GROWING SWEET POTATOES 107 



The buds or shoots which develop should be trans- 

 planted to the field only when the ground is quite warm. 

 Although plants are generally set in ridges, some grow- 

 ers prefer to set on a level. The ridge system is probably 

 most desirable in the north. The center of the ridges 

 should be about 3^2 feet apart, and the plants set 18 

 inches in the row. Good cultivation is necessary. This 

 should be frequent and shallow to save moisture, and it 

 will also add to the yield. 



Southern growers have changed their method some- 

 what, and now do not believe it is necessary to move the 

 vines to prevent rooting, except under unusual circum- 

 stances. Northern experiments show that there is not 

 so much difference between rows in which the vines were 

 undisturbed and those in which the vines were moved 

 twice. 



Potash is one of the most important fertilizers for 

 sweet potatoes, although in New Jersey, horse manure at 

 the rate of 10 to 20 tons per acre is used. It should be 

 well rotted. Attention to the vines, says Mr. Wells, 

 does not stop with the end of cultivation. They should 

 be lifted occasionally to prevent their taking root, and this 

 work can be quickly done by the use of a pitchfork. Once 

 a week is often enough. 



In the north the black-rot affects sweet potatoes, and 

 this is soon seen on the sprouts. Whenever a plant 

 shows a leaf that is black, it should be dug up and 

 destroyed. Potatoes from affected plants will rot quickly 

 after being dug. As the germs of the disease remain in 

 the soil over winter, the ground should not be used again 

 for this crop. 



