<![CDATA[[ANTAGONISTIC ACTIVITY OF A Bacillus sp. Bth22 AND Paenibacillus sp. CONSORTIUM AGAINST Ralstonia solanacearum IN CHILI (Capsicum annuum L.) UNDER IN VITRO AND GREENHOUSE CONDITIONS]. Bacterial wilt caused by Ralstonia solanacearum is a major constraint in chili cultivation. This study evaluated the antagonistic activity of Bacillus sp. Bth22, Paenibacillus sp., and their consortium against R. solanacearum under in vitro conditions, and their ability to delay symptom onset and suppress bacterial wilt intensity in chili under greenhouse conditions. The antagonism assay followed a completely randomised design with four treatments — pathogen without biocontrol agent, Bacillus sp. Bth22 + pathogen, Paenibacillus sp. + pathogen, and consortium + pathogen — with three replicates each; the greenhouse experiment used six replicates of five plants per replicate, with the replicate mean as the unit of analysis. Treatments significantly affected inhibition zone width (p < 0.001), with consortium + pathogen producing the widest zone (18.833 mm), followed by Paenibacillus sp. + pathogen (16.567 mm) and Bacillus sp. Bth22 + pathogen (13.967 mm), while pathogen without biocontrol agent produced none. The compatibility assay showed no inhibition zone at the intersection of the two isolates, indicating compatibility. In the greenhouse, first symptoms appeared at 2.97, 8.80, and 15.03 days in pathogen without biocontrol agent, Bacillus sp. Bth22 + pathogen, and Paenibacillus sp. + pathogen, whereas no symptoms appeared in consortium + pathogen until the end of the 28-day observation (censored value, >28 days). Disease intensity in consortium + pathogen remained 0% up to 28 days after inoculation, whereas P0 reached 95.57%. The consortium therefore showed higher antagonistic activity and disease suppression than the single isolates and is a candidate for biocontrol formulation; field efficacy and the nature of the interaction between the two isolates require further study.]]>
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