Apple, Obliquebanded Leafroller Control with Spinosad, Bacillus Thuringiensis, Abamectin and Chlorpyrifos in Spring, 1995

Abstract

Abstract Spinosad, 80% (formulation NAF-127, DowElanco); Bacillus thuringiensis (Bt) (Dipel 2X, Abbott Laboratories), abamectin Agri-Mek 0.15 EC (Merck & Co., Inc.) and chlorpyrifos (Lorsban 4E, DowElanco) were evaluated for their ability to control OBLR larvae of the overwintering generation. The test was conducted in an apple orchard in Mattawa, WA. The trees were 3-yr-old Delicious on dwarfing roots. Treatments were applied to 12-tree plots replicated 5 times in a randomized complete block. All treatments were applied with a handgun sprayer at 300 psi to the point of drip. Application dates were 5 Apr (pink) and 9 May (petal fall). Approximate application timings with regard to plant development stage are shown in the table. The post-treatment evaluation was made on 24 May by a count of the total number of live OBLR larvae on all trees of a treatment replication. Live larvae were collected to observe sublethal effects. Surviving larvae were reared on artificial leafroller diet in 3.25 oz portion cups until death or adult emergence. Any deformities possibly resulting from exposure to an insect growth regulator were recorded. Weather was good, calm winds and moderate temperatures, at the time of applications.