Biocontrol of Bean Rust by Bacillus subtilis Under Field Conditions. C. Jacyn Baker, Research Plant Pathologist, USDA, ARS, Plant Pathology Laboratory, Beltsville, MD 20705. J. R. Stavely, Research Plant Pathologist, USDA, ARS, Plant Pathology Laboratory, Beltsville, MD 20705; and Norton Mock, Senior Laboratory Technician, University of Delaware, Newark 19717. Plant Dis. 69:770-772. Accepted for publication 9 April 1985. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1985. DOI: 10.1094/PD-69-770.

In field tests at Beltsville, MD, bean rust severity was reduced at least 75% in 1982 and 1983 with three applications per week of Bacillus subtilis. Two isolates of B. subtilis were tested. Isolate PPL-3 had an inhibitory effect on yield and a stimulatory effect on plant growth. Isolate APPL-1 had no apparent effect on plant growth. In some tests, treatments with B. subtilis were more effective than the weekly application of the fungicide mancozeb.