Ink Spot of Warm‐Season Golf Course Turfgrasses

Abstract

Core Ideas Ink spot is a foliar disease of bermudagrass and zoysiagrass managed as golf course turf. Curvularia malina, a novel and sterile species, is the causal agent of ink spot. The turfgrass symptoms of ink spot include distinct, small chocolate‐brown to black spots. Curvularia malina is the causal agent of ink spot, a foliar disease of bermudagrass and zoysiagrasses used in golf course settings. Distinct, chocolate‐brown to black spots appear in conjunction with high amounts or frequent precipitation events in the southern United States. Foliar symptoms of ink spot consist of small, purplish‐black spots that develop into eye‐spot lesions on the leaves of zoysiagrasses but develop a round‐to‐elliptical lesion on bermudagrass leaves. Older, blighted leaves at the base of the plant cause the chocolate‐brown to black spots observed in the turfgrass sward. Crown and/or root rot has not been associated with ink spot. Isolation of C. malina is highly successful when using leaves of bermudagrass or zoysiagrass exhibiting ink spot symptoms. Curvularia malina is sterile; therefore, confirmation must be made using sequence data of ITS, GPD1, or TEF1. Curvularia malina has been isolated from bermudagrass and zoysiagrass expressing foliar symptoms of ink spot throughout the Gulf Coast region of the United States, which to date, includes Alabama, Mississippi, Tennessee, and Texas.