2005 Season Review: Turf Diseases

Rick Latin, Professor, Botany & Plant Pathology, Purdue University

The 2005 growing season was marked by long periods of heat and humidity that favored diseases such as brown patch, Pythium blight, and summer patch.  Root zone temperatures remained elevated from late May through mid-September, resulting in severe and widespread outbreaks of summer patch on Kentucky bluegrass and annual bluegrass.  Hot days and warm nights prevailed through July and August, promoting the establishment and spread of brown patch and Pythium blight.  Perennial ryegrass and certain types of bentgrass suffered serious Pythium-related damage across the Midwest.  Brown patch symptoms were evident on almost all cool season turf species throughout the summer.  The gray leaf spot pathogen was re-introduced into Indiana with rains from the remnants of hurricane Dennis.   Perennial ryegrass and tall fescue stands suffered severe damage from gray leaf spot at several locations as far north as Lafayette.  Diseases that were generally less severe in 2005 than in recent years included dollar spot and basal anthracnose.