The Ronan pioneer., 1917-05-04
VOLUNTEER GRAIN
SPREADS APHIS
THIS DISEASE, WHICH CAUSES
BIG LOSSES IN MONTANA,
EASY TO CONTROL.

One Pound of Forty Per Cent For
maldehyde to Forty-five Gallons o
Water Furnishes Solution Whicl
will Kill All Germs in Grain Treat
ed With 1t.
BY j. r. Parker, Assistant Entomolo
gist, Montana Agricultural Expert
ment Station, Bozeman.
In winter wheat districts where
the wheat aphis is known to be pres
ent, farmers should make every eff.
fort to keep summer fallowed fields
absolutely free from volunteer grains
and grasses. In a study of this seri-
GUS grain pest it was found that
whenever crop was seriously in
jured that the field had contained
considerable volunteer grain and
blue joint grass at the time of seed
ing. The reason for this is that dur
ing June and July the insects acquire
wings and migrate to volunteer
wheat and blue joint grass in sum-
mer fallowed fields. By fall, these
plants are loaded with wingless aph-
ids and when the new crop of wheat
comes up they act as centers of in
festation. Thus one good sized stool
of volunteer grain will reinfest. much
of the new crop within radius of
10 to 25 feet.
Keep Summer Fallow Clean.
1t is very simple matter to advise
that the wheat aphis can be COM
pletely controlled by keeping sum-
mer fallowed fields absolutely free
from volunteer grain and grasses,
but it is often a difficult and expen-
sive proposition for the farmer to
put the advice into practice Under
summer fallowed land, early plowing
and repeated diskings, some volun-
teer wheat and blue joint grass is
diskings are also Objectionable in
causes the soil to drift badly. Sew
eral OF the less common methods of
obtaining clean summer fallowed
particular reference to their bearing
on what aphis control.
Special Tools.
There are now on the market tools
of the duck-foot cultivator type,
which are composed of sets of over
tapping V-shaped knives which will
cut all vegetation just below the sur
face of the soil. These are much
efficient than the disk as destroyers
of vegetation, are of light draft, and
do not pulverize the soil as much as
the disk harrow. They have the dis
advantage Of not working we'll in
rocky ground.
The use of the hand hoe in des-
troying vegetation which has escaped
the first d4skings is practiced by
some growers, who report it cheap
er and more thorough method than
to continue the disking.
In discussing the wheat aphis with
many growers, surprisingly large
number have remarked that fields
plowed early, that is, in April and
May and up to June Is, were severe
ly injured, while nearby fields, plow-
ed after June Is, were uninjured
Such cases are easily explained. On
the early ploWed land volunteer
grain and grasses have an opportu-
nifty to start up during the season of
rainy weather that follows plowing,
this bringing about inviting condi-
tions to the migrants which are y
ing in June and July. In late plowed
fields all volunteer grains and grass
es that have started during the rainy
season are turned under and the
field is left bare during the migra-
ton period.
Some growers disk the stubble ear
ly in the spring and then do hot start
plowing until after June 5. The
disking has tendency to hasten the
termination of grains and weed seed
and makes plowing easier.
Some Plow Twice.
Some of the most successful grow
ers plow twice, shallow plowing in
early spring and a deeper plowing ,
after June Is, we'll toward the close
of the spring rains. Such fields are s
remarkably free from volunteer
grains and grasses, and are said to |
give increased yields over once (
plowed fields. No wheat aphis in {
jury has ever been seen on double
plowed fields.
Late plowed fields can undoubted-
ly be kept free from vegetation with {
much less labor than early plowed
fields and this practice, when it can '
be carried on without interfering {
with economic farm practices, is re-
commended in districts where the
wheat aphis is abundant. ]
Some farmers allow a small band {
of sheep or other stock to Craze on
summer fallowed land and where We {
getation is kept down in this manner
wheat aphis injury has never been /
noticed. t
Crops may be son on ground
where grain has been destroyed by ,
the wheat aphis. Wheat aphis in t
Jury generally appears early enough
in the spring SO that destroyed areas 1
may be seeded to spring grains or
other crops. Spring wheat may be
safely planted if infested wheat
plants are first plowed under. Spring q