YIELD OF NITROCIEN PER ACRE, 75 



It would seem from these results that the quality of lightness, 

 with its correlated qualities of high total and proteid nitrogen, is 

 hereditary. The question then arises, Why should the light wheat 

 accumulate more nitrogen per acre than the heavy wheat after the 

 first generation ? 



A possible explanation for this is that the light seed from the fii'st 

 preneration contained kernels whose lightness was due in some cases 

 to immaturity, and in other cases to the individual peculiarity of the 

 plant on which they grew. The latter class transmitted this pecul- 

 iarity in the crop, while the former became less conspicuous with 

 each generation, on account of the lesser vitality and productiveness 

 of the immature seed. 



A peculiar feature of these results is found in the fact that the 

 yield of grain from the light seed approaches each succeeding year 

 more nearly in quantity to that obtained from the heavy seed until, 

 in 1903, it becomes greater. These two qualities of seed were 

 raised on plots side by side, and every precaution was taken to obtain 

 an accurate estimate of the yield of each. While it is probable that 

 the results for 1903 are misleading, it is certainty significant that so 

 little difference in yield exists after three years' selection in this way. 

 Instead of the difference between the light and heavy seed becoming 

 greater each year it is without doubt becoming less. 



In considering the relative yields of the light and heavy wheat, it 

 must be borne in mind that the seeding was done with a drill set to 

 deliver 1^ bushels per acre of ordinary seed wheat. The result 

 would be to deposit a larger number of kernels of light seed per acre 

 than of heavy seed. In a season like that of 1903, when the rainfall 

 was large and the weather moderately cool until harvest, there 

 might be an advantage resulting from the thicker seeding, which 

 may account for the greater yield from the light seed in that year. 



It is possible that the same cause ma}' have operated in other 

 years to increase the yields from the light seed, but it is not likely 

 that it produced a very marked effect, because the seeding was a large 

 one for Nebraska, and, the wheat being sown in the ear\j fall, there 

 was abundant opportunity for it to stool, and thus equalize the stand. 

 It has never been observed that there was any difference between 

 the plots in this respect. 



Taking, together, the results of 1902, which show a decrease in 

 the weight of the kernels on a single head as the content of proteid 

 nitrogen increases, the results of 1903, which show a slight decrease 

 in the weight of the kernels from the plant, accompanying an increase 

 in the percentage of proteid nitrogen, and the yields of the light and 

 heav}^ seed for the four years beginning with 1900, there would 

 appear to be a plight decrease in yield of grain, accompanying an 

 increase in the percentage of proteid nitrogen. This loss in yield is 



