The fall armyworm Spodoptera frugiperda (J. E. Smith, 1797) has caused significant damage, mainly, in corn and sorghum growing in low land areas. A trial was carried out at Embrapa Clima Temperado de Pelotas, Estação Experimental de Terras Baixas, Capão do Leão, RS. The objective was to study the efficacy of S. frugiperda control based upon yield response of the corn cv Pioneer 30F33 and sorghum cv Aventis BRS 305. The experimental design was a random block with split plot. The insecticides and rate were Match CE (lufenurom), 300mL p.c. ha-1; Rimom 100 CE (novalurom), 150mL p.c. ha-1; Tracer SC (spinosad), 50mL p.c. ha-1; Lorsbam 480 BR (chlorpyrifos), 500mL p.c. ha-1 and Karate 50 Zeon (lambda-cyhalothrin), 150mL p.c. ha-1. Evaluations were done at 5, 10, 15, 20, and 25 days after application. The volumes of 0, 150, 200, 250 e 300L ha-1 were sprayed, respectively, for each treatment. The best control of S. frugiperda was obtained with lufenurom, novalurom, spinosad, chlorpyrifos and lambda-cyhalothrin sprayed with 150, 200, 250 e 300L ha-1, respectively, implying that treatment efficacy was independent of volume application. However, treatment efficacy was dependent oN corn and sorghum growth stage and timing of spray. Yield variation was not related to volume application for both, corn and sorghum.
fall armyworm; chemical control
