Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1904-03-18
CROWN GALL OF APPLES
NOT EASY TO CONTROL

Crown gall is disease of the apple
tree which has been much discussed
among fruit growers and nurserymen
of recent years, and seems to be one
of the hardest diseases to control.
No satisfactory remedy has yet been
found. but a number of experiment
stations are now working on this mat
ter.
The gals are simply wartlike
growths which appear on roots of GER
tain trees and plants, just above the
crown of the tree, hence the name
They also appear on the roots. The
warts are rough and altogether unlike
the engagements Of roots caused bN
the attack Of woody aphis. the latter
being spongy. with n smooth surface.
Prof. Tourney, of Arizona. SAYS the
crown gall is caused by Il slime mound
one of the lowest forms of fungi.
Some persons have claimed the disease
is due to certain methods of grating
but experiments have demonstrated
that the gals can be formed on seed
ling trees simply by planting pieces of
the minced gals near the roots of the
seedlings.
1t has been found that the gals will
grow again when they are cut off,
and therefore ii is not safe to plant
trees which are infected with the gals.
There is a difference of opinion among
growers and nurserymen as to the
ultimate result of planting trees with
gals upon them, some claiming they
will grow and make good trees in spite
of the gals. Others. however claim
differently, and to be on the safe side
one should watch carefully to see that
no infected trees are planted, for the
trees will not only continue to produce
gals. but healthy trees in the same
orchard may be inoculated with the
disease by means of pillow points.
The red raspberry is another plant
which is much subject to a gall
growth. \ number of experiment sta
tiOns are now at work trying to decide
whether the gals are the same species
as the one which attacks the apple,
| but it has been found that both apple
| and peach roots can be inoculated
with the raspberry gals, so'that it il
not advisable to plant the raspberries
among the orchard trees.
| In n series of experiments at the
Missouri experiment station Prof. W.
II. Howard tried great many cOmbi-
nations of remedies to overcome this
disease. \ great many of these had no
effect whatever upon the gals, and
where the latter We're cut away they
promptly grew again. Still others re-
tarded the growth of the gals some
what, but also injured the trees. 9th
ers prevented the gals growing, sim
ply because they killed the trees.
In Arizona some experiments were
conducted and it was found that
where the disease affected older trees
/ in orchards. it can be held in check
/ by carefully examining the trees every
! season and cutting away all traces
Of the gals from the crowns. The
wounds are then thoroughly covered
with paste made after the following
formula:
Copper sulphate Cbluestone) two
parts iron sulphate (copperas) one
part. lime (unslacked) three parts.
The three ingredients are reduced to
after which enough water is added to
make thick paste.
In view of the uncertainty as 10 the
disease and the fact that no satisfac-
tory way has been found to fight
crown gals. it would seem to be the
| part of wisdom en- the part of apple
tree planters 10 carefully inspect all
trees TO be planted and try TO keep
| the disease out of their orchards.