Hayes and Garber - Cucurbit Breeding

RESULTS OF SELECTION WITH SELF-FERTILIZED CROPS 131
As shown by the last column of the table, only two of the
thirteen pure lines gave lower average yields than the commercial
variety for the four-year period. They are Nos. 15 and 35.
Among oat selections (Anonymous, 1919) which have proved
their practical value may be mentioned Iowa 103, Iowa 105, and
lowar, all of which are pure-line selections from Kherson. These
selections were made by Burnett at the Iowa experiment station.
SELECTIONS IN OTHER SELF-FERTILIZED CROPS
An exhaustive account of the work that has been done in
isolating and testing pure lines of self-fertilized crops would
alone make a large volume. In this somewhat brief treatment
only a few typical examples are chosen.
The Iron cowpea (Orton, 1911), which is resistant to wilt,
is one of the notable examples of what has been accomplished
by the introduction of a promising variety. The isolation of
this form alone has produced thousands of dollars for the farmer.
M. A. C. Robust bean (Spragg, 1919), which is a selection out of
the ordinary navy bean, has proved to be very much superior
in yield to the commercial variety. At the Svalof Experiment
Station (Newman, 1912), in Sweden, progress has been made in
isolating pure lines of barley which possess superior brewing
qualities.
These few examples show the value of selection as a means
of crop improvement. The effect of selection is to isolate the
more desirable types from the commercial variety. After this
has been accomplished, crossing may be resorted to as a method
of obtaining a variety which combines the desirable characters of
several strains.