VIEW ARTICLE

Ecology and Epidemiology

Sensitivity of Eastern White Pine Clones to Acute Doses of Ozone, Sulfur Dioxide, or Nitrogen Dioxide. Yaw- Shing Yang, Assistant professor, Department of Plant Pathology and Physiology, Virginia Polytechnic Institute and State University, Blacksburg 24061; John M. Skelly(2), and Boris I. Chevone(3). (2)Former professor, Department of Plant Pathology and Physiology, Virginia Polytechnic Institute and State University, Blacksburg 24061, Present address: Professor and Head, Department of Plant Pathology, The Pennsylvania State University, University Park 16802; (3) Assistant professor, Department of Plant Pathology and Physiology, Virginia Polytechnic Institute and State University, Blacksburg 24061. Phytopathology 73:1234-1237. Accepted for publication 27 January 1983. Copyright 1983 The American Phytopathological Society. DOI: 10.1094/Phyto-73-1234.

Long-term pollutant fumigations were conducted to determine the relative sensitivity of three eastern white pine (Pinus strobus) clones to ozone (O₃), sulfur dioxide (SO₂), or nitrogen dioxide (NO₂) based on foliar symptom expression, needle length, chlorophyll content, and dry weight of first-year secondary needles. Plants were exposed to 0.00, 0.10, 0.20, or 0.30 μl per liter of air of each pollutant 4 hr daily for 35 consecutive days. Sensitivity of the white pine clones to pollutants varied with the type of pollutant, pollutant concentration, and plant response chosen as the indexing parameter. Results based on NO₂ exposure differed with most indexing parameters from those obtained from O₃ or SO₂ exposure. White pine clones used in this study were less sensitive to NO₂ than to O₃ or SO₂ at the same concentrations. Pollutant-induced foliar symptoms could not be used to distinguish the type of causal pollutant. Neither was the amount of foliar injury consistently useful in determining clonal sensitivity rankings to each pollutant. Further work is needed to define plant responses to each pollutant before such plant materials can be used as bioindicators for monitoring ambient pollutants.