Dong province began planting the grafted varieties in 2002, and the results of a 2013 questionnaire survey of over 200 farmers there indicated that there was a 100 percent adoption rate for the grafted tomato plant. In the Red River Delta, where farmer participation in field trials started in 2007, the findings of the survey revealed a 50 percent adoption rate. In a comparison of grafted and non-grafted tomato plants in the Red River Delta, the average yield was

over 30 percent higher for the grafted tomato plant, and their farm gate price for tomatoes was nearly 40 percent higher. The costs, particularly the labour costs, of cultivating grafted tomato plants were notably greater, but the difference in revenue was large enough to make them much more profitable.

Based on the average difference in profits between grafted and non-grafted tomato plants, the estimated profit in Lam Dong province for tomato farmers was USD 41.7 million higher than if the same area had been planted with non-grafted tomato plants. The study clearly shows that in areas where bacterial wilt and other soil-borne diseases affecting tomato plants are a problem, tomato grafting can deliver monetary benefits to farmers.
BOX 6. Low-cost anti-insect netting for small-scale vegetable growers in Africa.

Source: Martin et al. (2019)

<figure><img src="image_42.png" /></figure>

Since 2006, the African manufacturer A to Z Textile Mills Ltd in the United Republic of Tanzania, national and international research organizations, and farmers from Benin and Kenya, have been investigating the potential of nets to control pests in small-scale fruit and vegetable cultivation in tropical Africa. The technique applies the same principles of using mosquito nets to protect human health to fruit and vegetable crops. The main purpose is to reduce the use of pesticides, which are often applied weekly to tomato crops in open field cultivation, by placing a physical barrier

between the crop and the pest. Participatory approaches were followed to address the agronomic and economic impacts of the netting, as well as their environmental impacts and social acceptability.

On-station experiments were carried out to design the best net mesh, colour and thickness depending on the crop (tomatoes, cabbage, beans) and the targeted insects (moths, aphids, white flies). On-farm trials then collected information on the most economic and appropriate ways of handling, storing and recycling the netting. Most of the results

were encouraging, and small-scale farmers in Benin, Kenya and Senegal adopted the nets whenever they were available.

A cost benefit analysis in Benin revealed that using nets on cabbage crops is three times more profitable than the current practice. However, farmers in Benin, also stated that investment costs and the limited availability of nets, as well as the labour costs involved in the time and effort it took to manage small nets in a large field were constraints that made them reluctant to invest in them.
of grapevines. The insect had been introduced from North America and the solution was to graft North American grapevine rootstock, which had developed a resistance to *phylloxera*, with scions from the European plants. To this day, there is no other cure for *phylloxera*.

Vegetable grafting is also an old practice, but it only became widespread in the twentieth century. It began in the 1920s when resistant rootstocks were used in Japan and Korea to control Fusarium wilt, a soil-borne disease in fruit and vegetables caused by the fungus, *Fusarium oxysporum*. The practice is now rapidly spreading and has expanded to include vegetables such as cucumber, melons, eggplant, tomato, pepper and several other solanaceous crops. Vegetable grafting can make these crops more tolerant to a number of other widespread soil-borne diseases, such as bacterial wilt, that used to be fought with chemical products that are now banned (e.g. methyl bromide), and different species of nematodes that are very difficult and expensive to control with chemical pesticides (Box 5).

## Netting

Insect-proof nets (technically a form of protected agriculture) are physical barriers that cover fields to protect crops from flies, butterflies and moths, and depending on the mesh size, whiteflies, aphids and thrips. Many of these pests not only cause damage by eating the plants, but also act as vectors for disease-causing organisms, such as viruses and bacteria. Using nets reduces the need for insecticides and protects crops from pesticide resistant populations of insect pests (Martin *et al.*, 2015).

Under the appropriate climate conditions, and with careful management of possible higher temperatures under the netting, there are numerous benefits of insect-proof nets in tropical fruit and vegetable production (Box 6), such as:

* They are safe for human health and the environment compared to pesticides.

* For the greenhouses, 50 mesh anti-insect nets are usually recommended in combination with other sustainable protective measures (sticky tapes, disinfection at the entrance, etc.), which can reduce the use of insecticides by 70 to 90 percent.
* Anti-insect nets are also compatible with biological control options, such as using natural enemies of crop pests (predatory mites, small parasitoids) and insect attractants or repellents.

* They improve yields and the marketability of the vegetables.

* Investments in netting are recouped in one year and the nets last for three to five years after which they can be recycled.

* They are recommended for vegetable and fruit nurseries to produce disease free seedlings for transplanting to fields.

* The effectiveness of some biopesticides may be improved under the nets as a result of UV protection and microclimate enhancement.

* They also protect fruit orchards from hailstorms.

In fruit crops, physical protection against pests can be done by placing bags over the developing fruit. This practice, which originated in Asia, has been spreading to other regions. Fruit bagging is a plant protection option that requires significant inputs and is labour-intensive but has proven effective at reducing pesticide use and can contribute to improving the overall appearance of the fruit.

## Soil solarization and heat treatments

Soil solarization is a physical method used in warm climates for destroying soil-borne pathogens. It is a mulching process used primarily for vegetable crops that involves covering moist soil for a minimum of one to two months during the summer in transparent plastic film and leaving it exposed to sunlight. Soil-borne organisms are killed by the high temperatures that occur during the solar heating. Thermotherapy is also a physical method for eliminating plant pathogens, particularly fungi, viruses and bacteria. Simple in principle, it consists of heat treating plant parts at temperature/time regimes to kill the conserved pathogen and that only slightly injures the host. Heat is applied mainly by water, air or vapour. A large variety of plant parts can be heat treated: whole trees, scions, *in vitro* plantlets, seedlings, stalks, cuttings, sprouts, cut flowers, seeds, bulbs, tubers, corms, or fruit and vegetables in storage (Galindo *et al.*, 1994).
## Biological control

The use of biological control agents is a proven technology for fruit and vegetable crops. These control agents are organisms that feed on pests, pathogens (fungi, bacteria, nematodes) or weeds (Beed and Dubois, 2009).

Biological control can be mediated in three ways (Beed et al., 2011):

* conserving natural enemies of pests and diseases;

* augmenting the numbers of these natural enemies; and

* introducing new enemies.

Conserving natural enemies that act as biological control agents can involve providing alternative hosts or prey, food or nesting sites, or modifying cropping practices to favour natural enemies. The conservation of biological control agents can also be enhanced by maintaining semi-natural areas near the fields. These uncultivated spaces provide beneficial organisms (pirate bugs, ground beetles, lacewings, ladybirds, hoverflies and parasitoid micro-wasps) with habitats from which they can manage insect pests of crops. Nine out of ten natural enemies of pests (as opposed to only five out of ten pest species) need to retreat to semi-natural habitats at some time of the year in order to complete one or more phases of their life cycle.

