SEED-EAR CHARACTERS AND PRODUCTIVENESS IN CORN 3 
MATERIAL AND METHODS 
A project for the production of improved varieties of corn for the 
different geographic sections of the United States was carried by 
the Bureau of Plant Industry of the United States Department. of 
Agriculture for many years. [Ear-row selection was conducted 
in a number of localities in connection with this project, and records 
of the individual productiveness of several thousand ears of corn 
were obtained, As measurements of the seed ears were recorded, 
the accumulated data are well suited to a statistical study of the 
relation between seed-ear characters and productiveness. 
EAR-ROW PLATS 
The same general plan was followed in all of the plats, though 
the details differed. Each ear was used to plant an individual row. 
The tassels were pulled from the plants at one end of each row before 
pollen was shed, the detasseled halves being at the opposite ends 
of adjacent rows. At harvest time each row was husked, and the 
weight of ears was recorded, with such other data asseemed desirable. 
Seed ears were selected from the detasseled plants of the higher 
yielding rows for the next year’s planting, additional ears being 
selected from the general field in some seasons to avoid too close 
breeding. The plats were grown under conditions that were reason- 
_ ably uniform. The rows were the same length for any one season 
1 ria 
and variety. More seeds were planted than the number of plants 
desired, and the plats were thinned later to the final stands. 
VARIETIES 
Data were used from experiments covering from 9 to 14 years 
with each of four varieties, comprising 3,265 ears in all.2 They 
were chosen because they represented more or less distinct types 
erown in different environments and were more continuous over a 
longer period than for the other varieties. Brief notes on each 
variety follow. 
Cereal Investigations (C. I.) No. 77 originated in 1880 as a cross and has been 
kept pure since that time. It is a white dent variety with white cobs. The 
plants are 9 to 10 feet high and require 120 days to mature. The ear-row plats 
were on productive bottom lands of the Scioto River near Piketon, Ohio, from 
1907 to 1920, inclusive. The size of the plats differed from year to year, the 
extremes being 30 rows in 1911 and 199 rows in 1920. Data on 1,230 ear rows 
were used. The ear rows were not planted in duplicate. 
Cereal Investigations No. 119 is a selection from Boone County White. It is 
a large-eared white dent corn with white cobs. It has been kept pure since 1880. 
The plants are 8 to 10 feet high and require at least 120 days to mature. The 
ear-row plats have been located at various places near Washington, D. C., from 
1907 to 1918. ‘The number of ear rows ranged from 26 in 1909 to 73 in 1914, the 
total for the period being 621 rows. The ear rows usually were planted in 
duplicate. 
Cereal Investigations No. 120 originated as the cross Hickory King X C. I. 
No. 119, made at Arlington, Va.,in 1902. Since that time it has been kept pure. 
The kernels are broad, white, and rather flinty. The plants are about 7 feet 
high and require about 120 days to mature. The plats were located near Round 
Hill, Va., from 1907 to 1918. The plantings were all made in duplicate. The 
4 The records on which these studies are based were made by H. H. Biggar, E. B. Brown, G. J. Burt, 
as age J. M. Hammerly, C. P. Hartley, C. H. Kyle, F. D. Richey, H. M. Steece, C. E. Trout, 
and J. G. ier, 
