July i, 1925 Productiveness and Deleterious Characters in Corn 
97 
and the Boone County White varieties. Moreover, these lines had 
been selfed only for four and three generations, respectively. When 
the data are considered as a whole, however, they are in agreement 
with those obtained with the Garrick variety in indicating that lines 
characterized by relatively low numbers of rows on the ears are more 
resistant to smut than those characterized by larger numbers of 
kernel rows. 
RELATION OF VIGOR TO NUMBER OF ROWS OF KERNELS 
Reference already has been made to the selection of selfed lines of 
Cuban Yellow and Boone County White and to the fact that no 
attention was paid to the number of rows of kernels on the seed ears. 
These lines were selected on the basis of their general vigor, freedom 
from abnormality, and productiveness. 
Most of the ears of the Cuban Yellow had 14 or 16 rows of kernels 
when selling was begun. After four generations of selection for vigor, 
without reference to the number of rows of kernels, nearly all of the 
breeding ears had 12 or 14 kernel rows, the 12-rowed class being the 
largest (Table XIII). Most of the ears in the Boone County White 
variety had 16 or 18 rows of kernels when selling was begun. After 
three generations of selection for vigor, without reference to the 
number of rows of kernels, 20 of the 27 breeding ears had 14 or 16 
rows. Thus, selection for vigor and productiveness in the selfed 
lines of both of these varieties has decreased the characteristic number 
of rows of kernels on the ear. 
The seventh selfed generation of the Garrick lines was grown at 
Baton Rouge, La., in 1923, in cooperation with the Louisiana Agri¬ 
cultural Experiment Station. Thirteen of the 108 original selfed 
lines of 1917 were represented in this planting and each oi these lines 
or families was represented by from 3 to 13 ear rows. 
The seed ears representing a family in 1923 varied somewhat in 
regard to the number of rows of kernels in 11 of the 13 families. The 
ear rows of each of these 11 families were classified into desirable and 
undesirable rows according as the plants in them approached the 
normal stability and vigor of open-fertilized corn. This classifica¬ 
tion was based upon a consideration of the culms, roots, leaves, 
chlorophyl, ears, and manner and time of dying. 
Data on the relation of the number of kernel rows on the parent 
ears to the desirability or undesirability of the ear rows grown from 
them are shown by families in Table XIV. The last column in this 
table shows the differences between the average number of kernel 
rows on the parent ears producing desirable and undesirable ear rows 
in each of the 11 families. The parent ears producing desirable 
ear rows had fewer kernel rows than those producing undesirable 
ones in 9 of the 11 families, and averaged 1.52 of a row less in all of 
the rows. 
If the future breeding stocks are selected on the basis of the most 
vigorous and productive ear rows, it is evident that the tendency 
will be to reduce the number of kernel rows on the ears in the families 
with higher numbers until the numbers in all families are about the 
same level. This is in agreement with the change in the number of 
rows in the Cuban Yellow and Boone County White varieties which 
showed the effects of this tendency during four years and three years 
of selection, respectively. 
59836—25f-7 
