EFFECT OF FOLIAR APPLICATION OF MANGO LEAF EXTRACT ON BACTERIAL LEAF SPECK SEVERITY OF TOMATO (Solanum lycopersicum L.) IN KASHERE, NORTH EASTERN NIGERIA

Bacterial leaf speck of tomato, caused by Pseudomonas syringae pv. tomato, is among the most economically important bacterial diseases in many tomato-growing regions causing economic yield loss. Two field experiments were conducted, during the wet and dry seasons of year 2023 and 2024, to evaluate the application of mango crude leaf extract for the control of bacterial leaf speck of tomato. The experiments were laid out in a split-plot design with three replications. Mango leaf extract was applied as foliar sprays on two tomato cultivars (Tandino and Dan Syria) at 25, 50 and 75% concentrations. Plots without treatment (0%) and with streptomycin (0.2%) served as negative and positive controls, respectively. Results revealed that application of 75% mango leaf extract at 9 week after transplanting, reduced bacterial wilt severity to 1.00 in both seasons, which were significantly lower than 5.00 and 4.83 (no application); 4.83 and 4.00 (25% application), and 3.50 and 3.50 (50% application) during the wet and the dry seasons, respectively. The optimum fruit yield (20.48 and 21.49 t/ha) were recorded for plants treated with streptomycin, which were not significantly different from fruit yield (20.13 and 21.19 t/ha) recorded for plants treated with 75% concentration of mango leaf extract at both wet and dry seasons, respectively. Tandino cultivar had significantly higher yield (10.19 and 10.81 t/ha) than Dan Syria (8.37 and 8.92 t/ha) during the wet and dry season, respectively. The results showed that application of mango leaf extract at 75% concentration could be an alternative promising natural bactericide against bacterial leaf speck of tomato for fruit yield enhancement.