Initial Studies of American Elm Diseases in Illinois

A PLANT disease epidemic is difficult enough to combat when the cause of the disease is known, but when it is unknown, as in the case of this elm malady, the problem is even more serious. As the prevalence of this elm malady in Illinois was steadily increasing year after year, it became obvious that immediate steps were required to prevent an epidemic which might prove very destructive to the elms of the state. In the latter part of September 193U. the Illinois State Natural History Survey undertook an investigation of the elm malady. This was done at the request of the state's Chief Plant Inspector, whose desire in this regard was endorsed by the Illinois State Nurserymen's Association. This paper is a report of the first results of the investigation. It includes an account of previous work on Illinois elm diseases, the importance of the present malady in nurseries and cities, the general symptoms manifested by diseased elms in Illinois, a detailed consideration of symptoms, effects, and probable pathogens for several important and minor diseases and of fungi obtained infrequently, as well as an account of two preliminary experiments relating to the control of "elm wilt" in nurseries. It is realized that much more experimentation is necessary to complete our knowledge of the elm malady and especially to develop control measures more adequate than those reported herein. It is not, therefore, intended that the facts given here shall be taken as complete and absolute, but instead that they are the best statements regarding the Illinois "elm wilt" that can be made at this time.published or submitted for publicationis peer reviewe