31 



this and practice it, but they frequently start plowing 

 and harrowing too late, trying to save "the moisture after 

 it has already escaped. 



Irrigation is usually of great benefit and frequently 

 it is absolutely necessary for several months in the winter. 

 In some soils it is possible to preserve enough moisture 

 to keep the trees in growing condition "by constant culti- 

 vation, but a great many soils become too dry and the 

 bloom which should form in February does not appear 

 before June. AVith irrigation not only the time, of 

 blooming may be controlled but many insect pests as 

 well. 



The method of irrigating will depend on local con- 

 ditions. Water can seldom be obtained from streams by 

 gravitation, and it must therefore be pumped from 

 natural supplies or from w-el } ls. The cost of this will 

 vary according to the 'height the water has to be lifted 

 and the machinery used. If there is an unlimited supply 

 of water within 15 to 20 feet of the surface the problem 

 is a simple one because under such 'conditions a 4 inch 

 centrifugal pump driven by a 4 horse power engine,, 

 supplying about 300 gallons per minute would be enough 

 for a ten acre grove. Where the lift is 100 to 200 fast 

 like in some groves in Cuba, the problem becomes more 

 complicated and the cost very great. In connection with 

 pumping plants it is usually necessary to have some 

 kind of storage tank unless the capacity of the plant 

 is large, because the main thing is to be able to supply 

 large volumes of water when needed. A windmill can 

 not be relied on where much water is needed, !but for a 

 small supply a windmill in connection with a storage 

 reservoir may sometimes be satisfactory. The water may 



