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

Managing the complex use of microbial biocontrol
agents against plant diseases in a context of IPM

<figure><img src="image_2.png" /><figcaption>Plant Pathology Research unit
Avignon, France</figcaption></figure>

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

RÉPUBLIQUE
FRANÇAISE

Liberté
Égalité
Fraternité

INRAE

<figure><img src="image_4.png" /><figcaption>Philippe C. NICOT</figcaption></figure>

<figure><img src="image_5.png" /><figcaption>Marc BARDIN</figcaption></figure>

marc.bardin@inrae.fr
# Disease control = “weak link” of IPM in cropping systems ?

## An increasing number of registered biocontrol products for disease management

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

**91 microbial biocontrol strains**

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

**41 microbial strains approved in Europe**

(EU pesticide database, 07/2023)

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BioControl
DOI 10.1007/s10526-017-9801-4

<figure><img src="image_9.png" /></figure>

**Biological control using invertebrates and microorganisms:**
plenty of new opportunities

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

**Mission accomplished ?**

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

**How are these products actually used by farmers?**
## Survey of French vegetable farmers and farm advisors

* Online questionnaires disseminated to more than 500 professionals (217 answers):

**2 key lessons from the analysis of responses:**

✓ Only few biocontrol products known (21/32) and used (15)

✓ Efficacy perceived as low

* Face-to-face interviews performed (42 / 217 respondents):

**3 key lessons**

✓ Aware of possible benefits of applying biocontrol products to manage plant diseases

**But...**

✓ Difficulties in using biocontrol (with other cultural practices) and need for guidelines

✓ Unstable efficacy

## Using microbial biocontrol for disease control in French vegetable production: An analysis of the perspectives of farmers and farm advisors

Thomas Pressecq<sup>a, b, *</sup>, Philippe C. Nicot<sup>a</sup>, Jean François Bourgeay<sup>a</sup>, Aurélie Rousselin<sup>b</sup>, Claire Goillon<sup>b</sup>, Marc Bardin<sup>a</sup>, Marc Tchamitchian<sup>a</sup>

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

→ What are the possible causes for this instability in the efficacy of protection?

<footnote><sup>a</sup> INRAE, Pathologie Végétale, 84140, Montfavet, France</footnote>

<footnote><sup>b</sup> Association Provençale de Recherche & d'Experimenter Légumière - APREL, 13210, Saint-Rémy-de-Provence, France</footnote>
# Example of factors that can modulate the efficacy of biocontrol against plant diseases

Climatic conditions

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

Cultural practices

Agron. Sustain. Dev. (2014) 34:641-648

DOI 10.1007/s13593-013-0168-3

RESEARCH ARTICLE

Nitrogen fertilization impacts biocontrol of tomato gray mold

Manzoor A. Abro • François Lecompte • Marc Bardin

Philippe C. Nicot

<figure><img src="image_13.png" /></figure>

<figure><img src="image_14.png" /></figure>

<figure><img src="image_15.png" /></figure>

## 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 the target pathogen to biocontrol

<figure><img src="image_16.png" /></figure>

frontiers
in Plant Science

REVIEW

published: 27 July 2015

doi: 10.3389/fpls.2015.00560

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

Marc Bardin<fnref n="1" />*, Sakhr Ajouz<fnref n="1" />, Morgane Comby<fnref n="1" />, Miguel Lopez-Ferber<fnref n="2" />, Benoit Graillot<fnref n="1" />,<fnref n="2" />, Myriam Siegwart<fnref n="1" /> and Philippe C. Nicot<fnref n="1" />

## Mode(s) of action and their activation

<figure><img src="image_17.png" /></figure>

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

ESTELLE TURC<fnref n="1" />,<fnref n="2" />, THOMAS PRESSECO<fnref n="1" />,<fnref n="3" />, PHILIPPE C. NICOT<fnref n="1" /> AND MARC BARDIN<fnref n="1" />*

Temperature

Water potential

pH

Nutrients

Plant

Microbiota (including pathogen)

<figure><img src="image_18.png" /></figure>

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

Induction of resistance

Antibiosis

Microbial biocontrol agent

Hyperparasitism

Interference with the pathogenesis

Competition for nutrients/space

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

Ecological competence of the microorganism

Formulation

Strategy of application in the field

Intrinsic factors related to the biocontrol product

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

<footnote n="1">¹Plant Pathology Unit, Institut National de la Recherche Agronomique, UR407, Montfavet, France, ²Laboratoire de Génie de l'Environnement Industriel, Ecole des Mines d'Alles, Institut Mines-Telecom, Alles, France, ³Natural Plant Protection, Arysta LifeScience Group, Pus. France, ⁴Plantes et Systèmes de Culture Horticoles Unit, Institut National de la Recherche Agronomique, UR1115, Avignon, France</footnote>

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

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

<footnote n="3"><sup>3</sup>INRAE, Ecodéveloppement, Avignon, France</footnote>
# Classification of efficacy factors for a biocontrol microbial strain

* 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

Efficacy

- Ecological competence of the microorganism

- Mode of action

- Dose / quality / formulation of product

- Method / condition of use

- Physical (T°C, humidity, light...)

- Chemical (pH, O₂, CO₂...)

- Biochemical (nutrients)

- Microbial

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

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

How to deal with this complexity
and help farmers use biocontrol
"correctly" ?
# How to deal with this complexity and help farmers?

<figure><img src="image_23.png" /></figure>

<figure><img src="image_24.png" /></figure>

* Develop **practical guidelines** helping the farmer to choose <u>the most adequate products</u> for specific situations, and to

* obtain indications about the <u>most efficient way to use</u> a biocontrol product

→ Where to find the information needed for developing the guidelines?

