Efficacy of neem formulations compared to chemical insecticides against hoppers and leaf webber.
Gajendra Singh
Author Affiliation: G.B. Pant University of Agriculture and Technology, Pantnagar-263145, India.
: 745-749
Abstract : Neem formulations containing azadirachtin are safer, cheaper and environment friendly. Presently, several of these compounds have been registered in India and are available on the market. Studies were conducted in 1996-97 and 1997-98 against two major pests of mango. With hoppers [Idioscopus spp.] and leaf webber Orthaga euadrusalis it was shown that freshly prepared 4% neem seed kernel extract (NSK) and 0.2% nimbicidine and deltamethrin gave significant reductions in hopper populations (16 and 15.5 hopper per 5 panicles) as compared to control (47.6 hopper per 5 panicles). These were at par with cypermethrin (0.0025%) and imidacloprid (0.002%) and monocrotophos (0.05%). Populations of pollinators were not affected. NSK at 4% effectively reduced hopper populations up to 50% even after 7 days of spraying, which was comparable to deltamethrin and cypermethrin and better than quinalphos. Against leaf webber, Nimbicidine 0.2% and Nemactine 0.4% were better than carbaryl 0.1% and at a par with endosulfan (0.07%) and imidacloprid (0.02%). Neem formulations such as Rakshak (0.2%), Neem gourd (0.4%) were inferior to the above and Vangourd (0.4%) was the most inferior to the 4th instar larvae.