Evaluation of biocontrol agents in tomato/Botrytis cinerea and peach/Monilia spp. pathosystems for sustainable crop production

Biocontrol agents are tools for sustainable agriculture, offer- ing balanced and efficient solutions for disease management as they generally have low impacts on health and the envi- ronment. Tomato and peach are two important crops, and gray mold and brown rot, caused by Botrytis cinerea and Monilinia spp., respectively, are two of the major fungal diseases affecting these crops. This study aimed to evaluate the efficacy of several formulated candidates as biocontrol agents toward the two plant pathogens. In vitro tests were used to assess the antifungal efficacy of the formulations based on Bacillus spp. and chitosan against Monilinia spp. and B. cinerea, while a commercial formulate containing essential oils was only evaluated against Monilinia spp.. Furthermore, the concentrations that completely inhibited in vitro growth of Monilinia spp. and B. cinerea were cho- sen to assess the efficacy in vivo in the two pathosystems. Our results showed that these BCAs inhibited the mycelial growth of the two pathogens in vitro at different concen- trations with relation to the tested pathogen. In particular, the formulated candidates showed a percentage of growth inhibition of Monilinia spp. ranging from 50 to 80% and a growth inhibition of B. cinerea from 80 to 100% at 1000 µg mL−1. The formulated candidates also confirmed their effectiveness in vivo against the two plant pathogens by reducing the disease severity also delaying symptoms on fruits.