Alfalfa Sprout Rot Caused by Erwinia chrysanthemi. Luellen Pierce, Staff Research Associate, Department of Plant Pathology, University of California, Berkeley 94720. Arthur H. McCain, Extension Plant Pathologist, Department of Plant Pathology, University of California, Berkeley 94720. Plant Dis. 71:786-788. Accepted for publication 20 January 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0786.

Erwinia chrysanthemi caused a soft rot disease of alfalfa sprouts, a relatively new crop in California. Temperature greatly affected disease severity. Little or no disease occurred at 15 or 18 C, but severe rot occurred at temperatures higher than 28 C. Disease severity was related to inoculum concentration; disease occurred when seeds were soaked in a bacterial suspension of at least 10² cfu/ml. Soaking inoculated seeds for 2 hr in 0.5% sodium hypochlorite or calcium hypochlorite controlled the disease. E. chrysanthemi did not survive longer than 1–2 wk on inoculated seeds or in infected alfalfa sprouts.