Creeping Bentgrass Foliar Disease Control by Fungicides Immediately Watered-In After Application in Chicago, 2023

Dollar spot, caused by the fungal pathogen Clarireedia jacksonii, is a chronic disease of creeping bentgrass ( Agrostis stolonifera ‘SR1119’ and ‘Providence’) in cool, humid environments in the United States. In closely mown golf-playing surfaces, symptoms include small, circular, sunken spots of blighted turf that if left untreated will coalesce into larger areas. This report evaluates the efficacy of demethylation inhibitor (DMI) and succinate dehydrogenase inhibitor (SDHI) group fungicides to suppress dollar spot when immediately watered-in after application for the prevention of fairy ring caused by various basidiomycete fungi in sand-based golf greens. An SDHI nematicide was similarly investigated. A study was conducted on a mature push-up constructed nursery green at North Shore Country Club in Glenview, IL. Results indicate that golf course superintendents can also suppress dollar spot if certain preventative DMI and SDHI group fungicide programs are in place for fairy ring and/or nematodes.