OBJECTIVE: To determine whether fall fungicide applications help suppress
development of yellow patch of bentgrass caused by Rhizoctonia cerealis
PERSONNEL: Ned Tisserat
SPONSORS: Ciba, PBI Gordon, Rhone Poulenc, AgrEvo, Bayer, Rhom & Hass,
Zeneca, Heart of America Golf Course Superintedent's Association,
Kansas Golf Course Superintendent's Association, and the Kansas
Turfgrass Foundation.
MATERIALS AND METHODS:
A section of Cohansey bentgrass at the Orchards Golf Course in Lawrence, KS was used for the experiment. Fungicides were applied on 6 Nov 95. Symptoms of yellow patch were just beginning to appear on the golf course at the time of fungicide application. Individual plots were 5 X 6 feet and replicated four times. Fungicides were applied in 2 liters of water/120 sq ft at 30 psi with 8003 flat-fan nozzles using a CO2 backpack sprayer. Plots were not watered in after fungicide application.
RESULTS:
The fall of 1995 was very mild and dry. Yellow patch severity at the time of fungicide applications was minimal. Winter conditions following fungicide applications were relatively cold and extremely dry. Nevertheless, a moderate amount of yellow patch was present in early March. Symptoms continued through March.
All fungicide applications significantly reduced the % area of turf in each plot damaged by the yellow patch fungus. No phytotoxicity was noted on any of the fungicide-treated plots.
Table 1. Preventive fungicide applications for control of yellow patch on bentgrass, 1995-1996.
| Treatment* | Rate | % Plot Area Damaged** |
| No fungicide | 31.3 e | |
| Banner 1.2MC | 2 fl oz | 13.3 d |
| Medallion 75WG | 0.5 oz | 1.3 ab |
| Banner plus Medallion | 2 fl oz + 0.5 oz | 5.6 bcd |
| Polyoxorim 2.2WP | 4 oz | 0.0 a |
| Polyoxorim 11.25DF | 0.8 oz | 0.0 a |
| Chipco 26019 50DG | 4 oz | 0.0 a |
| Prostar 50WP | 3 oz | 0.8 ab |
| Lynx 25DF | 1 oz | 3.3 abc |
| Bayleton 25DF | 2 oz | 3.8 abc |
| Eagle 40W + Fore 80WP | 0.6 oz + 6 oz | 10.0 cd |
| RH 0611 62WP | 6 oz | 2.5 ab |
| Heritage 50WP | 0.4 oz | 1.3 ab |
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