200 Proceedings of Indiana Academy of Science. 
Early blight caused by Alternaria solani was found epidemic in a field of 
sarly potatoes near Indianapolis July 17, and the disease was also noted at 
Lafayette in the late crop. In October Gregory and Gaylord found early 
blight prevalent in Floyd and Clark counties in the extreme southern end 
of the state. 
Fig. 8. Potato seab. 
Common seab (Fig. 8) was of general occurrence where untreated seed 
yas used and soil infestation is not uncommon since scab occurred in 
some fields planted with treated seed. As a result of the observations of 
Gaylord and Gregory scab is known to have been present in Lake, Porter, 
Laporte, St. Joseph, Lagrange, Dekalb, Fulton, Cass, Whitley, Carroll, 
Tippecanoe, Clinton, Madison, Hancock, Marion, Clark and Floyd counties. 
Black scurf caused by Rhizoctonia solani was of widespread occurrence 
as a blemish of the tubers. The disease also caused the stunting and death 
of young plants. Gaylord and Gregory report black securf from Lake, 
Porter, St. Joseph, Elkhart, Lagrange, Fulton, Tippecanoe, Madison and 
Clark counties. In seed disinfection tests in Lake county as high as 67 
per cent of the tubers in the check rows showed black seurf. The occur- 
rence of a small percentage of black scurf on the tubers from disease-free 
and treated seed indicated that the soil of this field which had not been in 
potatoes for five years was infested to some extent. 
Gregory reports cases of black-leg caused by Bacillus phytophthorus in 
Laporte, Tippecanoe and Hancock counties. 
Gregory found the non-parasitic leaf roll disease in St. Joseph, Noble, 
Fulton, Hancock, Clark, Floyd and Dekalb counties and reports it rather 
serious in fields noted in the latter three counties. In one field in Dekalb 
county he reports a 50 per cent incidence of the disease and a 25 per 
cent reduction in yield. When potatoes grown in the Wanatah region were 
planted in the greenhouse a low percentage of typical leaf roll plants 
resulted. 
Three typical and extreme cases of the mosaic disease oeccurrd in an 
