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Spot Lesion of Barley Net Blotch Disease Caused by Drechslera teres f. sp. maculata Observed in South Carolina. G. C. Kingsland, Department of Plant Pathology and Physiology, Clemson University, Clemson, SC 29634-0377. Plant Dis. 75:537. Accepted for publication 3 January 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0537E.

Net blotch of barley (Hordeum vulgare L.), caused by Drechslera teres (Sacc.) Shoemaker (teleomorph = Pyrenophora teres Drechs.), has not been reported in South Carolina, Elliptic, necrotic leaf lesions 8-15 mm long and with brown to tan centers and darker borders with chlorotic halos were observed on winter barley (cv. Keowee) in the field in western South Carolina in 1987. These symptoms match the spot-type lesion form of net blotch, caused by D. teres f. sp. maculata Smedegaard-Petersen (1,2). D. t. maculata was isolated from 60% of the lesions placed on cornmeal agar or placed on filter paper in moist chambers. No other suspected pathogens, such as Bipolaris sorokiniana (Sacc.) Shoemaker, were isolated from any lesions. Typica[ necrotic lesions developed on 57% of the seedling leaves of Keowee barley inoculated with conidia of D. t. maculata. The pathogen was reisolated into pure culture from all of the 61 lesions plated onto cornmeal agar or placed in moist chambers. Symptoms did not develop on uninoculated control plants.

References: (1) H. E. Bockelman et al. Plant Dis. 67:696, 1983. (2) C. B. Karki and E. L. Sharp. Plant Dis. 70:684, 1986.