Control of brown patch of tall fescue using fungicides and biofungicides, 2005

摘要

A fungicide trial was conducted on a 4-year-old sward of tall fescue 'Kentucky 31' grown on a clay loam soil (pH 5.8) at the Georgia Experiment Station, Griffin, GA. Fertilizer treatments consisted of 1.0 lb nitrogen (Lesco 24-4-10) per 1000 sq.ft applied on 7 Junand 7 Jul. The turfgrass was maintained at a height of 3-in. by mowing once a week. Turfgrass cultural practices were similar to those prescribed for maintenance of tall fescue lawns in Georgia. Treatments were arranged as plots (4.5 ft x 4.5 ft) in a randomized complete block design with four replications. Initial applications were applied on 7 Jun in 2.5 gal water per 1000 sq ft with a hand held, CO2- pressured boom sprayer at 30 psi. Subsequent applications were made at 21-day intervals until 18 Aug.Turf was inoculated 24 hr after the initial fungicide applications by hand-dispersal of grain infested with R. solani into the foliar canopy. The plots received approximately0.1-in of irrigation water 3 times daily at 11:00, 15:00, and 19:00 hr to ensure nightly foliar wetness for infection. This irrigation regime was in place for 10 days followed by normal irrigation of 0.24-in applied daily at 3:00 hr. Visual estimates ofdisease severity were made using the Horsfall-Barratt rating scale. Values were subjected to analysis of variance and means were statistically separated using the Scott- Knott cluster analysis procedure.