112 
Nebraska Agricultural Exp. Station , Research Bui. 20 
NATURAL COMPETITION AS A FACTOR IN CORN IMPROVEMENT 
Competition and survival of the fittest has long been recog- 
nized as a principle in the evolution of living organisms. Inves- 
tigations have been made with two varieties of corn — Hogue's 
Yellow Dent and Nebraska White Prize — to determine whether 
this natural principle might be utilized in the improvement of 
corn. With reference to this principle, corn was planted in 
three rather large plats at the rates of 1, 3, and 5 plants per 
hill respectively. Hills were 44 inches apart each way. 
In the case of Hogue’s Yellow Dent> corn, continuous seed- 
ing at the three rates has been carried on since 1905, and with 
the other variety since 1911. Each year from thirty to fifty of 
the best developed ears produced under the respective planting 
rates were mixed for continuing the seed the next year. The 
seed ears were harvested from the standing stalks to be certain 
that they actually came from plants growing at the specified 
rates. Typical seed ears of the three groups are shown in figure 
20 . 
In addition to the seed increase plats, other plats have been 
planted for determining the comparative yields of the various 
lots. In these yield tests, each of the three lots of Hogue’s Yel- 
low Dent have been compared at the three planting rates, viz, 
1, 3, and 5 jolants per hill. The Nebraska White Prize, on the 
other hand, has been tested for yield only at the rate of three 
plants per hill, which is considered normal for this region. The 
yields per acre are given in Tables 44 and 45. 
As an average for the seven years 1911 to 1917, when the 
Hogue’s Yellow Dent was tested at the normal rate of three 
plants per hill, the seed which had been previously grown at 
the rate of live plants per hill has yielded 0.0 bushel more while 
seed previously grown at the rate of one plant per Hill has 
yielded 1.8 bushels less per acre than the seed grown at the cus- 
tomary rate of three plants per hill. 
In a similar comparison during eight years with Nebraska 
White Prize, the seed previously grown at the rate of five plants 
per hill has yielded 0.2 bushel more while seed from the one 
rate yielded 0.1 bushel per acre less than the seed grown at the 
customary rate of three plants per hill. 
The results obtained from the Hogue's Yellow Dent “com- 
petition" strains when tested at the respective rates of one plant 
and five plants per hill were rather similar to those obtained 
