Deseret evening news. [volume] (Great Salt Lake City [Utah]) 1867-1920, 1903-09-08

| Ing rapid growth Of new soft tissues.
| Climatic conditions greatly influence
| the disease warm and moist weather,
with frequent showers tayoring II; airy,
| cool, and sunny weather hindering II;
and very dry weather soon checking 1t
| entirely.
The pear blight microbe is very
| delicate organism and cannot WITH
stand drying for any length OF time.
| In the bIlghted twigs exposed TO or
binary weather Il dries out In q week
or two and dies 1t causes the greater
part of the damage In the month or
two following blossomlng time, but twlS
blight may be prevalent ut any time
| through the summer when new growth
| IL coming out, In the nursery severe
| attacks often occur through the sum
mer. In the majority of cases, how
| ever, the disease stops by the close or
the growing season, At that time the
line Of separation between the 1--we ana
dead wood Is quite marked, and prop
ably not one cae IN several hundred
would be found where the diseased
wood blends OF into the healthy parts
and the blight Is still In active progress
In the old, dried bark, where the dis
ease has stopped, the microbes nave
all died and disappeared.
1t has been claimed that the blight
miorobe lives over winter In the sou.
and for long time the writer supposed
this to he the case; but after careful
investigation the idea was abandoned,
for In no instance could II be found
there. Unless the microbes keep on
multiplying and extending in the tree,
they soon die out This ia,a very mn
portant point, for II affords opportunity
10 strike the enemy AZ disadvantage
In certain cases the blight keeps up q
sort OF slow battle with the tree through
the summer, so that at the close of the
season. when the tree goes into dor
maut condition. active blight is still at
work In 1t. This Is olso true of late
summer and autumn infections. In
these cases the blight usually continues
through the winter. The germs keep
alive along the advancing margin of
the blighted area, aud. although their
development Is very slow, X Is Continu"
Gus. Probably the individual microbes
| live longer in winter. At any rate, the
infected bark retains its moisture long
en-. and generally the dead bark con-
tains living microbes during a much
longer period than II does In summer.
II has already been found that this
microbe stands the cold well, Even
when grown In broth in warm room
lHty may III lIOLen vi pluNtu III AZ ltil-
perature of II. and not suffer.
When root pressure begins In early
| spring the trees are g0rged with sap.
| Under these favorable conditions the
microbes which have hved over wlner
| start anew and eXtene INTO now bark
| The new blight which has developed In
winter and spring Is easily recognized
| by the moist and fresh appearance Of
| the blighted bark, as contrasted with
| the old, dead and dry bark of the
previous summer The warm and moist
weather which usually brings out the
| blossoms is particularly favorable to
| the development of the disease. AT
| this time II spreads rapidly, and the
| gum is exuded copiously from various
| points In the bark and runs down the
| tree IN long line. Bees, wasps, and
| les are attracted TO this gum and UNI
| doubtedly carry the microbes to the
| blossoms. From these first flowers II Is
| carried to others, and SO on till the
| blossoms are all killed or until the
| close of the blossoming period. Even
| after the blooming perid IL Is almost
| certain that Insects accidentally carry
| the blight TO the young tips and so
are instrumental In causing twig blight
also. The key to the whole situation
| Is found In these cases of active blight
comparatively few which hold over
| winter. Ii they can be found and des-
| troyed, the pear blight question viii he
| solved for the reason that without the
| microbes there can be no blight, no
| matter how favorable the conditions
| may be for Il; to use q common ex-
| preston there viii be none left for seed
| TREATMENT OF PEAR BLIGHT.
The treatment for pear blight may he
| Chased under two general heads. %
| Methods which aim to put the tree in
! a condition to resist blight or to rem
| der II less liable to the disease; aud CD
| methods for eXterminating the mcrobe
| itself which Is of first Importance. for,
| II carried out fully. there can be no
| blight. The methods under the first
| head must unfortunately he directed
| more or less TO checking the growth
| of the trees, through the withholding Of
| moisture, fertilizers. and cultivation.
and therefore are undesirable except
| In cases where IL Is thought that the
blight will eventually get beyond con-
| troll IN the orchard. Check the tree by
Withholding tillage, so that II makes a
| short growth and bears small fruit,
and II viii be in better condition to
withstand blight than II would were 1t
| cultivated,
DIFFERENTIATION OF THE BLIGHT
MICROBE.
We now come to the only really sat.
| isfactory method of controlling pear
| blight--that is, discriminating the mi.
crobe which causes II. by cutting out
| and burning every particle of blight
when the trees are dormant. Not a SIN
| gle case of active blight should be all
| lowed TO survive the winter In the or
| chard or within a half mile or so from
| II. Every tree of the pome family. in
GLIDING the apple. pear ounce. Sibcrl-
| ap crab apple, Wild crab apple, the
mountain ash, service berry aud all the
| species of Cratacgus, or hawthorns.
| should be examined for this purpose,
| the blight being the same IN all The
| orchardist should not stop short OF alb
| solute destruction OF every case, for a
| few overlooked may go long way to-
ward undoing all his work. Cutting
| out the blight may be done AZ any time
| In the winter or spring mp to the period
| when growth begins The beat time.
| however, Is undoubtedly In the fall,
! when the foliage is still ON the trees
aud the contrast between that on the
| bllghted and that on the healthy limbs
| Is so great that II " an easy matter to
| find AL the blight. II Is important to
! cut out blight whenever II Is found
| even In the growing season. At that
| time Of year. however. II cannot be
| hoped TO make much Roadway against
| the disease as new cases constantly
occur which are not sufficiently devel-
| oped 10 be seen when the cutting IL
| done. In orchards where there ere only
| a few trees,and the owner has sufficient
| time to go over them daily, he will be
| able to save some which would other
| wise be lost. However, when the trees
| stop forming new wood, the campaign
| should begin In earnest.
OF course. the greater part OF the
| blight can be taken out the first time
! the trees are gone over. II this be in