192 VEGETABLE GARDENING. 



used, which vary as to the amount of lime and water, but the 

 above gives good satisfaction when used properly. 



Internal brown rot is the name given to a disease which has 

 recently appealed in a few potato growing sections in this 

 country. It is first noticed by the darkening of the starchy 

 portion of the tubers, which may become very much discolored 



without any manifestation of 

 its presence on the outside: 

 later on the potato rots. The 

 life history of this disease is 

 not known, nor are any reme- 

 dies known for it. Ordinary 

 prudence, however, would in- 

 dicate that seed potatoes in 



Fig. lui.— internal brown rot of the 

 potato. 



the least affected with this trouble should not be planted. 

 SWEET POTATO. (Ipomwa batatas.) 

 Native of South America. — Perennial but cultivated as an 

 annual. — It is a near relative of the morning glory and 

 scarcely resembles the 

 common potato in any 

 particular. It probably 

 cannot be profitably 

 raised in the extreme 

 Northern states, but may 

 be grown in a small 

 way in warm, sandy soil 

 as far north as Minne- 

 sota and will produce 

 even there very large tu- 

 bers. The plant never 

 flowers at the North 

 and is never cultivated 

 from seed. 



. Culture. The sweet po- 

 tato is raised from 

 sprouts, which are pro- 

 duced abundantly if the 

 tubers are planted in a 

 hotbed in the early spring 

 the tubers and are planted out after the soil has become warm. 



Fig. 102.— Sweet potatoes and piece of vine. 

 The sprouts are carefully pulled from 