Augmenting biological control involves increasing the numbers of natural predators and parasitoids or pathogens of crop pests and diseases. This can be done through commercial biological pest control products, such as insecticides that contain the naturally occurring pathogens of fruit and vegetable pests (Bacillus thuringiensis, a bacterium; or Beauveria bassiana, a fungus). Biological control can also be augmented by releasing, at strategic times, large numbers of mass-reared natural enemies of crop pests, such as lacewings (Neuroptera: Chrysopidae), predatory mites (Acari: Phytoseiidae) and flower bugs (Hemiptera: Anthocoridae). This service is often carried out by commercial or government institutions, although there are some small-scale businesses also raising beneficial insects.

Introducing exotic natural enemies of fruit and vegetable pests and diseases as biocontrol agents is a complex and environmentally sensitive process, and is usually undertaken, or regulated, by public organizations, and done on a large scale in collaboration with farmer groups and agricultural research and development institutions (Upanisakorn et al., 2011). For example, from 1989 to 1992, the Asian Vegetable Network (AVNET), united national agricultural research systems in Indonesia,
Malaysia, the Philippines and Thailand to implement an IPM programme to control the diamondback moth. The programme included introducing exotic parasitoid wasps (Diadegma semiclausum, Diadromus collaris), releasing indigenous wasps (Cotesia plutellae and Trichogrammatoidea bactrae) that kill diamondback moth larvae, and applying biopesticides containing Bacillus thuringiensis (AVRDC, 1993). The introduced species are quite vulnerable to pesticides, so farmers had to work together to adopt IPM strategies to reduce their pesticide use in order to allow the new predator insect species to establish themselves. Farmer Field Schools (FFS) were used as a means of informing the farmers about biological control methods and fostering collective action. For farmers involved in the field schools, the programme resulted in increased production and significant reductions in pesticide use and associated costs.

A similar programme using FFS was then carried out in Viet Nam in 1996 by the country's Plant Protection Department with the support of the FAO Regional Vegetable IPM Programme and the international development organization Centre for Agriculture and Bioscience International (CABI) (Guan Soon, 1997; Nga and Kumar, 2008). From 2000 to 2008, with funding from the International Fund for Agricultural Development (IFAD), the International Centre of Insect Physiology and Ecology (ICIPE) worked with national agricultural research and extension systems in Ethiopia, Kenya, Uganda, and the United Republic of Tanzania to implement IPM for brassica farmers that included rearing, releasing and monitoring Diadegma semiclausum as a biological control agent, which was imported from the World Vegetable Center in 2001 (Momanyi et al., 2006). From 2012 to 2016, a scaling-up project was carried out in Malawi, Mozambique, Rwanda and Zambia. A comprehensive overview of past and more recent experiences was made by Bonsignore and Vacante (2017).

**The sterile insect technique and area-wide integrated pest management**

This is an environmentally friendly technique that has been used for over 60 years to control insect pests of livestock and fruit and vegetable crops as well as insects that act as vectors of diseases. It involves mass breeding of specific flying insect pests and sterilizing the male flies with low doses of radiation. Released into infested areas, the sterile males mate with wild females. If the sterile males vastly outnumber the fertile wild males, the wild fly population quickly dies out.

For this technique to be cost-effective, the density of the pest population in the wild must already have been reduced to low levels
through area-wide IPM strategies that include insecticide baits, orchard sanitation practices and biocontrol agents. Such programmes are complex and long-term and require research, feasibility studies, regulatory measures and field pilot studies before they can become operational. To be successful, these programmes demand a collective effort by farmers and farmer organizations, national plant protection organizations, government agencies, and the private as well as the public sector. FAO and the International Atomic Energy Agency (IAEA) have played a fundamental role in supporting countries all over the world to implement these programmes.

Used in combination with area-wide IPM strategies, the sterile insect technique has been successful in controlling species in the fruit fly family (Tephritidae); for example, the technique was used in programmes to eradicate the Mediterranean fruit fly (Ceratitis capitata) from Mexico and parts of Guatemala (1984), northern Chile (1995), southern Argentina (2004) and the Dominican Republic (2017). As a result of these programmes, pesticide use has been reduced and the countries have overcome phytosanitary barriers and are now able to export fruit to profitable markets in North America and Asia. Chile and Mexico, in particular, have become two of the leading fruit-exporting countries in the world.

The technique has also been used to eradicate the Mediterranean fruit fly in other regions, for example in Western Australia. In the Hex River Valley in South Africa, it has been used to create an internationally recognized area of low pest prevalence for the fruit fly, and has substantially reduced control costs for grape producers and has lowered the number of produce rejections by phytosanitary inspectors.

Other species of fruit fly that have been controlled using the sterile insect technique include the Mexican fruit fly (Anastrepha ludens), which has been eradicated from California and Texas, in the United States of America, as well as from northern Mexico where the West Indian fruit fly (Anastrepha obliqua) has also been eradicated. In Asia and the Pacific, the technique has been used as part of an area-wide IPM programme to eradicate the melon fruit fly (Bactrocera cucurbitae) from Okinawa in Japan and the Queensland fruit fly (Bactrocera tryoni) from Western Australia. In Thailand, the technique has been used successfully to suppress the Oriental fruit fly (Bactrocera dorsalis) and reduce losses for fruit producers.

The technique can also be used on fruit against moth pests. In Mexico in 2009, an outbreak of the Cactus moth (Cactoblastis cactorum (Berg)) was controlled and the pest eliminated from islands off the Yucatán Peninsula. In New Zealand, the technique was used to eradicate the Australian
painted apple moth (Teia anartoides). In the Okanagan valley of British
Colombia, the technique has been used since 1994 to suppress the
codling moth (Cydia pomonella) in apple and pear orchards and in South
Africa since 2007 to suppress the false codling moth (Thaumatotibia
leucotreta) in citrus groves.

The technique has also been used to suppress the onion fly (Delia antiqua (Meigen)) in the Netherlands. Since onion flies do not disperse widely, individual growers can purchase sterile insect technique services from private companies (FAO, 2019d; Marec and Vreysen, 2019).

● Crops and varieties and access to genetic resources

The tremendous genetic diversity of fruit and vegetable species and varieties provides options for small-scale famers to grow crops that are adapted to their specific environment and markets. To realize this potential, the seeds and planting materials used must be of high quality (homogeneous, disease free and with high germination rates and vigour).

Access to seeds and planting materials

Whatever crops they grow, farmers obtain their seeds and planting
materials through either informal or formal seed systems. In informal
systems, farmers save seeds and planting materials from their own
crops, collect seeds from neighbourhood seed stands or from high-
performing trees, trade for seeds and planting materials with other
farmers, or purchase seed and planting materials from non-regulated
local seed producers and traders, non-governmental organizations
(NGO) or community-based schemes. FAO has produced and regularly
updates the Voluntary Guidelines for National Seed Policy Formulation
(http://www.fao.org/seeds/en/) and a six-module seed toolkit to
impart the knowledge and skills needed to deliver high-quality seeds
and planting materials of well-adapted crop varieties to farmers.

In a formal system, farmers obtain the seeds and planting materials of
clearly indicated varieties whose traits and quality have been assured or
certified through a rigorous regulatory process. In many cases, farmers
access these seeds and planting materials through agrodealers which
themselves have access to national or transnational seed companies.
In some countries, government or parastatal seed suppliers, agricultural universities, or national and international agricultural research institutions may also be sources of certified seeds. In some West and Central African countries, it has been noted that cooperatives have become registered as certified seed producers and can be viewed as being part of a formal seed system. Their portfolios generally feature crops not covered by seed companies, with different cooperatives producing seeds for indigenous and traditional vegetables. However, the long-term viability of seed-producing cooperatives is not always certain (Access to Seeds Foundation, 2018).

