CHAPTER SEVEN 

 TUBER CROP PROJECTS 



Potatoes and sweet potatoes comprise the tuber crop group. 

 They are so different in soil and cHmatic requirements that com- 

 paratively few instructions relating to their culture apply equally 

 well to both vegetables. Sweet potatoes grow best in sandy soils 

 and in the warm climates with long seasons, while the potato 

 produces the most satisfactory crops in sandy loams or in other 

 types of soils which do not become too compact, and in climates 

 which are fairly cool. 



Project XIII. Growing Potatoes 



The potato belongs to the potato family. Another important 

 commercial plant belonging to this family is the tomato. Closely 

 related, although quite different plants, are the common or black 

 nightshade and the bittersweet. The potato is a native of South 

 America, where it was doubtless first cultivated by the people of 

 Chili and Peru. Unlike the tomato the potato grows best in a 

 cool, moist climate. This fact can be appreciated when it is 

 known that our best potato-producing regions in the United States 

 are our northernmost states. 



The roots of the potato plant are fine and fibrous. The " po- 

 tatoes," or as they are properly known, tubers, are often considered 

 a part of the root system but they are in reality underground stems. 

 These underground stems grow out to a length of three or four 

 inches from the main axis or stem and their tips become swollen to 

 form the tubers. The fact that the tubers are modified stems is 



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