88 DISEASES OF GINSENG. 



The disease seems to be aggrravated and probably induced 

 entirely by the presence of too much moisture in the shack. That 

 is, if the fungus is in the soil, it will under these conditions produce 

 the disease. One man who was havnng trouble with this disease 

 stopped it almost immediately by lifting sections in the roof and 

 aerating the shack. The old rotted roots should be dug and de- 

 stroyed so as to remove the chance of infection from the cup stage 

 in the spring. 



NEMATODE ROOT GALL. For the following account of the 

 Nematode Root Gall, I am indebted to Van Hook: 



"A glance at (Fig. 38) will show the external appearance of 

 roots affected with nematodes. They attack the fibers most readi- 

 ly, but may begin at any point on the root. The largest knots 

 seem to be formed on the main roots, although these are fewer in 

 number. A single root may contain hundreds of galls. These are 

 of any size up to two inches, but their usual size is three-eights 

 to one-half inch. One eilect of galls is to increase the number of 

 fibers. From a single gall produced on a small fiber, a half dozen 

 or more secondary fibers will be produced. Each of these is fre- 

 quently as large as the fiber on which the gall was originally pro- 

 duced; sometimes a fiber is even larger below. 



The galls are at first more or less smooth and white, but 

 with age become roughened and show watery, translucent spots. 

 This is from the decay within — the bark not yet being ruptured. 

 The bark soon breaks, however, and if not too badly decayed 

 within, wart or canker-like places are distributed over the'surface. 

 These may be mere spots with a rusty-yellow opening or a crack 

 of considerable length and of a like color. Decay usuallytcon- 

 sumes the entire gall, in the end. Frequently the gall complete- 

 ly collapses on being picked up. 



