Effect of Seed Treatment with Triadimenol on Severity of Take-All of Spring Wheat Caused by Gaeumannomyces graminis var. tritici. D. E. Mathre, Professor, Department of Plant Pathology, Montana State University, Bozeman 59717. R. H. Johnston, Research Associate, Department of Plant Pathology, Montana State University, Bozeman 59717, and R. Engel, Assistant Professor, Southern Agricultural Research Center, Huntley, MT 59037. Plant Dis. 70:749-751. Accepted for publication 28 February 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-749.

Triadimenol seed treatment of irrigated spring wheat delayed symptom development of take-all caused by Gaeumannomyces graminis var. tritici. Depending on the inoculum level and the dose of triadimenol on the seed, the onset of aboveground symptoms was delayed up to 53 days compared with the untreated control. Lesions on seminal roots and the subcrown internodes of 5-wk-old plants were reduced 50% by a triadimenol seed treatment at a rate of 0.22 ml a.i./kg of seed. Yield increases over the untreated controls were significant in both infested plots and a naturally infested commercial field.