Evaluation of new fungicide products for early curative control of dollar spot in creeping bentgrass putting greens, 2016

摘要

Fungicides were evaluated for their effect on dollar spot, caused by Sclerotinia homoeocarpa. This trial was conducted at the Paint Branch Turfgrass Research Facility in College Park, MD on '007' creeping bentgrass maintained as a golf putting green.Mowing was performed 5 times wk-1 at 0.15 in. Rolling was performed 3 days wk-1 using a Salsco sidewinder beginning in mid-June through the end of the trial. The experimental area received 1.95 lb N 1000 ft-2 applied as urea throughout the growing seasonand wetting agent (polyoxalkylene polymers) was applied monthly. Treatments were applied to plots measuring 3 x 6 ft arranged in a randomized complete block design with 4 replications. Treatments were applied in water equivalent to 2 gal 1000 ft-2 usingTeejet AI9508E air induction nozzles powered by a CO2 pressurized backpack sprayer. All treatments were initiated on 4 June and reapplied at either 14-or 21-d intervals through 15 July. The experimental area was evaluated periodically for dollar spot development (no. infection centers plot-1) and turf quality (scale 1-9: 1=dead, 9=best, and 6=minimum acceptable). Season-long disease severity and turf quality ratings were used to calculate area under progress curves (AUDPC and AUQPC) using the trapezoidal method described by Madden et al., 2007. All data were subjected to analysis of variance and means were separated using Fisher's Protected LSD (a=0.05).