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.