Evaluation of Botanicals for The Suppression of Cowpea Bacterial Blight Disease

Bacterial blight of cowpea is a serious production constraint causing severe yield loss of 2.7–92.2%. Among the several management options eco-friendly measures such as use of botanicals which are relatively safe, economical and non-hazardous to control this deadly disease was given importance. Studies on in vitro evaluation of botanicals tested at different concentration of 5, 7.5 and 10% on the growth of Xanthomonas axonopodis pv. vignicola causing bacterial blight of cowpea revealed that out of nine botanicals or plant extracts used, only garlic (Allium sativum) extract was found effective with an inhibition zone of 1.18 cm at 10% concentration followed by soapnut (Sapindus mukorossi) extract (1.07%). These two botanicals also inhibited the bacteria at lower concentration of 5 and 7.5%. Whereas neem, tulsi and nilgiri found moderately better in inhibition while remaining four botanicals, lantana, durantha, onion and chilli failed to inhibit the growth of cowpea bacteria.