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Irrigati on of the New England Fruit Farm 



Large, arjiual yields of quality fruit are obtained \vhere moisture 

 supply and necessary mineral elements are in proper balance. If a given 

 acre of land can furnish only enough water during the growing season for 

 a 100-bushel crop of apples, a larger yield is unlikely regardless of the 

 fertilizer program. Heavy applications of nitrogen on a drouthy soil may, 

 in the case of apples, encourage early dropping of the fruit, stippen or 

 bitter pit, internal cork, etc. On a deep, well-drained, retentive soil 

 enough v;ater is available to take care of the needs of a fruit tree even 

 during a three or four weeks' drouth. This of course is not the case on 

 a coarse, excessively-drained soil or where subsoil conditions prevent deep 

 rooting. Irrigation is one means of supplementing rainfall on such handi- 

 capped soils. 



It has been estimated that a mature apple tree may require as much 

 as 4500 gallons of water during the growing season. If we consider 27 such 

 trees grov;ing on an acre of land, the v/ater requirement for an entire season 

 amoxmts to less than 5 acre-inches of rainfall. And since our average rain- 

 fall in Massachusetts amounts to 3 or 4 inches per month, it is difficult to 

 see why a shortage of moisture should occur. The fact is, of course, that 

 only a small percentage of the water which falls as rain ever becomes avail- 

 able to the tree. Much of our rainfall comes while the ground is frozen. 

 In ma^y orchards, compact soil conditions or a scanty cover results in sur- 

 face runoff instead of penetration to the soil zone occupied by the roots. 



In analyzing moisture relationships in an orchard we need only to 

 compare the appearance and behavior of fruit trees with deep root systems on 

 a fertile retentive soil with those on a drouthy, impoverished soil. Luxurious, 

 dark green foliage with rapidly sizing fruit tj/pifies the normal tree. Here 

 the cover crop seldom shows signs of drouth. In fact, a deep-rooted tree 

 will thrive long after the cover crop shows drouth sjrmptoms, since it has 

 access to vra.ter in the subsoil not available to shallower-rooted plants. 



In years past considerable stress has been placed upon elevation and 

 slope in the location of an orchard, vAiile very little attention has been giv- 

 en to soil type. As a result, orchards have been planted on all sorts of 

 soils ranging from those that are too wet to those that are hopelessly over- 

 drained. As an example of the latter type, the Hinckley soil series ought 

 not to be considered for orchard purposes since the moisture supply is totally 

 inadequate for good production. Orchards noxv planted on soils either too wet 

 or too dry should be removed and such mistakes avoided in the future. 



Severe drouth sjonptoms in an orchard are easily detected. They 

 manifest themselves in a slovdng up or actual stopping of the grov-iih of the 

 fruit, yellowing and dropping of the leaves, and in severe cases, a drying 

 up of the cover crop. A moderate shortage of water, however, is seldom de- 

 tected. Only the observing grovrer will sense the demand for additional water 

 before the shortage actually occurs. Here is where irrigation may prove 

 highly beneficial. Without irrigation in a dry season, the fruit at harvest 

 time is smaller, may drop prematurely, and may be affected by Baldwin spot or 

 internal cork. 



Irrigation is now being used by a few Massachusetts fruit growers 

 to supplement our annual rainfall, which averages 43.7 inches. In irrigated 



