> Understanding the factors influencing the efficacy of biocontrol against plant diseases for an optimal use in the field

Marc Bardin

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Plant Pathology Research unit
Avignon, France

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RÉPUBLIQUE
FRANÇAISE

Liberté
Egalité
Fraternité

INRAE
# Augmentative biocontrol of diseases: increasing number of registered products

## At world level against diseases (virus, bacteria, oomycetes, fungi)

* **91 microbial strains:**

49 fungi/yeast/oomycetes + 37 bacteria/actinomycetes + 5 virus/phages

BioControl
DOI 10.1007/s10526-017-9801-4

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Biological control using invertebrates and microorganisms: plenty of new opportunities

Joop C. van Lenteren · Karel Bolckmans · Jürgen Köhl · Willem J. Ravensberg · Alberto Urbaneja

van Lenteren et al, 2018. *BioControl*

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* ~90 microbial strains commercialised / used

(Europe, USA, China, Russia, Oceania, Japan)

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Pressecq, unpublished
Various fungal species represented

BURLEIGH DODDS SERIES IN AGRICULTURAL SCIENCE

Improving integrated
pest management in
horticulture

Edited by Professor Rosemary Collon, Warwick University, UK

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by burleigh dodds
SCIENCE PUBLISHING

Advances in bioprotectants for plant
disease control in horticulture

Philippe C. Nicot, Thomas Pressecq and Marc Bardin, INRAE, Pathologie Végétale, France

Fungi

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EU
Australia

Canada

China

Japan
New-Zealand

Russia
USA

65 products (27 species)
including 34 Trichoderma-based products
Various bacterial species represented

BURLEIGH DODDS SERIES IN AGRICULTURAL SCIENCE

Improving integrated
pest management in
horticulture

Edited by Professor Rosemary Collor, Warwick University, UK

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

by burleigh dodds
SCIENCE PUBLISHING

Advances in bioprotectants for plant
disease control in horticulture

Philippe C. Nicot, Thomas Pressecq and Marc Bardin, INRAE, Pathologie Végétale, France

Bacteria

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EU
Australia

Canada

China

Japan

New-Zealand

Russia

USA

72 products (28 species)
including 43 *Bacillus*-based products

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## Some challenges remain

Protective efficacy of biocontrol agents against plant diseases remains variable and unpredictable in the field

* Due to the many factors that can modulate their efficacy in the field

* Lack of confidence among farmers

* How can we promote the use of biocontrol on farms?

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# How to deal with the complexity of the deployment of biocontrol agents?

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## Example of questions farmers are likely to ask regarding the implementation of a biocontrol solution :

* what are the biocontrol solution(s) available for the crop and for the target pathogen?

* what is the expected protection efficacy?

* when is the best time to apply the biocontrol solution?

* what is the frequency of use of the biocontrol solution and at what intervals should it be applied?

* what restrictions apply to the use of the biocontrol solution?

* what are the favorable/unfavorable climatic conditions?

* ...

* ✓ Can the data available in scientific articles help answer these questions ?

* ✓ Is it possible to translate the complex scientific knowledge available into operational information for farmers ?

* ✓ Can this information be integrated into a decision support system useful to farmers ?
Objectives

* Define the efficacy factors of interest for a biocontrol microbial agent

* Build a database on efficacy factors of microbial biocontrol agents

* Translate the data integrated into the database concerning biocontrol agents into decision rules to optimize their use

* Develop a decision support tool
Objectives

* Define the efficacy factors of interest for a biocontrol microbial agent

* Build a database on efficacy factors of microbial biocontrol agents

* Translate the data integrated into the database concerning certain biocontrol agents into decision rules to optimize their use

* Develop a decision support tool
# Define the efficacy factors of interest for a biocontrol microbial agent

## Example of factors that can influence the success of biocontrol against plant diseases

### Climatic conditions

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### Cultural practices

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### Other phytosanitary treatments including biocontrol

Biological Control 46 (2008) 476-483

Compatibility between biopesticides used to control grey mould, powdery mildew and whitefly on tomato

M. Bardin<sup>a,*</sup>, J. Fargues<sup>b</sup>, P.C. Nicot<sup>a</sup>

### Resistance of pathogen to biocontrol

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frontiers

in Plant Science

REVIEW
published: 27 July 2015
doi: 10.3089/fta.2015.00566

Is the efficacy of biological control against plant diseases likely to be more durable than that of chemical pesticides?