Many small-scale farmers do not rely on a single system – they use the two systems in different ways depending on their specific needs and resources (Sperling and Cooper, 2004). It is, therefore, important not to prioritize one system over the other. To ensure that small-scale farmers can access and afford the vegetable and fruit crop diversity they need, both formal and informal seed systems need to be strengthened and treated as complementary services (Croft et al., 2018).

In general, vegetables are annual crops grown from seed whereas the main fruit crops are perennial grown from vegetatively propagated materials. For this reason, fruit and vegetables are considered separately.

## Vegetable crops

The percentage of vegetable seeds received through formal systems is far greater than for other food crops; for example in West and Central Africa in 2013 only 12 percent of arable farms used certified seed, and in a nine-country study, formal systems supplied less than 5 percent of seed used by small-scale farmers for most cereal and legume crops, but for vegetable crops this was over 20 percent (Djamen, 2016; McGuire and Sperling, 2016). A seed survey in the Sudan found that 90 percent of seed used by farmers came from the informal sector, but for vegetable seed, the percentage was only 53 percent. The remaining seeds were imported varieties (29 percent) and locally certified varieties (18 percent). The seed obtained from the informal sector included leafy vegetables, such as arugula, parsley, fennel, jute mallow (*Corchorus olitorius*) along with beet, squash and chili pepper. Imported certified seeds were used for watermelon, sweet melon, carrots and tomatoes, and locally-certified seed were used for okra and eggplant (Key2Market, 2018).
A common assumption is that traditional crops and varieties are associated with informal systems and that improved varieties are associated with formal systems (Sperling and Cooper, 2004). In the United Republic of Tanzania, 70 to 75 percent of traditional vegetable seed originated in the informal sector (Ellis-Jones et al., cited in FAO and ICRISAT, 2015). However, for exotic species, most farmers cultivated certified varieties, even in sub-Saharan Africa, in part because of relatively modest seed costs (Ellis-Jones et al., cited by Lynam et al., 2010). A survey from 2000 in Nigeria, found that for tomato, okra, amaranth and hot pepper most farmers bought seeds of improved varieties from agrodealers that were produced by either private companies or national agricultural research institutions, and there was minimal seed exchange between farmers (Daniel and Adetumbi, 2004). This suggests the disappearance of indigenous varieties, species and landraces, and the dependency of farmers on a restricted choice of exotic ones, with impacts on food sovereignty.

While some NUS of vegetables are associated with informal seed systems it is important to stress that NUS often predominate in local markets, despite not being major global commodities. A market survey in the town of Foumbot in Cameroon found that African nightshade (*Solanum nigrum*), an indigenous vegetable, was sold by the largest share of vegetable vendors (26 percent) followed by tomato (25 percent), and that more vendors sold garden egg (*Solanum gilo*), an indigenous variety of eggplant, than green peppers, carrots and lettuce (Schippers, 2000). For African leafy vegetables in western Kenya, 72 percent of growers sourced seeds from local markets and then saved their own seeds when possible (Abukutsa-Onyango, 2005).

Neglected and underutilized species, being adapted to local environments and with long-standing consumer acceptance, have been described as "development opportunity crops" (Kahane et al., 2013). Further adoption would be facilitated by greater access to high-quality seeds, particularly in Africa (Schippers, 2000; Adebooye et al., 2005).

## ☐ Vegetable seed production

For cereals, there is no botanical distinction between seed and grain (the edible part of the plant is the same as that used to grow crops), but for vegetables the edible part of the plant is different to the seed used to grow the crop (although the seed may also be eaten). Therefore, the multiplication of vegetable seeds is a specialized process that is distinct from food production. This specialization creates numerous distinct challenges for small-scale farmers and informal seed suppliers,
and partly explains why the cost share of vegetable seeds is higher relative to cereals. However, this demand for specialized seed services provides opportunities to develop local enterprises to supply farmers with high-quality seeds through an intermediate or semi-formal seed system.

To produce vegetable seeds that are true to type (that will generate a plant with the same desirable traits as its parents), the mode of pollination must be understood. Many major vegetable crops (tomatoes, green peppers and chili peppers, eggplants, green beans, lima beans, sweet peas) are self-pollinated and thus do not need pollinators (birds, insects or bats), or other agents (wind, water) to reproduce. But if they are grown in greenhouses, the flowers must be gently shaken by hand or by an insect (often bumblebees) to ensure pollination. Seeds that are saved from these crops are likely to have relatively little genetic variation from one generation to the next, except when first generation (F1) hybrid seeds were used.

Cross-pollinating crops (brassicas, cucurbits) require pollinators and are at risk that the plant with the desired traits will receive pollen from plants of different varieties. For some crops (such as carrots), cross-pollination can be from weedy varieties and the seeds produced will be genetically different from the parents and will not be true to type. Cross-pollinating crops and also self-pollinating crops that cross-pollinate easily (such as amaranth, onion), need to be grown isolated from other varieties (sometimes up to one kilometre) or under a protective net to ensure that the seeds produced are genetically identical to their parents.

For seed processing, the methods will also vary depending on the type of vegetable. The seeds of leafy vegetable crops (amaranth, lettuce) and some other vegetables (okra) can be dry processed using mature seeds collected from plants (threshing, winnowing, cleaning). The seeds from vegetables that are botanical fruit (tomatoes, cucurbits, eggplants) must be wet processed (separated from the fruit structure, cleaned and dried). After processing, the seeds must be stored properly in dry and cool conditions to minimize respiration and to protect them from pests and diseases. This is critical to ensure their viability and health status. In tropical countries with hot and humid climates, it can be challenging or costly to maintain adequate seed storage conditions, particularly when electricity for cooling and drying is unavailable or unreliable. Furthermore, prior to planting some seeds (such as tomato), the seed will also need to be soaked in water or fermented, a prerequisite for seed germination.

Seed produced locally by farmers and communities can often become infected by seed-borne or seed-transmitted viruses, fungi, bacteria and insects, and they may include an undesirable degree of genetic variation, which will reduce the crop yield and perhaps even lead to complete crop

<figure><img src="image_43.png" /><figcaption>Okra (Abelmoschus esculentus L.)</figcaption></figure>
failure. To satisfy the demand for high-quality vegetable seed, it is critical
that informal systems are provided with the necessary technical capacity
(FAO and AfricaSeeds, 2018). Along with these challenges, local suppliers
operating at a semi-formal level must also contend with difficulties related
to economies of scale to provide high-quality seed that is also affordable.

□ Formal seed systems

It is the formal seed system, especially private and global companies,
that plays a significant role in supplying vegetable seeds to small-scale
farmers, though with a lesser reach in Africa. Government and parastatal
seed companies, generally focusing more on staple crops, continue
to operate in some countries, but their prominence has diminished in
the wake of the deregulation and privatization of the seed sector in the
late 1990s. In Asia, where there is a strong consumer demand for fresh
vegetables, there has been particularly strong growth of the private
sector into the vegetable seed market (Lynam et al., 2010; Spielman and
Kennedy, 2016; FAO, 2020b).

