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UNITED STATES DEPARTMENT OF AGRICULT 
Washington, D. C. March 21, 1925 
A STATISTICAL STUDY OF THE RELATION BETWEEN SEED-EAR 
CHARACTERS AND PRODUCTIVENESS IN CORN 
By Freprrick D. Ricury, Agronomist in Charge of Corn Investigations, and 
J. G. WiLuiER, Assistant Agronomist, Office of Cereal Investigations, Bureau 
of Plant Industry 
CONTENTS 
Page | ge 
Previous investigations__.-_---..--~---2----2 1 | Correlations between the ear characters and 
Material and-methods: 22222 es Ses ee 3 VICL Geo. k= SSS el g Sie es ee 12 
Bar-rowiplats..c so Jas Pe AUS 3 Coefficients of the zero and first orders___ 12 
DViaTLe LIES ere eaten Aten a eT a 3 Coefficients of multiple correlation______- 15 
Waariai les esc) oe ee ee EET) IS PISSY OYE em ern wo aoe ee eee 16 
Methods of computation___________..__- OF | SMM ary ets. eo rrr ya peek ee 17 
Basis. of inteEpretation= =... 5--. + .---2 9s Literaturecited=. 2-4-2 ee 19 
Correlations among the ear characters------- 10 
PREVIOUS INVESTIGATIONS 
The question of a possible relation between the physical characters 
of seed ears and productiveness is an important one in corn breeding 
and has been given much attention. Earlier investigations have been 
reviewed in detail (7)! and need be considered but briefly. The 
conclusion reached by investigators using data from ear-row plats 
has been practically unanimous that slight differences in the physical 
characters of good ears were of no value in determining their produc- 
tiveness. This conclusion unquestionably was warranted on the 
basis of the individual studies. Nevertheless, when the data are 
considered as a whole certain trends are apparent. Thus, most of 
the comparisons were in favor of the heavier, longer, fewer rowed 
ears and those with a lower shelling percentage or smoother indenta- 
tion. It should be noted that many of the differences are not statis- 
tically significant and that all are negligible practically. The real 
evidence consists in the preponderance of small differences in 
productiveness among ears that already were above the average of 
their respective varieties, at least in weight, length, and circum- 
1 The serial numbers (italic) in parentheses refer to ‘‘ Literature cited,” at the end of this bulletin. 
22050°—25;——-1 
