QUANTITY OF WATER REQUIRED 155 



the plainest deductions from experience is that small, tough fruit makes 

 unprofitable dried fruit, and that the best development of the fruit is 

 essential to the best results from drying. Many comparative weighings 

 have shown that the greatest yield in dried form has been secured 

 from trees which have had water enough to produce good, large fruit. 

 Even to bear fruit for drying, then, the tree must have moisture enough 

 to develop size and quality. If lacking moisture, the tree serves its own 

 purpose in developing pit and skin and reduces the pulp, in which lie 

 the desirability and value of dried fruits. 



Of course the water should be applied at proper times, in proper 

 amount, and in a proper way. 



HOW MUCH WATER SHOULD BE USED? 



This is by its very nature an elusive question and any attempt to 

 answer it by a definite prescription is more apt to produce folly than 

 wisdom. For as it appears that whether irrigation is at all needed or 

 not depends upon several conditions which must be ascertained in 

 each place, so the amount of water, which is really an expression of the 

 degree of that need, depends also upon local conditions of rainfall, of 

 soil depth. and retentiveness, of rate of waste by evaporation, of the 

 particular thirst of each irrigated crop, etc. The result secured by the 

 use of water is really the ultimate measure of the duty of water in each 

 instance. In the case of fruit trees and vines, then, whatever amount 

 of water secures thrifty and adequate wood growth and strong, good- 

 colored foliage, but not excessive or rank growth; and abundance of 

 good-sized and rich, but not monstrous and watery fruit, is the proper 

 amount for that place and that product, and to the ascertainment of 

 that amount by local experience of himself and others, the grower 

 should employ his most earnest thought and his keenest insight. 



During recent years the writer has continually renewed his data 

 of the irrigation practice of California fruit growers by systematic 

 inquiry and has prepared four bulletins* which have been published 

 by the Irrigation Investigations of the U. S. Department of Agriculture. 



A study of local practice shows that infinite! variety exists and in 

 the nature of the case must exist, and that any definite prescription 

 of the duty of water under various conditions is impossible. In some 

 cases the amount of water at each irrigation must be small, and appli- 

 cations frequent because the soils are shallow, overlying bedrock, and 

 a small amount saturates them. In other places an acre-foot of water 

 is readily absorbed and retained in the deep soil. The annual rainfall 

 also has little relation to the amount of irrigation, because neither fine 

 shallow, nor deep coarse soils, can retain the volume of water which 

 falls upon them during the rainy season. Then the varying rate of 

 evaporation, the character of the tilth, etc., enter as factors and it 

 becomes clear that he is fortunate who knows how much water to use 

 on his own place. 



*Farmers' Bulletin No. 116, "Irrigation in Fruit Growing;" Farmers' Bulletin No. 138, 

 "Irrigation in Garden and Field;" Bulletin of Experiment Stations No. 108, "Irrigation Prac- 

 tice Among Fruit Growers of the Pacific Coast;" annual report of irrigation and drainage 

 investigations, 1904, "Relation of Irrigation to Yield, Size, Quality, and Commercial Suitability 

 of Fruits." 



