DISEASES OF GINSENG. 91 



CHAPTER XXIII. 

 DISEASES OF QINSENQ. 



End Rot, Fiber Rot, Rust Or Scab. 



(BY H. H. WHETZEL.) 

 The "fiber rot'' or "end rot", while among the more recent 

 of the maladies added to the list of ginseng diseases, is quite well 

 known to the growers. Nearly all have had more or less loss 

 from it. The fungus, however, which causes the disease is by no 

 means unknown to plant pathologists. It has been known for 

 many years both in this country and Europe as a serious root 

 disease producing organism on other crops. It causes a very 

 serious rot of tobacco, affecting the plant in much the same as it 

 does the ginseng. 



History of the Disease. — Since the fiber rot fungus is evi- 

 dently a common inhabitant of the soil, it is probable that the 

 disease occurs in its natural habitat. Certain it is that this malady 

 has long been present on the cultivated plant in our ginseng gar- 

 dens. Van Hook ('04), in his early work on the diseases of gin- 

 seng, observed and described this disease on seedlings, giving it 

 the name of "end rot." Though he did not discover the cause of 

 the disease at that time, later (Selby '04) working at the Ohio 

 State Experiment Station he found the casual organism and showed 

 it to be the same as the one on tobacco. Since that time, it has 

 been frequently found here at our laboratories on diseased roots. 

 Not until the summer of 1909, however, did the disease become 

 sufficiently destructive to attract the attention of the growers. 

 The disease was probably aggravated by the excessive dry weather 



