Fusarium Scab of Irrigated Wheat in Central Washington. Carl A. Strausbaugh, Graduate Research Assistant, Department of Plant Pathology, Washington State University, Pullman 99164-6430. Otis C. Maloy, Professor, Department of Plant Pathology, Washington State University, Pullman 99164-6430. Plant Dis. 70:1104-1106. Accepted for publication 22 July 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-1104.

A survey for scab caused by Fusarium spp. was conducted in central Washington by sampling 107 wheat fields. F. graminearum, F. culmorum, F. nivale, and F. avenaceum incited scab in irrigated fields, but F. graminearum was most prevalent. Scab was not found in dryland (nonirrigated) fields. Scab was more prevalent in fields under center-pivot irrigation and most severe in the centers of those fields. The percentage of infected heads in fields ranged from a trace to 89%. Of the fields with scab, 76% had plants with 4% or fewer of their heads infected. Fusarium from scabbed heads occasionally invaded the culm, causing discoloration in both field and greenhouse.