CONTROL OF INFECTION AND SPORULATION OF BOTRYTIS-CINEREA ON BEAN AND TOMATO BY SAPROPHYTIC BACTERIA AND FUNGI

Sixty isolates of saprophytic microorganisms were screened for their a bility to reduce the severity of grey mould (Botrytis cinerea) infecti on and sporulation. Isolates of the bacteria Xanthomonas maltophilia, Bacillus pumilus, Lactobacillus sp., and Pseudomonas sp. and the fungu s Gliocladium catenulatum reduced germination of conidia of the pathog en and controlled disease on bean and tomato plants. Their activity un der growth room conditions was good, consistent, and similar to the ac tivity of the known biocontrol agent, Trichoderma harzianum T39 (non-f ormulated). Although the tested isolates may for nutrients with the ge rminating conidia of B. cinerea, resistance induced in the host by liv e or dead cells were also found to be involved. Inhibitory compounds w ere not detected on treated leaves. Sporulation of B. cinerea after it s establishment on leaves was also reduced by the above mentioned isol ates and by Penicillium sp., Arthrinium montagnei, Ar. phaeospermum, S esquicillium candelabrum, Chaetomium globosum, Alternaria alternata, U locladium atrum, and T. viride. These sporulation-inhibiting fungi did not reduce the infection of leaves by B. cinerea. Most of these selec ted fungi and bacteria were capable of reducing lesion expansion.