Rogue River courier. (Grants Pass, Or.) 1886-1927, 1910-12-30
The Pear Blight and the Best
Way of Getting 1t Under Control
BY P. J. oGara. Copyrighted by Mail Tribune.)
Summary of Preceding TnstaIments.


ceding chapters carefully, 1t may
seem unnecessary to add anything
more, as 1t Is believed that all of the
important facts about pear blight
have been clearly stated. However,
a resume will bring before us all the
pertinent facts, so that the reader
may see at a glance what he may
want to know without reading the
text again.
/. The history of pear blight
dates from the year 1880; the first
record was published In 1874 In the
transactions Of the Massachusetts,
Society for the Promotion of Agri-
culture. This first paper on pear
blight gave to the highlands Of the
upper Hudson the distinction of being
the birthplace OF the disease. How
ever, at the time of the discovery
the disease had wider spread
throughout the New England states
than has been recorded.
2. The disease, knowl as pear
blight, is not known outside OF North
America. Europe, Asia, Australia
and all other parts OF the known
world are free from the disease.
8. The true character of the dis
ease was worked out by Professor T.
J. Burrell, OF the University of. Him
oils, in 1878, and was published to
the world In 1880. DR.. Burrell found
that the disease Is caused by a small
germ belonging to the great family OF
bacteria, whic.. are minute, micro
scoplc plants, the smallest vegetable
organisms In the world. The pear
blight bacillus Is only 1-50, 1000 of an
inch in diameter, and about 1-25, 900
of an inch In length; under the micro
scope, when magnified 100 diam
eters. Its appearance Is that of hy-
phen, "-".
4. The pear blight germ attacks
all species belonging to the pome or
apple family, and also In a small way
infects plums and the apricot. Among
the cultivated fruits. therefore, Il at
tacks the apple pear, ounce, loQuat,
plum and apricot. The following wild
fruits indigenous to the Pacific coast
states are also attacked by It. I
shall give the common names and af-
ter them the botanical or scientific
names, so that students OF botany
may be able to look them up:
(1 Service berry or June berry
(amelanchier alnifolIa).
(2) Thorn apple or haw (crat-
aegus douglassD.
(9 Christmas berry or Toyon
(heteromeles arbutifolia).
(D Wild pear or apple tpyrus
rivularis).
60 Mountain ash or rowan (sor-
bus occldentalis)
There are many more species OF
the above genera to be found in the
eastern and southern states, bur al
knowledge OF the fact that all pomo
fruits blight should be sufficient
s. The damage by blight In the
eastern and southern states has been
such that practically all OF the bet
ter varieties OF pears have gone out
and commercial pear growing Is an
industry OF the past.
6. The blight has spread into
every known section OF the United
States, southern Canada and north
ern Mexico; anly very few small
districts still remaining free from Il
Z, The first appearance of the
blight is made evident by the bios
SONS and young shoots becoming
wlthered and black, finally drying
up Later branches and limbs, as
well as the bodies and root system
become infected Even the fruit may
become infected and wlther away |
3, The infections first noted in
the spring come from holdover cases
which have resulted from the prevl-
Gus years infection These hold
overs may be found In the larger I
limbs, bodies and roots Of the pear
apple, ounce, loQuat and even our
Wild fruits, though less frequently |
During the blossoming period these
holdovers ooze and this gummy sub
stance, which is filled with the bac-
teria, become points for the starting
OF new infections In the blossoms and |
twlgs.
.. The germs from the holdovers
are carried about by bees and other
Insects Biting and sucking insects
cause Infections In the young twlgs
and even the bodies sapsuckers, or
woodpeckers, may also spread the |
blight, The use OF pruning tools, not
dislnfected, also spreads t. Tho
blight may also enter small growth |
cracks In the twlgs, limbs, bodies or
rNrds