THE ASCOSPORE AND OTHER FUNGI 



255 



lished that on potatoes this disease may be prevented by 

 rotation of crops and soaking the tubers to be planted in a 

 solution of formalin of the strength of one ounce to two 

 gallons of water. 



From the viewpoint of geographical distribution, the Early 

 Blight of the Potato seems even 

 more important than the Late 

 Blight. The former is distrib- 

 uted throughout the United 

 States, while the latter is chiefly 

 destructive in New York and 

 New England. The Early 

 Blight appears about the time 

 the plants blossom, showing as 

 small brown spots scattered over 

 the leaves. Sometimes the spots 

 enlarge and run together into 

 blotches. The whole plant is 

 often killed long before its time, 

 so that the tubers in affected 

 fields are small, though there is 

 no rotting effect on account 

 of this disease. Fortunately, 

 spraying with Bordeaux mixture is an efficient preventive. 



The Anthracnose of Beans is another widespread and im- 

 portant disease. It is familiar to most people who have 

 attempted to grow string beans, because the reddish brown 

 spots upon the pods are too conspicuous to be overlooked. 

 Sometimes the disease is called the Pod Spot. Such in- 

 jured pods are generally worthless, and the whole crop is 

 often ruined in wet seasons, for moisture is an important 

 factor in the development of the parasite. 



When the pods are seriously affected by the fungus, 



POTATO LEAF AFFECTED BY 

 EARLY BLIGHT 



