CORN BREEDING 
29 
Under what may be called the direct method of ear-to-row selec- 
tion, the plat is gone over every day or every other day during the 
tasseling period and alternate halves of alternate rows are detasseled. 
Thus, the tassels are pulled from the plants in one end of rows 1, 3, 
5, etc., and from the plants in the other end of rows 2, 4, 6, etc. The 
tassels are pulled as soon as possible after they appear, and before 
they begin to shed pollen. Just before harvest the better ears from 
the better detasseled plants in each row are picked for possible use 
as seed, the ears from each row being kept separate. The plat is then 
harvested and the yield of each row determined. The best 6 to 10 
ears from detasseled plants in the 10 to 15 more productive rows are 
used for the next year's ear-to-row plat. The other seed ears from 
the more productive rows are shelled together and the seed used to 
plant a multiplying plat from which seed is selected for general 
planting. 
Under the remnant method the ear-to-row plat is a test plat in 
which to determine the relative value of the different ears. Only a 
part of the seed from each ear is planted in this plat. The remnant 
seed of the few best ears then is used for planting a multiplying 
plat the following year. The remnant seed of the one to three highest 
yielding ears is used to produce pollen-parent plants, the seed from 
the second-best producing ears being used to produce pistillate- 
parent plants. These two lots of seed are planted in such a way that 
there will be one row of pollen-parent plants alternating with one, 
two, or three rows of pistillate-parent plants. The latter are de- 
tasseled before they shed any pollen, so that the seed produced on 
them is pollinated by pollen from the pollen-parent plants. Only 
the seed from the detasseled plants is used for general planting, 
ears being selected from the general field for another ear-to-row plat. 
EESULTS OF EAR-TOEOW SELECTION 
As already noted, ear-to-row corn breeding came into immediate 
prominence. The method seemed fundamentally sound. The earlier 
results showed wide differences in the productiveness of the seed 
from different ears. Later, the yield of seed from high-yielding 
ear rows was shown to be larger than that from low-yielding ear 
rows or from mass-selected seed. As a consequence nearly all of 
the agricultural experiment stations and many seedsmen and farmers 
took up ear-to-row breeding. 
Table 2. — Average oil and protein content of corn of four selected strains and 
of the parent variety in Illinois 
[Data from the Illinois Agricultural Experiment Station (28, p. 193-194)} 
Designation of variety and strain 
Years 
Oil con- 
• tent 
Protein 
content 
High-oil strain 
Low-oil strain 
High -protein strain 
Low-protein strain 
Burr White (parent variety). 
1911 to 1915. 
do 
do 
do. 
Per cent 
8.02 
2.03 
Per cent 
14.53 
7.74 
10.92 
