Influence of Nonhost Summer Crops on Take-all in Double-Cropped Winter Wheat. Craig S. Rothrock, Department of Plant Pathology, University of Georgia, Georgia Station, Griffin 30223. G. W. Langdale, USDA-ARS, Southern Piedmont Conservation Research Center, Watkinsville 30677. Plant Dis. 73:130-132. Accepted for publication 25 August 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0130.

Sorghum and soybean were grown as summer crops in double-cropping systems with winter wheat on southern Piedmont soils. Wheat following sorghum had significantly less take-all than wheat following soybean over three growing seasons at two sites. Site one had no history of take-all and site two had a history of severe take-all. Sorghum also reduced take-all on wheat when grown as the summer crop in 2 of the last 3 yr compared with a continuous soybean summer crop at site one. Wheat yields at both sites were significantly (P = 0.05) greater following sorghum than following soybean. Wheat yields also were negatively correlated (P = 0.0001) with take-all damage in both studies.

Keyword(s): crop rotation, Gaeumannomyces graminis var. tritici, Glycine max, Sorghum bicolor, Triticum aestivum.