ROOT CROPS. 



521 



Propagation. 



Many failures with this crop have arisen through planting it in a similar 

 manner to that adopted with the ordinary potato, i.e., using the roots whole 

 or cut as sets. Whilst this practice will produce a crop, though somewhat 

 late, in the North Coast or long-season districts, yet in a short-season or a 

 dry district to adopt such a practice is to court failure at the outset. 



The crop is best propagated by means of shoots or " plants " which grow 

 from the tuber. When bedded or planted (see Fig. 1), sometimes as many 

 as fifty '"plants" w r ill grow 7 from a single small tuber, and two or three 

 pullings may be obtained in a single season. 



How to raise "Plants." 



The plants necessary for producing an early crop are obtained by placing 

 the roots — usually small, slender tubers, kept over for this purpose from 

 the previous season — on sand in a cold frame or hot bed. These seed tubers 

 are placed close together, but not touching each other. They are then 

 covered with 2 or 3 inches of sand (river sand preferred) ; the whole bed is 

 then well watered and covered with a glass sash or frame of hessian. By 

 raising a corner of the frame, enough air is admitted to prevent rot setting 

 in. The bed should be kept moist, but not wet, and covered until the plants 

 show through the sand. The covering is then removed during the daytime, 

 but replaced at night. This "is done until all danger of frost is past. The 

 " plants." when fi or 8 inches long, are ready for planting out. (Sec Fig. 1.) 



Fig. 1. Sweet Potato "root," with plants ready for breaking off and planting ou:. 



By bedding the roots early, the addition of bottom heat is unnecessary 

 in comparatively warm districts. If tubers are set in the frame about the 

 end of July or beginning of August, plants will be ready as early as it is 

 safe to put them out. Plants raised on sand, and without artificial heat, 

 are hardier than if raised in a rich compost and on a hot bed, and in addi- 

 tion, the risk of introducing disease is lessened. In a cold district, or where 

 bedding-down has been delayed, it will probably be found necessary to use 

 some sort of bottom heat. 



