Hayes and Garber - Cucurbit Breeding

FARMERS' METHODS OF PRODUCING PURE SEEDS 291
desirable tubers for planting are produced, there are some methods
which are of help to him in saving
tubers.
tubers is one common cause of lack of purity of type.
Ordinarily the plants grown from tubers of a single plant
are alike except for the occasional changes which occur in the
inherited characters of the plant itself. Mixture in commercial
The selection
of tubers, therefore, gives the grower an opportunity to improve
his variety and also insures a constant supply of tubers free
from diseases. This freedom from disease is a very important
point (Tolaas and Bisby, 1919).
The first step of the grower
is to obtain the best available
variety, true to type and free from disease. After obtaining
such a variety, one of the following plans may be followed. Both
are alike for the first year's work.
DIAGRAMMATICAL ILLUSTRATION OF TUBER SEED PLOT SELECTION OF THE
POTATO
1st year 2d year 3d year
4th
year
4th year