The herald., 1894-01-07
TO HORTlCULTURISTS.
SOME INTERESTING MATTER FROM
ORANGE COUNTY.
A Graphic Statement of the Varieties
of Root Knot Diseaae-vxiua-
bic Information for
Frnit Growers.

Hiram Hamilton, horticultural COM
missioner of Orange county, has the fol-
lowing in the Orange County News:
The planting season being now close
at hand and the danger being ever pres
ent of introducing into the country new
pests and diseasee of trees and shrub
berry, | wish to call attention of all in
tending to plant nursery stock imported
from abroad to ordinance No. II of the
board OF supervisors, requiring ell per-
sons receiving such stock to notify the
nearest inspector of the arrival of the
same and submit to an examination OF
said stock bsfore planting.
By said ordinance No. IL all stock
brought into this county is in quaran
tine until inspected and passed by a
horticultural commissioner, and any
person violating the provisions OF this
ordinance subjects himself to the PEN
alties therein contained,
To secure the friendly cooperation of
ell planters have requested Prof. New
ton B. Price, government expert OF
division OF vegetable pathology, located
ct Santa Ana, and he has kindly con-
sented to give me for publication a
graphic statement of the varieties of
root knot that afflict end threaten to n
jure (unless prevented from introduce
tion by close quarantine) horticulture in
Southern California. 1t is as follows;
First-Gall on the smaller roots of
walnut, fig, peach and other trees and
plants. They are induced through the
work OF several species of Nematode
worms. The worms may be introduced
in new regions by means of infested
nursery stock and otherwise. Most in
jury is done TO plants in moist and
sandy soils. Nursery stock aud beets
auffer to some extent in California.
Second-Galls on the fibers of grape
vines, especially upon the finer roots
They are induced through the work OF
phyiloxera vastatrix, a very destructive
insect easily introduced in new regions
by means of infested plants. All Euro
pean varieties OF vines are killed by it.
Vines are killed most rapidly on heavy
soils.
rhird-Tubercle on the roots of pea
vines and closely related plants. Tney
are induced through the action of micro.
organisms, and are considered beneficial
to the farmer.
Fourth-Tubercles on the roots OF
cabbages and closely related plants. A
diseased condition induced by slime
mold (piasmodi ophora brassicae) and
called clubroot, ingers-and- etc
The fungus may be carried into new
regione by means of infested plants. 1t
is not yet known in the gardens OF Cali
fornia.
Fiith--Knots on the roots and
branches OF apple and other fruit trees.
They are induced through the action of
The woody aphis ((schizoneura lanigera).
Che insect causes great injury to the
trees it infests, and s easily carried on
infested plants into new regions.
sxth--Knots of cherry and plum
branches. This trouble is known in
q east as black knot, and is induced
through the action OF parasitic fungus
(sphaeria morbosa) infesting the
branches. These knots have never
been seen in California, so far as known,
but the fungus is liable to be introduced
ON infested plants.
Seyenth-Knots on olive branches
This disease is known as olive tuDercu-
losis, and is caused by bacillus. IL is
not yet certainly known in California
1t is common in Southern Europe and
elsewhere and may be introduced on in
Tested plants.
Eighth-Knots and canBer like inju-
ries of roots, trunks and branches of de-
ciduous trees and vines. This group
includes variety OF affections varously
known as root-knot, black-knot, crown
gall, etc These affections are common
to the peach, walnut. grape, and numer-
Gus other plants. 1t ia not yet demon
strated what the cause or causes may
be. 1t has not been shown in salts
factory manner that these diseases are
contagious.
Ninth-There are many gals, knots,
tubercles and swellings of various parts
of great variety of plants not included
in the above list. They are induced by
many different parasitic plants and ami
mails. Swellings caused by the mistle-
toe. oak gals, etc, are examples.