Marc Bardin<sup>*</sup>, Sakhr Ajouz<sup>†</sup>, Morgane Comby<sup>†</sup>, Miguel Lopez-Ferber<sup>†</sup>, Benoit Graillot<sup>1,‡</sup>, Myriam Siegwart<sup>1</sup> and Philippe C. Nicot<sup>†</sup>

### Mode(s) of action and their activation

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### Modes of Action of Microbial Biocontrol Agents against Plant Diseases

ESTELLE TURC<sup>1,2</sup>, THOMAS PRESSECO<sup>1,2</sup>, PHILIPPE C. NICOT<sup>1</sup> AND MARC BARDIN<sup>1*</sup>

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<footnote><sup>a</sup>INRA, Unité de Pathologie Végétale, UR 407, F-84140 Montf岳, France</footnote>

<footnote><sup>b</sup>INRA, Centre de Biologie et de Gestion des Populations, Campus international de Baillarguet, CS 30 016, 34988 Montferrier-sur-Lez cédex, France</footnote>

<footnote><sup>†</sup>Plant Pathology Unit, Institut National de la Recherche Agronomique, UR407, Montf岳, France, <sup>‡</sup>Laboratoire de Génie de l'Environnement Industriel, Ecole des Mines d'Alès, Institut Mines-Télécom, Alès, France, <sup>1</sup>Natural Plant Protection, Arysta LifeScience Group, Pau, France, <sup>2</sup>Parigi et Systèmes de Culture Horticoles Unit, Institut National de la Recherche Agronomique, UR115, Avignon, France</footnote>

<footnote n="1"><sup>1</sup>INRAE, Pathologie Végétale, Montf岳, France</footnote>

<footnote n="2"><sup>2</sup>Groupe Éléphant Vert France, Serris, France</footnote>

<footnote n="1"><sup>1</sup>INRAE, Ecodéveloppement, Avignon, France</footnote>
# Define the efficacy factors of interest for a biocontrol microbial agent

* Efficacy factors organized into 4 groups

* Each group includes a number of related factors

* Possible interactions between factors

* Type of disease

* Inoculum pressure

* Level of sensitivity

* Cultural practices

* Plant species, genotype

* Fertirrigation

* Phytosanitary treatments

Pathogen

Cropping practices

Biocontrol

Environnement

* Ecological competence

* Mode of action

* Dose / quality / formulation of product

* Method / condition of use

* Physical (T°C, humidity, light...)

* Chemical (pH, O₂, CO₂...

* Biochemical (nutrients)

* Microbial

Efficacy

BURLEIGH DODDS SERIES IN AGRICULTURAL SCIENCE

Improving integrated pest management in horticulture

Edited by Professor Rosemary Collar, Warwick University, UK

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

burleigh dodds
SCIENCE PUBLISHING

Advances in bioprotectants for plant disease control in horticulture

Philippe C. Nicot, Thomas Pressecq and Marc Bardin, INRAE, Pathologie Végétale, France
# Build a database on efficacy factors of microbial biocontrol agents

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INRAE

RÉGION
SUD
PROVENCE
ALPES
CÔTE D'AZUR

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* Search for relevant scientific publications

All peer reviewed scientific publications on **biocontrol microbial strains registered in Europe** (excluding reviews)

Research equation : Full name of biocontrol agent (**species + strain name**) AND current (and possibly previous) commercial name
# Build a database on efficacy factors of microbial biocontrol agents

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INRAE

RÉGION
SUD

PROVENCE
ALPES
CÔTE D'AZUR

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* Search for relevant scientific publications

* Extract data on efficacy factors and integrate them into the database

Every publication is analyzed according to the following framework:

## Context

* Biocontrol name
  (strain, commercial product)

* Crop

* Pathogen targeted

* ...

