Disease Note.

First Report of Arthrinium arundinis Causing Kernel Blight on Barley. Concepción Martínez- Cano, Department of Plant Pathology, Montana State University, Bozeman 59717-0314. William E. Grey, and David C. Sands. Department of Plant Pathology, Montana State University, Bozeman 59717-0314. Plant Dis. 76:1077. Accepted for publication 16 July 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-1077B.

Barley (Hordeum vulgare L.) kernel blight is characterized by a brown discoloration in the basal portion of the kernel. Several pathogenic bacteria and fungi were isolated from discolored barley kernels harvested from plants grown at Fairfield, Montana. Among the pathogens was Arthrinium arundinis Dyko & Sutton, a saprophyte of decaying grasses. On potato-dextrose agar, A. arundinis is characterized by white mycelia and coconut-shaped brown conidia borne laterally on short to nondistinguishable conidiophores. Koch's postulates were completed using barley cv. Busch 2601, inoculated at dough stage with a conidial suspension (10⁶ spores per milliliter) of A. arundinis. Plants were incubated in a growth chamber at 100% relative humidity for 48 hr and transferred to the greenhouse at 24 C until harvest. The average frequency of discolored kernels was 45%, and A. arundinis was isolated from all diseased kernels. Barley grown in highly humid environments may be susceptible to kernel blight caused by a saprophyte such as A. arundinis.