ASCOMYCETES 233 



XXXII. WILT DISEASE OF COTTON, COWPEA, AND 

 WATERMELON 



Neocosmospora vasinfecta (Atkinson) Erw. Smith 



ATKINSON, GEO. F. Some Diseases of Cotton. III. Frenching. Ala. Exp. 



Sta. Built. 41 : 19-29. 1892. 

 ORTON, W. A. The Wilt Disease of Cotton and its Control. Div. Veg. Phys. 



and Path., U. S. Dept. Agl. Built. 27: 1-16. pis. 1-14. 1900. 

 ORTON, W. A. The Wilt Disease of the Cowpea and its Control. Bureau of 



Plant Industry, U. S. Dept. Agl. Built. 17: 1-20. pis. 1-4. 1902. 

 SMITH, ERW. F. Wilt Disease of Cotton, Watermelon, and Cowpea. Div. 



Veg. Phys. and Path., U. S. Dept. Agl. Built. 17 : 1-53. pis. i-io. 1899. 



This is a fungous disease which has become prominent only 

 during the past fifteen years, and it is already a serious foe. The 



FIG. 96. EFFECTS OF THE COTTON WILT FUNGUS IN A FIELD OF NON- 

 RESISTANT COTTON. (Photograph by W. A. Orton) 



fungus has been studied extensively both in its general biological 

 and also in its cultural relationships, but it is not yet certain that 

 the forms on the different host plants are properly referable to the 

 same species. If so, however, it would certainly seem that these 

 hosts have caused at least a racial variation in the parasite. 



Distribution. The wilt disease of cotton is now known to be 

 one of the most destructive parasitic diseases of this crop, and it 

 is probable that the fungus is distributed practically throughout 



