298 Gardening 



may be present. It will not destroy the fungus after it 

 has gained entrance to the inside of the leaf, however. 

 Spraying with Bordeaux mixture can therefore only 

 prevent the appearance and spread of the disease ; it 

 cannot cure diseased plants. Cucumber growers who 

 plant on a large acreage do not wait for the disease 

 caused by downy mildew to appear, but spray about 

 seven times during the growing of the crop. The home 

 gardener should at least begin spraying as soon as he de- 

 tects signs of disease. If, however, the disease has been 

 present in previous years or is known to be in the lo- 

 cality, it is advisable to begin spraying as soon as the 

 cucumber plants are well above the ground, and to 

 spray thereafter at intervals of about 10 days. If rains 

 occur soon after spraying, much of the poison will be 

 washed from the leaves ; it will then be necessary to 

 spray again immediately. 



LEAF BLIGHT OR LEAF SPOT OF THE TOMATO 



It is estimated by the United States Department of 

 Agriculture that the tomato-leaf blight causes a loss to 

 tomato growers in the United States of at least $5,000,000 

 each year ; yet this loss could largely be prevented if the 

 growers would learn to recognize the symptoms of the 

 disease and to spray properly with Bordeaux mixture. 



The fungus which causes this disease attacks the lower 

 leaves first. Small angular or circular spots appear, 

 having grayish or light-colored centers and dark-colored 

 borders. These spots are seldom more than J inch in 

 diameter. Leaves thus attacked curl, and then dry and 

 fall. As the disease continues to extend to the newer 



