DISEASES OF GINSENG. 77 



shown in (Fig. 27). These are the thi'eads of the sterile fungus 

 rhizoctonia, now known to Ije mischievous in many kinds of 

 plants. Since this fungus has been found to be most destructive 

 to plants when they are surrounded Ijy unfavorable conditions 

 (i. e., when the soil is too moist and not well aired), the best 

 means of preventing the trouljle is to l)e secured in regulating 

 these conditions. The air should circulate freely among the 

 plants, and the soil must not he wet and packed about these tender 

 young stems. Stirring the surface of the beds to the depth of an 

 inch will dry out the top soil and at the same time preserve the 

 moisture below. 



[We have for a number of years practiced spraying plants 

 with ammonia, with good results, using three ounces of aqua am- 

 monia to one gallon of water, spraying once a week during the 

 months of June and July. While ammonia may not be a fungi- 

 cide, it is a strong fertilizer and probably has its benifiting effects 

 in that it stimulates the plants, making them more vigorous and 

 disease-resisting. — Author.] 



Rhizoctonia Rot Of Stems And Roots, 

 (by prof. h. h. whetzel.) 



While most diseases of ginseng already discovered attack 

 either the root alone or the parts above ground, there has appeared 

 recently especially, a fungus that attacks both. This is also a 

 fungus which seems to gain entrance to the plant through the stem 

 at a point near the surface of the ground. From this point it 

 spreads in both directions, up into the stem and down into the 

 root, causing a rotting of the tissue. The tops usually break over 

 from the weakening of the stem at the base, while the diseased 

 root becomes soft and pulpy throughout. This disease may be 

 readily recognized from the large black knots, or sclerotia, that are 



