DISEASES OF GINSENG. 93 



Symptoms. — In seedlings, the chief symptoms, during dry 

 weather, are a gradual change from a dark green to a light green 

 color, with premature coloring showing shades of red and yellow, 

 the leaflets finally withering and the stem wilting. In wet weath- 

 er, the color-changes maj^ not be so striking and the wilting 

 more sudden, the stem bending in a curve until the leaves (still 

 green) touch the ground, differing strikingly from the plants 

 affected with the "damping off'," in which disease the stem bends 

 at sharp angles near the ground. An examination of the root will 

 show the fibers neai-ly all rotted away and freciuently with merely 

 a bulb-like live crown with the bud left (Fig. 40). In the case 

 of older plants the tops show similar symptoms in the way of pre- 

 mature coloration and wilting. The fibers are more or less rotted 

 off, the whole root having a bare and stubby appearance when 

 taken up (Fig. 41). Often both seedlings and older roots show 

 brown scabby areas of dead skin which sluffs oft' leaving the root 

 more or less "pocked" or disfigured. In seedlings this may take 

 the form of a rusty band about the root a short distance below the 

 brown. This form of the disease is often spoken of by the grow- 

 ers as "rust" and while we have as yet no absolute proof that it is 

 only another kind of injury caused by the fiber rot fungus, still 

 the frequent presence of the spores of the parasite in these "rust" 

 spots, and the constant association of the "rust" symptoms with 

 the fiber rot indicates strongly that the two are but different forms 

 of the same disease. We may say, therefore, with some certainty 

 that "end rot," "filler rot" and "rust" or "scab" are all different 

 symptoms of the same disease. 



Etiology. — While the cause of this disease has not been 

 absolutely proven (by infection experiments) to be the soil fungus 

 Thelavia basieola (Fig. 42), nevertheless all the other evidence 

 points in that direction. When diseased specimens are carefully 