## Experimental conditions

* Experimental method
  (in vitro, controlled condition, in field...)

* Biocontrol treatment (type, dose, timing, frequency)

* Pathogen inoculation (natural or artificial, conditions)

* ...

## Data on efficacy factors

* Efficacy factor(s) tested (group and sub-group)

* Protective efficacy value

* Effect of factor(s) tested on efficacy
  (quantitative data if available)

* ...
# Build a database on efficacy factors of microbial biocontrol agents

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INRAE

RÉGION
SUD

PROVENCE
ALPES
CÔTE D'AZUR

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* Search for relevant scientific publications

* Extract data on efficacy factors and integrate them into the database

* Preliminary results

* More than 2300 publications collected: 901 on registered strains

* 34% with information on efficacy factors

* Heterogenous experimental conditions

* Few quantitative data available
Example of *Trichoderma* strains: lot of data but...

* If data is broken down by strain: little information available / commercial strain

* Some data not relevant: strain name not indicated, data obtained under artificial conditions...

Trichoderma strains used as active subtrates

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: Information not directly applicable by users
(e.g. in vitro studies, no direct effect on efficacy, ...)

Number of information on efficacy factors, sorted by groups
# What's next ?

* Increase the availability of data in future published articles for integration into the database

* ✓ Clearly indicate the strain name of the biocontrol agent used in the study

* ✓ Share data more widely, including “negative” results

* ✓ Standardise the names (and definitions) of efficacy factors

* Obtain more data on biocontrol agent efficacy factors

* ✓ Make agreements with companies (in progress)

* ✓ Integrate results of recent scientific projects, including "negative" results

* ✓ Carry out experiments under production conditions, recording as many variables as possible (climatic conditions in particular)

* Translate the data integrated into the database concerning certain biocontrol agents into decision rules
Thank you !

INRAO

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PATHOLOGIE
VEGETALE

<figure><img src="image_33.png" /><figcaption>Clémentine
LEPINAY</figcaption></figure>

<figure><img src="image_34.png" /><figcaption>Philippe
NICOT</figcaption></figure>

<figure><img src="image_35.png" /><figcaption>Jean-François
BOURGEAY</figcaption></figure>

<figure><img src="image_36.png" /><figcaption>Magali
DUFFAUD</figcaption></figure>

<figure><img src="image_37.png" /><figcaption>Margot
GRIMONPONT</figcaption></figure>

<figure><img src="image_38.png" /><figcaption>Awa
SANGARE</figcaption></figure>

<figure><img src="image_39.png" /><figcaption>Cathleen
ROBICHON</figcaption></figure>

<figure><img src="image_40.png" /><figcaption>Marc
TCHAMITCHIAN</figcaption></figure>

<figure><img src="image_41.png" /><figcaption>Thomas
PRESSECQ</figcaption></figure>

INRAO

RÉGION
SUD

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biocontrôle

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DeciControl

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Ecodéveloppement

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ADOPT
IPM

EU-China joint action
to increase the development
and adoption of IPM tools

The project has received funding from the Horizon Europe Framework
Programme of the European Union under grant agreement No 101060430

AGENCE NATIONALE DE LA RECHERCHE

ANR

Cap

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Phyto

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Liberté • Égalité • Fraternité
RÉPUBLIQUE FRANÇAISE

MINISTÈRE
DE LA TRANSITION
ÉCOLOGIQUE ET SOLIDAIRE

MINISTÈRE
DE L'AGRICULTURE
ET DE L'ALIMENTATION

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