20 IMPROVING THE QUALITY OF WHEAT. 



up at that time is, he says, used later for the development of the 

 grain. 



It is too well known to require substantiation by experimental 

 evidence that the yield of grain per acre and the weight of the indi- 

 vidual kernel increase as the grain approaches ripeness. It is there- 

 fore quite evident that immaturity, although resulting in a higher 

 percentage of nitrogen in the wheat kernel, would curtail the pro- 

 duction of nitrogen by the crop, and, furthermore, that the produc- 

 tion of proteids would be still further lessened by reason of the 

 greater proportion of amid substances present in the grain at that 

 time. 



INFLUENCE OF IMMATURE SEED UPON YIELD. 



Georgeson a selected kernels from wheat plants that were fully ripe, 

 and from plants cut w^hile the grain was in the milk. He seeded these 

 at the same rate on 2 one-tenth acre plots of land. The immature 

 seed yielded at the rate of 19.75 bushels per acre of grain and 0.8 ton 

 of straw, while the mature seed produced 22 bushels of grain and 

 1.04 tons of straw per acre. Georgeson says that in a similar experi- 

 ment the previous year the difference in favor of the mature seed 

 was still more pronounced. 



Although the evidence is limited, it may safely be considered that 

 the use of immature seed will result in a smaller yield of wheat than 

 if fully ripe seed be used. 



INFLUENCE OF CLIMATE UPON COMPOSITION AND YIELD. 



Lawes and Gilbert b state that "high maturation in the wheat crop 

 as indicated by the proportion of dressed corn in total corn, propor- 

 tion of corn in total product (grain and straw) , and heavy weight of 

 grain per bushel, is, other things being equal, generally associated 

 with a high percentage of dry substance and a low percentage of both 

 mineral and nitrogenous constituents." This is based upon the 

 wheat crops at Rothamsted for the years 1845 to 1854, inclusive. 



More recent publications c by these investigators reaffirm their 

 belief that the composition of the wheat kernel depends more largely 

 upon the conditions that affect its degree of development than upon 

 any other factor. They found almost invariably that a season that 

 favored a long and continuous growth of the plant after heading, 

 resulting in a large yield of grain, a high weight per bushel, and a 

 plump kernel, produced a kernel of low nitrogen content. 



a Abstract, Experiment Station Record, 4, p. 407, from Kansas Experiment Station 

 Bulletin 33, p. 50. 



b On Some Points in the Composition of Wheat Grain, London, 1857. 



c Our Climate and Our Wheat Crops, London, 1880, and On the Composition of the Ash 

 of Wheat Grain and WTieat Straw, London, 1884. 



