VIEW ARTICLE

Ecology and Epidemiology

Effects of Concentration of Sulfur Dioxide and Other Characteristics of Exposure on the Development of Lesions Caused by Xanthomonas phaseoli in Red Kidney Bean. J. A. Laurence, Boyce Thompson Institute for Plant Research, Ithaca, NY 14853; K. L. Reynolds, Boyce Thompson Institute for Plant Research, Ithaca, NY 14853. Phytopathology 72:1243-1246. Accepted for publication 18 February 1982. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-1243.

Sulfur dioxide (SO₂) supplied at constant (square wave) or variable (triangular wave) concentrations affected development of lesions caused by Xanthomonas phaseoli by increasing the latent period (time for symptom expression) and suppressing lesion expansion. Similar effects were found with both patterns of exposure. Timing of exposures relative to inoculation was important and generally was most effective when the exposure and inoculation periods were close together. The time between repeated triangular wave SO₂ exposures also affected lesion development and indicated a decay of inhibition if exposures were separated by >1 day.