Wheat Seed-Treatment Efficacy Against Hessian Fly and Aphids, 1992:

Abstract

Three rates of NTN 33893 240 FS seed treatment were compared to a standard of Disyston 15 G in-furrow for suppression of HF, aphids, and barley yellow dwarf virus (BYDV) symptoms. The test was planted 13 Nov on a Marlboro sandy loam in Barnwell County, SC. The experimental design was a RCB with 5 replicates. The experimental unit was a plot 50 x 5.3 ft (8 rows on 8 inch spacing). Granular Disyston was placed in-furrow with electric Gandy applicators. Seed treatments were made by adding 40-ml total volume dilutions of 6 lb of seed and thoroughly mixing in a plastic bag. HF counts were taken by randomly uprooting 10 plants from each of 4 plots (40 plants/treatment) and examining them in the laboratory for larvae and puparia. Aphids were sampled on 3 Feb by counting aphids on 2, random 6-inch samples per plot in 4 replicates (8/treatment). Aphid counts on 9 Mar were taken by shaking wheat plants from 6 inches of row into a sheet metal sampler, (2 samples/e.u., 8 samples/treatment) which extended beyond the full length of the plants. Specimens which could not be field identified were returned to the laboratory for microscopic examination. BYDV ratings were determined by counting the number of symptomatic flag leaves from four 50-ft rows (200 row ft) per plot (1,000 row ft/treatment). These were converted to % based on 2, random 1 m culm counts per plot. Yields were taken by harvesting the middle 6 rows with an Almaco plot combine.