Comparative Efficacy of Insecticide Molecules against the Management of Banana Pseudostem Weevil, Odoiporus longicollis Olivier in ‘Sugandhi’ Banana

Abstract

The pseudostem weevil (Odoiporus longicollis Olivier) is a major pest of banana, causing significant yield losses. A field experiment was conducted over two consecutive seasons (2021 and 2022) using a randomized complete block design (RCBD) with twelve treatments, including various insecticidal applications, a standard check and an untreated control, each replicated three times. The present study demonstrated that the stem injection with dinotefuran 20% SG at 5 ml/plant (30 g in 500 ml water) and soil application of chlorantraniliprole 0.4% GR at 10 g/plant were the most effective treatments. These recorded the lowest mean damage grade indices (1.23 and 1.48, respectively), highest benefit-cost (B:C) ratios (4.99 and 4.71), maximum yields (42.87 and 40.13 t/ha) and highest net returns (₹514,198 and ₹474,320, respectively). Both treatments significantly reduced the total number of active weevil life stages and produced the maximum bunch weights (18.64 and 17.61 kg) and highest number of hands per bunch (15.40 and 15.20). Clothianidin 50% WDG applied basally at 0.25 g/3L/plant and fipronil 0.6% GR applied to soil at 10 g/plant were the next most effective treatments recording mean damage grade indices of 1.52 and 1.57, B:C ratios of 4.39 and 4.53, yields of 38.79 and 38.73 t/ha and net returns of ₹449,396 and ₹452,801, respectively. These treatments also showed considerable reductions in active weevil stages and improvements in bunch weight (16.87 and 16.77 kg) and number of hands per bunch (14.40 and 14.43). In contrast, the untreated control exhibited the highest damage grade index (4.16), the lowest B:C ratio (2.57), the lowest yield (19.97 t/ha), lowest bunch weight (8.80 kg), and the least number of hands per bunch (11.13). These findings indicate that dinotefuran and chlorantraniliprole are highly effective for the management of O. longicollis in banana, offering significant agronomic and economic benefits followed by Fipronil and clothianidin.