1913] Shaw : Studies on Influences Affecting Protein Content of Wheat 75 



Average 53.7 90.2 



In each of the above cases the percentage of typical kernels 

 increased in the 1906 crop over those of the 1905 crop and the 

 average increase was from 53.7 to 90.2 ; it seems probable that 

 some climatic or soil factor is more than likely to have been the 

 cause of this change. This is particularly noticeable upon com- 

 paring the results between the two stations. 



The above figures not only do not indicate that there was 

 any strongly marked tendency toward lowering in quality, but, 

 on the other hand, the general tendency seems to be upward for 

 this season, particularly at Modesto. 



The Relation of Moisture.— Jt has been shown repeatedly 

 by many investigators that the composition of plants varies 

 considerably in different localities and in different seasons, 

 and that the principal factor seems to be the climate instead 

 of the soil, variations due to the latter being very slight if 

 any. This feature will be presented more in detail later in 

 this paper. While the relation of the water content of 

 the soil at various stages of the plant growth to the 

 protein content of wheats also forms a portion of these investi- 

 gations for later presentation, it may be said that the Utah 

 Station has conducted a number of experiments upon the effect 

 of water upon the composition of plants, the method of which 

 in each case has been to apply different amounts of water through- 

 out the season on contiguous plats of uniform land. The fol- 

 lowing selected results from the Utah experiments as affecting 

 the protein content of the grain are of interest in this connection. 



