UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1209 
Washington, D. C. T February, 1924 
EFFECTS OF SELECTION ON THE YIELD OF A CROSS BETWEEN 
VARIETIES OF CORN. 
By Frederick D. Richey, Agronomist in Charge of Corn Investigations, Office of Cereal 
Investigations, Bureau of Plant Industry. 1 
. 
CONTENTS. 
Page. Page. 
Basis for the investigation 1 Results of selection within self-fertilized lines. 12 
Results of mass selection 2 Method of selection 12 
Method of selection 2 Method of crossing 13 
Growing seed for comparison 2 Method of comparison 14 
Method of comoarison 3 Experimental data 16 
Experimental data 4 Discussion of data 17 
Discussion of data 10 Conclusions 19 
BASIS FOR THE INVESTIGATION. 
The productiveness of first-generation (Fj) corn crosses and their 
parent varieties has been compared from time to time ever since 
the experiments of Beal 2 in 1876. Although the results of such 
comparisons have shown that many individual crosses could be 
used to obtain increased yields of corn, their commercial utilization 
has not become common. On the other hand, although a frequent 
method of originating new corn varieties has been to cross two 
strains and follow with selection, the question of the relative produc- 
tiveness of the successive filial generations has received little or no 
experimental attention. In 1916 an opportunity was presented to 
study this problem in connection with an investigation of selection 
within self-fertilized lines and its effect on yield. 
In the corn varietal experiment at Armorel, Ark., in 1915 the one 
outstanding strain was the F x generation of the cross WhatleyX 
St. Charles White. This yielded at the rate of 81.9 bushels of air-dry 
shelled corn per acre, in comparison with 72.4 bushels for U. S. 
Selection Xo. 77, which ranked second. St. Charles White, the 
staminate parent, yielded 67 bushels per acre, or 14.9 bushels less 
1 The investigations here reported were conducted cooperatively as follows: From 1915 to 1918, inclusive, 
with Plantation Xo. 1, Lee Wilson & Co.. Armorel, Ark., W. B. Wallace, manager; from 1919 to 1921, inclu- 
sive, with Burdette Plantation, Burdette, Ark., J. F. Tompkins, manager: and in 1920 with W. B. Wallace, 
King, La. The writer wishes to express his appreciation for the facilities furnished him in connection with 
this work and for the manv courtesies shown during its progress. 
" Beal, W. J. Indian corn. In 19th Ann. Rpt. Mich. State Bd. Agr., 1879-80, p. 279- 289. 1>S0. 
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