Shepherdstown register. [volume] (Shepherdstown, Va. [W. Va.]) 1849-1955, 1912-08-08
Cedar Rust In Apple Orchards.

Owing TO the serious damage that has
been wrought by this disease throughout
the country and the entire section of the
Valley this year, few points regarding
the nature and cause Of this particular
trouble seem advisable.
As most of us are aware, II is fungous
trouble that is very low form OF plant
life, that lives and takes its nourishment
from the cells and tissue of the apple fruit
and foliage and also the Red Cedar. II
spends part of its life upon the Red Cedar
and produces the balls, generally known
as Cedar Apples" In the early spring
these balls attain considerable size and
produce countless numbers OF spores.
During wet weather the cedar apples be-
come swollen and have gelatinous ap-
pearance, giving evidence that its spores
are ready to be liberated and distributed,
These are dispersed by the wind, carried
long distances, and fall upon the foliage
and fruit OF the apple, germinate and
penetrate the cells of the leaves and fruit,
thereby producing the yellowish spots
that are so common on certain varieties,
notably the York Imperial.
These yellow spots on the leaves be-
come enlarged as the season advances
and finally spores are again produced on
the under surface OF the apple leaves,
along in July and August, appearing as
small cushions, with tubes dispersed by
the wind, and must find the red cedar
tree in order TO gerninate and form the
cedar apples or else perish.
The fungouS now begins in the tissues
of the cedar tree, growth continuing until
the cedar apples are ready TO form spores
again, and infect the fruit and foliage OF
the apple; this being always during the
spring OF the second year, from the time
the spores fall on the cedar. For in
stance, the spores that are being formed
on the apple trees this month and next,
return to the cedar and grow during the
fall OF 1912 and the entire year OF 1913.
In the spring of 1914 these spores will
again return and infect the apple trees.
Thus understanding the life history OF
this fungouS, the theory that is put tor-
ward by some men claiming that the
cedars have nothing to do with cedar
rust and that the rust Is more or less
prevalent, due to different methods OF
orchard management, is seen TO be ao-
surd.
The varieties that seem 10 be most
susceptible are York Imperial, Maiden
Blush, Rome Beauty and Jonathan. The
Grimes Go den, North Western Green
ings, Winesaps and Ben Davis, are more
or less resistant; however, the fruit OF the
Ben Davis appears TO be quite susceptible
in this section.
The thing of course which we are most
notably interested in and about which
we know the least, is the control OF The
disease. However, not only our State
Experiment Station, but many other tx-
pertinent Stations, where this disease is
prevalent, are strivingto find some means
looking toward control. One fact which
all the stations are decided upon is that
the cedars should be cut down wherever
possible, for of course if we remove the
nest cedar trees OF the fungus, we also
remove the fungus. On The other hand,
taking up spraying as means OF COM
batting this disease, at present not large
enough or extensive enough experiments
have been carried on by anyone TO def-
nitely say cedar rust can be controlled
under any and all conditions. However,
in our work here in the orchards In
Berkeley county this spring, we have
been successful in partially controlling
the disease when we sprayed on certain
day with certain spray materials. Whether
we are going 10 be able TO duplicate our
results another year, and work out a
good practical method for the fruit grow
ers 10 combat this disease, remains a
question. Nevertheless, we are in hopes
of forwarding a good, practical remedy in
the future.
DAVID c. NEAL,
Assistant Plant Pathologist,
/ III mt Ctafinn