104 



IMPROVING THE QUALITY OF WHEAT. 



TABLE 30. Summary of yields of plants, arranged according to percentage Icilled in each family. 



YIELD AND NITROGEN CONTENT OF GRAIN AS AFFECTED BY 

 LENGTH OF GROWING PERIOD. 



Early-maturing varieties of wheat are, in general, better yielding 

 sorts in Nebraska than are later maturing ones. There are some 

 exceptions to this rule, however, Turkish Red yielding better than 

 any earlier maturing variety. The advantages from early maturity 

 have usually been ascribed to the cooler weather and greater supply 

 of moisture that obtain in the early summer. The hot, dry weather 

 common in July is thought to prevent the filling out of the kernel and 

 to cause light yield and light volume weight. 



Each wheat plant on the breeding plots was harvested separately 

 in 1903, and a record was kept of the date of harvesting of each of 

 these plants. These data have been tabulated for the purpose of 

 showing the relation between the length of the growing season and 

 the yield of grain from individual plants of the same variety. 



Table 31 contains these data, tabulated according to the date of 

 ripening. Plants ripening between the 7th and llth of July, 1903, 

 form the first class, those ripening between July 11 and 15 the second 

 class, and the succeeding classes increase by four days until July 27, all 

 ripening after that date constituting the last class. The dates of 

 ripening thus extend over a period of three weeks. 



The season of 1903 was a very wet and cool one. The effect of 

 this upon the wheat crop is shown by the fact that the crop in the 

 field was not ready to harvest until July 10, while usually it is har- 

 vested between the 20th and 30th of June. Even at the close of the 

 ripening period the weather did not become dry or hot as compared 

 with the normal season. It will therefore be seen that the ordinary 

 advantages from early maturity did not obtain, or at least not in the 

 customary way. It may also be said that some of the later maturing 

 wheats yielded as well in 1904 as did the Turkish Red. 



Table 32 is a summary of Table 31, with a statement of the average 

 for each class. 



Table 33 is a summary of the same plants, tabulated according to 

 the yield of grain per plant. 



