1 6 THE POTATO 



manent roots about one and a half inches below the 

 surface. 



Blossoming, Tuber Formation, and Hilling. 

 Potatoes are hilled about the time they come into 

 bloom, and this is the time that tuber formation is 

 beginning. The ancestral type of potato developed 

 seed about this time and died ; the tendency acquired 

 by cultivation is to throw all the reserve material into 

 tuber production. These reproductive processes cause 

 a severe drain upon the plant's energies, and the fort- 

 night immediately following the blossoming period is 

 therefore a peculiarly critical time for the plant, during 

 which time its life hangs in the balance. At this time 

 it is subject to extreme heat, and may be injured; also 

 insects, fungi, etc., may attack it, and, to add to its 

 troubles, cutting off a lot of its roots, either just before 

 or about this time, is no doubt the common cause of a 

 decline from which the plant never recovers. Even 

 tuber formation, without the influence of other agen- 

 cies, may cause a plant to die. The importance of 

 studying the condition of the plant at this time will be 

 appreciated when it is remembered that the entire crop 

 of salable tubers is formed after this critical period is 

 past, and full success with the crop depends upon retain- 

 ing the plant healthy for from one to three months 

 after the blossoming period. During August, in one 

 case, 1 the crop of potatoes increased at the rate of over 

 50 bushels, or over 3,000 pounds, weekly per acre. 

 The importance of avoiding checking growth prepara- 

 tory to or during such a time is evident. 



' Ver. Bui. 72, !> 5- 



