The Florida agriculturist. [volume] (DeLand, Fla.) 1878-1911, 1879-02-26
Enemies of the Orange.
DISEASE OF THE FOLIAGE.

Editor Florida AgricuhurSst:
The disease known as smut or
black rust upon the leaves OF the
orange tree, is unknown in this neigh
6orhood, except on young trees in
tested with the scale insect and no
case has come under my observation.
The Microscopist of the Agricul-
tural Department in the monthly re-
ports of November and December,
1873, describes it as follows:
My attention was directed to the
investigation of the black matter on
the leaves, branches, and fruit. re-
moved portion of the black matter
from a leaf 1T appeared as if com
posed of black, granular matter, ce-
mented with flour paste, and formed
in thin sheets of the thickness of It's
sue paper. When dried it may be
cut into any form desired. Some
times it appears as fine, black pow
der scattered over the leaf and is fre.
quently found in quantity at the base
of the orange buds. On placing a
small portion of the black matter IN
der power of 100 diameters, it was
seen to consist of a branched and
jointed mycelium or spawn of fun
gus. After making many observa-
tions under a power of 800 diane
ters the fungus in its various
stages and was clearly defined
The surface OF the leai is gem
orally covered with these germ
mating spores when the black
mycelium is on the leaf; be4g
colorless they are invisible. Fpe-
quently vandyke colored cells Ere
seen on the leaf They consist Of
disjointed mycelium. TO the naked
eye the fungoid spores, etc.. assesss
black, but under the microscope thts
appear OF vandyke brown with the
exceptions noted. 1t is known to
mycologists as black myceliuni.
Berkley says that of late years the
black mildews have ragged to such an
extent in the Azores and Ceylon as
to threaten the complete humiliation
of the orange and coffee plantations,
and the ravages have been scarcely
less among the olives in some parts
of Europe. 1t is impossible that
light can have its proper effect
through such medium on the It's
sues OF the leaves. 1t would be as
rational to expect that plants would
thrive under brown bell glass as
that vegetation should not be i'm
paired when the greater part of a
plant is covered with thick, dark
felt The mildews are often accom-
panied or preceded by cocus. The
remedies suggested "are thorough
drainage, proper culture of the soil,
moderate manuring and destroying
the cocci and fungi by frequent wash
ings with weak alkaline solutions,
such as potash, soda or ammonia"
INSECTS.
The only insect, at present, doing
much harm to the orange tree is the
scale insect, known among entomolo-
gists by several names, as CocuS HIS
periduna by White, and Aspidjotus
glooerii by Packard. 1t is not neces-
sary to give description Of this in
sect, as it Is known to every practi-
cal orange grower. 1t is said to have
been introduced on the ST. Johns
river by trees imported from China,
while others state that they had seen
them in other parts Of the State be-
fore they appeared at Mandarin.
They are now scattered over the
State and California is not exempt
from their ravages. We must seek for
some efficient remedy to eXtlrpate
them. On large trees l have sue
ceeded in getting rid of them by
starting the tree to growing vigor-
ously by the use OF compost Of
bones, lime and potash, working it
into the ground with torked hoe. |
had a number Of young trees planted
near the kitchen, and the greasy dish
water was thrown on them. l no
ticed that the leaves looked black
and found the trees covered with.the
scale. l removed them to new
ground and soon the insect disap-
peared without my having made any