Audubon Republican. [volume] (Audubon, Iowa) 1894-1925, 1908-12-24
IMPROVING POTATOES.
Three Methods for Improving this
Staple Vegetable.

Three methods for improving the po-
tato are in use: "a Crossing desirable
plants and comparing their seedlings
under controlled conditions. (2) Sc
| tecting extreme fluctuations among
the plants and tubers OF a variety. CD
Finding and isolating sudden changes
or mutations.
That advance is possible by the first
method Is admitted from the results
OF Its use by the best breeders Theo-
retically. the new varieties obtained
are merely new combinations of quail
tiles which were held by the germ
cells of the two parents. II our knowl.
edge OF Inheritance in the potato were
adequate, We could make the proper
combination to- obtain what we wish
at win, but at present we can not do
this because our knowledge of mani
fest characters is meager and because
many characters are latent or hidden
in our present varieties and need com
bining with other characters in order
to develop. Therefore, until firm
foundation is laid in the science of
heredity, we can do little more than
make random crosses between varle-
ties known to possess desirable char
acters, and compare their progeny
with great care.
In this comparison 1t Is well to 5e
extremely conservative about drawing
conclusions. Not only should every
condition of environment be made as
uniform as possible, but 1t should be
remembered that there are stages OF
growth during the life of the plant
when surrounding conditions affect it
in different ways. And these dinre.-
ences are not hereditary qualities. For
example. one variety grows rapidly
and its tubers are half grown at
certain time, while at the same time
another variety has just begun to set
It's tubers. A drought at this time kills
the one variety but does not affect
the other. The first, however, may
really be the best variety and hasty
conclusions to the opposite would be
premature.
The real effect of selecting fluctua.
tons within variety (such as select,
ing the heaviest tubers to improve the
yield, is still questionable. 1t seems
definitely settled that the use of dis.
eased and immature tubers as seed
has an injurious effect upon the sue
ceeding crop, but there is no evidence
that planting the best tubers or plant
ing tubers from the best-yielding
plants will increase the yield of the
variety. Such an inheritance would
necessitate the superstition that germ
cells of large tuber have a different
constitution from those of small tu-
Der Of the same variety, and there Is
no warrant for such an assumption.
Wide variations or bud mutations
are rare and have never produced
anything especially valuable. They are
at present more worthy the study of
the scientist than the attention OF the
practical potato breeder.
The universal belief that potato
variety must degenerate through con-
tinued bud propagation appears to
have little ground either in theory or
practice. The degeneration that some
times does take place is due to effects
through the use of tubers which ere
abnormal, from inhospitable soil or
climate, or from the ravages of insects
or fungi on the plants. The old idea
that change of seed is necessary, is
also a mistaken one.-E. M. East