Aphid Control, 1987:

Abstract

Abstract ‘Early Round Dutch’ cabbage was planted 8 Oct into double-row beds with 1-m centers at the Texas A & M University Agricultural Research and Extension Center in Weslaco. Soil type was Raymondville clay loam. The plots consisted of 2 beds by 21 m with a buffer row between plots; each block was separated with a 4.5-m buffer. The experimental design was a randomized complete block with 4 replications. Granular applications were applied in the furrows 4.5 cm below the seed at planting time. Sidedress treatments were applied in a liquid fertilizer solution (66 kg N-32/ha) on 16 Dec through a liquid fertilizer applicator (two shanks/bed). Foliar sprays of MetaSystox-R were applied 9 and 16 Dec using a CO2-charged backpack sprayer calibrated to spray 93 liters/ha (84.3 kg cm2, 4 flat-fan nozzles/plot). Efficacy was evaluated by removing the roots of 3 plants from each plot and washing them in 3.75 liters of water containing 1 tablespoon of calcium chloride. Dislodged aphids were counted as they floated to the surface of the water. Yields were determined by hand-harvesting both beds in a 4.5-m section of plot. The number of heads and total weight in kg/plot were recorded. Only cabbage heads of commercially acceptable size were harvested during each harvest; thus weight/head was consistent among treatments. Yield was accumulated for each harvest date for analysis. Data were analyzed for treatment differences with ANOVA.