RELATION OF SIZE OF HEAD TO YIELD, ETC. 



Ill 



Table 32. — Summary of yield and nitrogen content of grain, tabulated according to length of 



growing period. 



Plants grouped according to 

 date ripe. 



Julv 7 to 11 



Julv 11 to 15... 

 Julv 15 to 19 . . . 

 Julv 19 to 23... 

 July 23 to 27 . . . 

 July 27, or later 



Num- 

 ber of 

 anal- 

 yses. 



49 

 65 

 50 

 56 

 52 

 83 



Average 

 date ripe. 



July 8. 9.. 

 July 13... 

 July 16. 2. 

 July 20. 1. 

 July 23. 2. 

 July 27. 2. 



Yield 



(grams). 



9.9067 

 7.6611 

 5. 1354 

 6.5399 

 4.9015 

 4.6636 



Percent- 

 age of 

 proteid 

 nitrogen. 



2.69 



2.81 

 2.87 

 2.93 

 2.93 

 2.94 



Weight 

 of aver- 

 age 

 kernel 

 (gram). 



0. 02024 

 . 01887 

 .01869 

 .01886 

 .01878 

 .01992 



Proteid nitrogen 

 (gram) in — 



Kernels. 



0. 26475 

 . 20820 

 . 14452 

 . 18064 

 . 136.54 

 . 12854 



Average 

 kernel. 



0. 0005356 

 .0005290 

 .000.5222 

 .000.5482 

 . 0005544 

 .0005800 



Table 33. — Summary of nitrogen content, etc., tabulated according to yield per plant. 



Plants grouped according to 

 yield (in grams). 



Below 1 



1 to 2.5 



2.5 to 5 



5 to 10 



10 to 15 



15 to 20 



More than 20 



Num- 

 ber of 

 anal- 

 yses. 



31 

 67 

 88 

 94 

 52 

 20 

 4 



Average 

 date ripe. 



July 20. 2. 

 July 21. 9. 

 Julv 20... 

 Julv 18.3. 

 July 15. 1. 

 July 15. 1. 

 July 14.5. 



Yield 

 (grams). 



0.6049 



1.7673 



3. 5683 



7. 6706 



12. 2.573 



17. 1908 



23.7186 



Percent- 

 age of 

 proteid 



nitrogen. 



Weight 

 of aver- 

 age 

 kernel 



(gram). 



Proteid nitrogen 

 . (gram) in — 



Kernels. 



2.91 0.01683 0.01731 



3.09 

 3.03 



2.68 

 2.71 

 2.54 

 2.55 



.01852 

 .01796 

 .01997 

 . 021.68 

 .02103 

 .021.59 



.0.5456 

 . 10794 

 . 20270 

 . 33433 

 .43921 

 . 60401 



Average 

 kernel. 



0.0004916 

 .0005730 

 . 0005445 

 .0005351 

 .0005774 

 .0005382 

 .000.54.50 



Table 3-4. — Summary of yield, etc., tabulated according to nitrogen content. 



Plants grouped according to 

 percentage of nitrogen. 



Below 1.5. . . 

 1.5 to 2 



2 to 2.25 



2.25 to 2.5... 

 2.5 to 2.75... 

 2.75 to 3 



3 to 3.25 



3.25 to 3.5... 



3.5 to 4 



More than 4 



Num- 

 ber of 

 anal- 

 yses. 



18 

 47 

 82 

 67 

 47 

 20 

 23 

 25 



Average 

 date ripe. 



4 Julv 

 2.5 Julv 



Julv 

 Julv 

 July 

 Julv 

 July 

 July 

 Julv 

 July 



22.5. 



18.5. 

 19.8. 



17.3 

 16.3 

 19.6 

 21.2 

 20.7 

 21.5 

 19.5 



Yield 



(grams). 



5.8099 

 2. 7423 

 8. 9.542 

 7.3389 

 8.0817 

 5.9093 

 4.4497 

 4.67.56 

 3. 6486 

 4.. 5431 



Proteid nitrogen 

 (gram) in— 



Kernels. 



0.07290 



.11620 

 . 19070 

 .18478 

 . 21280 

 . 16609 

 . 13847 

 . 15189 

 . 13513 

 .21239 



Average 

 kernel. 



0. 0002266 

 .0003867 

 .0004325 

 . 0004773 

 .0005102 

 .0005454 

 . 0005667 

 .0006213 

 . 0006807 

 .0008639 



RELATION OF SIZE OF HEAD TO YIELD, HEIGHT, AND 



TILLERING OF PLANT. 



The size of the head has always been considered to be closely con- 

 nected with the productiveness of wheat. The well-know^n work of 

 Hallet in increasing the yielding qualities of wheat is perhaps the 

 best example of wheat improvement by the selection of plants having 

 large heads. Whether large heads or a large number of medium- 

 sized heads on a plant are more desirable is still a question. 



Table 35 gives the yields, etc., of between 300 and 400 plants, tab- 

 ulated according to the number of kernels on the head. Table 36 

 is a summary of these, while Tables 37 and 38 consist of the same 

 data tabulated according to the yield per plant and yield per head, 

 respectively. 



