RELATIVE POTENTIAL OF DIFFERENT PLANT EXTRACTS AND ANTIBIOTICS AGAINST XANTHOMONAS AXONOPODIS PV. MANGIFERAE INDICAE CAUSING BACTERIAL LEAF SPOT OF MANGO IN LAB CONDITIONS

Abstract

Bacterial leaf spot is a remerging disease in mango orchards of Pakistan and significantly lowers the yield every year. The present study was conducted to evaluate the potential of different plant extracts and antibiotics against Xanthomonas axonopodis pv. mangiferaeindicae in lab conditions. Aqueous extracts of five different plants i.e. Olive (Olea europaea), Neem (Azadirachta indica), Parthenium (Parthenium hysterophorus), Conocarpus (Conocarpus erectus) and Ginger (Zingiber officinale) were evaluated at 5, 10 and 15 % against the bacterial leaf spot of mango pathogen using disc sensitivity technique. Only Olive (Olea europaea) at 15 % concentration was found effective to inhibit bacterial growth. None of the other plant extract at any concentration was found effective. Three different antibiotics i.e. Gentamicin, Enrofloxacin and Validamycine were evaluated at 300, 600 and 1000 ppm against Xanthomonas axonopodis pv. mangiferaeindicae. Gentamicin at 1000 ppm was found most effective to inhibit bacterial growth. From the present study, it was found that Olive aqueous extract at 15 % and Gentamicin at 1000 ppm may be used to manage the disease after the field experimental trials.