VIEW ARTICLE

Ecology and Epidemiology

Effects of Controlled Night Temperatures on Incidence of Verticillium Wilt in Field-Grown Cotton. Earl B. Minton, Plant pathologist, Agricultural Research, Science and Education Administration, United States Department of Agriculture, Cotton Research Laboratory, Lubbock, TX 79401; Jack R. Gipson(2), and J. E. Quisenberry(3). (2)Associate professor, Texas Tech University and the Texas Agricultural Experiment Station, Lubbock, TX 79401; (3)Research geneticist, USDA SEA/AR, Cotton Research Laboratory, Lubbock, TX 79401. Phytopathology 69:977-979. Accepted for publication 26 March 1979. 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, 1979. DOI: 10.1094/Phyto-69-977.

Cotton plants grown in field growth chambers developed foliar symptoms of Verticillium wilt after they were subjected to controlled night temperatures ranging from 10 to 27 C. High incidence of disease occurred at 10 and 15 C and lower levels at 20 and 25 C, but symptoms developed in only one of several susceptible cultivars at 37 C. Significant disease symptoms developed on cotton plants grown under 10 and 15 C temperature regimes, even though the maximum day temperatures exceeded 30 C, the level above which the development of Verticillium wilt is inhibited under field conditions. Cultivars with different levels of resistance to Verticillium wilt were more easily separated into disease classes about the middle of September than either earlier or later in the season. Interaction was significant between cultivars and temperatures. Application of methyl parathion to cotton plants did not affect disease development, but the interaction of insecticide and temperature treatments was significant.