170 



IRRIGATION FARMING. 



potatoes or a crop of ill-shaped ones. The irrigation is 

 usually discontinued about the first of September, 

 although if it is a dry fall a later irrigation may be 

 needed. A potato field under irrigation is the subject 

 of Figure 56. 



Around Greeley, Colorado, where potatoes are so 

 successfully raised, though they may appear to need 

 water, the farmers are careful not to irrigate them until 

 after the young tubers are set. The reason for this is 

 obvious. When irrigated immediately before setting, a 

 greater number of potatoes will be formed than the plant 



FIG. 56. IRRIGATING A CROP OF POTATOES. 



can properly support, few of them becoming large 

 enough for market. When the tubers are allowed to 

 form first and are irrigated afterwards, fewer potatoes will 

 form in each hill, but a large crop of marketable tubers 

 is the result. Keeping the ground mellow by thorough 

 and deep cultivation is important. If the ground is dry, 

 irrigate some time before beginning to set. If kept too 

 wet, a large amount of tops and few potatoes will be 

 produced. 



Sweet Potatoes. The most successful growers 

 find it best to plant the seed in hotbeds about the last of 



