Evaluation of Insecticides for Aphid Control (Trial 2), 1996

Abstract

Abstract This test evaluated the effectiveness of insecticides and insecticide combinations to control cotton aphids. Plots were 4 rows wide and 50 ft long with four untreated rows and a 10 ft planted buffer between plots. Plants in each plot were sampled at 3 to 4 day intervals early in the growing season for cotton aphids by selecting 10 random plants in each plot. One leaf from the terminal and one leaf four nodes below the terminal (mid-canopy level) were sampled on each plant. The total number of aphids on the terminal leaves and mid-canopy leaves was recorded. Treatment was initiated when population levels were rapidly increasing. All insecticide applications were applied with a high clearance spray tractor equipped with two TX4 hollow cone nozzles perrow traveling 4 MPH and delivering 5 gallons of water per acre. Plots within a replicate were sprayed sequentially to maintain true replicate integrity. Yield was estimated by mechanically harvesting the center two rows of each plot. Applications of insecticides for aphid control were made 23 Jun and 10 Jul.