Types of Rhizoctonia Foliar Blight on Soybean in Louisiana

Abstract

(...) Web blight caused by R. solani anastomosis group 1, intraspecific group IB (AG-1 IB), was the major type in Louisiana in both years. Aerial blight caused by isolates of R.s. AG-1 IA, previously considered the only type in the state, was also found. (...) Isolates of AG-1 IA and AG-1 IB could be differentiated on the basis of cultural characteristics on water agar and potato-dextrose agar. Maximum porduction of microsclerotia in the field occurred from late July through August. low numbers of microsclerotia produced by R.s. AG-1 IB were observed on plants at earlier and later soybean growth stages