Evaluation of preventive fungicide applications for dollar spot control on fairway height creeping bentgrass, 2014

摘要

Fungicides were evaluated for disease control at the University of Missouri Turfgrass Research Facility in Columbia, MO on 'Penneagle II' creeping bentgrass grown on a native soil (Mexico silt loam). Mowing was performed two times weekly at a height of 0.55-in. from 2 Apr to 19 Sep. Starting on 16 May to 8 Aug, UMaxx~R (47-0-0) at 0.375 lb N/1000 sq ft + Ferromec (10-2-4) + micros (0.015 lb N/1000 sq ft) was applied every three weeks. Plots were 5 ft x 5 ft and arranged in a randomized complete blockdesign with four replications. Treatments were applied in water equivalent to 2 gal/1000 sq ft with a CO2-powered sprayer at 26 psi using TeeJet 8008 nozzles. Following each application, all plots were watered in with 0.2-in of water. On 23 May, rye grain infested with the dollar spot pathogen was uniformly applied at a volume of 1.52-in.3 per plot using a small broadcast spreader and left on the turf surface for 3 days before mowing. Disease severity and turfgrass quality were assessed every 14 days from initial symptom development. Dollar spot incidence was assessed as number of infection centers per plot. Turfgrass quality was evaluated using a 1 to 9 scale (9=best, 5=acceptable) based on color, density, and uniformity. Data were subjected to analysis of variance and means separation using Fisher's Protected LSD (P=0.05). To stabilize variance, disease severity data was square-root transformed for analysis and back-transformed for presentation.