# Impact of temperature on protective efficacy of microbial biocontrol agents against Sclerotinia sclerotiorum

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

► To cite this version:

Margot Grimonpont, Estelle Turc, Adrien Lies, Noadya Monnier, Philippe C. Nicot, et al. Impact of temperature on protective efficacy of microbial biocontrol agents against Sclerotinia sclerotiorum. 16. IOBC-WPRS meeting of the working group "Biological and Integrated Control of Plant Pathogens". Biocontrol needs and challenges in future cropping systems, Wageningen university and research, Jun 2023, Wageningen, Netherlands. pp.88. hal-04308648

HAL Id: hal-04308648

https://hal.inrae.fr/hal-04308648v1

Submitted on 24 Jun 2025

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# Impact of temperature on protective efficacy of microbial
biocontrol agents against Sclerotinia sclerotiorum

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

Philippe, Marc Bardin

► To cite this version:

Margot Grimonpont, Estelle Turc, Adrien Lies, Noadya Monnier, C. Nicot Philippe, et al.. Impact of temperature on protective efficacy of microbial biocontrol agents against Sclerotinia sclerotiorum. IOBC WPRS, International Organisation for Biological Control, Jun 2023, Wageningen, Netherlands. pp.1. hal-05122321

HAL Id: hal-05122321

https://hal.inrae.fr/view/index/docid/5122321

Submitted on 20 Jun 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
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# Impact of temperature on protective efficacy of microbial biocontrol agents against *Sclerotinia sclerotiorum*

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

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

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

**Abstract:** Oilseed rape (*Brassica napus*), one of the main cultivated oleaginous crops worldwide is susceptible to white mold caused by the fungal pathogen *Sclerotinia sclerotiorum*. Control of this necrotrophic and polyphagous fungal pathogen relies mainly on chemicals. Therefore, the development of new biocontrol agents appears as a promising option to contribute to a more sustainable production of rapeseed. In previous work, two bacteria were identified as being effective against this fungus. These bacteria have shown particularly promising activities under controlled and in field conditions and are currently under development.

Microbial biocontrol products are often perceived as lacking efficacy or reliability when used in the field. This issue is generally attributed to biotic and abiotic factors that can interfere with their protective efficacy. For example, the microclimatic conditions encountered by microorganisms are considered key factors in their biocontrol activity. For this reason, we studied the influence of temperature at the time of plant treatment on the protective efficacy of the two selected antagonistic bacteria against *S. sclerotiorum* on rapeseed.

To this end, detached leaves of rapeseed were treated with biocontrol agents and incubated for six or twenty-four hours at different temperatures (5, 13, 21 or 28°C). These temperatures are representative of those encountered in the field during the flowering period of rapeseed, a period favourable for attack by the pathogen. After 24 hours of incubation, leaves were inoculated with the pathogen and incubated at 21°C, the temperature that favors the development of the pathogen.

First results showed that the temperature during the treatment could have an effect on the efficacy of protection provided by both bacteria. Understanding the impact of temperature should help guide future product development and recommendations for their optimal application in the field.

**Key words:** *Sclerotinia sclerotiorum*, white mold, biocontrol, efficacy, temperature