270 PLANT DISEASES 



pink or light rose color. The production of fruit is prevented 

 or reduced. 



Control. Early spraying with bordeaux mixture has been 

 advised. 



Cucumber. ANTHRACNOSE. See under MUSKMELON, p. 274. 

 BLIGHT or MILDEW (Pseudoperonospora cubensis). A blighting and 

 premature yellowing of the foliage. 



Control Spray with bordeaux mixture, 5-5-50. Commence 

 to spray when the plants begin to run, and repeat every ten to 

 fourteen days throughout the season. 



WILT (Bacillus tracheiphilus) . This is a disease caused by bacteria 

 that get into the sap tubes of the leaf and stem, clog and destroy 

 them, causing the plant to wilt. The bacteria are distributed 

 chiefly by the striped cucumber beetle. 



Control. Control the striped beetle. See p. 318. Gather 

 and destroy all wilted leaves and plants. 



WILT (caused by malnutrition). Excessive fertilizing with highly 

 nitrogenous fertilizers will sometimes produce a peculiar curling 

 and wilting of the leaves. 



Currant. ANTHRACNOSE (Glceosporium ribis). Small dark brown 

 spots, chiefly on the upper surface of the leaf. The leaves finally 

 turn yellow, and fall in July or August. 



Control. Thorough applications of bordeaux mixture, 5-5-50. 

 LEAF-SPOT (Septoria ribis, Cercospora angulata etc.). Whitish 

 spots with black centers. Appears in midsummer, and causes 

 defoliation. 



Control. As for ANTHRACNOSE. 



WILT or CANE-BLIGHT. A destructive fungous disease which 

 causes the canes to die suddenly. Character of the wilting much 

 like that produced by the cane-borer. 



Control. No satisfactory method known. The most that 

 can be done is to go over the patch three or four times during the 

 summer, cut out and burn the blighted canes. 



Ginseng. BLIGHT (Alternaria panacis). Papery brown spots on the 

 leaves, which spread until the whole leaf is involved. Also at- 

 tacks the seed heads, producing a blast. 



Control. In the spring before the plants come through the 

 ground spray the soil thoroughly with copper sulfate, 1 pound to 



