256 CROPS THAT REQUIRE TRANSPLANTING 



set with a spade and are placed about sixteen inches apart in the 

 row. A man thrusts the spade into the soft earth of the ridge 

 and moves the handle slightly forward, so that a wedge-shaped 

 opening is made. Into this opening a boy thrusts a plant, and 

 holds it in place until the spade is withdrawn and the soil rolls 

 back against the plant. As the man steps forward to make the 

 next hole he places his foot close to the plant already set, and 

 thus firms the soil against the roots. In this way the work pro- 

 gresses very rapidly. 



Cultivation. — Special tools are used in cultivating sweet pota- 

 toes, so that the ridges are retained intact through the season. 

 The principal tools are the " sweep " and " bull tongue," in addi- 

 tion to the one-horse turning plow, which is used at times to 



Fig. 158. — "Sweep " used in making Fig. 159. — Home-made device for smoothing 



sweet potato ridges. sweet potato ridges. 



'' bar-off " both sides of the ridge if crab grass threatens to gain 

 a foothold. In addition to the horse tillage, considerable hand 

 hoeing close to the plants is necessary, for the ridges are scraped 

 clean of all grass and weeds at frequent intervals. Cultivation 

 is continued until the vines nearly cover the ground between, 

 as well as on, the ridges. The crop is then laid-by and allowed 

 to remain undisturbed until time for digging. 



Harvesting. — Sweet potatoes should be dug before the vines 

 are injured by frost. Special diggers are often used for the purpose 

 where large areas are to be dug. These are equipped with two 

 rolling coulters to cut the vines, two plowshares to cut away both 

 sides of the ridge, and a U-shaped piece of steel that runs under 

 the ridge and loosens up the tubers (Fig. 160). After this machine 

 has passed along the row, the tubers are pulled out by grasping 



