Early Season Insect Control with Foliar Insecticides, 1990

Cotton was planted 25 Apr in 4 row plots on 40-inch centers × 50- ft at the Northeast Research Station (Macon Ridge Branch) near Winnsboro, La. The test field was not treated with an in-furrow insecticide at planting, but Terraclor Super × (10 lb form./acre) was applied to control seedling diseases. Treatments were arranged in a randomized complete block design with 4 replications. Insecticides were applied with a tractor mounted boom equipped with a compressed air delivery system calibrated to deliver 5 gal total spray/ acre through TX-4 hollow cone nozzles (2/row) at 44 psi. Plots were treated on 29 May and sampled on 31 May (2 DAT) and 5 Jun (7 DAT). Treatments were evluated by randomly collecting 10 plants each plot and processing samples with whole plant washing procedures. Thrips and aphids were washed from the plant foliage onto 300 mesh wire sieves, backwashed onto ruled filter paper (7 cm) and counted using a binocular dissecting scope. The test plots received 2.3-inch rainfall on 31 May and a trace amount of rainfall on 3 Jun.