SUGAR BEETS, POTATOES, ETC. 



299 



rows, although on soils with good lateral seepage it may be 

 sufficient to irrigate every other row. Occasionally, every 

 other row only is irrigated at the first irrigation, and every 

 row thereafter. (Figs. 76-79.) 



Potatoes need a good supply of water in the soil at 

 planting time. If the soil is too dry, it may be necessary 

 to irrigate the crop, which may be accomplished by 



FIG. 79. Irrigating potatoes at Greeley, Colo. 



applying water just before or after planting. Little water 

 is needed by potatoes during the first period of growth, 

 providing there is a plentiful supply in the soil at the time 

 of planting. Potatoes planted about the first of May 

 seldom need irrigation before July 1; and from then on 

 irrigation should be practised only as the plants need it. 

 One of the surest signs of water need is the darkening of 

 the foliage. If water, especially cold water, is applied too 



