In vitro and In vivo Evaluation of Bacterial Antagonists against Tomato Bacterial Spot Disease

This study evaluates the biocontrol potential of bacterial antagonists against Xanthomonas vesicatoria (Xv), the causative agent of bacterial spot disease in tomato, through both in vitro and in vivo assessments. Thirty bacterial isolates exhibiting epiphytic and endophytic traits were screened for antimicrobial activity against Xv. In vitro assays identified isolates 35E and 6E as having the highest inhibitory effects, with isolate 35E (Bacillus cereus CA18) demonstrating the most stable and significant disease suppression in in vivo trials. Molecular characterization confirmed the identity of isolate 35E, supporting its known biocontrol and plant growth-promoting properties. The results highlight the promise of Bacillus cereus CA18 as an effective biocontrol agent, offering a sustainable alternative to chemical pesticides for managing bacterial spot disease in tomato.