The Blackfoot optimist. [volume] (Blackfoot, Idaho) 1907-1918, 1913-08-21
Government Answers Critics
Of Combating Pear Blight

the state OF washington that certain
people are spreading the idea tina
the pear blight is not bacterial dis
ease, and that the Departments rec
ommendation that pear blight can b.
dealt with by cutting out the dis
eased portions of trees is not al
effective measure.
In the fear that these unscientific
opinions may stop orchardists from TO
lowing the highly successful practica
measures recommended by the fedora
specialists, and thus lose their owI
orchards and spread the disease amoni
neighboring orchards. the Department
has issued the following special state
ment:
THAT pear blight is bacterial dis
ease Of the pear tree is not open to
question. The scientists have clearly
established the existence of these
bacteria by means of microscopic ex
animation, and have reproduced the
disease by inoculating fruit and trees
with them. The germ is the Bacillus
amylOvorus. It is an oval-shaped body
and is 1-18000 of an inch long and
1-25000 of all inch across, and can be
clearly seen with a high power micro.
scope. Moreover, the scientists have
raised these bacteria in thoir labora-
tories and have used them a large nun
Der of times in experiments to in.
feet healthy trees and fruit. Wher-
ever this bacillus has been introduced
into a healthy tree or fruit the pear
blight has followed. The scientists also
have proved that the pear blight can
be communicated from the blossoms
of an affected tree to healthy trees by
bees and other insects, and that the
blight that is held over through the
winter can be communicated to
healthy portions of the same tree
or to other trees by flies or other
insects.
Pear blight differs radically from
the peach yellows in the way 1t At
fects tree. The peach yellows does
not show itself outwardly in a tree
until the entire tree is affected and
cannot be saved. The pear blight,
on the other hand, has purely local
effect and attacks certain blossoms,
tWigs, branches, or a section of the
bark and leaves the rest of the
tree uninjured except where girdling
has occurred.
In thousands of orchards, and in
the case Of hundreds of thousands Of
pear trees, especially in California
and Oregon, particularly in the Med
ford district, it has been proven that
by cutting out the portion of the
tree affected by the pear blight and
washing the cut with a solution of one
part of corrosive snhlimete Ca highly
poisonous substance) to 1000 parts
of water, orchardists can save most
of the individual trees and prevent the
spread of the disease throughout their
orchards. 1t therefore strongly urges
orrchardists in districts affected by
pear blight to continue to cut out
affected portions of the trees and
wash the cuts with this mixture. In
cutting they should wash their tools in
this disinfectant, so that the tool it.
self cannot communicate the bacteria
to healthy parts of the trees. EsDe-
cially orchardists are strongly advis.
ed to go over their orchards very
carefully in the fall and cut out all
cases of hold over blight, in order to
prevent the spread of infections in
diseased trees or the communication
OF infection to other trees in the
poisoning period
In addition to the cutting out and
disinfecting process, the Department
advises orchardists to take steps to
keep their trees healthy and strong,
but not over-vigorous, SO as to be
highly resistant to pear blight. 1t
warns orchardists to BIO careful in the
use of manures and fertilizers around
fruit trees, as anything which increas-
es the rate of growth Of the tree has
tens the spread of the localized in
lection.
The Department has thoroughly test.
ed all known or suggested measures
for coping with this blight. 1t has
found tho cutting out and washing wit
the solution the one reliable and
practical measure, and recommends
it as a fully tested and successful re-
NEEDY.
This cutting out method will not .
save all trees, nor is it effective with
certain varieties of pear trees which
are particularly subject to the ravages
Of the pear blight. 1t has, however,
saved the pear industry of California
and portions Of Oregon