Joseph W. Rimelspach
Kerry Kline
Karl Danneberger
Michael Boehm
A curative red thread fungicide study was initiated on a stand of perennial ryegrass (Lolium perenne) at the Ohio Turfgrass Foundation Research and Education Center in Columbus, Ohio. The perennial ryegrass (cultivar unknown) was maintained at 2.5 inch height of cut. The condition of the turf was fair. At the time of the application, May 28, 1997, the temperature was in the high 60s. Soil at the site was a clay loam with moderate moisture. Spray treatments were applied with a hand-held CO2 pressurized sprayer with two 6503 nozzle tips, spaced 18 inches apart, at 40 psi, delivering 2 gallons water per 1,000 square feet. Plot size was 6 feet by 8 feet with each treatment replicated three times. The design of the experiment was a randomized complete block design. The number of red thread patches in each plot was counted on June 4 , seven days after treatment (7DAT), and on June 20, 23 days after treatment (23DAT).
Heritage, Prostar, and Eagle at the 1.2 oz/M rate gave the best control, compared to the control of the other fungicides. Heritage showed rapid reduction of mycelium on the leaf blades with little present by June 20; all other plots had active mycelium present.
| Treatments | Rate oz/1,000 sq ft* | Number of Red Thread Patches per Plot | |
|---|---|---|---|
| 6/4 (7DAT) | 6/20 (23DAT) | ||
| Heritage 40WP | 0.2 | 9.0 | 2.3 |
| Heritage 40WP | 0.4 | 13.7 | 2.3 |
| Prostar 50WP | 2.0 | 16.0 | 4.7 |
| Eagle 40WP | 1.2 | 13.7 | 5.3 |
| Daconil Ultrex | 3.8 | 19.7 | 5.7 |
| EXP10790B | 4.0 | 17.3 | 7.0 |
| EXP10790A | 4.0 | 17.0 | 8.0 |
| RH-0611 | 8.0 | 12.7 | 9.0 |
| Bayleton 25WDG | 1.0 | 19.7 | 9.7 |
| Eagle 40WP | 0.6 | 21.0 | 12.0 |
| Procymindone 50WP | 1.0 | 23.7 | 14.7 |
| Check (untreated) | -- | 17.3 | 15.7 |
| LSD (0.05) | 10.5 | 10.7 | |