In 2019, the Access to Seeds Foundation published the second edition
of the *Access to Seeds Index*, covering 62 global and regional seed
companies of which 28 sell vegetable seed, from South and Southeast
Asia, Eastern and Southern Africa and Western and Central Africa
(Access to Seeds Foundation, 2019). Some seed companies are state-
owned enterprises (Ethiopian Agricultural Business
Corporation, Kenya Seed Company, National Seeds
Corporation from India, Punjab Seed Corporation
from Pakistan and Vinaseed from Viet Nam) and one
was a large NGO (BRAC Seed and Agro Enterprise
in Bangladesh). The 2019 *Access to Seeds Index
Synthesis Report* notes that small-scale farmers
constitute a relatively new clientele. However, two
global companies were exceptions: Advanta (the
global seed enterprise of United Phosphorus Ltd,
an Indian multinational focusing on agricultural
inputs and East-West Seed (Thailand). East-West
Seed, whose seed portfolio focuses heavily on
vegetables, has a business model based almost exclusively on supplying
seeds and relevant technical support such as agronomic guidance to
small-scale farmers. It is, therefore, not surprising that East-West Seed
had the Index's highest ranking in South and Southeast Asia. In Eastern
and Southern Africa, the regional seed company, East African Seed
(Kenya), ranked highest and in Western and Central Africa, it was Value
Seeds (Nigeria). Seed companies sometimes include local vegetable

<figure><img src="image_44.png" /><figcaption>Watermelon
(Citrullus lanatus)</figcaption></figure>
crops, which the Index also refers to as NUS crops, with East-West Seed selling the most with 16 species, Technisem (France), which is the largest portfolio of local crops available in Western and Central Africa, sells nine, and Limagrain (France), whose clientele is 81 percent small-scale farmers, sells seven.

For cross-pollinated and fruiting vegetable crops, global seed companies concentrate on selling hybrid varieties, which are obtained through the controlled cross-pollination of two parent lines, each with desirable traits. Seeds from hybrid varieties will not breed true, so there is no benefit to farmers saving these seeds. Hybrids offer seed companies repeat revenues from annual purchases and offer small-scale farmers higher yields and other desirable traits, such as greater resistance to abiotic stress, pests and diseases, and early and uniform ripening.

The open-pollinated vegetable crops (non-hybrid) will breed true for several seasons and thus are suitable for farmers to save. A few smaller regional seed companies, especially in Africa, offer portfolios with a mix of hybrid and open-pollinated varieties. Several global companies, Advanta, East-West Seed, Limagrain, Sakata (Japan) and Technisem focus on both open-pollinated varieties and hybrids. Many of the local vegetable crops sold are open-pollinated varieties (onions in West Africa, for example). It is common for farmers to use saved seeds from open-pollinated varieties before purchasing new seed (Access to Seeds Foundation, 2019).

Small-scale farmers will not benefit from improved seed purchased through formal systems, and seed companies will not gain repeat customers unless the seed companies offer their clients guidance and support in adopting farm management techniques that will deliver the promised increases in productivity. Most of the seed companies covered by the *Access to Seeds Index* provide extension services to their clients. However, these capacity building activities are mostly limited to companies' primary markets and, as a result, small-scale farmers in many countries, particularly in Western and Central Africa and Latin America, do not receive support.

Half of the seed companies covered by the Index incorporate small-scale farmers in their seed production activities. Corteva Agriscience, which has no vegetable seeds in its portfolio, involves small-scale farmers in all of its seed production locations in the countries included in the Index. East-West Seed and Advanta involve small-scale farmers in their seed production in most of the countries where they produce seeds.

The 2030 Agenda for Sustainable Development recognizes the need for public-private partnerships to achieve the SDGs. The fact that Mr Simon

<figure><img src="image_45.png" /><figcaption>African eggplant
(Solanum macrocarpon L.)</figcaption></figure>
Groot, the founder of East-West Seed, was awarded the 2019 World Food Prize because of the company's clear commitment to improving the livelihoods of small-scale farmers is a recognition of the important role private sector companies play in supporting sustainable agricultural development.

## Fruit crops

Farmers cultivating perennial fruit crops do not need to obtain seed every year but do require high-quality planting material to establish their orchards or plantations or natural stands. As with vegetables, fruit are diverse, and the constraints related to small-scale farmer access to planting materials are connected to how different species reproduce. In this respect, it is convenient to divide fruit crops into two main types: woody fruit crops, which include fruit trees (mango, oranges, avocado) plus fruit vines (grapes, kiwis and berries), and herbaceous fruit crops (banana, pineapple and strawberries).

### □ Woody fruit crops

Fruit grown on trees or vines can be cultivated from seed (if they are not a seedless hybrid variety). However, because fruit trees are cross-pollinating, trees grown from seed will not produce fruit with the same uniform characteristics as the parent. To obtain trees and vines that will produce the fruit of the desired quality, market-oriented fruit growers need access to seedlings that are genetic clones of the parent plant by having been produced through vegetative propagation or grafting. Vegetatively propagated or grafted fruit trees provide high-quality, true to type fruit and maturity is reached more rapidly than if trees are grown from seed.

Vegetative propagation of fruit trees and vines can be undertaken using different methods:

* Planting stem cuttings to take root in soil, which is applicable to only a few tropical fruit such as pitaya or dragon fruit (*Hylocereus* spp.), cactus pear (*Opuntia* spp.) and spondias (*Spondia* spp.);

* Air layering involves developing roots on a stem that is still attached to the parent plant before cutting and planting, which is applicable to tropical fruit such as guavas, lychees and longans; and
* Grafting involves splicing scions to robust rootstock, which is applicable to major temperate, tropical and semi-tropical fruit tree species (Wasielewski and Balerd, 2019).

The vegetative propagation of fruit trees is a delicate, specialized process that is both labour and knowledge intensive. Market-oriented small-scale farmers seeking either to embark on a decades-long venture to integrate fruit trees into their production system, or to upgrade or diversify their existing fruit production must be assured that they have disease-free certified planting materials. This material can generally only be obtained through commercial nurseries, or in some countries through government-run nurseries. In many countries of sub-Saharan Africa, the number of nurseries capable of producing high-quality fruit tree seedlings is limited. Relative to other crops, informal systems will play a considerably less prominent role in supplying tree fruit crop planting material to small-scale farmers.

## ☐ Herbaceous fruit crops

Traditionally, the major tropical herbaceous fruit crops, banana and pineapple, are multiplied by uprooting the suckers, the lateral shoot that develops from the mother plant. For pineapple, the crown can also be used as planting material. Large-scale banana producers that focus on a single type of banana (such as the most widely exported variety, Cavendish) and research institutes can produce millions of pest-free and high-quality tissue culture plantlets through *in vitro* cultivation. While Cavendish bananas account for nearly half of global banana production, there are over 1 000 varieties grown around the world. In Africa, which is the third largest regional producer, between 70 to 80 percent of the production are local varieties (OECD and FAO, 2020).

