! * :: 
ri f 
Julyl, 1925 
CEHEAL investigations. 
Productiveness and Deleterious Characters in Com 
93 
Table X .—Effect of selecting for numbers of rows of kernels upon number of ears 
per bearing plant , and length and diameter of ears> in selfed lines of Garrick 
grown at Florence , S. C., a and Rosslyn, Va., in 1921 
Kernel 
rows on 
Total progeny 
studied 
Ears per 
Average 
length of 
total ears 
Average 
diameter 
Yield 
index 
(AX&) 
parent 
ears 
Number 
of plants 
Number 
of ears 
plant 
per bear¬ 
ing plant 
(A) 
of ears 
m 
8 
1,091 
2,366 
2.17 
Inches 
13.21 
Inches 
1.48 
Inches 
28.94 
10 
1,742 
3,493 
2.01 
12.86 
1.58 • 
32.10 
12 
1, 587 
2,944 
1.86 
12.67 
1.68 
35. 76 
14 
1, 757 
1,348 
3. 209 
1.83 
12.13 
1.75 
37.15 
16 
2,091 
1.55 
9.92 
1.81 
32.50 
18 
867 
1,335 
1.54 
9. 76 
1.85 
33.40 
• The data at Florence, S. C., were obtained in cooperation with the Pee Dee Substation of the South 
Carolina Agricultural Experiment Station. 
The number of ears per plant tended to be inversely proportional 
to the number of rows on the parent ear and directly proportional to 
the length of ear per plant. The length of total ears per bearing plant 
tended to be inversely proportional, and the average diameter of ear 
tended to be directly proportional to the number of rows on the 
parent ears. The yield indexes were largest in the two middle classes 
for number of rows of kernels. The classes with 16 and 18 rows have 
larger yield indexes than the classes with only 8 or 10 rows. The 
yield indexes are based only on bearing plants and the differences are 
small. Inasmuch as the percentage of barren plants (Table XI) was 
materially larger in the classes with more kernel rows, the acre yield 
of the f ewer-rowed ears evidently was larger. This agrees, in general, 
with the data previously presented from open-fertilized corn. 
RELATION OF DELETERIOUS CHARACTERS TO NUMBER OF ROWS OF KERNELS 
Many abnormalities occur among corn plants in lines that have 
been self-fertilized in successive generations. Some of these are 
eliminated by selection and others become more or less fixed and 
characteristic of individual hereditary lines. All of these abnormal 
characters have a more or less deleterious effect upon yield. 
After five generations of selfing and selection for different num¬ 
bers of kernel rows, data were obtained on the proportion of plants 
in the different Garrick lines having certain deleterious characters. 
The characters considered were: Plaited and erect leaves, entangled 
leaves, chlorophyl blotch, dead blotch, red and yellow flame, and 
barrenness. The dead blotch and the red and yellow flame char¬ 
acters both result in the premature death of the plants having them. 
The data were obtained on a total of 4,013 plants in 158 ear rows 
grown in cooperation with the Pee Dee Substation of the South 
Carolina Agricultural Experiment Station, at Florence, S. C., and 
on 3,167 plants in 105 ear rows grown at the Arlington Experiment 
Farm, ftosslyn, Ya. Notes were taken on all of the deleterious 
characters in the experiment in South Carolina, but in the experi¬ 
ment in Virginia barrenness and red and yellow flame were the only 
ones noted. A summary of the data from these experiments, in 
so far as they relate to the present problem, is shown in Table XI, 
the data, being grouped according to the number of rows on the 
parent ears. . 
