Atlanta tri-weekly journal. [volume] (Atlanta, Ga.) 1920-19??, 1920-10-16
AGRICULTURAL EDUCATION
BY DR.. ANDREW M. SOULE

Protecting Trees From Winter DAM
Cold weather often does great
damage to our fruit and nut planta.
lions. This applies to all sections OF
the state, and of the south as well.
The loss has been known to ap,,
proximate SO per cent of the orchard
so that injury from this source be-
comes matter Of great Importance
to the orchardist.
Investigations made bv experts OF
the Georgia State College of Agr1-
culture reveal many facts concern.
inc this trouble which are worthy OF
note. All who are engaged In hort1-
cultural enterprises will do well
therefore to give. heed to the sum-
mary of suggestions prepared rela-
tive to this matter.
Observations made in bearing or
chards, especially peach, have shown
an unusual number of trees dying, in
some cases as-high as per cent.
Although there is little, If any, ques-
ton as to the cause of the loss
being generally accepted by growers
and scientists as due to winter in
jury, there has been some question
as to the cause of death among
bearing peach and pecan trees. The
loss of bearing peach trees has been
ease that causes plum wilt; of large
pecan trees, to insects. Although it
is possible that plum wilt and in
sects have caused trees to die, it does
not seem possible that these trou-
bles should have increased the death
rate over previous years. Plum wilt
ha.; been prevalent in the state for a
long time. The fungus which causes
it has been considered a very virulent
parasite on plums, but only attack
iy,rr ri, fIn frnn
weakened by other causes. 1t is
probable that trees weakened by
cold would be later infected by the
fungus. 1t is also very common to
find Valsa, another fungus on trees
which have been weakened by borers
or other troubles.
The peach industry of the state
represents very desirable annual
income and also a heavy investment.
Although there does not seem to be
unduiy alarmed, yet the Industry is
of sufficient importance for this
question to be worked out at once.
AS to whether the plum wilt Or any
other disease is menace to the
peach industry is question for a
question of insect damage to pecan
trees is for the entomologist to work
out, and fortunately representatives
of the government and different
states in which the pecans are grown
have been, investigating this and
will report soon, no doubt.
The question Of winter killing of
young pecan, peach and apple trees
is a clear-cut one, as there is no
doubt of the cause The object Of
and give recommendations for pre-
venting repetition Of the dam
age.
Young trees came into foliage in
the. spring; later the leaves turned
yellow, wilted and the trees died. In
some cases the trees died a few days
after starting to foliage; in others
they did not succumb until August;
and still others died all along be-
tween these periods. These are the
making more careful examination
of these trees, the twigs and main
branches were found to be green and
uninjured, but the cells beneath the
bark in that portion of the trunk
just, above the soil were found to be
dead. completely girdling the trees
If the examination was made early
enough in the spring, it would be
found that these cells in the first
fe-- inches above the soil were dis
colored and dead, while the roots be-
low and the trunk with it's branches
above were alive. This Is the COM
mon symptom, although some trees
have the entire trunk and portion of
the root system killed. while others
in addition to being girdled would
have dead spots at the crotches,
When the cells are killed deep into
the sap wood, sap usually collects
in this girdle portion. turning sour
and and giving off a disagreeable odor:
the roots often send up growth.
When the cells are not killed to any
great depth under the bark, the
top Of the tree continues it's growth
late into the summer. but sprouts
are thrown up from the roots. Young
trees with vigorous sprouts coming
from the roots show these outward
signs of winter injury.
Sun scald is also a common form
OF winter injury. This shows a long
the tree. 1t is caused by the sun
warming up that side Of the tree,
while the other side being shaded
by the trees own trunk. is of a
m nlaca 10 lower r,1 tempe da It takes
nights. 1t does not kill the trees.
as rule. but weakens them and
gives the borers a good place for en-
trance.
TW wig killing I suffers from injury
sometimes but not often severe
enough to kill the trees. It affects
bearing, as well as young trees. 1t
cuts off the years crop when af-
In handling trees to minimize win
ter injury proceed as indicated be-
low:
L. Give the trees long, unbrolen
growing season. 1t is the nature of
deciduous trees-trees that shed
| their leaves-to grow during the
summer and rest, remain dormant, in
winter. This is due to the season,
but Il tree that grows continuously
and steadily in summer has a ten
dency to- remain more thoroughly
dormant in winter, while one that
has rested in summer has a tendency
to start growing in winter, if wealth.
or conditions are suitable.
2. Have the trees mature at frost
Maturity is one of the most impor-
tant features affecting the hardness
of plants. Investigation has shown
that of the parts of the trees above
the soil, the cells at the base are the
least mature in winter. The cells
in the crotches are also poorly ma
turcd sometimes. This explains the
nature of the symptoms described
above. To get trees to mature thor
oughly, it is important to have them
growing through the spring and sum-