The Lamar register. [volume] (Lamar, Colo.) 1889-1952, 1906-05-09
PEACH MILDEW
Description Of the Disease and Mcans
of Combating 1t.

ricultural College Colles Expert
ment Station.)
Peach mildew hos made Is appear
ance in few orch is and appears to
be spreading Viii lie no great amount
of damage has yet been done. some of
the growers are beginning to spray
their trees for the control of the dis
ease.
The injury in Colorado is due to a
fungus which attacks leaves, twigs and
fruit alike. 1t appears on the fruits
while they are yet small and immature.
often causing them to fall prematurely.
Its first appearance is indicated by a
musty or frost-like patch upon the sur
face. When well established, the spots
become almost pure white; the color
being due to the mycelium and its
fruiting branches, which Oyerrun the
surface upon which the fungus estab-
fishes itself. The flesh of the fruit be-
comes hard under these spots and the
skin takes on a brown or dead color.
The appearance upon the twig is very
much the same, II being very conspic-
uous as white blotches along the
twigs; the underlying bark becoming
dry and brown. Where the attack is
very severe the leaves fall. the bark
becomes shriveled, and the young tips
only appears on the current years
growth, it being able to establish it.
self upon the more tender growing
parts only. On the leaves it generally
appears upon the under surface, most
prominently along the midrib as white,
irregular blotches. The attack Is not
confined to the under surface of the
leaf, but is found there more often,
probably because strong sunli ght is its
worst enemy. The leaves become
crimpled and curled, the younger ones
near the tip often falling during Sc
we're attacks. The tissues OF the leaf
are deadened, and it folds more or less
along the midrib, the upper surface
folding upon itself
Attacks of this fungus often injure
The fruit, in some cases almost ruin
ing the crop for market. The young
twlgs are checked in their growth, and
sometimes killed outright. while the TO
liage is greatly reduced. If 10 injury
to the crop is experienced during the
season OF attack 1t is no doubt true
that the future crops and good health
of the tree is at stake. Fruit buds for
the coming year cannot be developed
on half-dead twigs. poorly nourished by
a scant supply of foliage. Neither is
the tree in shape to withstand other
troubles to which the unhealthy peach
tree falls heir.
AS preventive measures. several OF
more or less Importance can be men
toned. AS the fungus thrives best In
warm. moist and shaded location.
anything that will overcome these con
ditions might be classed as a prevent
i've. Too close planting is not recon-
mended, as in such plantations
free circulation of air is shut off.
Pruning to an open head would no
doubt be an advantage In IA
vor OF the tree. In other words. plant
and prune the orchard to favor free
circulation of air and plenty of sun
about and on the inside of the tree.
Experience with other mildews would
seem to suggest that as a preventive
measure a cool soil and location be Sc
lected. Some have recommended the
planting of varieties that seem to be
free from attack. but in this state lit
tie or no preference has been shown by
the fungus for certain varieties. The
statement has been made that the
disease seemed to be restricted to the
serrate, glandless-leaved varieties. but
in three lots of infected material sent
into the station by fruit growers of the
state two had serrate leaves and very
conspicuous glands. while the third
was serrate. glandless. 1t has been no
tlced that 1t is especially bad on seed
lings In infected localities. 1t seems
hardly necessary to take out infected
trees as some have recommended, but
no doubt the seedlings above men
toned could be disposed of at little
loss to the grower and may noticeably
check the spread of the disease.
Peach mildew being surface
l.. of
our standard fungicides might not be
employed in fighting it. thorough
spraying, before the trees come into
bloom, with formula A or c is recon-
mended. After the blossoms have
fallen, an application of b or ID should
be made Follow this at intervals of
EN- days or two weeks with one or two
more applications of b or II. While
and are sometimes recommended
for use on the peach while the tree Is
in full leaf. they are liable to burn the
foliage more or less. and though 1t may
not prove dangerous to the life or
health of the tree. 1t Is well to give
up their use for others that are safe
as well as efficient. Formula b is
modification of the regular Bordeaux
mixture sometimes recommended for
the peach. and can be safely used upon
Formula is very safe and effective
spray for the first applicable II before
the leaves come out, but others given
are much more simple in preparation
and just as effective.
Formula A bordeaux MiNture)-
Copper sulphate (blue stone or blue
vitrioD, lbs; quick lime, lbs.; water,
Is gal.
Formula B-Copper sulphate. lbs:
quick lime, lbs; water. As gal.
Formula Cooper sulphate, l lb.;
water. 25 gal.
Formula D-Copper sulpha:e. lb.;
water 400 gal.
The effectiveness OF any OF these
sprays depends upon the thoroughness
with which 1t is applied, and pains
should be taken to reach all parts of
he tree. A nozzle that breaks mp the
spray well will save much time. Fresh
unslacked lime only should be used. II
should be Stacked in water in sap
arate vessel diluted to a thin white
wash and strained through one or two
thicknesses of burlap or sacking. or
81. x,,tth iy,u he.