EXISTENCE OF PSEUDOMONAS SYRINGAE PV. SYRINGAE IN MANGO GROOVES OF SOUTHERN PUNJAB PAKISTAN REVEALS AN EMERGING THREAT OF APICAL NECROSIS DUE TO CLIMATE CHANGE

Mangifera indica L., the 2nd profusely productive fruit in Pakistan. It is facing an emerging threat of necrosis and blackening of floral buds. In a survey of different mango orchards in Multan, various pathogens were isolated as Pseudomonas syringae pv. syringae, Fusarium mangiferae, Colletotrichum gloe-osporoides and Alternaria alternata. From infection frequency assessment, Pseudomonas syringae pv. syringae was found to be the most frequent isolated (79.53%) pathogen followed by Colletotrichum gloeosporoides (57.73%), Alternaria alternata (15.93%) and Fusarium mangiferae (13.33%) at the flowering stage. Infection frequency of Pseudomonas syringae pv. syringae was maximum (93.33%) at stage A and minimum (58.67%) at stage J. It was also proven that Pseudomonas syringae pv. syringae infection was favored by high relative humidity i.e., >80% and low temperature (15-20°C) with r value of+0.85 and -0.71 respectively. Amongst six chemicals evaluated in-vitro by poisoned food technique, copper hydroxide was remarked as most effective at 200 μg/ml concentration with colony inhibition of 37.444% followed by streptomycin sulphate 200 μg/ml (29.67%) as compared to control (0.00%).