Ecofriendly management of banana leaf and fruit scarring beetle basilepta subcostatum jacoby in Assam

Abstract

Botanical (azadirachtin 0.15%), biocontrol agent (Beauveria bassiana, 1x107 conidia/ml), chemical pesticide (carbaryl 0.3%), cultural practices (tilling and clean cultivation, bunch covering with plastic bag) and some combination of cultural and botanical treatments (tilling and clean cultivation+ azadirachtin 0.15%) and (azadirachtin 0.15% spray+ bunch covering) were evaluated against banana leaf and fruit scarring beetle Basilepta subcostatum. Observations on beetle population, number of scars and fruit infestation (pulp-skin ratio, finger weight and yield) were compared. The best treatments in reducing the leaf injury and population were carbaryl 0.3% spray followed by azadirachtin 0.15% spray with bunch covering, tilling and clean cultivation with azadirachtin 0.15% spray, bunch covering with plastic bag, tilling and clean cultivation, azadirachtin 0.15% spray and B. bassiana suspension spray. Fruit infestation was observed to be the lowest in azadirachtin 0.15% spray with bunch covering treated plots. The highest yield of 45.16 tonnes/ha was obtained with azadirachtin 0.15% spray with bunch covering treated plots followed by tilling and clean cultivation with azadirachtin 0.15% spray, carbaryl 0.3% spray, bunch covering with polythene bag, tilling and clean cultivation, azadirachtin 0.15% spray, B. bassiana suspension spray, against yield of 34.71 tonnes/ha in the untreated control plots.