Daily capital journal. (Salem, Oregon) 1903-1919, 1915-11-20
County Fruit Inspector
Discusses Brown Rot

Continuing MS articles on the diseas-
es of fruits grown in this valley, their
causes and control, G. 0. Constable,
county fruit inspector, discusses in to-
days article, brown rot, especially
found in the peach growing districts
of the east, and in this section, on the
prune, cherry, apricot as well. as the
peach. The cause and development of
the brown rot, and best means for its
control are fully discussed.
At the request Of several orchardists
who were interested in the article which
appeared in The Capital Journal on
| Cylindrosporium Leaf Spot, Brown Rot
and Syneta Albida, also later article
on the life history of Cylindrosporium,
bI have promised as best l can to write
the life history of the other two. The
one on the Syneta Albida will appear
later
The following is from the Oregon Ag
ricultural college,
Brown Rot of Stone Fruits.-The
brown rot is one OF the most serious
and wide spread diseases which is
known to attack the stone fruits. In
most of the peach growing districts of
the east and middle west this is the
most serious disease, and in seasons of
frequent ummer rains may cause enor-
nous losses. In Oregon, on account
of less frequency of summer rains, sell
dom appears in epidemic form, but is
not uncommon on the prune, peach, and
cherry, and occasionally on the apricot.
Cause.
The brown rot on prunes, peaches and
apricots is caused by a fungus known
as sclerotinia fructigena. This fungus
exists in two spore forms. The summer
spore form has already been described.
The winter or sexual spore stage de-
velops in early spring from mummies
tnat have fallen to the ground. This
stage does not ordinarily develop ON
the mummies until after they have lain
on the ground Is months.
The stage of fungus is developed
from resting masses of mycelium called
sclerotia, which develops in the tissues
of mummified fruits. A definite fruit
body is produced known as an opo.
: thecium and commonly spoken Of as a
"cup fungus - This consists of a
slender stalk bearing at the summit a
: cup-shaped structure one-quarter to
one-half inch in diameter. These are
found at the surface of the ground, sur
rounding buried or half buried mum
mics. Several may be formed from the
same mummy. The inner surface of the
expanded bell-shaped portion is lined
by great numbers of cylindrical sacks
{ called asci, each of which contains
eight spores. These asci form a smooth
layer The details of structure are Wis
, ible only on microscopic examination
The spores are elected forcibly from
: the asci, and waited by currents of air
reach the trees. 1t is probable tna
much of the blossom blight is caused
by direct infection from the spores.
Control.
From what has been said, it is evi
: dent that the destruction of all mummi
, fled fruit in fall and winter would ait
in controlling the disease. 1t is q ba,
remain in orchards, since, as show
above, the fungus is capable of living
over winter in such mummies and start
! ing the disease in the spring. Earl,
l plOwing is to be recommended whert
= possible, and when consistent witt
good horticultural practice. This meth
' cd would probably not entirely preven
! the formation of the winter spore stag,
= and therefore, where practical the de
cayed fruit shuld be gathered and de
stroyed in the fall.
Peaches saould be thinned so that nj
two fruits touch each other, as it il
found that moisture may be retained
at the point where the fruit touch ant
thus favor infection.