Cabbage and Green Peach Aphid Control on Seed Broccoli, 1992

Abstract

Four insecticide treatments were applied to broccoli grown for seed within a fabric-meshed greenhouse of Rogers-NK Seed located near Yuma, AZ. Treatments were applied with a back-pack CO2 sprayer calibrated to deliver 13.8 gal/acre at 30 psi with two T-Jet 23 disc cones and D2 orifice discs on 13 Mar. Plots were 25 ft long X 1 row wide (40 inch) and treatments were replicated four times in a randomized complete block design. Vegetable Oil Concentrate was added to all insecticide treatments at a 1 qt/acre rate. Broccoli was in full bloom when treatments were applied and CA were present in moderate numbers. Plants were sampled in 14, 19 Mar, 2, 10 and 17 Apr with sampling being discontinued as plants were drying and being harvested. Plots were sampled by tapping six inches of flower/seed stalk from three plants over a 6.5 inch wide round plastic bowl, collecting the aphids, which were then frozen and later counted. Heavy rains on 26 Mar prevented a sample during that week. The sample in 14 Mar consisted of examining 30 flower stalks/plot for presence/absence of CA. CA were counted in all samples by GPA were present only in Apr samples.