Hayes and Garber - Cucurbit Breeding

292 BREEDING CROP PLANTS
First Year. (a) Remove from the part
of the field used for
saving tubers all plants which show evidences of diseases.
should be done during the growing season.
This
(b) At harvest time dig at least 100 hills by hand, keeping
each hill separate.
(c)
Use tubers from a number of the better hills for the stock
plot the following year.
Second Year. Method I. Plant all good tubers from previous
year's selection of best hills in a bulk seed plot. Enough tubers
should be used to plant about J acre. This requires approximately
5 bushels, which allows some tubers to be discarded.
Method II. This is the hill-to-row method. In order to
compare the productive capacity of each selected hill it is desirable
to have each row the same length and planted from the
same total weight of potatoes. All of the progeny of some hills
will be discarded this second year. Those that give a good yield
and are desirable in other ways may be further tested.
Third Year. Method I. Continue the stock plot by the same
means as used in Method I for the second year's work, and use all
good tubers produced each year in this seed plot for field planting.
This work may be continued each succeeding season by the same
plan.
Method II. Make a further test of the best selections as
determined by the second year's test, growing much longer rows,
thus obtaining more reliable results. All tubers free from disease,
of the best yielding strain or strains, may be used to increase
the stock the following year.
The essential features of these two methods are presented on
page 291 in diagrammatical form. Method II probably is
somewhat better if all details of the test are carefully performed.
For the average farmer, Method I is less cumbersome and if
constantly practiced would probably give about as good a result
as Method II.
IMPROVEMENT BY SELECTION OF SUCH CROPS AS
CLOVER, AND GRASSES
ALFALFA,
Obtain, if possible, a variety which is especially adapted to the
conditions. Breeding work should aim at producing a variety
which excels in resistance to winter injury and to plant diseases
and is also a high producer of hay and seed.