238 DISEASES OF ECONOMIC PLANTS 



spotted, depleting the vigor and productiveness of the plants. 

 The seed crop is sometimes completely lost. It can be 

 controlled by thorough spraying. Use copper sulphate, 

 1 pound to 10 gallons, before the plants come up, thor- 

 oughly soaking the soil ; then Bordeaux mixture 5-4-50 

 as soon as the plants come up, and repeat every other day 

 during the first few weeks, less often later. The mixture 

 will adhere better if 2 pounds resin, 1 pound sal soda, and 

 1 gallon of water, boiled together until clear brown in color, 

 be added. 



Wilt, fusariose {Fusarium vesinfectum Atk.). — The most 

 disastrous ginseng disease in the West is the wilt described 

 by Reed,^ which caused destruction, in Missouri, of whole 

 plantations in a single week. With the first symptom of 

 attack the leaflets droop, yellow, and die; then the entire 

 leaf dies to the base, drys up, and falls off. The immature 

 seeds shrivel and fail to mature. The dead, black stem 

 alone remains standing. The roots are not killed, but the 

 season's growth is ended, and the buds to produce the next 

 season's growth are dwarfed. Secondary decays, ,soft rots, 

 may follow. 



The cause of this disease is said to be the same as that 

 of the watermelon wilt, and remarks made in that con- 

 nection as to its habits, spread, etc., apply here also. 



It is claimed that the wilt fungus cannot attack ginseng 

 plants unless they are previously weakened by the inroads 

 of some other parasite. Prevention of other diseases 

 therefore renders the wilt harmless. Thorough spraying 

 • for all diseases affecting this crop is thus doubly important. 

 Diseased plants should be removed and burned. 



» Reed, H. S., Mo. Agr. Exp. Sta. Bui. 69. 



