60 DISEASES OF GINSENG. 



CHAPTER XX. 



DISEASES OF QINSENQ. 



The Alternaria Blight, 

 by prof. h. h. whetzel. 



This is the most common, wide-spread, and best known of 

 the diseases of ginseng. Nevertheless, isolated gardens here and 

 there appear to have thus far escaped the malady, though nearly 

 every mail during the growing season brings specimens of the 

 disease from new localities. Every grower must expect sooner or 

 later to meet this enemy of his crop. His success in combating 

 the disease will depend less upon his peculiar location, character 

 of soil, and special methods of shading, etc., than it will upon his 

 accurate knowledge of the disease and the methods of controlling 

 it. Notwithstanding the very general occurence of this blight in 

 all the ginseng growing sections of the country and the repeated 

 descriptions of the disease with the means for its control, many 

 growers appear to be unacquainted with its symptoms, the nature 

 of the fungus causing it and the pro|jer use of the fungicides in 

 combating the parasite. Many who are well acquainted with the 

 spottin i of the leaves (Fig. 19) by this fungus, are unaware of 

 the important fact that it always appears first upon, the stems 

 (Fig. 20) of some of the plants early in the season, forming long 

 dark brown spots on which spores are produced in great abundance. 

 The spores, carried by the wind to the leaves, produce the spotting 

 and blighting of the tops. Because of the too general lack of in- 

 formation on this common disease of cultivated ginseng, it seems 

 desirable to again present the main facts in regard to this malady 

 and its control. 



