Agronomy for Sustainable Development (2014) 34, 641-648

Manzoor A. Abro, François Lecompte, Marc Bardin and Philippe C. Nicot (2014)
Nitrogen fertilization impacts biocontrol of tomato gray mold
Agronomy for Sustainable Development 34 (3), 641-648
Abstract: Gray mold, caused by Botrytis cinerea, is a common threat for greenhouse production of tomatoes. Control of this disease can be difficult even with chemical treatments, and alternative methods are needed. Nitrogen (N) fertilization is known to modify the impact of pathogens on plants. However, there is scarce knowledge about the effect of fertilization on the efficacy of biocontrol. Here, we studied the effect of N fertilization on biocontrol agents Trichoderma atroviride and Microdochium dimerum that protect tomato against B. cinerea. Plants were grown for 2 months in a greenhouse with a soil-less drip irrigation system. Differential N fertilization (five concentrations of nitrate) was applied for the last 4 weeks prior to leaf pruning, biocontrol agent application, and B. cinerea inoculation. Results show that increasing N fertilization up to 10 mmol/L reduced disease by half for controls. High N fertilization also increased biocontrol, with a protection index rising from nearly 0 to up to 100 % depending on the biocontrol agent and the pressure of the pathogen. Indeed, high N fertilization delayed stem symptoms and slowed lesion expansion. To our knowledge, this is the first report of an effect of N fertilization on the efficacy of biocontrol against an airborne disease. Therefore, adapting N fertilization is a promising technique to protect greenhouse tomato.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Philippe C. Nicot

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Botrytis cinerea	Tomato (Solanum lycopersicum)
Trichoderma atroviride (antagonist)	Botrytis cinerea	Tomato (Solanum lycopersicum)
Fusarium dimerum (antagonist)	Botrytis cinerea	Tomato (Solanum lycopersicum)