VIEW ARTICLE

Temperature Ranges Inducing Susceptibility to Phytophthora megasperma var. sojae in Resistant Soybeans. D. W. Chamberlain, Research Plant Pathologist, Crops Research Division, ARS, USDA, U.S. Regional Soybean Laboratory, Urbana, Illinois 61801. Phytopathology 60:293-294. Accepted for publication 9 September 1969. DOI: 10.1094/Phyto-60-293.

Recovery of resistance to Phytophthora megasperma var. sojae in heat-treated Harosoy 63 soybean plants began between 12 and 16 hr after treatment, and was completed between 20 and 24 hr after treatment. Loss of resistance was irreversible in plants treated for 2 min at 50 or 55 C. Heat-treated plants stored at 10 C did not recover resistance in 48 hr. Stem tissues 2 cm above the treated area were susceptible; tissues 3 cm above the treated area were resistant.