FORAGE CHOPS 379 



spotted, and the loss in hay, through falling of the leaves, 

 may be considerable. The vigor of the plants is also seri- 

 ously impaired, both by the loss of green tissue of the leaves 

 that persist, and by the loss of leaves that fall. The plants 

 are never killed by this disease, though young fields which 

 have not yet become well established may be ruinetl. 



The leaf spot attacks yellow trefoil, and a disease which 

 is perhaps identical with it is found upon red clover. 



Its mode of dissemination is unknown, but infection 

 through seed is probabl}^ one method. Notwithstanding 

 this fact, seed treatment would probably be without avail 

 as a preventive. 



The only practicable treatment is to mow down l^adly 

 diseased plants with the hope that the new shoots which 

 spring forth may overcome the disease. If the disease 

 appears just before cutting time, the mowing should be 

 hastened a few days in order to avoid loss from leaf shedding. 



Sclerotiniose, wilt (Sclerotinia Trifoliorum Eriks.). — 

 This wilt, which in some respects resembles lettuce 

 sclerotiniose and which may be caused by the same fungus 

 which causes that disease, has been noted in several widely 

 separated sections of the United States. 



It kills the plants, and under favorable weather conditions, 

 the chief factor of which is a humid atmosphere, it may ex- 

 tend from plant to plant and cause large sick areas in the 

 field. 



Sick plants may show a variety of symptoms. Some- 

 times the leaves droop, and become matted together in a 

 sodden mass at the base of the plant, and overgrown with 

 a white cotton-like mass of mycelimn, in which black scle- 

 rotia, similar to those described under lettuce, are found. 



