Thiv Yuma .Mf.sa 247 



the trees, in some instances entirely choking them out. When the 

 orchards were set about a pound of bone phosphate was applied in 

 each tree hole. This was supplemented by liberal applications of 

 stable manure to crops planted between the rows of trees. Furrow 

 irrigation was practiced, but very frequently the trees suffered 

 from a lack of water. During several summers they were injured 

 to such an extent as to cause their leaves to drop. 



From a careful study of the orchards, and from information 

 secured from past as well as present owners and managers, it 

 appears that the failure of these plantings to yield profitable re- 

 turns was largely due to the following causes : 



1. High cost of water, with consequent lack of sufficient irriga- 

 tion. 



2. The absence of methods of culture tending to improve the soil, 



particularly the growing of leguminous cover crops between 

 the rows of trees. 



3. Absentee control, with frequent changes of managers. 



4. Orchard trees being planted wider apart than necessary with 

 numerous vacancies being allowed to exist. 



5. The use of too large a number of varieties rather than a few 



standards. 



6. General neglect, particularly during later years, in matters of 

 cultivation, pruning, and irrigation. 



RECENT CITRUS PLANTINGS 



In addition to the old citrus grove of sixty acres there are at 

 the present time on the Mesa eighty-eight acres of young orchards, 

 set in the spring of 1916. As evidenced by Figures, 11, 12 and 13, 

 the trees have made a very substantial growth. By actual meas- 

 urement the growth per season has averaged from two to four 

 ieet, which compares very favorably with the growth made by 

 young trees in older citrus regions. The methods employed in 

 the handling of these orchards are extremely simple and such as 

 would make practical the development of large areas. The trees 

 have been fertilized in some cases with stable manure, but no soil- 

 building crops have been grown, owing to the added expense of 

 supplying them with water. If water is furnished in abundance at 

 reasonable cost such crops can be planted between the rows of 

 trees, in which case a better growth of tree will result and the 

 matter of handling the orchards will be still further stimulated. 



In order to determine the possibility of growing cover crops 

 on the Yuma Mesa, Mr. George M. Hill planted a small area of his 



