Okolona messenger. (Okolona, Miss.) 1900-current, 1908-11-25

of fuSnrinm stage from NuttF udIh VI NNN'
stem; b, hyphae and microconidia from YES
sells OF freshly wltcd stem; Q, chamydospores
from bark of root d, brightSred peritheeia
from root of dead plant; e. asci and ascos
pores borne in the perlthecla,
that as a general rule the large-bou
F, sorts, Russell, Truitt etc, are more
subject 10 wilt than other groups OF
varieties. The most resistant OF the
American Upland varieties tested was.
the Jaskson Limbless, which produced
about 40 per cent of crop where
other kinds failed. The original Jack
son was not sufficiently resistant to
| Justify its general cultivation, but 1t
has been of value as basis for breed
ing better races.
Egyptian cotton is more resistant to
wilt than Upland cotton, but it has
not as yet been found practicable TO.
utilize this quality, as the Egyptian
varieties do not succeed in our South
eastern States and it is easier TO breed
resistance direct from Upland varie-
ties than from crosses with Egyptian
cotton.
The individual differences in cotton
plants have been utilized as basis
| for breeding new resistant strains.
The work of the Bureau of Plant In
dustry has now been continued along
this line for eight years, and has re-
suited in the successful development
of two new varieties that can be
grown on the worst infected land. pro-
vided a rotation of crops for the con-
troll of root-knot is practical.
| The development of such varieties
however, is neither quickly nor easily
accomplished, but requires breeding
by exact methods for several years.
1t will not suffice to send pickers
through the fields to gather seed cot
ton from apparently resistant plants,
as some have recommended. Our ex-
perience has been that such mass Sc
lection is expensive and ineffective.
Much of the seed obtained 10 taken
from plants not truly resistant, ana
the succeeding crop is nearly as much
diseased as the first While such a
method should result in increasing
the resistance of the crop in the long
run, the cross-pollination between re-
sistant and nonresistant plants greatly
delays the results. The correct
method is to select with great care
small number of plants that appear
to be healthy, though growing in the.
worst infected areas. The seed from
each of these plants must be kept
separate and planted in parallel rows
on infected land the next year. The
resulting progeny will show which of
the plants selected transmits the re-
sistant quality in the most effective
manner. The rows will also vary
much in productiveness and other
qualities The best one should be Sc
lected and the other discarded. In
some cases a resistant row of salts
factory quality has been found the
first year, and only two more sea-
sons were required to multiply the
seed. but more often complete success
has not been had at once and the
work had to be repeated.
The origination of new wilt-resistant
varieties is work for the plant breeder
rather than the general farmer, and
there is need for men in every county
to take up the business of breeding
to supply this demand. The farmer.
however, should practice selection to
further improve the strain purchased
from breeders, or at least to preserve
It from deterioration. The Bureau OF
Plant Industry desires to stimulate
the breeding and sale of improved
varieties of cotton. To this end it will
place the varieties already developed
in the hands of men who will improve
them and offer them for sale.