82 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



V. M. Cone, formerly connected with the irrigation investigations of 

 this office, was appointed irrigation engineer. 



Under the Adams fund, work on new irrigation projects was begun 

 and new devices and apparatus were installed to facilitate and expe- 

 dite the work in the field and in the laboratory. 



Investigations on the occurrence of excessive amounts of nitrates 

 in Colorado soils and their effects on plants, especially orchard plants 

 and sugar beets, were actively pursued and the third bulletin on this 

 line of work was published. The area of actual destruction of crops 

 examined included 300 to 400 acres. Among the soils examined some 

 contained as high as 6.54 per cent of sodium nitrate. The rate of 

 fixation of nitrogen in these soils was found to be very high and 

 further evidence, pointing to the fact that the excess of nitrates is 

 due to phenomenal bacterial activity, was secured. The bacteriologist 

 determined a large number of very active forms of Azotobacter 

 having a pronounced power of brown pigmentation in the presence 

 of nitrates from these soils. 



The investigations on hold-over blight in pear and apple trees 

 were completed, and work was continued on the causes of raspberry 

 yellows, and incidentally on tests of sprays as remedial agents. The 

 investigations on a bacterial disease of alfalfa were also completed, 

 but observations on the blight resistance of 84 varieties of alfalfa 

 growing at Rocky Ford were continued. 



The department of entomology carried forward its studies of plant- 

 louse life histories, and published several papers on the data secured 

 during the year. 



With Hatch and State funds the agronomist continued work on 

 improvement of wheat, study of rotations in cooperation with farm- 

 ers in different parts of the State, and tests of forage crops suited to 

 Colorado conditions. Experiments were also continued on the cul- 

 ture of crops suited to high altitudes, and a preliminary report on 

 these experiments was prepared. Much attention was given to selec- 

 tion and breeding and the correlation of characters of field crops, 

 particularly grains and alfalfa. The work with alfalfa was quite 

 extensive and consisted of collecting, testing, and distributing im- 

 proved strains and breeding for frost, drought, and blight resistance. 

 Promising strains of alfalfa were discovered, and these were tested 

 with other promising varieties in different parts of the State. Im- 

 portant data were also secured with reference to the relation of root 

 growth and stooling habit to drought and cold resistance. In addi- 

 tion to this work, considerable attention was given to the study of 

 varieties, adaptation, and methods of culture of the field pea, and to 

 tests of methods of preparing new land. A grass garden was started 

 at the station during the year, and cooperation with this department 

 in testing varieties of sugar beets was continued. 



