98 THE POTATO 



Good potatoes are grown with one to five ir- 

 rigations, the last one not much later than August 

 20th, to give forty to sixty days for finishing growth 

 and ripening. Some of the best growers irrigate 

 alternate rows at each irrigation, taking two 

 waterings to go over the entire field. 



There is good reason why irrigation conditions 

 are ideal for the production of potatoes. The 

 value of this crop, as of many others, depends on a 

 right amount of moisture at the right time, the 

 demand for moisture being heavy while the tubers 

 are forming and developing. In Wisconsin it is 

 assumed that the eighteen inches of water generally 

 counted on during the growing season is sufficient 

 to mature a maximum crop. In ten of the past 

 twenty-one years the amount of rainfall during 

 the growing season has been fourteen inches or 

 less. Prof. F. H. King, the soil expert, found at 

 the Wisconsin Experiment Station that the 'ad- 

 dition of two acre inches of water by irrigation 

 increased the yield of marketable potatoes 100 

 bushels per acre. In the Twin Falls country 

 in Idaho and some other places in the Rocky 

 Mountain country the moisture supply is under 

 absolute control, making, with an ideal soil, a 

 sufficient and legitimate reason for the production 

 of the most perfect potatoes. 



It requires from 270 to 500 pounds of water to 

 make one pound of dry matter in the vine and 

 tuber of the potato plant. 



The best growers favor several rather light irri- 

 gations to fewer heavier applications. 



In "Bulletin 132" of the Maryland Agricultural 

 College is given the result of an experiment to ascer- 

 tain whether deep or shallow cultivation would pro- 

 duce the best potato crop. The summary follows : 



