Hayes and Garber - Cucurbit Breeding

FARMERS' METHODS OF PRODUCING PURE SEEDS 283
of different strains. Many farmers sustain annual losses, which
are not small, due to using seed of an over-exploited variety
which has not proved its worth in competitive tests. With
many crops, quality is of prime importance and must receive
some consideration if a No. 1 grade product is to be obtained.
Purity. For crops like wheat, oats, and barley, which are
self-fertilized, uniformity is the rule, providing the grower
is willing to pay some attention to eliminating accidental mixtures.
For cross-fertilized crops, of which corn is a good example,
purity of type is of less importance, although certain general
standards of purity are desirable.
Hardiness. Hardiness is a feature of adaptability but it deserves
especial mention. Ability of annual crops like rye and
wheat to withstand winter-killing as well as winter hardiness
for perennial crops such as alfalfa is of high importance and is
generally given much consideration by experimenters before
recommending a particular variety.
Strength of Stalk. Ability to stand up, which obviates injury
from lodging, is of much importance in grain and hay crops. In
small grains early lodging often causes shriveled seeds. The
difficulty of harvesting is greatly increased when the crop is flat.
Disease Escaping or Resistance. Some varieties are much
freer from disease than others. There are various factors, but the
chief ones may be considered under disease escaping and disease
resistance.
Disease escaping may be due to early maturity, as
in the case of Marquis wheat, which often escapes stem rust epidemics
when late varieties such as Bluestem are seriousty injured.
Disease resistance is the condition which obtains when the
organism gains entrance to the plant yet causes no appreciable
injury. There is, for example, a distinct tendency for durum
wheat to be resistant to stem rust; some durum strains being
much more resistant than others.
The above are some of the important agronomic or horticultural
characters which separate one variety from another. By a knowledge
of these the grower is enabled to obtain the best available
strain for his conditions. Seed of this selected variety must then
be saved in such a manner that it will have germinating ability,
i.e., will grow vigorously. In order to do this the seed must be
mature and well developed and free from transmissible diseases.
Freedom from obnoxious weed seeds is also an important consideration.