Fungicide program for dollar spot management of creeping bentgrass in Georgia, 2006

摘要

A fungicide trial was conducted on a 14-yr-old sward of creeping bentgrass grown on a sand/peat root zone (pH 6.2) at the Georgia Experiment Station. Fertilizer treatments consisted of 1.0 lb and 0.5 lb nitrogen (Lesco 24-4-10) per 1000 sq ftapplied on 1 May and 4 Sep, respectively. The turfgrass was maintained at a height of 0.2 in. by mowing three times per week. The objective of the trial was to establish a management program that provides disease control and high turf qualitythroughout the bentgrass management year with a rotation of fungicides. Two management programs were evaluated termed “preventive” and “curative”, respectively. Treatments were arranged as plots (3.3 x 5 ft) in a randomized complete blockdesign with four replications. Initial fungicide applications were made on 22 May and followed a pre-set schedule (see footnotes of table). Fungicides were applied using 2.5 gal of water per 1000 sq ft with a wheel-mounted, CO2-pressured boom sprayer at30 psi using XR TeeJet 8002VS nozzles. Subsequent sequential applications were made according to the preset schedule. The turfgrass was inoculated with autoclaved tall fescue seed infested with a bentgrass isolate of S. homoeocarpa six hours after the initial applications. The plots received approximately 0.24 in. of irrigation water daily at 15:00 and 17:00 to ensure foliar wetness for infection. Visual counting of dollar spot infection centers was conducted at 14- day intervals from the initial application date. Values were subjected to analysis of variance and means were statisticallyseparated using the Fisher’s Protected LSD procedure at a probability value of α=0.05.