NHarmony performance trial for control of Botrytis bunch rot and sour rot of grape in Virginia, 2014

摘要

The trial was conducted in a 'Viognier' vineyard in Front Royal, VA, and a 'Chardonnay' vineyard in Mt. Jackson, VA. The grapevines were trained to a vertical shoot positioning (VSP) system with bilateral cordons, with a spacing of 5 ft between vinesand 10 ft between rows. Each trial consisted of a row of vines. A vine was an experimental unit, and there were six replications per location with a buffer vine between each treatment. Treatments were applied with a 4-gal backpack hand-pumped air sprayer, regulated to 21 psi by a Gate CFValve through a single boom with a TeeJet 8003VS flat fan nozzle. The interval between applications was 7 days. The NHarmony treatment was applied five times: on 13 Aug (bunch closure), 20 Aug, 27 Aug (Veraison), 2 Sep,and 9 Sep. The treatment was prepared less than 2 hours prior to application, stored at room temperature, and shaken vigorously prior to application. The treatment was applied in addition to the growers' spray schedule to see if it would have an additiveeffect on the management of Botrytis and sour rot of grape. Diseases were visually assessed weekly on 13 Aug, 20 Aug, 27 Aug, 2 Sep, 9 Sep, and 16 Sep, and results from the last two assessments are shown. Twenty randomly selected clusters per vine wereassessed. The estimated percentage of infected area (disease severity) per cluster and the percentage of clusters with diseased berries (disease incidence) were recorded. The linear mixed models procedure (PROC MIXED) in SAS was used to conduct a Student's T-test.