The newspaper., 1906-04-06
PEACH MILDEW.
Interesting and Instructive Bulletin from
the Agricultural Collage.

The phenomenal growth OF the
peach industry in that part OF Colo
RADIO west of the Continental Divides
due, to a certain extent, at least, to
the absence ofinsect pests and fungus
disease. While it is probable that
our growers will never have the
large array of these pests, which are
common in many other regions, to
contend with, we cannot hope to be
entirely immune from such attacks.
From a business standpoint, then,
we should be constantly on the look
out for anything in the nature OF a
pest, SO that it may be studied and
means devised for its control before
it's attacks become serious.
Peach mildew has made it's ap-
pearance in a few orchards and ap-
pears to be spreading. While no
great amount OF damage has yet
been done, some OF the growers are
beginning to spray their trees for the
control of the disease.
1t is the purpose OF this Bulletin to
point out the nature OF the disease
and describe some Of the means OF
combating it which have been used
in other states. The Experiment
Station has had no opportunity as
vet to conduct experiments OF this
kind, but there is no reason to sup
pose that these remedies will fail in
Colorado if properly made and ap-
piled.
The injury in Colorado is due to a
fungus which attacks leaves, twigs
and fruit alike. 1t appears on the
fruit while they are yet small and
prematurely. Its first appearance is
indicated by a musty or frost-like
patch upon the surface. When well
established, the spots become almost
pure white; the color being due
to the mycelium and it's fruiting
branches, which overrun the surface
upon which the funges establishes
ITSELF The flesh of the fruit becomes
hard under these spots and the skin
takes on a brown or dead color.
The appearance upon the twig is
very much the same, it being very
conspicuous as white blotches along
the twigs; the underlying bark be-
comes dry and brown. Where the
attack is very severe the leaves fall,
the bark becomes shriveled, and the
position. 1t only appears on the cur
rent years growth, it being able to
establish itself 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 isfound
there more often, probably because
strong sunlight is it's worst enemy.
The leaves become crimpled and
curled, the younger ones near the tip
often falling during severe 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
twigs are checked in their growth,
and sometimes killed outright, while
the foliage is greatly reduced. If no
injury to the crop is experienced dur
ing the season of attack it is no
doubt true that the future crops and
good health OF the tree are at stake.
Fruit buds for the coming year can
not 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 a warm, moist and shaded loca-
ton, anything that will overcome
these conditions might be classed as
a preventive. Too close planting is
not recommended, as in such planta-
tions free circulation OF air is shut
off. Pruning to an open head would