Field-efficacy of a novel ready-mix molecule pyriproxyfen 5% + fenpropathrin 15% EC against hopper complex of mango

Abstract

Field efficacy of different (pyriproxyfen 5% + fenpropathrin 15% EC) treatment schedules was assessed against hopper complex populations on mango (cv. Amrapali) at Horticulture Research Station, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur during 2015 and 2016. Pyriproxyfen 5% + fenpropathrin 15% EC registered 70.49-84.53% mean reduction of mango hopper complex population at higher dosages while a single molecule of pyriproxyfen 10% EC and thiamethoxam 25% WDG revealed 59.51-69.38% mean reduction. Though pyriproxyfen 5% + fenpropathrin 15% EC @ 150 g a.i. ha-1 proved relatively toxic towards lacewing and spider (11.5 and 9.4% mean reduction respectively), but, the treatment at lower to medium dosages were safer (4.1-7.9% reduction) as compared to thiamethoxam 25% WDG (19.4 and 15.7% respectively) and dimethoate 30% EC (16.8 and 15.5% respectively). LT50 value of pyriproxyfen 5% + fenpropathrin 15% EC (21 hours) at 100 ppm concentration was statistically at par with pyriproxyfen 10% EC (20 hours) for Apis mellifera L. At 200, 500 and 1000 ppm concentration, LT50 values of pyriproxyfen 5% + fenpropathrin 15% EC (17, 13 and 9 hours respectively) differed significantly from thiamethoxam 25% WDG (12, 9 and 4 hours respectively) and dimethoate 30% EC (13, 9 and 5 hours respectively). The yield of fresh marketable mango also varied significantly among different treatment schedules of pyriproxyfen 5% + fenpropathrin 15% EC (29.5-42.2 kg tree-1).