CHAPTER XV 

 IRRIGATION OF FRUIT TREES AND VINES 



Whether fruit shall be grown with irrigation or not is a local 

 and specific question, and it must be answered with due regard 

 for several conditions, among which are : First, the minimum 

 local rainfall ; second, the depth and character of the soil and sub- 

 soil ; third, the situation and environment of the ground on which 

 the fruit is to be grown ; fourth, the kind of fruit which it is desired 

 to produce. 



These conditions are all correlated, and a knowledge of them 

 all is necessary to an intelligent decision as to correct practice 

 in any given locality. For example, the amount of rainfall which 

 is adequate in one locality, or in one situation, even, may be 

 quite insufficient in another, because, first, one soil may be deep 

 and fairly retentive, into which roots can penetrate and find abun- 

 dant moisture; second, another soil may have sufficient depth, 

 but be so porous as to lose its moisture by evaporation, or so 

 leachy as to lose it by drainage; third, still another may be shallow, 

 and quickly dried out under a fervid sun, or quickly drained by 

 reason of a sloping substratum of rock or hard-pan, while another 

 similar soil, differently situated, may receive abundant moisture 

 from the drainage of the slope above it ; fourth, possibly in all the 

 soils cited there might be adequate moisture for deciduous fruits, 

 but citrus fruits would require irrigation ; or enough for young, 

 but not for bearing trees. 



Thus it appears that even to decide whether a location has 

 sufficient rainfall for the growth of fruit without irrigation, one 

 must pass judgment upon all the conditions first mentioned. It is 

 hardly worth while, then, to discuss such a topic upon theoretical 

 grounds, or to attempt to answer the general question, Shall irri- 

 gation be employed in the growth of fruit? The true guide is 

 enlightened local experience, and the true test is the growth of 

 the tree and the excellence of its fruit. So long as the grower 

 is able to secure every year a generous amount of good-sized 

 and excellent fruit by natural rainfall, he need concern himself 

 very little about irrigation ; if his tree shows distress, and his fruit, 

 even when properly thinned out, is not up to market standards 

 every year, he may do well to provide himself with irrigation 

 facilities, either for constant use or to supplement rainfall when 

 it is occasionally deficient. 



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