Biocontrol potential of Bacillus subtilis Lb22 against fruit rot of King chilli, Capsicum chinense Jacq.

Fruit rot is one of the most destructive diseases of Capsicum chinense Jacq., popularly known as Bhoot jolokia or King Chilli an export oriented crop in North East India. Morpho-cultural characterization of the isolated fungal pathogen from diseased fruit identified the pathogen as Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. Pathogenicity test further confirmed its association with the disease. A few bacterial and fungal microbial biocontrol agents (MBCAs) were screened in vitro against C. gloeosporioides as a potential solution in organic and integrated crop management practices. Among all the MBCAs Bacillus subtilis LB22 showed highest inhibition (85.00%) on mycelial growth of the pathogen followed by P. fluorescens (84.33%) and B. vallismortis (83.22%). Trichoderma pseudokoningii were recorded the lowest inhibition (53.22%). Our study put forth further exploration B. subtilis LB22 (NCBI accession no. ON386193 and NBAIM accession no. NAIMCC-B-03226) in planta and their response in disease suppression as well growth promotion in Bhut jolokia as a component of sustainable crop health management program.