Evaluation of Kabuto and Velista for preventative spring dead spot control on bermudagrass, 2017-2018

摘要

Fungicides were evaluated for the control of a natural infestation of spring dead spot caused by Ophiosphaerella herpotricha at the University of Missouri Turfgrass Research Facility in Columbia, MO on 'Riviera' bermudagrass. The soil was a Mexico silt loam. Mowing was performed twice weekly at a height of 0.75-in. During the trial period, no fertilizer was applied. Plots were 5 ft x 10 ft and arranged in a randomized complete block with four replications. Treatments were applied in the fall on 16 Oct 17 (A) and 15 Nov 17 (B). Treatments were applied in water equivalent to 2.0 gal/ 1000 ft2 with a CO2-powered sprayer at 26 psi using TeeJet 8008 nozzles. Fungicides were watered-in immediately after application with 0.2-in. of overhead irrigation. Disease severity was assessed every 14 days from initial symptom development. Disease severity was assessed as a visual estimate of the percent symptomatic area per plot. Turf color (green-up) was evaluated on a 0 to 100% scale (0= dormant turf, 100= complete green-up, no dormant grass present). Data were subjected to analysis of variance and means separation by Fisher's protected LSD (P = 0.05).