Control of Insect Pests on Cabbage with Spinosad, 1996

Abstract

Two rates of Spinosad were tested in Michigan State University Entomology Research Farm, in East Lansing, MI, for the control of imported cabbageworm, cabbage looper, and diamondback moth and their effect on beneficial insects. Seedlings were transplanted on 18 July at 2-ft spacing into four row plots 40 feet long. There was a 10-ft untreated zone between each plot within each row and an untreated row (3-ft spacing) on either side of the plots. Treatments were replicated three times and assigned to plots in a RCB design. Insecticides were applied using a CO2 backpack sprayer with a single boom (40 psi, 20 gal/A), on 12 and 23 Aug. and 4 Sep. All insects on 10 randomly selected plants were sampled in each plot on 7, and 16 Aug, and 2 and 10 Sep. The percent defoliation of outer leaves was assessed on 17 Sep, when 8-10 heads per plot were harvested. These were then rated for marketability: no damage, slight damage (damage to outer leaves of head only), or unmarketable (damage to head beyond outer couple of leaves).