Evaluation of fungicides for control of gray leaf spot in perennial ryegrass turf, 2007.

摘要

The study was conducted at the Valentine Turfgrass Research Center, University Park, PA, on perennial ryegrass maintained under golf course fairway management conditions, and mowed three times per week at 1.0-in. cutting height. The soil was Hagerstown silt loam with pH 6.8. The experimental turf area was fertilized with 1.0 lb nitrogen (IBDU) and 1.0 lb nitrogen (18-9-18) and per 1000 sq ft on 5 Jun. Scimitar (7.5 fl oz/A) was applied for cutworms on 8 May. Additionally, 0.1 lb nitrogen (Urea 46-0-0) was applied on 1 A g. Treatment plots, 3 ft X 6 ft, were arranged in a randomized complete block design with three replications. Treatments were applied with a CO2-powered sprayer using a TeeJet 11008E nozzle at 40 psi,in water equivalent to 2 gal per 1000 sq ft. Treatments applications were made 25 Jul, 8 and 22 Aug, and 5 Sep, for 14-day intervals. The experimental turf area was inoculated with M. oryzae on 9 Aug. The turf was maintained at a 2.0-in. cuttingheight following the inoculation, and mowed once a week. Disease severity was assessed on 21 and 28 Aug, and 4 and 11 Sep using a disease severity index of 0 to 10 (0=turf asymptomatic; 10=>90% turf area symptomatic). Data were subjected toanalysis of variance and multiple comparisons of the mean values were made using the Waller-Duncan k-ratio test (k=100).