# Temperature impacts the protective efficacy of microbial
biocontrol agents

Margot Grimonpont, Estelle Turc, Adrien Lies, Noadya Monnier, Philippe C. Nicot, Marc Bardin

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## To cite this version:

Margot Grimonpont, Estelle Turc, Adrien Lies, Noadya Monnier, Philippe C. Nicot, et al.. Temperature impacts the protective efficacy of microbial biocontrol agents. 12. International congress of plant pathology (ICPP), Aug 2023, Lyon, France., pp.937-938, Book of abstracts ICPP 2023. One health for all plants, crops and trees. Lyon, 20-25 August, France. hal-05122297

HAL Id: hal-05122297

https://hal.inrae.fr/hal-05122297v1

Submitted on 20 Jun 2025

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# Temperature impacts the protective efficacy of microbial biocontrol agents

Grimonpont M. (2), Turc E. (1,2), Lies A. (1), Monnier N. (1), Nicot P. (2), Bardin M. (2)

(1) Groupe Elephant Vert France, 77700 Serris, France

(2) INRAE, Pathologie Végétale, F-84140, Montfavet, France

## Specific category : 01.05 PROGRESS IN DISEASE CONTROL - Part1

The development of biocontrol agents could be a promising option to decrease reliance on fungicides for the control of white mold caused by *Sclerotinia sclerotiorum* on oilseed rape. Two bacterial strains have shown promising activities against this pathogen. Their effective use in the field requires that various factors be considered, which may interfere with their protective efficacy. For example, knowledge of the impact of temperature on treatment efficacy could guide recommendations for more reliable application in the field.

The aim of this study was to determine the level of efficacy of these two bacteria against *S. sclerotiorum* under different temperature conditions. To this end, detached leaves of oilseed rape were treated with the bacteria and incubated during 6 or 24 hours at temperatures representative of those encountered in the field at the time of flowering, the favorable period for pathogen infection (5, 13, 21 or 28°C). Two strains of *S. sclerotiorum* with different levels of aggressiveness were inoculated on the leaves 24 hours after treatment and incubated at 21°C, a temperature favorable to the development of the pathogen. Temperature at the time of treatment had a substantial effect on the protective efficacy of biocontrol, depending on the strain of *S. sclerotiorum*. These results emphasize the need to know the factors modulating the efficacy of biocontrol agents before their use in the field.