PROTECTING PLANTS 209 



and burning of affected trees is the only procedure now to be recom- 

 mended. The disease is reported in New England and western New 

 York. 



Chrysanthemum leaf-spoL — Spray with bordeaux, 5-5-50, every 

 ten days or often enough to protect new foliage. Ammoniacal copper 

 carbonate may be used, but it is not so effective. 



Cucumber diseases. — ''W\\i" is a disease caused by bacteria that 

 are distributed chiefly by striped cucumber beetles. Destroy the 

 beetles or drive them away by thorough spraying with bordeaux, 

 5-5-50. Gather and destroy all wilted leaves and plants. The most 

 that can be expected is that the loss may be slightly reduced. 



Downy mildew is a serious fungous disease of the cucumber known 

 among growers as "the blight." The leaves become mottled with 

 yellow, show dead spots, and then dry up. Spray with bordeaux, 

 5-5-50. Begin spraying when the plants begin to run, and repeat every 

 10 to 14 days throughout the season. 



Currant diseases. — Leaf-spots and anthracnose are caused by two 

 or three different fungi. The leaves become spotted, turn yellow, and 

 fall prematurely. They may be controlled by three to five sprayings 

 with bordeaux, 5-5-50, but it is doubtful whether the diseases are 

 sufficiently destructive on the average to warrant so much expense. 



Gooseberry powdery mildew. — The fruit and leaves are covered 

 with a dirty white growth of fungus. In setting a new plantation, 

 choose a site where the land is well underdrained and where there is 

 a good circulation of air. Cut away drooping branches. Keep the 

 ground underneath free from weeds. Spray with potassium sulfide, 

 1 oz. to 2 gal. ; begin when the buds are breaking and repeat every 

 7 to 10 days until the fruit is gathered. Powdery mildew is very de- 

 structive to the European varieties. 



Grape black-rot. — Remove all "mummies" that cling to the arms 

 at trimming time. Plow early, turning under all old mummies and 

 diseased leaves. Rake all refuse under the vine into the last furrow 

 and cover with the grape hoe. This cannot be too thoroughly done. 

 The disease is favored by wet weather and weeds or grass in the vine- 

 yard. Use surface cultivation and keep down all weeds and grass. 

 Keep the vines well sprouted ; if necessary sprout twice. Spray with 

 bordeaux mixture, 4-4-50, until the middle of July, after that with 

 p 