Small-scale banana farmers rely heavily on informal systems for obtaining suckers and grow a range of cultivars. In a study from the Mukono district in central Uganda, banana farmers grew 10 different banana cultivars and were aware of 40 others (Kilwinger et al., 2019). This diversity ensured that harvesting could be done all year and reflects the many different uses of the banana cultivars: for cooking, dessert, roasting and brewing. Other parts of the plant are used for fodder, packaging, mulch, fibres and the male flower is consumed as a vegetable. Farmers obtained most of their suckers (almost 60 percent) from their own farms, as well as from friends, relatives and neighbours with only 5 percent supplied through the national agricultural advisory services
and the government extension programme. The farmers preferred to source suckers from existing mats on their own farm because they were familiar with their properties and performance. Sourcing planting material through informal seed systems presents the risk of spreading pests and diseases and new techniques need to be developed.

## Breeding

Developing and selecting new varieties with improved traits (nutritional density, taste, shape, colour, cooking times, the removal of anti-nutritional compounds, high yields, hardiness to pests, diseases, temperature and water fluctuations, salinity and suitability for transport, storage or processing) is of critical importance to provide small-scale farmers with options suited to their environments and markets.

Historically, farmers, through the careful selection of plants that meet their particular environmental and cultural needs, have helped make available the great diversity of fruit and vegetables that exist today. In the last century, formal plant breeding has become increasingly sophisticated and demands significantly high fixed costs in terms of fields, equipment and scientific expertise. It can take between 5 to 20 years of research to develop an improved variety and the process to register a variety in a country or region can also take a few years and significant investments. In general, only large private companies or subsidized public entities can afford such ventures (Minot et al., 2007). However, in Asia smaller companies have started developing their own vegetable varieties (Schreinemachers et al., 2017a). Countries that do not have mature breeding programmes or a viable seed industry must rely on imported seeds that will not always include varieties adapted to local conditions and markets (cabbage seeds are imported by South Asian countries, carrot seeds are exported by New Zealand).

## Vegetables

The 2019 *Access to Seeds Index* found that in South and Southeast Asia, the portfolios of all the regional companies involved included vegetables, and all of the companies, except two that were state-owned, have breeding programmes. However, for both Eastern and Southern Africa and Western and Central Africa, breeding activities were largely limited to maize with very little attention paid to vegetables.
BOX 7. The cucurbit breeding programme of the World Vegetable Center and private sector partnerships. Source: Dhillon et al. (2016; 2020a,b)

<figure><img src="image_46.png" /><figcaption>THAILAND TYPES</figcaption></figure>

<figure><img src="image_47.png" /><figcaption>CHINA TYPES</figcaption></figure>

<figure><img src="image_48.png" /><figcaption>OKINAWA TYPES</figcaption></figure>

<figure><img src="image_49.png" /><figcaption>VIET NAM TYPES</figcaption></figure>

<figure><img src="image_50.png" /><figcaption>TAIWAN TYPES</figcaption></figure>

<figure><img src="image_51.png" /><figcaption>PHILIPPINE TYPES</figcaption></figure>

<figure><img src="image_52.png" /><figcaption>INDONESIA TYPES</figcaption></figure>

<figure><img src="image_53.png" /><figcaption>SOUTH ASIAN TYPES</figcaption></figure>

The global cucurbit breeding programme of the World Vegetable Center focuses on four species: bitter gourd (Momordica charantia), tropical pumpkin (Cucurbita moschata), ridge gourd (Luffa acutangula), and sponge gourd (Luffa cylindrica syn. L. aegyptiaca). This programme is based in Thailand and recognizes that cucurbit crops make an important contribution to global food and nutrition security and are economically important to small-scale farmers, who account for 83 percent of global cucurbit production in Asia.

Considering bitter gourd; there are a range of shapes, spine types, colours, tastes and cooking characteristics

favoured by different markets.

While improved varieties have been developed by the private seed industry, repeated recycling of lines derived from elite hybrids has narrowed the genetic base and reduced genetic gains for yield and other key traits. What is required is a concerted effort to introduce new genetic variability into elite hybrids.

The World Vegetable Center developed a breeding consortium with various seed companies to facilitate access to the Center's new breeding lines derived from hitherto unexploited landraces to develop genetically diverse, improved cucurbit cultivars with higher yields and

enhanced resistance to major diseases. Private seed industry staff engaged in breeding, product development, sales and marketing select lines and F1 hybrids based on their performance and characteristics demonstrated through annual field visits.

The benefit to the World Vegetable Center is continued financial support, while each seed company obtains lines with improved traits that can be incorporated into their breeding programmes for eventual varietal registration and mass seed production and distribution (protected by rigorous quality assurances). The benefit to small-scale farmers is access to affordable seeds of improved varieties.
BOX 8. Fruit and vegetables in the International Treaty on Plant Genetic Resources for Food and Agriculture. Source: International Treaty for Plant Genetic Resources for Food and Agriculture (http://www.fao.org/plant-treaty/en/)

The International Treaty on Plant Genetic Resources for Food and Agriculture was adopted by the Thirty-First Session of the FAO Conference in 2001. The objectives of the International Treaty on Plant Genetic Resources for Food and Agriculture are the conservation and sustainable use of all plant genetic resources for food and agriculture and the fair and equitable sharing

of the benefits arising out
of their use, in harmony
with the Convention on
Biological Diversity, for
sustainable agriculture and
food security. The Treaty
established the Multilateral
System (http://www.fao.org/
plant-treaty/areas-of-work/
the-multilateral-system/
the-smta/en/) for access
and benefit sharing that
places 64 of the world's most
important crops into an easily
accessible global pool of

genetic resources that is freely
available to potential users in
the nations that have ratified
the Treaty for research,
breeding and training for
food and agriculture under
a Standard Materials Transfer
Agreement.

The fruit and vegetables
included in Annex 1 of the
Treaty are:

* Vegetables: asparagus, beet, brassica, carrot, eggplant;

* Fruit: apple, banana,
breadfruit, citrus, strawberry.

Due to the impacts of disasters and climate change, breeding for tolerance to abiotic stress and resistance to pests and diseases is recognized as a priority. Although some breeding has been done to improve the provitamin A content of some staple crops (orange fleshed sweet potato, yellow cassava and yellow corn), breeding for higher nutritional value remains the lowest priority in breeding programmes (Access to Seeds Foundation, 2019).

The seed portfolios of the world's largest seed companies have been significantly shaped by the work carried out by national and international research institutes, and for vegetable varieties the World Vegetable Center has made critical contributions. Based on available information on companies' sourcing of varieties, three-quarters of market varieties were developed by national and international agricultural research institutes. For regional companies, the share was 80 percent; for global companies, 50 percent. State-owned companies almost exclusively sell varieties developed by their national agricultural research system, though on a limited scale.

