444 



Thirty-first Annual Report 



holding of irrigation water as late in the spring as is possible 

 without severe stunting of the cotton plants. These experimeni- 

 also include work in connection with the controlling of the black 

 arm or angular leaf spot; experiments in topping cotton; and a 

 very complete set of experiments dealing with cotton fertilizers. 

 In this latter experiment barnyard manure applied at various rate- 

 is compared with cotton grown without fertilizers of any kind, 

 with cotton fertilized wath complete commercial fertilizer as ordi- 

 narily sold in the southern states, with cotton fertilized by the 

 application of cottonseed meal, with cotton fertilized by the appli- 

 cation of sodium nitrate, acid phosphate, and various combinations 

 of the above fertilizers. This fertilizer experiment is an exact 



Fis 



3. — Cooperative crop demonstratien. Orange sorghum grown without irriga- 

 tion — yield eight tons silage per acre. Navajo County. 



duplication of the experiments carried in 1919, and, by the close 

 of the season of 1920 will, we believe, supply some very definite 

 information of value to the farmers of the Salt River Valley and 

 other cotton growing sections of the State. 



VI. CULTIVATION AND MANAGEMCXT OF WINTER AND SPRING GRAINS, 

 INCLUDING WHEAT, OATS, AND BARLEY 



These experiments were for the most part an exact duplication 

 of the experiments carried during the previous year. During the 

 winter and early spring small grain crops appeared exceedingly 

 promising. However, the moist conditions of early spring favored 

 the development of the various rust diseases, and, by harvest time, 



