The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1898-04-07
FARMER AND PLANTER.
COTTON LEAF RUSTS,
The Origin and Cure of Destructive Dis
eases Of the Cotton Plant.

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eases of the Cotton Plant.
The two most common well-known
! and destructive diseases of the cotton
plant are the so-called red rust and
''blac6 rust" A third disease, also
very common, but less noticed, is some
times called yellow rust"
Both red and yellow rusts appear
early in the season, often before the
plants a.'e half grown, but black rust
rarely appears until after the plants
have lowered A long study of these
! diseases as they appear in central
North Carolina has shown the writer
that both red and yellow rusts are due
to unfavorable conditions of the soil
and the weather-never to parasitic
fungi Black rust is ALWAYS due to fun
gus closely related to that which pro-
duces early blight" or brown ring
spot on leaves of Irish potato and
| tomato plants.
Diseases due to soil or weather are
called physiological diseases. For
these the fungicidal sprays. found so
useful in orchard or garden, are of no
| value. Although black rust is fun
gous disease, the use of spray against
, 1t IS not recommended.
The fungus never attacks healthy
leaves, but only those which have been
injured by some other agent. On the
cotton plant black rust always follows
yellow or red rust on the same leaves.
and completes the destruction which
the others began. So. if we can pre-
vent red and yellow rust. there will be
no damage from black rust.
Red and yellow rusts are caused
primarily by a lack of plant food and
OF moisture in the soil. They are most
common and destructive upon old.
Worn and dry soils which are lacking
In vegetable matter. Such soils are al
ways deficient in nitrogen and potash
The diseases may also occur on better
soils during very dry and hot seasons.
and when the soil has been improperly
prepared or the cultivation is wrong.
Red and yellow rusts are nothing
more or less than the premature ripen-
| ing of the leaves When either mois-
ture or inorganic food is wanting. the
leaves dry up, their green coloring mat
ter. chlorophyl, changes by oxidation
into red or yellow coloring mat
ter, consisting of carotin and
Nanthophyl respectively. These latter
coloring matters, unlike chlorophyl,
have no power to break up the GORDON
lc acid of the air OR to elaborate the
crude sap sent into the leaf from the
! root. The leaf itself ceases to be
nourished or to nourish the plant
The leaf withers and the plant starves.
| remains dwarfish and feeble, setting
none or few bolls. This is where the
damage comes in. The remedy for
these two diseases is partly but not
wholly within the control of the cot
| ton planter. 1t may be summarized as
| follows:
1. Deep breaking and shallow after
| cultivation of the soil. to enable it to
absorb and retain moisture.
| 2. Liberal fertilization, especially in
the matter of nitrogen and potash.
| ). The restoration of vegeta BILE mat
ter-humus-to worn soils by blowing
in green crops or carting on stable
manure.
4. A more judicious and moderate
use of phosphate fertilizer. The
| power of acid phosphate to hasten the
| maturity OF the crop is well known to
all cotton growers. But early crops
and small yield are an invariable
sequence in cotton as well as vegetable
| crops.
S. Old worn soils must have their
humus restored by blowing in green
crops or by putting on stable manure.
The best form of concentrated nitro
genous fertilizer for cotton is cotton
| seed meal
The best form Of potash fertilizer is
kainit.
The best form of phosphate is acid
phosphate.
The following formula. originally sug-
gested by the director of the North
| Carolina experiment station, has been
widely used throughout the cotton belt,
and on the average upland soil has in
thousands of eases given admirable re-
suits:
Cotton seed meal 300 to 400 lbs. per acre
Acid phosphate. 400 to 500 lbs. per acre
hainit ACKNOWLEDGEMENTS. 400 to 800 lbs. per acre
NoTE-Soils rich in vegetable matter,
Or which have had a crop of clover or
peas turned under, will require less
cotton-seed meal. Soils very poor in
vegetable matter should never receive
more than 400 pounds per acre Of acid
| phosphate. In no case should less than
| 400 pounds of kainit be given 900
| pounds is not too much), if a maximum
crop is desired
For clover or pea crop use same
| formula. without cotton-seed meal
These crops do not need nitrogen. For
a grain crop give 50opounds cotton-seed
meal, 400 pounds acid phosphate and
500 to 1000 pounds kainit.-tierald Me-
earthly, Botanist n. c. Experiment Sta
| ton.