These figures illustrate how partnerships between public
organizations and private companies have been critical for both the
development of new vegetable varieties and their delivery to farmers.
In 2017, the World Vegetable Center and the Asia and Pacific Seed Association (APSA) jointly established the APSA-WorldVeg Vegetable Breeding Consortium in order to further strengthen these partnerships. In 2018, the World Vegetable Center and the African Seed Trade Association (AFSTA) jointly formed the Africa Vegetable Breeding Consortium (AVBC). The cucurbit breeding programme of the World Vegetable Center has been particularly innovative in seeking support from private seed companies to benefit small-scale farmers (Box 7). Several global vegetable seed companies have also come together to establish the International Licensing Platform, which ensures companies have access to vegetable germplasm on reasonable terms for breeding purposes.

Plant breeders, both public and private, recognize the need to develop appropriate traits in their varieties through cooperation with small-scale farmers. This can be achieved through participatory varietal selection, as was done, for example, for African vegetables in Mali (Diouf, Gueye and Samb, 2017). This process is considered to be particularly relevant for areas that do not have prime agricultural land to grow more local crops (Weltzien et al., 1999). A review of publications on participatory plant breeding found few were focused on vegetables (Ceccarelli and Grando, 2020). For an example of participatory plant breeding for tomato in Spain, see Casals et al. (2019).

Once new breeding lines are developed their availability may be limited to the public or private companies that have invested in creating them, or limited to the country where they originate, by global regulations from the Convention on Biological Diversity or national regulations depending on whether governments have ratified and complied with the Nagoya Protocol. While an International Treaty was established to facilitate the accessibility of several crops recognized as being of critical importance to agriculture in the developing world, the number of fruit and vegetable species is limited, and efforts to increase this number would support the global development of the sector (Box 8).

## Fruit

Given the time it takes for fruit trees to reach maturity, the process of breeding more adapted varieties of these species is much slower than for vegetable crops. Only the major tropical fruit crops (avocado, banana, citrus, mango, papaya, pineapple) as well as (water)melons, are subject to significant breeding activities, and these are driven by the demands of large-scale producers and international trade markets.
## Conservation

The conservation of plant genetic resources for food and agriculture serves to maintain genetic diversity among and within plant species. Conservation strategies include safeguarding resources such as crop wild relatives (CWR) *in situ* (in their natural habitats); managing a diversity of crops and their varieties on-farm (including farmers' varieties, landraces and NUS); and conserving samples (accessions) *ex situ* in genebanks (FAO, 2017b). Much of this plant diversity is important for cultivating and breeding well-adapted crop varieties that are suited to various environmental conditions and/or that fulfil consumer preferences.

The breeding of high-quality and well-adapted fruit and vegetable varieties, and their adoption by small-scale farmers, is a prerequisite for production systems that are sustainable and inclusive. The genetic material from local varieties and their wild relatives is of crucial importance in developing improved varieties, such as for tomatoes. Virtually all significant disease resistant genes have been sourced from wild relatives (Ebert and Schafleitner, 2015). Therefore, breeding of fruit and vegetable varieties must be supported by conservation and characterization of their genetic diversity combined with that of their wild relatives.

### In situ conservation

Conservation of genetic resources *in situ* involves locating, describing the conservation status, and actively managing and monitoring targeted wild plant populations in their natural habitats. Many populations of CWR are at considerable risk from drivers such as habitat loss, habitat fragmentation, changes in land use and disasters and climate change. Unfortunately, many countries lag behind in protecting CWR, especially in their natural environments, despite the increased public, political and scientific interest in conserving plant genetic resources (FAO, 2017c).

### On-farm management

A significant amount of crop diversity is maintained only in farmer's fields, orchards or home gardens (FAO, 2019c). Many farmers continue to cultivate farmers' varieties and landraces due to agronomic, culinary, or quality preferences as well as locally important cultural values.
This continued on-farm management of diversity results in exposure to different production regimes, environments, farmers' selection and seed exchange systems, contributing to their continued evolution and adaptation (Jarvis et al., 2000). Unfortunately, crop diversity managed on-farm is also threatened by urban encroachment on farmland, unsustainable use of natural resources, introduction of alien invasive species and climate change, as well as the absence of, or inappropriate, legislation and policy, and the promotion of genetically uniform varieties in replacement of local varieties and changing patterns of human consumption (Dhillon et al., 2016, 2020a,b; FAO, 2019c). Efforts in this area require, and create opportunities for, collaboration between farmers, breeders and organizations working to conserve genetic resources. For an example of community-based conservation and sustainable use of cultivated and wild tropical fruit tree diversity, see Sthapit et al. (2012).

## Ex situ conservation

The conservation of plant genetic resources *ex situ* in genebanks safeguards a large and important number of resources that are vital to present and future global food security. Conservation in genebanks and other facilities includes storage of seed in seed genebanks and safeguarding species that produce nonorthodox seeds or propagate clonally as live plants in field genebanks or as plantlets through *in vitro* culture or cryopreservation (FAO, 2014a). *Ex situ* conservation involves the acquisition, storage, regeneration, characterization, evaluation, safety duplication and documentation of accessions.

It is crucial to secure adequate storage or maintenance conditions for the genetic materials already collected. This is possible through the application of standards and procedures that ensure their continued survival and availability (FAO, 2014a). Genebanks globally hold *ex situ* collections of a broad range of crop diversity, including CWR, with the overall aim of long-term conservation and the accessibility of plant germplasm to plant breeders, researchers and other users. Germplasm of crop species and their wild relatives is conserved in more than 700 genebanks worldwide, with approximately 5.4 million accessions maintained under medium- and long-term conditions (FAO, 2020a). Many *ex situ* collections, however, are still vulnerable, exposed to natural hazard-induced disasters and man-made calamities such as civil unrest, as well as lack of funding and/or poor management.
BOX 9. Germplasm collection of bananas in the world.

<figure><img src="image_54.png" /></figure>

The world's largest
collection of banana
germplasm is maintained
by the Bioversity International
Musa Germplasm Transit
Centre (ITC), hosted
at the KU Leuven University,
Belgium. The conserved
germplasm, which includes
more than 1 500 accessions
of edible and wild species of

banana, is placed
in the Multilateral System
of Access and Benefit Sharing
of the International Treaty
on Plant Genetic Resources
for Food and Agriculture.
The accessions are kept
*in vitro* under slow growth
conditions at 16 °C and
the samples are also
frozen to -196 °C through

cryopreservation.
The cryopreserved
collection is duplicated
at the *Institut de recherche
et de développement* (IRD) in
Montpellier, France. For more
information about the long-
term conservation and use of
*Musa* genetic resources visit
the site http://www.musanet.org/

Vegetable genetic resource conservation

Globally, about 1 million accessions of crops used at least partially as vegetables are conserved ex *situ*. For crops that are exclusively used as vegetables, there are about 500 000 accessions representing 7 percent of the 7.4 million accessions of plant genetic resources that are maintained ex *situ* (Ebert, 2013). Among vegetable commodities, tomato, capsicum, melon and cantaloupe, brassicas, cucurbits, alliums, okra and eggplant are well represented in ex *situ* collections at the global level, with between 22 000 and 84 000 accessions per vegetable group.
The WorldVeg Genebank (https://avrdc.org/our-work/managing-germplasm/) maintains the world's largest public vegetable germplasm collection with more than 65 000 accessions from over 150 countries of more than 450 species. The collection includes the WorldVeg Genebank in Arusha, United Republic of Tanzania, which maintains about 2 400 accessions of 35 traditional African vegetables. The World Vegetable Center collaborates in the collection and conservation of vegetable germplasm with national partners which maintain duplicate collections. Since 2013, 183 000 seed samples of promising accessions and open-pollinated breeding lines of traditional African vegetables have also been distributed to farmers in East Africa (Stoilova et al., 2019).

