VIEW ARTICLE

The Influence of Dutch Elm Disease and Plant Water Stress on the Foliar Nutrient Content of American and Siberian Elm. Bruce R. Roberts, Plant Physiologist, Crops Research Division, ARS, U.S. Forest Service, USDA, P.O. Box 365, Delaware, Ohio 43015; Keith F. Jensen, Plant Physiologist, Crops Research Division, ARS, U.S. Forest Service, USDA, P.O. Box 365, Delaware, Ohio 43015. Phytopathology 60:1831-1833. Accepted for publication 24 July 1970. DOI: 10.1094/Phyto-60-1831.

Two-year-old seedlings of American elm (susceptible to Dutch elm disease) and Siberian elm (resistant to Dutch elm disease) were inoculated with Ceratocystis ulmi or subjected to plant water stress by withholding water. Nutrient analyses made on the foliage of all seedlings at the end of the experiment showed a significant difference in phosphorus and nitrogen content between species, but no difference in calcium or potassium. Inoculated seedlings of both species exhibited significantly lower levels of potassium and phosphorus when compared to stressed and noninoculated control plants. Water-stressed seedlings of both species showed a similar pattern of transpiration for the duration of the experiment. After 4 weeks, however, transpiration in inoculated Siberian elm was twice that of inoculated American elm when compared to corresponding healthy plants. The relationship of these findings to the development of symptoms in Dutch elm disease is discussed.