First Report of Leaf Blight Caused by Curvularia verruculosa on Zoysiagrass (Zoysia japonica) in Korea

Abstract

Zoysia japonica Steud. is widely used for turfgrass, particularly on golf courses and teeing areas in East Asia (China, Japan, Korea). In Korea, zoysiagrass use has recently increased about threefold between 2003 and 2012 (Kang et al. 2016). In October 2016, zoysiagrass showing leaf spot symptom, with disease incidence of less than 5 % of the plants, was observed in a public park (37°20'39N, 126°56'50E) in Gyeonggi province, Korea. Infection began as yellow to brown spots on leaf sheaths. The spots measured 0.1‒0.3 cm in diameter and often enlarged up to 0.5 cm. Diseased leaf pieces were rinsed in distilled water and placed on PDA with streptomycin (50 µg/mL), and after 3 days white mycelia were observed. Pure cultures were obtained from transferring the agar plugs onto CMA, PDA, and V8A. After one week at 25 °C, colonies were dark greenish to grayish black, velvety, and measured 2 cm, 5 cm, and 7 cm diameters, respectively, in the three media. Conidiophores were brown to pale brown, simple but rarely b...