Soil Populations and Anastomosis Groups of Rhizoctonia solani Associated with Peanut in Texas and New Mexico. K. E. Woodard, Texas Agricultural Experiment Station, Stephenville 76401. B. L. Jones, Texas Agricultural Experiment Station, Stephenville 76401. Plant Dis. 67:385-387. Accepted for publication 11 September 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-385.

Soil from 33 peanut fields in Texas and New Mexico was assayed for Rhizoctonia solani propagules (P). The range was from none detected to 14 P/100 g of soil, and the mean for all fields was 3.2 P/100 g of soil. Sixty-six percent of the fields assayed at two or fewer P/100 g of soil. The highest R. solani population on an area basis was in west Texas (Gaines County), with an average of 7.4 P/100 g of soil. Anastomosis group (AG) determinations were made with R. solani isolates from peanut field soils and diseased peanut plants. All isolates were in AG-4, except for one AG-2 isolated from field soil. Seven percent of the soil isolates and 6% of the plant material isolates were binucleate Rhizoctonia-like fungi.