Evaluation of fungicide programs for the management of dollar spot and brown patch of creeping bentgrass, 2010.

摘要

This trial was conducted to evaluate the efficacy of fungicide programs for the control of dollar spot and brown patch of creeping bentgrass putting greens in Oklahoma. Plots were established on a creeping bentgrass putting green at the Turfgrass Research Center located in Stillwater, OK. Plots were 3 ft wide and 5 ft long with 1-ft alleys between plots. The experimental design was a randomized complete block with four replicates. The turfgrass sward was a mature stand of creeping bentgrass established on a USGA sand/peat mix soil. Recommended maintenance and irrigation practices were followed throughout the growing season. Fungicide applications were initiated on 1 April for BAYER 1 and BAYER 2 treatments, 9 April for BASF 1 and BASF 2 treatments,and 23 April for all other treatments and were applied using 14-day intervals with the exception of the ADVISORY treatment. For the ADVISORY treatment, sprays were applied according to a regression-based disease prediction model developed for dollar spot(developed at Oklahoma State University). Additional programs were included from Cleary Chemical (CLEARY); and three alternative programs (OSU 1, OSU 2, and OSU 3). A non-fungicide treated control was also included. Fungicides were applied with a C02-pressurized wheelbarrow sprayer equipped with TX8008 flat fan nozzles and calibrated to deliver 87 gal/A or 2 gal/1,000 sq ft. Ratings of the number of dollar spot foci, percent of plot with symptoms of brown patch, and turfgrass quality (scale of 1 - 9 where 1 = no turf present, 5 = unacceptable turfgrass, 6 = acceptable turf, 9 = dense, dark color, thick stand of turfgrass) were taken at 7- to 10-day intervals from 1 Apr to 17 Sep. Dollar spot and brown patch disease data were subjected to the area under the disease progress curve transformation to account for season-long ratings. These data and average turf quality data were analyzed using ANOVA (a = 0.05). Multiple comparisons of means were performed using Fisher's test of protected least significantdifference (a = 0.05).