Shenandoah herald. [volume] (Woodstock, Va.) 1865-1974, 1911-05-26
A MENACE TO TREES.
DR.. NJ. B. Waite Tells How Ia
Eradicate the Orah.se or
Cedar, Rust.

In view OF the TACT that the CEDAR
rust has attacked large number of
fruit trees in Frederick county, caus-
ing loss to orchard owners, The
Winchester Star recently request d
DR.. M. B. Waite, the wellknown gov
eminent pathologist in charge of fruit
disease Investigations of the United
States Government, to give some ex-
pert advice concerning the methods of
controlling the disease. DR.. Waite's
reply to The Stars request for in
formation is in full as follows:
1.-The disease known as the oran &c
rust or cedar rust of the apple has
been increasing in severity in Vir-
iginia and adjacent states from Penn
sylvania to Tennessee during the last
| three or four years.
1t has been most abundant in the
valleys and slopes of the mountains,
and while it has been particularly bad
in the Shenandoah Valley, some of
| the other mountain districts have
sent in specimens to Washington full y
| as bad ss those obtainable from the
| Winchester and Martinsburg district.
In some of the districts, or particu-
larly certain corners or ends of or
chards adjacent to cedar trees, the
disease actually ruins the crop. TIE
| fruit in aytromo oosoc &c foo cp,. II IN a
| inferior and poorly colored to bear,
and goes into the Gull pile. This was
most true of the York Imperial The
fruit on the York Imperial is scarcely
attacked by the fungus, but the leaves
are severely injured, and it is their
destruction that spois the fruit. On
Ben Davis the leaves are only moder-
ately attacked, enough to be injured
to some extent, however, but on tn is
variety the fruit is frequently spotted
by fungus. Heretofore only certain
| varieties, like Pryor's Red, have been
| subject to the attacks of the cedar rust.
At the present time York Imperial.
which was regarded as immune, or
nearly so, appears to be becomip g
more susceptible to the disease.
| THE CEDAR RUST FUNGUS, ,
| The cedar rust fungus belongs to a
very remarkable group of parasitic
fungi, among which are some of the
most widespread and destructive OF
fungus parasites. The same group
contains the wheat rust, the oat rust,
the coffee disease which destroyed the
lcoffee plantations of Salama, and
have been destructive in other parts
of the world, not to. mention the car
nation rust~&hich annoys the green
house florist. the prune rust of Cal
lifornia, and numerous other diseases
of this sort characteristic OF the
fungus.
The group of rusts,- as is common
with many OF the fungi, has two, ant
even three, distinct forms of spores
or fruiting bodies. So far they are
not unlike the fungus which causes tht
brown rot of the peach, bitter rot O
the apple, and our common fungu;
pests Of the orchard and garden. Blu
in one important particular they are
ls,rikingly different, viz, that these
different severe forms occur on to,
TALLY different unrelated host plants
There is whole family of the cedar
rusts, and they have been quite e.ab
orately studied by botonists both II
Europe and the United States. Drs
lFarlow and ThaXter, of Harved Col
llege, have Strengthened out the rela
ltionship of most of the American
lspecies. The summer stage of this
family of fungi attacts every species
of the pome family, including not only
lapples, but ounces, occasionally
lpears and Hawthorne, the shad bush
or service berry, and in Europe the
lMedlar mountain ash, etc. The ma
Iture form, or winter stage, occurs on
the various species of juniper, O.
(which our red cedar is one, and GER
tain other trees and related plants
belonging to the family of Pomiperi
Jour common cedar rust is native
fungus. The winter stage attacks the
red cedar, producing little brown
lgalls varying in size from pin head
Iup to nearly two inches in diameter.
These develop during the latter part
of the growing season, and in the
latter part of April and the month of
May. They exude during spells OF
wet weather Yellowish- brown spore
masses an inch or SO in length. These
spore masses are literally made up o.
a mass of spores thrown out by the
little brown gals, or balls, which are
often spoken of as cedar apples in
this particular species The spores in
these yellow-brown masses do = not
terminate directly, though some of
them may possibly be carried onto
the leaves and fruit of the apple by
insects They have, however, much
more effective way of getting about.
Each cell of the spore throws out a
tube of quite large size compered tc
this diameter, and thin bread-like
branches are produced which carry an
Extremely minute bat light and deli
cate spore readily carried by the wind.
The spore masses therefore keep on
producing these minute spores, called
"sporidia. These are borne by the
wind and terminate and thr i've, no
on the rel cedar, but only on the ap-
pie and certain other plants. AS a
ma tier of fact, the particular pest in
question is native on the wild crab
| and Hawthorne, but is now adapting
itself more perfectly each year to the
cultivated apple. While the same
fungus occurs on the cedar and the
crab apple oyer large portion of the
United States. the peculiar adjust
ment which enables it to go back and