Cabbage Looper Control on Cabbage with Synthetic Pyrethroids, 1979

Abstract

Abstract Trials were conducted on cabbage planted at the University of Arizona, Mesa Branch Station where the soil type is Laveen Clay Loam. ‘Golden Acre Y. R.’ seed was planted in a dry seed bed on Aug 21 using a Stanhay precision planter which spaced the seeds approximately 2 inches apart. The planting was furrow irrigated and kept moist until germination. Seedling cabbage was thinned to a 14 inch spacing on Sep 27. Plots were 13.3 ft wide (4-40 inch beds) x 25 ft long representing 0.007 acre. Each treatment was replicated 4 times. Spray applications were made with a CO2 bak-pak sprayer utilizing a lightweight spray boom having 2 hollow cone nozzles. Each nozzle was fitted with a D-3 disc, No. 25 core and 50 mesh screen operating at 55 psi. A single nozzle per plant row was used when the plants were small and 2 nozzles per plant row were used when the plants became larger, insect counts were made at approximately weekly intervals by examination of 10 plants from the middle 2 beds of each plot. Thus 40 plants were examined for the presence of cabbage looper eggs and larvae. When mature all of the plants from the middle 2 beds of each plot were rated for insect damage using a scale of 1-5 (1 = no visible insect damage, and 5 = heavy insect feeding damage). In addition to the damage rating, the heads in the middle 2 beds were rated according to size using the scale 1-3, 1 = large, 2 = medium, 3 = small, plus culls.