Evaluation of chemical treatments for managing bacterial leaf spot in chili caused by Xanthomonas campestris pv. vesicatoria

Chilli, a highly important and valuable crop worldwide, belongs to the Solanaceae family. In Pakistan, Sindh is the leading producer of chilli. However, bacterial leaf spot (BLS) caused by Xanthomonas campestris pv. vesicatoria poses a significant threat, leading to yield losses of up to 40% globally. Effective management of BLS has become a critical concern. In the current study, five chemicals, Cabrio Top, Oxyrich, Kocide, Electus Super, and Forum Top, were evaluated for their efficacy in managing BLS. An in vitro experiment was conducted using a completely randomized design with three replications per treatment and three concentrations (200, 250, and 300 ppm) of each chemical. The results revealed that Cabrio Top exhibited the largest inhibition zone (18.710 mm), followed by Electus Super (16.730 mm), Forum Top (13.653 mm), and Kocide (11.759 mm), compared to the untreated control. Subsequently, an in vivo experiment was designed using the randomized complete block design with three replications and three concentrations (1, 2, and 3 g/L) of the best-performing chemicals. The combined treatment of Cabrio Top + Oxyrich demonstrated the most significant results, showing the lowest disease incidence (23.544%), followed by Oxyrich (31.559%) and Cabrio Top (37.193%). The findings of this study conclude that the combined application of Cabrio Top and Oxyrich is a promising approach for managing BLS in chilli under field conditions.