THE DRY FARMING CONGRESS. 



167 



"Before taking up the question of yield, it may be well to offer au 

 explanation as to the reason of this remarkable variation in protein 

 content. There is considerable difference in the length of the ripening 

 period in the localities where the tests were made, and 

 this one element of environment undoubtedlj^ brought about the variation 

 in protein content. 



Effect of Climate. 



"It is pretty well understood that the shorter the ripening period is, 

 the higher the protein content will be. The protein material of the wheat 

 berry rs elaborated first, and during the remainder of the period, starch 

 is accumulated. Hence we have a large percentage of starch in wheat 

 produced where the ripening period is long and cool, and a low starch 

 and high protein content in wheat produced in a short ripening period. 

 It is a well known fact that when we prolong the period of ripening by 

 applying irrigation water, we obtain a berry of low protein and high 

 starch content. 



"Our climate data show that the ripening period in California is 

 both longer and cooler than it is in Kansas. In South Dakota the ripening 

 period is shorter than that of California and Texas, and longer than that 

 of Kansas. The Texas ripening period is shorter than that of California 

 but longer than that of either of the other two stations. Kansas has 

 the shortest ripening period and produces the highest protein content in 

 wheat. South Dakota, Texas and California, in the other named, have 

 tixe next shortest ripening periods, and produce wheat vs^ith protein con- 

 tents varying uniformly, the shorter periods always producing the highest 

 protein content. The reports of the weather bureau show occasiona. 

 £[ight variations from the above enumerated features of the ripenij ; 

 periods; but the general average is as stated. 



Acclimated Seeds. 



"In all cases where the yield is recorded, the continuously-grown 

 seed produced from 1.5 to 5 bushels per acre more than the seed brought 

 from a distance. For example, in Texas in 1907, the Texas seed yielded 

 12 bushels, the Kansas seed, 10.68 bushels, and the seed from California 

 produced only 8.32 bushels per acre. These are yields of the winter wheat 

 (Crimean). In the same year, the Kubanka spring wheat grown at South 

 Dakota produced the following yields; continuously grown seed, 20.6; 

 Kansas seed, 15.16; California seed, 18.83 bushels per acre. In 1908, the 

 results were practically the same, the yield of the continuously grown 

 seed exceeding that of the seed brought from a distance. In other 

 words, our results show that there is no advantage, even in the yield, in 

 bringing seed of a given variety from a distance to replace home-grown 

 seed of the same variety. In fact, there is usually a loss in yield, and no 

 gain in quality. 



Keeping Pure Seed. 



"The points which I have attempted to bring out in this paper refer 

 only to the interchange or introduction of seed of the same variety and 



