Effect of MACRO-SORB^® foliar on Summer Patch (Magnaporthe poae) of Annual Bluegrass

Dr. J. M. Vargas, A. R. Detweiler, & N. M. Dykema, Michigan State University, 2001.

This study was established on an irrigated annual bluegrass fairway at Dearborn Country Club in Dearborn, MI. Fertility in all plots was maintained by applying ¼ lb. N/1000 ft2 per month. MACRO-SORB foliar treatment at 2 oz/1000 ft2 was applied every two weeks from 6/11 through 8/7. The plots treated with MACRO-SORB foliar had less disease than the control plots when evaluated on 7/30/01. These results are consistent with the ones obtained in a similar study last year. MACRO-SORB foliar reduces the incidence of summer patch of annual bluegrass.

Heritage plus MACRO-SORB foliar on Summer Patch

The treatments consisted of Heritage at a rate of 0.1 oz/1000 ft² with and without MACRO-SORB foliar applied every 14 days on 6/11, 6/25, 7/9, 7/24, and 8/7; Heritage at 0.4 oz/1000 ft² applied every 21 days on 6/11, 7/2, and 7/24; and Heritage at 0.4 oz/1000 ft² applied every 28 days on 6/11, 7/9, and 8/7. The percentage of diseased area per plot was determined on 7/30 and 9/6/01.

Heritage with or without MACRO-SORB foliar totally controlled summer patch when evaluated on 7/30 (data not shown). Summer patch redeveloped in September and even after the treatments had expired the recommended time period, little disease was observed in all treated plots. However, the lowest disease incidence was observed in the plots treated with the combination of Heritage at 0.1 oz/1000 ft² and MACRO-SORB foliar applied every 14 days.