VIEW ARTICLE

Techniques

A Qualitative Baiting Technique for Selective Isolation of Rhizoctonia zeae from Soil. A. S. Windham, Graduate research assistant, Department of Plant Pathology, North Carolina State University, Raleigh 27695-7616; L. T. Lucas, Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27695-7616. Phytopathology 77:712-714. Accepted for publication 15 October 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/Phyto-77-712.

A baiting technique was developed for selective isolation of Rhizoctonia zeae from naturally infested soil using fungicide-treated stem segments of cotton and a selective medium consisting of 2% water agar and benomyl, metalaxyl, penicillin G, and streptomycin sulfate at 10, 10, 50, and 50 μg a.i./ml, respectively. Cotton stem segments soaked in benomyl at 500 μg a.i./ml and metalaxyl at 100 μg a.i./ml or in benomyl at 1,000 μg a.i./ml were successfully used to isolate R. zeae from two naturally infested soils. Fungicide-treated stems were colonized in significantly higher numbers by R. zeae than untreated stems. The selective medium also increased recovery of R. zeae from colonized stems. Untreated stems were colonized by R. solani, binucleate Rhizoctonia-like fungi, Pythium spp., and a number of other common soil-inhabiting fungi.