218 IRRIGATION PRACTICE 



water applied is small. This effect is felt most in the 

 stalks of plants. In the leaves, which naturally contain 

 less water than do the stalks, the effect of varying quan- 

 tities of water is not so apparent; but the water content 

 of every part of the plant is somewhat affected by the 

 water supply. The underground parts of plants, such as 

 potatoes and sugar beets, contain usually a slightly 

 larger percentage of moisture, when grown on land 

 abundantly irrigated. 



Since most crops are not sold green, this effect of irri- 

 gation has little commercial value. True, in the case of 

 fruits, tomatoes and similar crops, which are usually dis- 

 posed of in an undried condition, the increased percent- 

 age of water in crops grown with much water may make 

 considerable difference in the final weight. Potatoes and 

 sugar beets, when irrigated heavily and late, may weigh 

 more per acre, but the increased yield is obtained only at 

 the sacrifice of quality. In most cases the difference is 

 so small as to be negligible. 



The water content of hay, grain and other crops that 

 are sold after thorough curing or ripening, is not influenced 

 by the irrigation during growth. However, hay, cured 

 under the dry conditions of the arid region, contains less 

 water and is to that extent more valuable than hay cured 

 in the humid regions. Likewise, the water content of 

 wheat and similar crops that ripen before harvesting is 

 only slightly influenced by the degree of irrigation; but 

 the dry conditions of the arid region tend to yield crops 

 containing less water than when grown under humid 

 conditions. In short, irrigated crops of the arid region, 

 that are dried before being placed on the market, are more 

 valuable, pound for pound, than those grown in humid 

 regions, for the reason that under humid conditions the 



