1904.] 



Quality in Wheat. 



333 



the same time, showed no such improvement. All this goes to 

 show that the nitrogenous constituents which had reached the 

 grain at harvest time were not in a state to confer strength in 

 the flour, but underwent some such gradual change during storage 

 as takes place more definitely and rapidly under the climatic 

 conditions prevailing where the strong wheats are grown. 



Although the main problem of the cause of "strength " is still 

 unsolved, it is clear that for the purposes of a selecting test 

 among a number of new varieties, grown side by side, it will be 

 sufficient to determine the total nitrogen. The total nitrogen, 

 as we have seen, fails to measure " strength " in any absolute 

 sense, but when wheats are grown under the same conditions, 

 the order of their nitrogen content will be the order of their 

 strength, or very nearly so. At any rate, it will be quite 

 possible to discriminate between the really strong wheats and 

 those which show no advance on the varieties commonly grown, 

 and the determination of total nitrogen can be rapidly made on 

 quite a small quantity of grain. It will not even be necessary to 

 grind the wheat into flour, as a fairly constant relation appears 

 to exist between the nitrogen content of the grain and of the 

 flour resulting from it as long as one is dealing with wheats 

 growing under similar conditions. Table VII. shows a series 

 of comparative analyses of the whole grain and of the flour 

 derived from it. 



In this way the immediate object of the investigation from 

 the agricultural point of view has been attained ; it has become 

 clear from the field experiments that no wheat exists at present 

 which satisfies the millers' requirements for strength, and yet 

 yields as well as the standard English varieties. But as 

 " strength " proves also to be congenital in certain varieties of 

 wheat, it is evident that new varieties can be bred both for 

 " strength" and yield combined, provided enough seedlings are 

 tried and selection is based upon " strength " as well as upon 

 yield. In such a selecting test a determination of the total 

 nitrogen in the grain, as compared with that present in the 

 grain of some standard variety grown under the same conditions, 

 will be found both convenient and accurate enough for a first 

 approximation. 



A. D. Hall. 



The Roshamsted Experimental Station. 



