Arizona Agricultural Experiment Station 279 



In addition to the large test plots, 65 pedigreed races were planted 

 in increase plots. Each of these races was selected from the best head 

 rows of the previous season's crop. The object of this experiment was 

 to increase the seed from these excellent races, and to further test their 

 yielding capacity when planted under practical field conditions. Al- 

 though some of these races suffered severely from a late frost, and 

 therefore made low yields, others outyielded the original races from 

 which they were selected. A selection of Turkey Red wheat produced 

 51 bushels per acre, while the original stock from which this selection 

 was made produced only 43.2 bushels in 1915. A similar gain in yield 

 was obtained from nine other selections. The abnormal conditions of 

 the spring weather,- such as cold weather and late frosts, make it nec- 

 essary to repeat this series next year. 



The wheat hybridization project has been continued this year, and 

 data on the third generation has just been completed. Reciprocal 

 crosses of the following varieties have been studied : Early Baart x 

 Macaroni, Sonora x Macaroni, Algerian Red x Macaroni. 



The object of this project is to combine the hardiness, disease re- 

 sistance, and high yielding qualities of the macaroni with the high mill- 

 ing quality of the bread wheats. A very exhaustive study of heredity 

 in wheat has also been made. About twenty-five thousand hybrid wheat 

 plants were grown at Yuma and harvested in the spring of 1916. Care- 

 ful individual plant records were made of the following characters : 

 Date of first head, height of plant, date of maturity, strength of straw, 

 and rust resistance. The heads of each plant were harvested in a sepa- 

 rate bag and the whole lot was shipped to Tucson where laboratory 

 notes were taken on the following head characters : Number of heads, 

 the dimensions of the largest head of each plant, length of awns, and 

 color of chaft". A very extended study of sterility has been planned 

 and carried forward during the past two years. This is one of the 

 most difficult problems with which the plant breeder has to deal in 

 producing high yielding strains. 



ALFALFA 



The alfalfa plots on Land 1 1 at Yuma were continued through the 

 year 1916. Table X gives the total yields per acre from these plots. 



Table X shows that the Peruvian alfalfa leads in yield, as it has 

 done during the two previous years. It should be said that Plot 39b 

 of the Peruvian is not thoroughly level. About one-third of this plot 

 is too high to receive the same quantity of water as the other plots. 

 This accounts for the low yield on this plot. A seed crop was also 



