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A Rapid Technique for Inoculation of Phaseolus vulgaris with Multiple Pathotypes of Uromyces phaseoli. J. R. Stavely, Research plant pathologist, Plant Pathology Laboratory, Plant Protection Institute, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705; Phytopathology 73:676-679. Accepted for publication 3 January 1983. 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, 1983. DOI: 10.1094/Phyto-73-676.

Modification of a readily available, inexpensive, hand-held, pressurized spraying device was made by attaching a 5-cm-long, 12-mm-diameter, section of Plexiglas tubing over the spray nozzle. This modification permitted inoculation of bean plants with each of many pathotypes of Uromyces phaseoli. Negligible differences in numbers of uredinia among pathotypes were obtained by standardizing the concentrations of viable urediniospores. Each unifoliolate leaf was inoculated with four pathotypes per leaf 6- 8 days after seeding and the first trifoliolate leaf was inoculated with up to six pathotypes 6- 8 days later. Resistant and susceptible host reactions to specific pathotypes were not affected by simultaneously or sequentially inoculating other leaf areas with other pathotypes. The rapid technique described here is potentially useful for determining linkage relationships among host resistance genes and in breeding beans for resistance to multiple pathotypes of U. phaseoli.