*Ex situ* conservation of vegetable genetic resources in genebanks or botanical gardens removes the species from their natural ecological and evolutionary context, which leads to "a 'static' conservation in which evolutionary and adaptive potential are frozen" (Galluzzi et al., 2010). *In situ* conservation of vegetable genetic resources (the management of genetic diversity and landraces on farms and in home gardens) is also critical and the best strategy is to have both (Galluzzi et al., 2010; FAO, 2019c).

## Fruit genetic resource conservation

The conservation of tree fruit genetic resources (and that of some perennial vegetables) is particularly challenging, as these species have recalcitrant seeds that cannot be dried and stored in cold conditions and, therefore, won't survive in genebanks. This makes it crucial to find solutions for their on-farm and *in situ* conservation. Efforts in this area will require, and create, opportunities for collaboration among farmers, breeders and organizations working to conserve genetic resources. For an example of community-based conservation and sustainable use of cultivated and wild tropical fruit tree diversity, see Sthapit et al. (2012).

### Protected cultivation systems

Protected cultivation includes different types of structures, providing a fully, partially or modified microclimate around the plants to protect them against adverse climatic conditions, and extending the cultivation season or providing out of season production.
<figure><img src="image_55.png" /><figcaption>Protected cropping
system, low-tech
(plastic tunnels)</figcaption></figure>

Growing vegetables in greenhouses and nethouses is a common approach for many larger commercial growers (refer to the section on plant health for more details on netting as a crop protection technique). In some temperate countries, grapes are grown in protective structures, and growing bananas and sometimes papayas in greenhouses is becoming increasingly popular in places without the ideal conditions for the crop. However, in general, fruit trees are seldom grown under protected cultivation, as is more common for vegetables.

In some instances, the gradations between open field cultivation and protected cultivation can be difficult to discern. For example, the use of mulch is technically considered a protected cultivation technique. Protected agriculture also includes material or structures such as low tunnels that are set up over the bed rows, high shelters that are placed over the entire crop to protect the plants from harsh sunlight (shade nets), insects (insect nets), hail (hail nets) or heavy rains (rain shelters) and grafting chambers, which provide dark environments with high humidity to encourage adhesion between the rootstock and scion.

There are advantages to protected cultivation systems. In tropical countries, where high temperatures and high humidity create favourable conditions for many plant pests and diseases, the shift to protected cultivation is practiced to reduce problems with pests and diseases. Protected cultivation in the tropics also protects the crop against wind, drought, flooding and physical damage by heavy rains (FAO, 1999). In cooler climates, protected cultivation allows farmers to extend the growing season, and increase the number of harvests per year, and, perhaps, to achieve year-round production. This gives farmers the opportunity to meet consumer demand for out-of-season fresh produce and obtain higher prices on the market. Other advantages of protected cultivation include higher yields, quality and greater food safety but agronomic principals such as crop rotation or diversification are still required to avoid an accumulation of pests and diseases.
<figure><img src="image_56.png" /></figure>

Protected
cropping
system
high-tech
(automatic
glasshouse)

In all parts of the world, climate change is leading to greater seasonal variations in temperature and precipitation and extreme weather events are increasing in frequency and intensity. This makes it harder for farmers to plan their cultivation schedule and increases the risks of losses in production and quality. Protected cultivation can help farmers adapt to these impacts while also making more efficient use of land, water and nutrients.

Recently, vertical farming has been gaining more interest in places, such as in city centres, where there is limited access to land. Vertical farming is a broad term that includes open structures that use commonly known vertical spaces, such as walls or rooftops, as well as high-tech indoor farming structures with complete climate control. Vertical farming maximizes the use of limited space by increasing production upwards. In the cities of some upper- and upper-middle-income countries, plant factories and vertical farms are now supplying vegetables to urban consumers.

Whatever the level of technology, cultivating fruit and vegetables in greenhouses involves very different practices and technologies for managing water resources, protecting plants from pests and diseases, soil health and crop species and varieties. It should be noted that growers can combine open field cultivation with protected cultivation, such as when seedlings and other planting materials are raised in protected nurseries before being transplanted to open fields.
FAO has enabled technical networks to capitalize on experience and to exchange knowledge on protected cultivation in the Mediterranean climate areas and in south eastern European countries. This regional cooperation has resulted in the compilation and publication of two technical papers on good agriculture practices for greenhouse vegetable production in these regions (FAO, 2013c; FAO, 2017d).

## Climate management

When growing crops under protected cultivation, farmers seek to create and maintain a stable microclimate within the structure that can provide the plants with the ideal conditions for growth. But there is no single type or design of greenhouse that can provide optimal results for plant growth in all settings. The selection of the greenhouse site and the type and design of the greenhouse will depend on the local climate conditions, as well as on the financial means of the farmer. Furthermore, higher crop production and improved quality will not happen automatically but is dependent on the knowledge and skill of the farmer.

Net houses are often used in warmer climates and/or areas with low rainfall. They can serve several purposes, although they are primarily used to protect crops from insect pests. A simple structure with a high net roof (or polyethylene sheeting) can be used to protect the plant from damage from heavy rains. Net houses can also be used to moderate the temperatures around the crop. In summer months, the netting can help reduce heat stress by providing shade, while in winter it can raise temperatures to promote growth. As the seasons change, side netting can be added or removed or opened up as necessary to regulate the temperature and circulation of the air. This can be done when the structure uses a combination of plastic sheeting and net. As the seasons change, the plastic sheeting on the sides is opened or removed to increase ventilation. In general, removing or opening nets is not recommended, as insect pests and disease vectors would not be excluded.

The net covering also protects the crops against excessive UV radiation and, depending on what type and colour of plastic or net is used, can create more diffuse light, which is conducive to plant growth. In hot climates, net houses are particularly suited for commercial or on-farm nurseries, where they protect delicate fruit and vegetable seedlings from excessive heat and heavy rains.

Greenhouses tend to be used in colder climates (such as in temperate regions and at higher altitudes) to increase temperatures and to extend the growing seasons for some crops. In all protective cultivation
structures, but especially in greenhouses, proper ventilation is essential
to keep the temperature and humidity from becoming excessive so that
it does not promote infection from fungal diseases such as Botrytis or
powdery mildew.

