137 VEGETABLE GROWING IN SOUTHERN ARIZONA. 



the soil is moist and the field is harrowed or rolled after the fur- 

 rows are made, irrigation will not be necessary until after they 

 are up, but in some eases it is well to have furrows left for use, in 

 ease the soil becomes too dry before they are up. It should be 

 remembered that, unlike seeds, the early stages of germination 

 proceed as well in dry as in moist soil. Not until the stem puts 

 out roots is much moisture needed. The less the soil is irrigated 

 and the more it is cultivated, the mellower it will remain. If the soil 



■'.,•«'• --"J 



a**** 



CTC -* >"'0> '-'4. ■««*>"* J > 





ik<l 



r 



Fig. 4. View in experimental potato plat. 



becomes too dry at any time, irrigation is apt to start a new growth 

 that will be detrimental to the crop. It is very important that the 

 soil be prevented from baking about the roots and tubers. To this 

 end, the irrigation stream should, by keeping the furrow midway 

 between the rows, be kept as far away as possible. Thorough 

 cultivation should follow each irrigation. By following these 

 methods, the yields have been from 60 to 175 bushels per acre at 

 the vStation farm during the past two years. 



