16 The Sweet Potato 



CLIMATIC EEQUIEEM'ElirTS. AND SOIL TYPES 



A liberal rainfall, with warm nights and abundant 

 sunshine, lasting throughout the growing season, with 

 less moisture during the two months preceding matur- 

 ity, constitute ideal weather conditions for sweet pota- 

 toes. A growing period of at least 130 days is essential 

 for the production of maximum yields. 



While requiring a heavy rainfall during the late 

 spring and summer to insure vigorously growing plants 

 and the formation of an abundant and well-shaped 

 tuber crop, considerably less rain is needed as the time 

 of harvest approaches. In fact, much rain at this time 

 may result in a considerable loss to the grower by injur- 

 ing the flavor of the potato and greatly impairing its 

 keeping and shipping quality. An unusually long con- 

 tinued spell of wet weather in the fall has often resulted 

 in great loss to growers along the Atlantic and Gulf 

 coasts, sometimes causing the entire crop to rot in the 

 field and more often causing a souring of the potato 

 which makes it easily susceptible to disease attack on 

 the slightest bruising, and rendering it practically im- 

 possible of successful storage. This condition occurred 

 throughout all the counties bordering the Gulf of Mexico 

 in the fall of 1918 and in the same year the crop was 

 more or less injured all along the Atlantic coast. (The 

 handling of the crop under these conditions is fully 

 treated under Chapter X.) It is also believed by 

 some growers that heavy late rains increase the tendency 

 to cracking or splitting in the tubers, although the scien- 

 tific reason for this common occurrence has not yet been 

 satisfactorily determined. Such late rains following a 

 dry season, though not excessive, tend to create a re- 



