126 THE HANDBOOK FOR PRACTICAL FARMERS 



in the dry earth and irrigate immediately after transplanting. 

 A week following the date of transplanting another irrigation is 

 given. Where irrigation is practiced it is better to plant on one 

 side of the ridge rather than on top or on both sides. 



Distances for planting sweet 

 potatoes vary with different 

 varieties and soils. The aver- 



half feet between rows and 

 eighteen inches apart in the 

 row. The vineless varieties, 

 which are rather light bear- 

 ers, may be planted closer to- 

 gether. 



Cultivation. — The cultiva- 

 tion of the sweet potato is easy 

 or difficult in direct proportion 

 to the texture of the land and 

 its freedom from weeds. The 

 essential j^oints in the cultiva- 

 tion are to keep down weeds, 

 to conserve moisture, and to 

 retain the ridges intact. Spe- 

 cial tools are provided for the 

 cultivation of this crop, but 

 any implement in common use 

 for white potatoes and cotton 

 may be used successfully for 

 sweet potatoes. 



Continue cultivation until 

 the vines almost cover the 

 ground. Remove Aveeds on the 

 ridge with a hand hoe. 



Experiments conducted in 

 several states to test the value 

 of pruning and uprooting sweet 

 potato vines show conclusively 

 that the practice cuts down the 

 yield of tubers. 



Harvesting. — Sweet potatoes 

 should be dug before the vines 

 are killed by frost. In trucking 

 sections they are often dug as 



Fig. 41.— Black-rot of sweet putatc- 

 Farmcrs Btdlct'm ll.'i. 



