Control of Fall Armyworm in Field Corn, 1985

Abstract

Abstract 'Pool 24' corn was planted on 5 Jul at the Poza Rica Experiment Station, Puebla, Mexico. Twenty four treatments were replicated 4 times in a randomized complete block design. Plot size was 6 rows (0.75 m apart) × 5.0 m. Corn was thinned to 40,404 plants per hectare. All rows were infested, but only the four central ones were treated and evaluated. An avg of 26.4 larvae/plant were initially applied on 18 Jul when the crop was at the 3 expanded leaf stage. On 1 Aug the crop was reinfested at the 7-8 expanded leaf stage with an avg of 21 larvae/plant. The insecticides were applied on 24 Jul with corn at the 5.5 leaves stage. Liquid formulations were applied with a bicycle compressed air sprayer, using 8004 nozzles, 2.8 kg/cm2 and delivering 483 liters/ha. Granular formulations were applied with hand applicators, delivering 0.2 cc/stroke. Evaluations consisted of: a) Number of total and undamaged plants, at three intervals: one week after initial infestation, one week after treatment application ;md one week after reinfestation; b) Plant and ear height, on 12 Sep; c) Number of harvested plants and ears, and grain yield (15% moisture) on 24 Oct.