Control of Small, Medium, and Large Velvetbean Caterpillars, Total Soybean Loopers, and Total Green Cloverworms on Soybeans in Alabama, 1983

This field test was conducted on soybeans planted at the Auburn University Wiregrass Agric. Exp. Substn. at Headland, Ala. Nine treatments and an untreated check were replicated four times in a randomized complete block design. Each 0.012 acre plot was four rows wide (40-in. row spacing) and 40 ft long. Treatments were applied on 16 Sept. with a tractor-mounted boom sprayer equipped with one control droplet applicator nozzle per row adjusted to produce approximately 150 micron droplets. Spray pressure was 20 lb/in2 and the sprayer was delivering 1.6 gal/acre. Each of three insecticides (Ambush, Cymbush, and DPX 5249, a more oil-soluble formulation of Lannate) were applied alone, with soybean oil, and with Agridex. Agitation was achieved with recirculation of the insecticide solution. Insect populations were sampled by placing a standard 3-ft beat sheet between the rows and beating the plants on both sides. Larvae were identified and recorded; velvetbean caterpillar larvae were separated into small (instars 1 to 2), medium (instars 3 to 4), and large (instars 5 +) larvae. F6ur samples from each plot were taken 3, 7, and 11 days postspray (19, 23, and 27 Sept.)