Southwestern Corn Borer and Fall Armyworm Damage on Maize in Relation to Seed Treatment with Selected Insecticides, 1993

Abstract

Abstract This study was undertaken with the objective of determining whether maize plants grown with insecticide treated seeds would affect damage by SWCB and FAW. The specific objective was to determine whether the systemic insecticide Gaucho, which is effective for protecting maize plants against the attack of leafhoppers and aphids, would also protect the maize plants against the attack of SWCB and FAW. Experiments were conducted at the International Maize and Wheat Improvement Center’s stations at Tlaltizapan (18°41’N; 940 m above sea level) and Poza Rica (20°30’N, 50 m above sea level), Mexico in summer season of 1993. Two single cross maize hybrids from the CIMMYT collection used were ‘Ki-3’ × ‘CML 131’ (susceptible) and ‘CML 67’ × ‘CML 135’ (resistant). Prior to planting, the seeds of each hybrid were treated with insecticides at the rate of 350 g Al/ha or 700 g Al/ha. The insecticides used were Semevin (AI Thiodicarb 31.5%, Rhone-Poulenc Agro Mexico), Furadan (AI Carbofuradan 27.5%, FMC Agroquimica de Mexico) and Gaucho (AI Imidacloprid 70%, Bayer, Mexico). These insecticides were used alone as well as in different combinations. For seed treatment, the calculated amount of insecticide was thoroughly mixed with the desired number of seeds in a plastic cup and dried. At each location, single-row plots were 2.5 m long, spaced 0.75 apart and thinned to 11 plants per row with 0.25 m space between plants within a row. Trials were planted in “zero” tillage plots. A randomized complete block experimental design was used with 4 replicates. At the whorl stage of plant development (6 leaves), plants at Tlaltizapan were artificially infested with 60 neonates of SWCB per plant and plants at Poza Rica were artificially infested with 40 neonates of FAW per plant using a ‘bazooka’. The plants were visually rated for leaf feeding damage on a scale of 1 to 9 at 2 and 3 wk after infestation with FAW and SWCB, respectively. Data were subjected to ANOVA and LSD tests.