The Anderson intelligencer. [volume] (Anderson Court House, S.C.) 1860-1914, 1874-09-03
Bust in Cotton.

| Professor Stubs. Of the Alabama Agricul-
! tural College, says true rust is fungus growth
similar in It's nature to smut mildew, ETC. In
examining with the microscope the various
$50 called rusts'' we find them entirely unlike
in different sections. We have found but little
information on this subject, but since il is a
source Of much evil to the Southern planter,
perhaps it may yet elicit some attention from
the celebrated botansts and entomoloSlsts OF
the present day. BY examining some leaves
of cotton we find that they have been changed
to a bright yellow, tingel here and there with
red, and with occasional marks of brown. On
others we find rusty brown spots on the under
side resembling inr pient rust-%hlle again on
others we find yellow surfaces with little or no
appearance of vitality, edges curlcd up, and
whole leaf seeming withered and dead. The
first under the microscope gives no marks OF
an insect on any part of the leaf-the growth IS
vegetable, a real fungus, and is The true rusC.
With q powerful microscope we find the second
to be the work of a minute red spider (genus
acarus) which attacks the under side of the
leaves, puncturin@ them until they are stunS
and spotted all over and finally fall from the
plant. The third is caused by the cotton louise
"a species of aphis) which pierces the outer
coating Of the leaves on the under side. From
the constant drainage OF the sap by this insect,
the leaves arc enfeeblcd, curl up, turn yellow,
and finally fall. Later in the season young
shoots arc also attacked and arc often COM
plctely covered by these pests.
l3u. Uncre is anOlnCr Gllcctloll VI lliC CottOl
plant, which is found very prevalent in alluvial
bottoms, and sometimes in uplands. Ii is
usually improperly styled 'black rust," but in
reality is species Of blight. an Intelligent
observer thus describes it: This blight ap-
pears very suddenly. Que day all of the plants
of 4 field may seem to be perfectly healthy and
vigorous, while on passing through the same
field Oh the next day many OF them may be
observed with dropping leaves, as if affected
by the heat OF a midday sun. y few days
thereafter all the leaves will wither and fall to
the ground, leaving the stem bare though still
green and the ready formed, and in some cases
fully matured, opening bolls adhering to the
branches. After remaining III a state OF appa-
rent lifeeSsnesS for some time, should ram anG
favorable growing weather follow, the affected
pn. will often send up suckers FROM the crown
of the roots, and even sometimes young snootS
from the iuuctures of the branches with the
steln." This is the blight, and glance will
show q wide difference from the "red rust.
In the latter the leaves turn yellow and are
blurred with red, while in the former they
suddenly withcr and droop without changing
to yellow, then turn brown and black, and fall.
The bolls also shrivcl, dry up, and the whole
plant gradually dies.
1 have not been able to observe this plant
throughout all stages Of the disease but on eX-
amining all old blightcd plant, and dividing
longitudinally the stem, L found u black or
brownSh appearance presented by the plth and
hear! Of main root, stem and branches ust as
if the centre was rotten. This may be the proX-
innate cailse Of the whitening of the leaves. On
examination, no insects nor their punctures
could DO disccrned. 1t is obvious then that
the whole plant IS in 4 state of disease which
most probably is caused by the excess of some
vegetable acid. by the deficiency OF some
chemical clement in the soil necessary to health
and perfection Of plant, or perhaps by tap root,
penetrating INTO hard, sour or otherwise un-
favorable subsoi. In examining the soils
which rust cotton, we find no excess Of veg
etabe acid, but we do find sad deficiency of
sulphuric acid, Il substance so essential to the
full maturity Of every plant, and subsoll
whose mechanical condition is such as to pre-
clude the hcathiul growth Of a tender root.
Again, we learn from intelligent farmers that
fields freshly cleared will not rust cotton until
third or fourth year. by this time the small
amount of sulphuric acid is exhausted, soil
s,lrchanged with the eXcrctory vegetable acids
left in soil by continuous cultivation of same
crop and the subsoil baked and hardened by
descending rains and hot suns which easily
penetrate the porous, cultivated top soil. This
being then the probable cause of rust, to pre-
vent this we should seek to supply our lands
with sulphuric acid rotate our crops, and tho
roughly undcrdrain and subsoil our lands.
Sui phuric acid is most economically applied in
form Of suphatc lime Gland plaster) or sui
Dhate iron (cOppCraS).