164 IRRIGATION PRACTICE 



the grain and hay stand high, and often the grain crops 

 become so tall that they fall over and give a great deal of 

 trouble at harvest time. Similarly, it is commonly 

 observed that with little water the crops are short. Under 

 dry-farming conditions, where the rainfall is small, the 

 wheat is usually so short that instead of binders, which 

 cannot be used, headers are employed which simply cut 

 off the heads of the grain leaving the high straw standing. 

 Further, as irrigation water is increased, the clusters of 

 seed-bearing heads increase in number. The general 

 appearance of the plant, therefore, depends on the quan- 

 tity of water added to the soil during the growing season. 



Of chief importance is the effect of varying quanti- 

 ties of water upon the stooling of the grains, that is, the 

 number of seed-producing stalks from one seed. The 

 more water is used, the more profuse becomes the stooling; 

 the less water is used, the less stooling occurs. This is of 

 particular importance wherever the seed is the chief 

 product at the harvesting. 



In practically every experiment conducted on this 

 subject, however, it has been found that, while the length 

 of the plant and the number of seed-bearing stalks increase 

 as the water increases, there is a limit to this correlation. 

 The increase due to the increased irrigation continues only 

 up to a definite limit, beyond which, if more water is 

 added, a diminution occurs and the plant becomes shorter, 

 the seed-bearing stalks less developed and with fewer 

 seeds, and growth is arrested. A medium quantity of 

 water would therefore be better than a very large quan- 

 tity to produce large plants with many seeds. 



The nature of the leaves is influenced by the applica- 

 tion of water. With little water the leaves of the grains 

 are distinctly green and firm; with much water, they are 



