Chemical management of inflorescence dieback of Arecanut under Karnataka conditions

Abstract

Among the various factors causing considerable loss in production of arecanut in the state, inflorescence dieback is a destructive disease of arecanut caused by the fungus Colletotrichum gloeoporioids. During 2014, a field trial was undertaken to develop management practices to reduce the severity and spread of the disease at ZAHRS, Shivamogga, Karnataka. Among the tested five fungicidal treatments spraying of 0.25% Carbendazim 12%+ Mancozeb 63% was found significantly superior in controlling the disease. The results from the experiment reveals that, Carbendazim 12%+ Mancozeb 63% (0.25%) sprayed trees has significantly increased the number of nuts/bunch (best treatment was found 80.79), green nut wt/ac (9521.46 kg) and dry nut wt/ac (1238.16 kg) with decreased number of infected inflorescence (0.81/palm) and fallen nuts/palm (4.73). Whereas, in unsprayed control plot a minimum green nut and dry nut yield of 5266.47 and1238.16 kg/ac was recorded. The B:C ratio was also found higher in Carbandazim 12% + Mancozeb 63% (1:1.65) and Propineb (1:1.61) sprayed plots compare to other fungicides and untreated control plots over three seasons. From the present findings it could be concluded that Carbandazim 12% + Mancozeb 63% (0.1%) was very effective fungicide for lowering inflorescence dieback severity under field condition.