66 University of California Publications in Agricultural Sciences [Vol. 1 



Total Protein in Dry Matter 



1906 1907 1908 1909 1910 1911 1912 



Kubanka 9.68 9.90 14.71 14.30 14.87 10.60 14.93 



Crimean 10.38 11.38 11.75 13.27 12.18 10.60 12.11 



Little Club Av. of 5 plats 10.29 9.78 9.98 13.00 



That the quantity of available nitrogen in the soil has com- 

 paratively little bearing, if any, beyond its necessity in sufficient 

 quantity to insure the normal growth of the plants, is indicated 

 on a series of fertilizer plats of very uniform land, discussed 

 further on in this paper. The seasonal effect is apparent, how- 

 ever, from the check plats in the same series. 



Varietal Variation. — Variation in protein content occurs be- 

 tween different varieties of wheat, even though the strain be a 

 pure one and the soil conditions under which they are grown be 

 the same. The analyses given below are from plants of pure 

 strain grown during the course of breeding experiments in cent- 

 gener plats under just as nearly the same conditions as it is 

 possible to secure in the field. The soil was uniform and the 

 plants were 4 inches apart each way and seeded at a uniform 

 depth of 2 inches. 



Grown at Davis, 1908 



In addition to the varietal variations here shown, the above 

 figures are of interest in showing that Kharkov, which is a hard 

 winter wheat, when grown under California conditions in the 

 same season does not carry a higher percent of protein than a 

 good quality of the White Australian belonging to the white 

 wheat class. 



