Comparison ofRhizoctonia solani isolates from web blight and basal canker of cowpea and from soil

Summary Isolates ofRhizoctonia solani from web blight and stem basal canker of cowpea and those obtained from soil had similar linear growth rates on potato dextrose agar (PDA) at various temperatures but differed in other features. The web blight isolates differed from the basal canker and the soil isolates in cultural appearance on PDA and on potato marmite agar (PMA). The web blight isolates readily formed discrete sclerotia on PDA, PMA and soil but the other isolates did not. In greenhouse tests, the former were generally the most virulent in inciting foliage and stem basal necrosis and damping-off of seven crop species. Of the plants tested, the legumes were the most susceptible toR. solani.