Evaluation of IPM technologies for the management of fall armyworm, Spodoptera frugiperda J E Smith on maize in Tamil Nadu

Abstract

Fall armyworm, (FAW) Spodoptera frugiperda J.E. Smith, an invasive lepidopteran pest, caused severe damage in maize crop with an area of 35,000 ha, in Salem and Namakkal districts of Tamil Nadu during September to November, 2018. The field experiment was conducted to evaluate the effectiveness of IPM technology against fall armyworm in maize. The observation based on population of larvae in plant, leaf injury rating, per cent damage in tassel and cob formation stage, grain yield and benefit cost ratio showed that, among the different treatment tested the application of IPM technology was found significantly most effective which caused the maximum reduction of FAW larval population was ranging from 0.03 - 0.10 Number/ plant, leaf damage 22.33 - 56.67 %, tassel damage 10% and cob damage of 3.33 - 42.67% were recorded. It was followed by farmers practice with the larval population of 0.23 to 0.78 number/ plant, leaf damage 22.33 to 56.67 %. An increased average yield of 8920 kg/ha was obtained with higher benefit ratio of 4.05 in IPM fields when compared to poor yield of 4750 kg/ha and low benefit ratio of 1.29 in Non- IPM fields. This implementation of the IPM technology with the adoption rate of 90 to 95 % in these districts resulted in reduction in damage level viz., leaf damage 10-18 %, whorl damage 6-15 %, tassel damage 5-8% and cob damage of 2 %. Natural enemies in IPM fields was observed maximum from 0.37 to 1.33 number/ plant where as in Non - IPM fields, natural enemies population was very low. IPM technology proved sustainable in FAW management with higher yield and very healthy and good filling cobs.