Effect of Different Insecticides against Fall Armyworm, Spodoptera frugiperda (J. M. Smith) in Maize at Belaka Municipality, Udayapur, Nepal

Abstract

This research was conducted to evaluate the five selected commercial formulation of insecticides against newly introduced Fall armyworm spodoptera frugiperda in the farmer's field at Belaka Municipality of Udayapur district, Nepal. The experiment was laid out in Randomized completely blocked design (RCBD) from 23rd Feb 2021. The prepared field was divided into six treatments and four replications (Imidacloprid 70 % WDG@0.3ml/ltr water, Spinetoram 11.7% SC@0.3ml/ltr water, Chlorantraniliprol 18.5% W/W@0.4ml/ltr water, Emamectin Benzoate 5% WDG@0.4ml/ltr, Azadirachtin 0.03% EC @5ml/ltr and control). Total three spray of the insecticides were done at the interval of 7 days after the initial damage symptoms starts to appear. The field experiment showed that all the insecticides were significantly effective in reducing the number of live larvae per plant after 3rd spray whereas fast and foremost reduction in live larvae was seen in the plot sprayed with spinetoram and chlorantraniliprole. There was 89% reduction of live larvae after 1st spray in the plot sprayed with spinetoram and chlorantraniliprole followed by emamectin benzoate, 66%. Similarly, no damage symptoms were seen in the plot sprayed with spinetoram and chlorantraniliprole after 3rd spray. The highest grain yield per plot was also gained from chlorantraniliprole (8.8 ton/ha) and spinetoram (8.5 ton/ha).