VIEW ARTICLE

Ecology and Epidemiology

Effects of Sulfur Dioxide on Expansion of Lesions Caused by Corynebacterium nebraskense in Maize and by Xanthomonas phaseoli var. sojensis in Soybean. J. A. Laurence, Assistant plant pathologist, Boyce Thompson Institute for Plant Research at Cornell University, Ithaca, NY 14853; A. L. Aluisio, former research assistant, Boyce Thompson Institute for Plant Research at Cornell University, Ithaca, NY 14853. Phytopathology 71:445-448. Accepted for publication 18 September 1980. Copyright 1981 The American Phytopathological Society. DOI: 10.1094/Phyto-71-445.

In order to assess the effects of air pollution on plant disease development, we investigated the effects of SO₂ on lesion development by two bacterial pathogens. Maize or soybean plants were exposed to sulfur dioxide (SO₂) at 524 μg m^–3 or 262 μg m^–3 before, after, or before and after inoculation with Corynebacterium nebraskense or Xanthomonas phaseoli var. sojensis, respectively. Lesion development was inhibited in both cases, regardless of when the exposures occurred. The time of exposure, however, altered the subsequent effect on lesion size. Dry weight and sulfur content of host tissue were not altered by the joint effects of the pollutant and the pathogens.