VIEW ARTICLE

Disease Detection and Losses

The Impact of Ozone on Peanut Exposed in the Laboratory and Field. J. Ensing, Department of Environmental Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada; G. Hofstra(2), and R. C. Roy(3). (2)Department of Environmental Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada; (3)Research Station, Agriculture Canada, Delhi, Ontario, N4B 2W9, Canada. Phytopathology 75:429-432. Accepted for publication 15 October 1984. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/Phyto-75-429.

Laboratory studies and observations for 2 yr in the field demonstrated that ambient levels of ozone (O₃) have the potential to injure peanut (Arachis hypogaea) crops. Assessment of O₃ injury following exposure in the laboratory showed that the Spanish-type USDA PI 268661 peanut was more sensitive than the Valencia-type McRan peanut. The antioxidant, EDU (ethylene diurea), reduced foliar injury on USDA PI 268661 in both the laboratory and field. EDU protected McRan from injury in laboratory exposures. Little or no injury was observed on McRan peanut grown in the field, and EDU treatment had no effect on yield. High levels of foliar injury on USDA PI 268661 were associated with significant reductions in yield, reduced N fixation, and increased leaf drop.