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Ecology and Epidemiology

Changes in Growth Rate and Nitrogen Content of Tomato Plants After Exposure to NO₂. John J. Troiano, Research Intern, Department of Plant Biology, Cook College, Rutgers–The State University of New Jersey, New Brunswick, NJ 08903; Ida A. Leone, Professor, Department of Plant Biology, Cook College, Rutgers–The State University of New Jersey, New Brunswick, NJ 08903. Phytopathology 67:1130-1133. Accepted for publication 8 March 1977. Copyright © 1977 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-67-1130.

Lycopersicon esculentum (tomato) plants were grown in sand culture under two different levels of nitrogen nutrition (28 mg/liter NO₃-N and 140 mg/liter NO₃-N) supplied in Hoagland’s solution. One month after being transplanted, one group of plants was fumigated either with 0.47 mg/m³ NO₂ for 80 hr or with 0.76 mg/m³ for 164 hr and a second group received charcoal-filtered air. The stems and/or leaves were harvested immediately and/or 48 hr after fumigation. Tissue analyses (Kjeldhal method) indicated that total N content had increased following exposure to NO₂, particularly in the leaves of the 140 mg/liter NO₃-N treatment, as had fresh and dry weights. No NO₂ injury was apparent on any of the fumigated plants.