Resistance in Pisum sativum to Epicotyl Rot Caused by Rhizoctonia solani. Randy J. McCoy, Research Assistant, Vegetable Crops Production, Agricultural Research Service, U.S. Department of Agriculture, Prosser, WA 99350. John M. Kraft, Research Plant Pathologist, Vegetable Crops Production, Agricultural Research Service, U.S. Department of Agriculture, Prosser, WA 99350. Plant Dis. 68:491-493. Accepted for publication 13 December 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, 1984. DOI: 10.1094/PD-68-491.

Resistance to epicotyl rot caused by Rhizoctonia solani was correlated with epicotyl thickness among 20 pea lines tested when peas were exposed to 20 sclerotia per gram of soil (r = – 0.91) or when epicotyls were inoculated directly with mycelial disks (r = –0.88). Severity of epicotyl rot could be predicted by measuring the epicotyl diameter of uninoculated 9-day-old seedlings, using the regression equation obtained from the original 20 test lines. Resistance to epicotyl rot was not related to anthocyanin pigmentation of the seed coat or rate of seedling emergence. The rate of tissue destruction caused by R. solani was also found to vary among pea lines. Of four fungicides applied separately as a slurry, only chloroneb adequately protected the cotyledons, epicotyl, and hypocotyl of Dark Skin Perfection from colonization by germinating sclerotia of R. solani.