Development of brown patch and Pythium blight in tall fescue as affected by irrigation frequency, clipping removal, and fungicide application

TLDR: Preventive applications of azox-ystrobin at 35-day intervals or postinfection applications of chlorothalonil reduced brown patch severity, but only the azoxystrobin treatment provided aesthetically acceptable (<10%) levels of brown patch control.

Abstract: Settle, D. M., Fry, J. D., and Tisserat, N. A. 2001. Development of brown patch and Pythium blight in tall fescue as affected by irrigation frequency, clipping removal, and fungicide application. Plant Dis. 85:543-546. We studied the effects of irrigation frequency, clipping removal, and fungicide application on the development of Rhizoctonia brown patch (Rhizoctonia solani) and Pythium blight (Pythium aphanidermatum) in tall fescue. Brown patch severity was not significantly different between plots irrigated daily and those irrigated on alternate days. Similarly, no differences in brown patch were observed in plots where grass clippings were returned to the sward with a mulching mower compared with plots where clippings were removed. Preventive applications of azoxystrobin at 35-day intervals or postinfection applications of chlorothalonil reduced brown patch severity, but only the azoxystrobin treatment provided aesthetically acceptable (<10%) levels of brown patch control. However, azoxystrobin applications also increased Pythium blight compared with untreated or chlorothalonil-treated tall fescue, especially in plots that received daily irrigation.