Insight into the prevalence, phenotypic identification and in vitro sensitivity assays of tomato bacterial leaf spot caused by Xanthomonas species in Telangana and Andhra Pradesh, India

Abstract: Tomato bacterial spot caused by Xanthomonas species, a major concern leading to 22-44% yield losses and reduced market value in warm, humid conditions, prompted this study to investigate the disease incidence, phenotypic traits, and species profile of Xanthomonas strains in Telangana’s major tomato-growing areas. The percent disease index (PDI) of BLS ranged from 14.7% to 72.5% in the surveyed tomato fields. A total of 22 Xanthomonas strains were isolated, of which 45.45% (10 out of 22) demonstrated the ability to utilize starch and pectin. All isolates were pathogenic to tomato and were identified as X. euvesicatoria through cultural, physiological and biochemical characteristics. In vitro evaluations of bio-control agents revealed high sensitivity of the Xanthomonas isolates to Bacillus subtilis strains. Additionally, streptomycin-resistant strains were identified, underscoring the need for effective control measures to manage the disease and prevent the spread of streptomycin resistance.