Biology, Etiology, and Management of Dollar Spot in Turfgrasses

Managed turfgrass areas (golf courses, lawn care companies, sport facilities, others) are vastly important for businesses in the New England economy. Intensively managed areas on golf courses, in particular, are challenged by abiotic and biotic (mostly by fungi) stresses that require monetary investment for maintaining optimal appearance. Dollar spot disease (caused by plant pathogenic fungi) is one of the most economically challenging pathogens, requiring repeated chemical inputs annually to maintain acceptable playing surfaces. Unfortunately, as result of repeated application of chemical fungicides, the pathogen causing dollar spot has developed resistance to more major fungicide classes than any other fungal disease. Therefore, early and accurate pathogen detection prior to infection and fungicide resistance monitoring is vital for effectively managing the disease and mitigating environmental concerns.  As part of the NRS regional project, UMass is participating in understanding the biology of dollar spot with two specific objectives: 1) develop molecular diagnostic assays to quantify how much dollar spot fungus exists in the plant, soil, and thatch prior to showing initial symptoms (or pre-symptomatic) and 2) develop molecular diagnostic assays to quickly and accurately determine the sensitivity of dollar spot strains to a number of fungicide classes. Also, monitoring the resistant populations that have already developed is economically beneficial for turfgrass practitioners to manage this important disease.