Figure 8. - Stalactiform rust canker. Laboratory Identification Figure 9. - Cowwheat. The rust diseases are controlled in nurseries by spraying seedlings with a protective fungicide. Alternate hosts growing in or near nurseries should be removed. Rust-infected seedlings should not be planted.
Research is underway to develop a jack pine that is resistant to stem rusts.
If infection in a stand is heavy, conversion to another tree species should be considered. Authors Kathryn Robbins, Plant Pathologist, Northeastern Area, State and Private Forestry, USDA Forest Service, St. Paul Mn. Dale K. Smeltzer, formerly graduate student, Department of Plant Pathology, University of Minnesota, St. Paul, Mn. D.W. French, Professor, Department of Plant Pathology, University of Minnesota, St. Paul, Mn.