Evaluation of antagonism of Trichoderma sp. and Bacillus subtilis against three garlic pathogens

Abstract

The production and quality of the cultivate garlic field (Allium sativum) is limited by diverse fungal diseases and bacteria that lead the producer to implement the application of chemical control strategies and in some cases the abandonment of the activity by an increase in losses. Biological control is a useful strategy to combat these types of microorganisms. The objective of this research was to evaluate the in vitro antagonism of the Trichoderma sp. and Bacillus subtilis against three major pathogens of garlic: Sclerotium cepivorum, Penicillium sp. and Pseudomonas marginalis. The species mentioned were isolated and identified by biochemical and taxonomic keys respectively and tested for antagonistic activity and inhibitory effect on growth using dual plates. Strain B. subtilis showed a low potential with low values of PICR, 14,087 against S. cepivorum and 3,328 against Penicillium sp., this is bad biocontrol. Regarding Trichoderma sp, it presented a very high potential, with values of 40,210 PICR against S. cepivorum and 45,034 against Penicillium sp. The valuation classifies it as a very good biocontrol. The results obtained in these studies support the potential of the strains of Trichoderma sp as biological control agents against Penicillium sp garlic rot, P. marginalis bacteria and white rot by S. cepivorum. This is not the case with B. subtilis, as the isolate proved otherwise.