MICHIGAN ACADEMY OF SCIENCE. 277 



INTRODUCTION. 



Diseases of red clover are common and are of great economic im- 

 portance. Nevertheless^ little attention has been given them. 

 These diseases are doubtless as widespread as the culture of the plants 

 and although the annual loss caused has not been accurately 

 determined, it is certainly large. In recent years the culture of red 

 clover has rapidly decreased in extent. The factors producing this 

 change in agricultural practice are doubtless many, but fungous diseases 

 are believed to play an important role. The general abandonment of a 

 crop of such agricultural importance must give rise to apprehension. 

 Investigations which throw light upon the diseases of this plant are 

 especially in demand at this time, and close research is warranted by the 

 seriousness of the situation. The very important hindrance to the 

 culture of red clover known as "clover sickness" or failure to secure a 

 "catch" may eventually be found to be a soil problem which is to be 

 solved by proper soil management. The control of fungous diseases of 

 the crop, however, opens up a big field of endeavor. There can be no 

 doubt that imi^ortant gains in yields will come with prevention of the 

 ravages of disease. 



This paper deals with a leaf-spot disease of red clover, caused by 

 Macrosporium sarcinaeforme Cav. This disease was very serious in the 

 vicinity of East Lansing, Michigan, during the entire growing season 

 of 191.5. It is probably the most important leaf disease of the red clover. 



This work was done at the botanical laboratory of the Michigan Agri- 

 cultural College, under the direction of Dr. E. A. Bessey and Dr. G. H. 

 Coons, whose help and encouragement throughout the work and in the 

 preparation of the manuscript, I wish to acknowledge. 



HISTORICAL. 



The first mention in the literature of the red clover disease caused by 

 Macrosporium sarcinaeforme was made by Cavara, F., (1890) who dis- 

 covered it in the vicinity of Pavia, Italy. He gave a brief description 

 of the casual organism and named it Macrosporium sarcinaeforme Cav. 

 He characterized the disease as "a leaf spot." Tubeuf and Smith (1897) 

 in their text book were the next to record the disease, but added nothing 

 new. Malkoff, V. K., (1902) found the disease at Gottingen, Germany. 

 He inoculated the organism upon red clover leaves kept damp under a 

 bell jar, and observed characteristic spots within five to seven days. 



