The use of biological agents in controlling diseases of shallots for tss production

Abstract

Stemphylium disease caused by Stemphylium vesicarium is an important disease that becomes an obstacle in TSS production. The disease attacks can lead to seed harvest failure. In the field. Stemphylium disease is associated with purple spot disease caused by the fungus Alternaria porri. The purpose of this study was to obtain biological agents that were effective in controlling S vesicarium and A porri on TSS production. The tests were carried out in-vitro in the laboratory and in planta in the field under a plastic shade. The experimental design used a randomized block design with 11 treatments (Bacillus sp.1. Bacillus sp. 3., Pseudomonas florescens (Pf)., Trichoderma sp.2., Trichoderma sp.3., Bacillus sp.1 + Trichoderma sp.2 + Pf., Bacillus sp.3 + Trichoderma sp.2 + Pf., Bacillus sp.1 + Trichoderma sp.3 + Pf., Bacillus sp.3 + Trichoderma sp.3 + Pf, and Control). Each treatment was repeated 3 times. The results showed that the biological agents Trichoderma sp., Bacillus sp., and Pseudomonas fluorescent as antagonist agents have varying inhibitory abilities against pathogens Stemphylium vesicarium and Alternaria porri. Inhibition by Bacillus sp. against S. vesicarium by 60.51-63.75% and by Trichoderma sp. by 25.78-31.47%. Meanwhile for A. porri. both bacterial and fungal antagonist agents had an inhibition between 45.09-79.15%. Antagonist agents Trichoderma sp.3 alone and the combination of Bacillus sp.1 + Trichoderma sp.3 + Pseudomonas fluorescens can increase the number of leaves and the number of seedlings of shallots. Antagonist agent Trichoderma sp.3 alone and in combination between Bacillus sp.3 + Trichoderma sp.3 + P. fluorescens can reduce the attacks intensity of S. vesicarium and A. porri diseases.