Eradication of Xanthomonas campestris pv. translucens from Barley Seed with Dry Heat Treatments. E. Fourest, Former Graduate Research Assistant, Department of Plant Pathology, Montana State University, Bozeman 59717. L. D. Rehms, D. C. Sands, M. Bjarko, and R. E. Lund. Research Assistant, Professor, Research Associate, Department of Plant Pathology, and Experiment Station Statistician, Montana State University, Bozeman 59717. Plant Dis. 74:816-818. Accepted for publication 23 April 1990. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0816.

Dry heat eliminated Xanthomonas campestris pv. translucens, the seed-transmitted causal agent of bacterial black chaff and leaf streak of cereal grains, from barley seed without an appreciable reduction in germination. The pathogen was not detected in heavily infested seed exposed to temperatures of 71, 75, or 84 C for 11 days. In contrast, the pathogen was apparently eliminated from moderately infested seed after exposure to 72 C for 4 days. The heat treatment decreased bacterial numbers much more rapidly the first day than on subsequent days. Reduction in germination was practically negligible for seed treated at 71 or 72 C for 7 days or less. Germination was reduced an average of only 8% for 25 cultivars of barley treated for 11 days at 71 C. Heat treatment may prove to be a convenient, nonchemical way to produce viable bacteria-free seed.

Keyword(s): bacterial diseases, seed treatment.