Evaluation of insecticides against rice gundhi bug, Leptocorisa acuta (Thunberg) in South Gujarat

Abstract

An experiment was conducted during kharif 2014 to 2016 at Main Rice Research Centre, Navsari Agricultural University, Navsari to evaluated some newer insecticides against rice gundhi bug, Leptocorisa acuta (Thunberg) in South Gujarat. Among all the insecticides tested, treatment of emamectin benzoate 5 WSG 0.015% @ 3 gm/litre was found the most effective in controlling rice gundhi bug and it was at par with the treatment of imidacloprid 17.8 SL 0.05% @ 3 ml/10 litres. The next best treatment was novaluron 10 EC 0.01% @ 1.0 ml/litre, rynaxypyre 20 SC 0.004 @ 0.2 ml/litre and profenophos 50 EC 0.05% @ 1 ml/litre in terms of reduction of rice gundhi bug populations in both sprays. The highest grain yield of rice was recorded in the treatment of emamectin benzoate 5 WSG 0.015% @ 3 gm/litre (6109 kg/ha) and it was at par with the treatment of imidacloprid 17.8 SL 0.05% @ 3 ml/10 litres (5882 kg/ha). The next treatment was followed bynovaluron 10 EC 0.01% @ 1.0 ml/litre (5711 kg/ha) and rynaxypyre 20 SC 0.004 @ 0.2 ml/litre (5607 kg/ha). As far as straw yield, the treatment of emamectin benzoate 5 WSG 0.015% @ 3 gm/litre (7212 kg/ha) was recorded highest straw yield and it was at par with the treatment of imidacloprid 17.8 SL 0.05% @ 3 ml/10 litres (6998 kg/ha). In terms of BCR the treatment of imidacloprid 17.8 SL 0.05% @ 3 ml/10 litres (1:2.29) was found most superior among all treatments and it was followed by emamectin benzoate 5 WSG 0.015% @ 3 gm/litre (1:2.02) over the rest of the treatments.