In temperate high-income countries (such as the Netherlands), greenhouses are equipped with the latest technology to precisely monitor and regulate temperature, humidity, radiation and carbon dioxide, as well as a range of other inputs such as water and nutrients; and to practice biocontrol to avoid using chemical pesticides. This ensures intensive year-round production. For small-scale farmers in low- and middle-income countries, this level of technology is out of reach. However, in cooler climates, there are some low-tech options that small-scale farmers have for heating greenhouses. For example, greenhouses can be constructed alongside the residence of the farmer, to share the heating that is used for the house. Another example is the Chinese passive solar greenhouse. Typically it is composed of three walls of brick or clay with the fourth side on the south. This side consists of transparent material (usually plastic foil) to allow the sunlight into the greenhouse. The heat that is accumulated in the walls during the day is released at night, allowing crop cultivation in cold climates. In tropical climates, keeping temperatures and humidity at optimal levels in greenhouses and net houses without expensive mechanical (forced) ventilation or cooling can be a challenge. In higher altitudes in the tropics, it is possible to add vents to the roof of the greenhouse and situate the structure in a place where the prevailing breezes pass, to create natural (non-forced) ventilation.

Water management

Net houses allow rainfall to reach the plants, but greenhouses do not. Greenhouses and nethouses can be equipped with gutters to collect rainwater and store it in tanks, which will reduce the need for freshwater withdrawals for irrigation. The benefit of greenhouses is that the water transpired by plants condenses onto the inner greenhouse surfaces and is made available again to the crop, as opposed to open fields where the water transpired by crops is lost. By protecting crops from the heat generated by sunlight, net houses can reduce water demands.

The water requirements of the crops must be understood and
compared with water availability to allow the determination of the
most appropriate areas, crops to cultivate and irrigation techniques for
protected cultivation systems. In general, because of the water demands
of vegetable crops and the cost to invest in protective structures,
drip irrigation systems, including fertigation, are preferred over furrow and hand watering, which are seldom practiced in greenhouses. Farmers growing vegetables in greenhouses have the added impetus to irrigate judiciously, as excessive watering can increase humidity and the risk of fungal and bacterial diseases.

Greenhouse technologies offer the possibility of growing vegetables in ways that significantly optimize water consumption using soilless culture. Different techniques of soilless cultivation exist. In hydroponic systems, for example, plants are grown in containers with hydroponic solutions supplied by pipe. They are held in place artificially without substrate, with their roots suspended below. The hydroponic solution contains nutrient profiles tailored to the type of crop and its development stage. Hydroponics is up to 90 percent more water-efficient than open field cultivation (Sharma *et al.*, 2019).

Plants can be grown in vertical structures that may or may not be protected (on shelves or in tubes, etc.) to maximize the use of scarce land, especially in cities, drought prone areas or where soil has been depleted or is infested with soil-borne pathogens. Since they can be established almost anywhere, hydroponic greenhouses can produce food nearer to markets and consumers, which can reduce transportation costs and food losses. It is critical that clean water be used, or a disinfection/sterilization system be installed, as water-borne pathogens such as fungi and bacteria can spread rapidly and destroy the whole crop.

## Soil health

Crops can be grown in soil under protected cultivation, and options for maintaining soil health and providing nutrients to the plants are similar to those described previously for open field cultivation. Soilless cultivation involves containers, such as bags, pots or trays, filled with a substrate, which can be organic (peat, rice husk, coconut fibre, sawdust, bark) or inorganic (perlite, rock wool, vermiculite), or a combination of both. Substrates are also used in the form of prepared cubes (rockwool cubes), mats (polyurethane foam) and troughs (rockwool). Using substrates allows farmers with limited amounts of land, or with poor quality soils, to cultivate high-value crops. While they also increase costs, substrates can help farmers avoid economic losses due to nematodes and other soil-borne diseases.

Depending on the type of material used, the substrate can either be replaced completely at regular intervals or sterilized (with soil solarization) to ensure that it contains no crop pathogens. In the highly
advanced and large-scale protected cultivation systems in high-income countries, growing vegetables in substrates is common, and locally sourced relatively low-cost options are available to small-scale farmers in low- and middle-income countries as well. Irrespective of whether soil or substrate is used, fertigation systems can deliver optimal nutrient profiles for any given crop and development stage.

## Plant health

Insect-proof net houses are used to exclude insect pests from crops and seedlings in nurseries. However, in low altitude tropical areas where temperatures are high, the need to provide adequate ventilation and reduce heat stress can make it difficult for farmers to keep their crops protected with insect-proof nets at all times during the growing season. Polyethylene plastic sheets that are used in tropical areas to protect crops from excessive rain can allow fungal and bacterial diseases to proliferate. In some cases, when crops are protected from direct rainfall in semi-open structures, the infestation by some pests can be higher than under non-protected conditions (red spider mite (Tetranychus urticae) on tomatoes).

As with open field cultivation, scouting remains a critical element of plant protection. It is also important to keep the greenhouses or net houses well maintained and to repair holes or gaps where insects and other pests can enter. To reduce the risk of pest and disease outbreaks, it is critical to keep the interior of the structure sanitized and well weeded.

In commercial greenhouses, insect pheromone traps and biological control methods have become widespread and are particularly successful because of the confined space, and lack of wind and other predators. In greenhouse vegetable cultivation, for example, the release of the predaceous mite (Phytoseiulus persimilis) to control the red spider mite is a common IPM strategy. More than 30 species of natural enemies are routinely used against more than 22 pest species. Between 1970 and 2013, the greenhouse area to which biological pest control was used increased from 400 ha to over 50 000 ha (Abdelhaq, 2013).

## Crops and varieties

Just as for open field cultivation, farmers need to select the crops and crop varieties that are best adapted to their growing conditions as well as market and economic conditions, crop characteristics and requirements, compatibility between crop and microclimate and soil
characteristics and soil-borne diseases. Not all vegetable crops are suitable for cultivation in greenhouses and net houses, and often the preferred crops are those that can be continually harvested (such as tomatoes, cucumbers or peppers) or those with short crop cycles (e.g. lettuce). Certain varieties of these crops have been bred and selected for traits specific to high performance under protected conditions.

## Pollination

For some vegetable species special care is needed to ensure natural pollination occurs. This can be facilitated by introducing bees, for example in brassicas, cucurbits and carrots. Other species that have closed bisexual flowers and can self-pollinate require assistance to shake off the pollen at the appropriate time to reach the female pistil. Bumblebees are particularly effective for this, and mechanical devices can also be used (for example, on tomato).

## Adoption constraints

For small-scale farmers, a major obstacle to the uptake of protected cultivation technologies is the cost, both in terms of initial investment and maintenance. This is especially true for the more advanced systems such as hydroponics and fertigation. Conversely, many farmers who can afford the investment and would use protected cultivation technologies or materials cannot access them in the local market.

However, for many farmers the lack of financial capital is perhaps not the main obstacle. In fact, banks often have a greater willingness to invest in protected cultivation systems because the production is high value, it can yield high off season returns, and the risk of crop loss is less than in open field cultivation systems. Some countries also provide subsidies to support farmers to make a shift to protected cultivation systems. However, to obtain these loans and subsidies, farmers need to be able to demonstrate that they have the skills and knowledge to avoid the risk of financial loss and make the venture a success. Overcoming a lack of capacity is often the primary obstacle that prevents farmers from engaging in the protected cultivation of high-value vegetables.

Labour can also be a constraint. It is often mistakenly believed that protected cultivation requires less labour than open field cultivation, whereas the opposite can be true. Protected cultivation is labour-intensive