THE POTATO 107 



grown seed. Especially is this true when northern grown 

 potatoes are taken farther south. Not only is the yield 

 increased, but the time required for maturing is shortened 

 by securing seed from colder regions. Great care should* 

 be taken in importing seed tubers not to introduce new 

 forms of potato diseases. 



5. Potato Enemies 



Potatoes have many enemies, and the number seems to 

 be increasing, owing to diseases being brought in from 

 other countries. 



Scab. Scab is one of the most wide-spread and de- 

 structive of potato diseases. It causes a rough, pitted, 

 scabby condition which may attack the tuber in patches, 

 or extend over the entire surface. Whether scab is caused 

 by a fungous growth or a species of soil bacteria is not 

 certain. It is fortunate, however, that a very simple and 

 effective remedy is known. This consists in treating seed 

 potatoes before planting. 



There are several mixtures used for this purpose, the 

 cheapest and most easily applied of which is a formalin 

 solution. This is prepared by mixing one pint of formalin 

 with thirty gallons of water. The seed potatoes are soaked 

 in the solution for two hours, and then planted without 

 allowing them to come into contact with bags or utensils 

 in which scabby potatoes have been kept. 



Leaf, or early blight. Leaf blight is another common 

 potato disease. It attacks the leaves and stems, first show- 

 ing about the time that the tubers begin to form. Its pres- 

 ence may be detected by the presence of grayish brown 

 spots on the leaves, the part of the leaf attacked soon be- 

 coming hard and brittle. Within three or four weeks the 

 leaves are all killed, and the stem is also affected. The tubers 



