308 Annual Report Agricultural Experiment Station 



Progress has been made on definite projects in Pomology as 

 follows. 



a study in the CULTl'RK AND MANAGEMENT OF DATE ORCHARDS 



This ])roject conducted at the Yuma Date Orchard and Horti- 

 cultural Station was begun in the summer of 1918. The work in- 

 volves a comprehensive study of a number of features of orchard 

 culture and management, with particular reference to the compara- 

 tive effect of clean tillage, cover crops, sod, and mulches, together 

 with dift'erent methods of fertilizing, on the yield, quality, time of 

 ripening, size of fruit and growth of tree. The orchard contains 

 about four acres, and the trees have been set 10 years. It is divided 

 into six plots with each plot containing two rows of trees. The plots 

 are being handled as follows : 



No. (1) Planted to alfalfa, cuttings allowed to remain where 

 they fall. 



No. (2) Planted to sour clover in the fall, followed by cow- 

 peas in summer. 



No. {3) Planted to vegetables during both summer and win- 

 ter. 



No. (4) Wide, shallow basin maintained about each tree with 

 a heavy manure mulch. 



No. (5) Wide, shallow basin maintained about each tree with 

 a thick straw mulch. 



No. (6) Clean culture thruout the year. 



The rows are divided crosswise to allow four different treat- 

 ments with commercial fertilizer. 



A STUDY OF CULTURAL METHODS WITH CITRUS FRUITS 



These investigations, begun in the summer of 1918, are being 

 conducted on the Yuma Mesa in cooperation with Mr. George W. 

 Hill. The orchard in which the tests are being made contains about 

 ten acres, and the trees composed of the Washington Navel variety 

 of orange and the Marsh Seedless variety of pomelo, were set in 

 the spring of 1916. The area is divided into ten plots, each of 

 which is being given a distinct method of culture, particularly in 

 the matter of cover crops. The plots are divided crosswise so as 

 to allow four trees in each plot being given a different fertilizer 

 treatment. Records of growth and general phenological notes are 

 being made, and it is hoped that during the next few years data 

 may be gathered on the cumulative effect of each cultural method 

 and fertilizer treatment on the growth of tree and the size and 

 quality of the fruit. 



