1913] Sliaw: Studies on Injtuences Affectiiig Protein Content of Wheat 103 



EFFECT OF SUNSHINE ON THE COMPOSITION OF THE WHEAT 



KERNEL 



It has long been a matter of common knowledge that the 

 composition of plants varies greatly under different conditions 

 and in different localities. The exact environmental factor or 

 factors which cause this variation in composition has been the 

 cause of much discussion and investigation. 



It has alread}' been remarked above that in 1882 Richardson 

 observed that wheat grown in Colorado had by reputation a 

 much higher gluten content than wheat grown from the same 

 seed in Oregon. Not only was there a marked difference in the 

 composition of the wheat grown in the two states, but he found 

 that the wheat grown in Colorado had a higher gluten content 

 than the original seed, while that grown in Oregon had a lower 

 gluten content than the seed from which it was produced. From 

 these observations Richardson and Blount concluded that the 

 soil was the modifying factor. 



Wiley, however, draws the conclusion that the difference in 

 gluten content is due to climatic conditions. 



Lawes and Gilbert in an elaborate series of experiments have 

 shown that the use of manures and fertilizers have very little 

 influence on the composition of the wheat kernel. On the other 

 hand, they found a wide variation in composition in different 

 seasons. 



Deherain in France also observed that a difference in seasonal 

 conditions, especially during the ripening period, had a marked 

 influence on the gluten content of wheat. 



Similar observations have been noted by Thatcher of Wash- 

 ington, and others. 



From these numerous observations and experiments it has 

 come to be generally conceded that the gluten content is influ- 

 enced mostly, if not wholly, by the climate. 



Wheat grown in the coast states is, as a class, much lower in 

 gluten content than w^heat grown in the central west, or the 

 northwestern states. Even when seed of a high gluten content 

 is introduced, a product, as Richardson observed, considerably 

 inferior is the result. 



