Efficacy of Pencycuron Against Isolates Representing Different Anastomosis Groups of Rhizoctonia solani and Rhizoctonia-like Binucleate Fungi. Donald R. Sumner, Department of Plant Pathology, University of Georgia, Coastal Plain Experiment Station, Tifton 31793-0748. Plant Dis. 71:515-518. Accepted for publication 10 December 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0515.

Pencycuron was evaluated for efficacy against isolates of Rhizoctonia solani and Rhizoctonia-like binucleate fungi in soil in the greenhouse at 10.0, 1.0, and 0.1 µg/g of soil. Soil was infested separately with isolates of R. solani (AG-2 type 1, AG-2 type 2, and AG-4) and isolates of Rhizoctonia-like binucleate fungi (CAG-2, CAG-3, CAG-4, and CAG-5) from soil and plants in Georgia. Of the 14 isolates, only one isolate of R. solani AG-2 type 1 was resistant to pencycuron and caused root and hypocotyl rot in snap bean at all dosages tested. Root and hypocotyl rots of snap bean caused by isolates of R. solani AG-2 type 2, AG-4, a second isolate of AG-2 type 1, and isolates of CAG-5 were controlled by pencycuron at 10.0 and 1.0 µg/g of soil. Colony-forming units of only one isolate each of AG-2 type 1, CAG-4, and CAG-5 were detected in soil 3 wk after treatment at 10 µg/g.