This test was conducted in 2002 at The Ohio State University Turfgrass Research Center, Columbus, Ohio, on a stand of Kentucky bluegrass established in 1972. Mowing height was 3.5“, and the clippings were returned to the plots.
The area was not irrigated. The condition of the sward was fair with no thatch; it had a thin density. No fertilizer was applied in 2002 prior to the study. The soil was Crosby B silt loam with a pH of 7.3.
Individual plots measured 6‘ x 10’, with 6’ between blocks, and were arranged in a randomized complete block design with three replications.
Treatments were applied with a hand-held, CO2 -powered boom sprayer, with 6503 TeeJet nozzles at 40 psi (water equivalent to 2.0 gallons water/1,000 sq ft).
Treatments were a single application on May 28. The average high and low air temperatures (F) and rainfall for each month respectively were:
| Month | Average High | Average Low | Rainfall |
| April | 65.4°F | 43.7°F | 4.2” |
| May | 70.7°F | 47.3°F | 10.2” |
| June | 85.2°F | 62.4°F | 7.6” |
There was little disease activity in early spring. At the end of May, a sudden, severe, and uniform outbreak of red thread occurred in this area from natural inoculum. An evaluation of products for curative control was initiated.
The disease period was rather short so only a single application of products was made. All treatments demonstrated significant disease reduction within 10 days after application. Ratings are visual inspections of the plots to determine percent of the area blighted by red thread. Insignia at 0.9 oz and Heritage at 0.4 oz provided outstanding disease reduction. No phytotoxicity, growth regulator, or color effects were noted on the turf.
| Percent of the Plot Area Blighted by Red Thread. | |||
| Treatment and Rate /1,000 sq ft (A single application was made on May 28.) | |||
| May 28 | June 7 | June 14 | |
| Untreated | 11.7 | 10.0 | 16.7 |
| Insignia 20WG 0.5 oz | 16.7 | 1.0 | 0.3 |
| Insignia 20WG 0.9 oz | 11.7 | 0.7 | 0.0 |
| BASF 50503 50WG 0.2 oz | 15.0 | 2.7 | 0.3 |
| Cuprofix MZ30 42DF 6.0 oz | 11.7 | 1.3 | 0.0 |
| Bayleton 50DF 0.5 oz | 15.0 | 5.0 | 0.3 |
| Heritage 50WP 0.4 oz | 15.0 | 0.7 | 0.0 |
| Bayleton 50DF 1.0 oz | 13.3 | 3.3 | 1.3 |
| Endorse 2.5WP 4.0 oz | 15.0 | 2.0 | 1.0 |
| LSD (P0.05) | 6.2 | 4.3 | 4.6 |
Joseph W. Rimelspach, Plant Pathology; T. E. Hicks, Plant Pathology; and Michael J. Boehm, Plant Pathology.