Aphid and Virus Control in Winter Wheat, Washington, 1984-85 Crop

Abstract

Abstract Ten insecticides were evaluated at 2 locations to determine their effect on grain aphids, barley yellow dwarf virus (BYDV), plant growth, and grain yields in winter wheat. Trial 1 was planted with ‘Wanser’ on 31 Aug ‘85 on the Roza Research Farm. Trial 2 was planted with ‘Daws’ on 4 Sep ‘84 on the Headquarters Farm. Both farms are part of the Washington State University Irrigated Agriculture Research and Extension Center at Prosser, WA. Trial 2 was furrow-irrigated in the spring; Trial 1 was not. Aside from the differences stated, the trials were arranged, treated, and evaluated the same. Treatments were applied as foliar sprays on 4 Oct ‘84 (early tillering stage of growth) with a compressed air plot sprayer mounted on a bicycle-wheeled carriage, calibrated to deliver 49 gpa at 40 psi. Plots in each trial were 4 rows (12 inches between rows) 17 ft in length, replicated 6 times in a randomized complete block design. Plots were planted using a tractor-mounted 4-row belt-cone Almaco grain drill with double disc openers. Seeding rate was 40 lb/acre. Aphid control was determined on the basis of berlese funnel aphid extractions (6 plants/plot/posttreatment sample). BYDV was rated visually on 4 Jun 1985 using a 1-6 scale, where 1 = no virus; 6 = severe symptoms. Average height was taken 4 Jun 1985. Plots were harvested 11-26 Jul 1985 with a Hege Combine.