DISEASES OF GINSENG. 63 



SYMPTOMS OF THE DISEASE. Contrary to the common opin- 

 ion of the growers, the first s.vmi)tf)ms of the disease are to be ob- 

 served on the stems of the plants (Fig. 20) instead of on the leaves. 

 (Fig. 19). After the plants are well up, a careful inspection of the 

 gardens, especially where the disease was present the year before, 

 will often reveal diseased stems here and there throughout the beds. 

 These show dark-brown spots of some length on one side, usually 

 just above the surface of the ground. (Fig. 20). 



Affected stems are usually not numerous and, unless especi- 

 ally sought, will be overlooked. The grower occasionally disco- 

 vers these diseased stems as they sometimes become so seriously 

 affected that they rot oft' and break over. While the diseased 

 stems seldom become numerous enough in a garden to cause serious 

 loss from this alone, they serve for the production of millions of 

 the spores of the fungus which, scattered through the gardens, pro- 

 duce later the too well known blighted leaves and tops. The 

 symptoms of the disease on the leaves is quite characteristic and 

 generally well known. Spots of varying size, usually half an inch 

 or more in diameter, appear in the leaves. At first water-soaked, 

 they gradually dry out, leaving a light papery center with a rather 

 broad rusty- brown border. The spot may gradually spread and, 

 viniting with other spots, involve the entire leaflet. The disease 

 may also attack the tops at the point where the leaflets are attached 

 to the leaf stalks (Fig. 22), or where these leaf stalks arise at the 

 top of the stem (Fig. 23). The drooping of the leaflets from the 

 end of the leaf stalk, or of the leaf stalks from the top of the stem, 

 are symptoms also characteristic of the mildew, but are readily 

 distinguishes from that disease by the velvety brown color of the 

 stem and the leaf stalks at the point of attack. This velvety 

 brown appearance of the parts, when affected with the Alternaria 

 Blight, is due to the multitude of spores of the fungus covering the 