<figure><img src="image_25.png" /></figure>

→ the data available in scientific literature will make it possible to obtain this information

✓ Is there a substantial amount of published knowledge on the factors governing the efficacy of microbial biocontrol agents?

✓ Is it possible to gather suitable information to develop guidelines for the practical application of these products by farmers?
# Analysis of published knowledge on the factors that govern the efficacy of microbial biocontrol agents

## 1. Collect relevant peer-reviewed scientific articles

All publications on the **41 biocontrol microbial strains registered in Europe** (excluding reviews)

Research equation : Full name of biocontrol agent (**species + strain name**)
OR current (and possibly previous) commercial name

<figure><img src="image_26.png" /></figure>

WEB OF SCIENCE

* ✓ 808 publications collected about microbial strains registered in Europe

* ✓ Great majority of publications concerned strains in species of **Bacillus** (255 publications) and of **Trichoderma** (263 publications)

* ✓ Most studied strains: **B. amyloliquefaciens** QST 713 (133 publications) and **T. afroharzianum** T-22 (115 publications)
# Analysis of published knowledge on the factors that govern the efficacy of microbial biocontrol agents

1. Collect relevant peer-reviewed articles

2. Review of scientific information on the efficacy factors

✓ 37% of articles with information on efficacy factors (296)

✓ Certain articles can include results for different factors of efficacy

✓ **No information** for 13 of the 41 strains registered in Europe
# Analysis of published knowledge on the factors that govern the efficacy of microbial biocontrol agents

1. Collect relevant peer-reviewed articles

2. Review of scientific information on the efficacy factors

**3. In-depth analysis of publications: extraction of data on efficacy factors**

**a. Every publication 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)

* ...

✓ For a given scientific paper, several relevant information units can be obtained

- Type of disease

- Inoculum pressure

- Level of sensitivity

- Cultural practices

- Plant species, genotype

- Fertirrigation

- Phytosanitary treatments

Pathogen

Cropping practices

<figure><img src="image_27.png" /></figure>

Efficacy

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
# Analysis of published knowledge on the factors that govern the efficacy of microbial biocontrol agents

1. Collect relevant peer-reviewed articles

2. Review of scientific information on the efficacy factors

**3. In-depth analysis of publications: extraction of data on efficacy factors**

a. Every publication 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)

* ...

b. Build a database on efficacy factors of microbial biocontrol agents against plant diseases

=> analysis of the database:

* ✓ Not much quantitative data available

* ✓ Very heterogenous distribution of information among biocontrol strains and among types of efficacy factors
Example of Trichoderma strains: there are data, but ...

✓ Some data not relevant (e.g. strain name not indicated)

✓ Little information available / commercial strain / efficacy factor

✓ Information not directly applicable (e.g. data obtained under artificial conditions)

Trichoderma strains used as active substances

<figure><img src="image_28.png" /></figure>

<figure><img src="image_29.png" /></figure>

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

Groups and sub-groups of efficacy factors

<figure><img src="image_30.png" /></figure>

Number of information units on efficacy factors, sorted by groups
Conclusion

* Is there a substantial amount of published knowledge on the factors governing the efficacy of microbial biocontrol agents ?

→ **Most of the data currently published on microbial biocontrol agents in scientific journals do not involve commercial strains or efficacy factors**

* Is it possible to gather suitable information to develop guidelines for the practical application of these products by farmers ?

→ **Tremendous amount of additional data required for the development of guidelines for farmers**
# 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

* Obtain more data on biocontrol agent efficacy factors

* ✓ Make agreements with companies (in progress)

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

* Translate this scientific knowledge into decision rules

* ✓ Transform the data collected in the database into *operational* information

* ✓ Integrate this information into a decision support system useful to farmers

DeciControl

<figure><img src="image_31.png" /></figure>

http://ephytia.inra.fr/fr/P/175/DeciControl

<figure><img src="image_32.png" /></figure>

SynDev
L'orchestration des biosolutions
Thank you 谢谢

<figure><img src="image_33.png" /><figcaption>阿维尼翁, 普罗旺斯</figcaption></figure>

INRAO

<figure><img src="image_34.png" /></figure>

NUGNON
PATHOLOGIE
VEGETALE

<figure><img src="image_35.png" /></figure>

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

<figure><img src="image_37.png" /><figcaption>Thomas
PRESSECQ</figcaption></figure>

<figure><img src="image_38.png" /><figcaption>Marc BARDIN
marc.bardin@inrae.fr</figcaption></figure>

<figure><img src="image_39.png" /><figcaption>Marc
TCHAMITCHIAN</figcaption></figure>

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

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

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

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

RÉPUBLIQUE
FRANÇAISE

Liberté
Légitié
Fraternité

<figure><img src="image_43.png" /></figure>

FRANCE

<figure><img src="image_44.png" /></figure>

anr

<figure><img src="image_45.png" /></figure>

INRAO

CULTIVER
PROTÉGER
autrement

CAP

<figure><img src="image_46.png" /></figure>

PHYTO

<figure><img src="image_47.png" /></figure>

biocontrôle

<figure><img src="image_48.png" /></figure>

<figure><img src="image_49.png" /></figure>

Liberté • Égalité • Fraternité
RÉPUBLIQUE FRANÇAISE

MINISTÈRE
DE LA TRANSITION
ÉCOLOGIQUE ET SOLIDAIRE

RÉGION
SUD

MINISTÈRE
DE L'AGRICULTURE
ET DE L'ALIMENTATION