Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1915-05-30
V|RC|N|A's ORCHARDS
AND ORCHARD BLIGHT
Some Facts About the So-Called
Blight-An Experts Views as
to the Disease.
HAVE WE REALLY TIE DISEASE?
Some Orclardists Think Not; Others
Listen to the EXpcrts-All Are
Agreed That if Disease Is Here 1t
Should BE Hit.

J
Orchardists in Virginia and elsewhere
arc now much concerned about dis
| ease that is attacking trees in many
| orchards. and G. H. Crabill assistant
| pathologist at the experiment station.
located over at BlacksburE. gives some
points about the disease. The infor-
nation he gives should prove valuable
In controlling the blight before further
damage is done. Mr.. Crabill writes a
special letter To the Industrial Section
Did YOU. Mr.. Farmer, or Mr.. Orchard
| list. ever sec an apple tree on which
about two weeks to month after
blooming large majority of the fruit
, spurs and twig tips appeared to be
burned. or, at least, singcd? AS mat
ter of timely interest to those who
have seen il. it is dcsira bio to discuss
the why's and wherefores of this condi-
ton. We may call this disease '.twis
blight" and take up in order the
symptoms. cause, transmission and con-
troll of the malady.
Symptoms-TwiG blight appears in
spring two weeks to one month after
hlossoming. The leaves on twir tins
and fruit spurs wilt in succession and
gradually turn black. resulting. finally
in the complete blackenng and dea IN az
al branches and spurs upon which
flower clusters were borne In some
instances scarcely flower tin on an
infected tree is free from this general
attack The disease progresses down
ward, killing the leaves and twirs
until. in the course Of some weeks, the
branches arc killed back II foot or more
from the tips. The leaves are by that
time dry, black and leathery, aChcri,r
tenaciously to the twig The tin Of the
iwiE is usually bent in the form OF a
shepherds crook
JUST WHEN SYMPTOMS
BEGIN TO DIE OUT
on most varieties of apples the dis
ease ceases to spread by midsummer.
many OF the dead twigs fall away dur
ing the following winter and tho next
spring the performance is repeated
ON rev, however, such as Ren Davis
ana Grimes, the blight may extend
downward into the large limbs or even
INTO the trunk. killing all tissue as il
goes In general, trees appear to have
been scorched by hot blast
CauSe-Twig blight is bacterial
disease caused by minute germ
known 10 science as bacillus amvlovor-
Gus. This is the same organism ms
mat which causes the widespread and
destructive pear blight or fire hlich,
az pear trees. the collar blight or some
varieties OF apples and the twig blight
oil ounces As we shall see. this germ
Is transmissihle from one to the other
OF these fruit trees. and or each !,
produces the characteristic blight
IranSmlssion-It Is a notable fact
ma Young appl" trees very rarely havn
twig blight. Only those trees which
arc old enough to bloom contract IN.
disease. and usually tho greater amount,
OF the bloom the orsc the twip hlirn,
Ihc reason for this is that the iufoc-
non OF the apple tree occurs through
ne blossom The germs which give
rise 10 the twir blight are carried hv
insects. principally by bees. from dis
"as"d wood blighted the previous wear.
The bacteria winter over. in relatively
re-" affected branches. undcr conditions
wnerc moisture is sufficient and protcc.
tion from drying is adequate
HOW THE THING
GETS BUSS N SPRING;
II is from such diseased wood or
hoid-ovcr cankers" that tho disease ia
spread IN spring. Al the beginning OF
CONTINUED on Ninth Pascl