Vol. LXVIII. No. 3089. NEW YORK, APRIL 10, 1909. weekly, $i.oo per year. 
DESTROYING WEEDS BY SPRAYING. 
A Success in the Northwest. 
Last year we spoke of the experiments conducted 
by Prof. H. L. Bolley, of North Dakota, in using 
chemical sprays to destroy weeds. Few of us at this 
end of the country realize how this method has 
grown in favor. In a recent letter Prof. Bolley says: 
‘‘To indicate to you somewhat the extent to which 
the spraying operations have already attained, I will 
say that one firm has placed in its warehouse at 
Fargo a thousand tons of iron sulphate. Their letter 
states that they expect to hold this amount continu¬ 
ally in stock.” 
A good many of our 
readers can remember 
when such a thing as 
spraying with arsenic or 
Bordeaux Mixture to kill 
leaf-eating insects or com¬ 
bat diseases would have 
been considered folly. They 
have seen the practice 
grow until several new 
lines of business have de¬ 
veloped around it. In much 
the same way this process 
of destroying weeds in the 
Northwest by spraying has 
grown beyond all calcula¬ 
tions. When we asked how 
freely farmers use the 
chemicals Prof. Bolley says : 
‘‘The North Dakota 
farmers use iron • sulphate 
and copper sulphate in ton 
lots. Some of the larger 
farmers are spraying thou¬ 
sands of acres for the de¬ 
struction of mustard, spray¬ 
ing directly over the grain 
fields. Where the weeds 
have been holding full 
sway, the increase in crop 
is a phenomenon. Farmers 
have reported as high as 
five bushels of wheat per 
acre increase, besides rid¬ 
ding the land of the 
weeds.” 
We asked him if he 
thinks the plan would work 
as well at this end of the 
country. Apparently he 
doubts it, for he says in 
reply: 
“It is possible that people 
living in eastern and south¬ 
ern States may not get 
success with spraying that 
accompanies it here in the 
Northwest, but I am not sure of that. One of the 
reasons why we meet with such marked success in 
The cereal grain fields of the Northwest, I believe, 
is due to the short, rapid growth season of the 
grain. Scarcely more than a month to six weeks 
need intervene between the weed spraying time and 
the harvest time, hence, weeds which come from 
seed that germinate after the weed spraying process, 
fail to mature before harvest, and as the plowing 
•time immediately follows they are disposed of. This 
results in destroying even such a weed as Canada 
thistles, for the spraying defoliates the thistle and 
prevents the seed production. Again, it is cut off 
by the binder and just about the time it is again 
able to refoliate, it receives further smothering by 
the Fall plowing, so there is little risk of survival.” 
With our longer growing season the conditions 
with us would be different. Yet we have several 
reports of success in spraying grain fields to kill 
out wild mustard. The following list of weeds 
which may be controlled by chemical sprays is 
given by Prof. Bolley: False flax, wormseed mus¬ 
tard, tumbling mustard, common wild mustard, 
shepherd’s purse, pepper-grass, ball mustard, corn 
cockle, chickweed, dandelion, Canada thistle, bind¬ 
weed, plantain, rough pigweed, kinghead, Red-river 
weed, ragweed, cocklebur. The most effective work 
seems to have been done in killing Canada thistle 
and mustard. One of our readers in Iowa asked 
if sulphate of iron would kill sand-bur in a young 
orchard. This question was referred to Prof. Bol¬ 
ley, who says: 
“I have had no experience with the sand-bur. As 
cultivation will be beneficial to his young orchard 
and vineyard I would recommend that surface cul¬ 
tivation be used to destroy the sand-burs. There 
will be places where he cannot reach them with the 
cultivator. In that case he will probably find that 
direct spraying with salt will be destructive to this 
annual grass, and it will do no injury to the land 
whatever. The iron sulphate, if used over and over, 
results in killing annual grasses, but it is not strong 
enough to be recommended for that purpose. A 
spray of sodium arsenite where it can be directed by 
hand is by far the most efficient weed. destroyer, 
and where desirable this will kill grasses by re¬ 
peated sprayings.” ‘ ‘ '. 
A number of substances are used—such as com¬ 
mon salt, sulphate of iron and arsqpite of soda. 
The most popular is iron sulphate. In spraying 
for mustard a solution is made by dissolving from 
75 to 100 pounds of the iron sulphate in 52 gallons 
of water, and this makes about the amount to use 
on an acre. The spraying is done with any kind 
of a sprayer that will cover the land at the time 
when the mustard plants are just beginning to show 
the first bloom. A bright, 
still day is best. When 
salt is used 54 of a barrel 
is dissolved in 52 gallons of 
water. For the same 
amount of water 154 pound 
of sodium arsenite is used. 
For ragweed the salt and 
iron sulphate give best re¬ 
sults, while for Canada 
thistle the arsenic is most 
effective—with salt next. 
The arsenic is a deadly 
poison and great care must 
be taken in using it. When 
trying to kill the Canada 
thistle in pastures it will be 
safer to use strong solutions 
of common salt. On the 
whole, it appears that the 
method is considered a suc¬ 
cess in the Northwest— 
ranking as a farm practice 
with spraying to kill insects 
and fungus in a fruit-grow¬ 
ing section. One of-the 
first questions asked is how 
these chemical sprays de¬ 
stroy the weeds, yet leave 
the grain and grass un¬ 
harmed. 
Prof. Bolley states that 
without doubt grasses and 
grains can resist a coating 
of the chemicals that would 
kill the weeds growing 
alongside. His reasons for 
this are stated as follows: 
“The grasses and grains 
are peculiarly protected for 
several reasons: 1. They 
do not have extended ab¬ 
sorbing surfaces as com¬ 
pared to most weedy 
growths. 2. They are in¬ 
determinate growers while 
young, growing from the 
inside outward at the stem 
ends, the young or growing point, being protected 
while the leaves have the growing point situated at 
the base or sheath. Those parts of the- grasses 
which come most into contact with the spray are the 
tip portions of the leaves and at the time spraying 
is usually done, these portions have already done 
their chief physiological work. Even if the tips of 
such leaves are killed, the basal portions extend the 
growth, furnishing at once new surfaces to the sun¬ 
light. The grasses and cereals also have a pretty 
good protective feature in the bloom or waxy cov¬ 
ered cuticle. In this they are better protected than 
most weeds. I have only to call attention to the 
fact that dewdrops upon wheat and other cereals 
and grasses stand up as round spheres as if from 
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