1

j

l

I

)

1

l

.

·."'

,

·

('

re-

be­

are

cli-

Con-

and

how

over

indi­

more

weed

after

agen~

which

Valley

appar­

is

danger

farmer

neglect

scientific

and

growers

and state

"The

live

granted.

the

for

use.

problems

curly-top

weeds

Livestock,

Agriculture.

ranges

the

state

the

and

54,

to

only

pests.

now,

for

this

of

the

types,

upon

toward

these

and

weeds

from

in and

Joaquin

put

only

Not

Sacramento

tomato,

ROBBINS"

unnoticed;

before

of

these

Even

Station.

taken regions.

soil

ann~ally

common

Circular

California

of

Johnswort),

1

go

carry

are

not

San

land

fields

losses

Station.

W.W.

lower Robbins.

Among

both

tending

Department

(St.

delta

crops,

often

many

blight

which

their

AND

south range agriculture

the

necessary.

community

influence their

of

Extension

attention.

Experiment

methods

combating

State

W.W.

giving

of

for

of

frequently

weed

challenge

by

the

the

now

in

the

and

dissemination

and

habits,

scientist.

yellow

Experiment

in

are

be

more

in

dangerous,

labor expended

Valley,

acres

that

Station.

that

intervening

3]

the

MADSON,•

circular,

is

and

wide

supersedes

spent

diversity

[

their

available

California

and

in

they

may

and

A.

the

Klamath

increasingly CONTROL

Madson,

Leafhoppers,

if

this

its

in

western

and

are

publication.

B.

annuals

is

their

weeds

A.

cooperation

Salinas

in

100,000

of

the concentration

more

and

wide

time

the

years

started.

this

problems

B.

INTRODUCTION"

Control,

with

Experiment is

however,

fall

Botanist

but

the

effort

of

and.Agronomist

and

hopeless, however,

how

and

few

reduced

was

The

weeds.

uncontaminated,

the

in

control

Ball,

and

program.

revision

agriculturist

a

claims

Weed

and

CRAFTS,"

and

allowing

valleys,

in

back

S.

a

mentioned

not

combated

WEED

beet

of

S.

is

presents

show

curb

pest

is

W.

the

inconspicuous

example

and

A.

time control

largely

to

Botany

weeds

Agronomy

by

weeds

.at

demanded,

dam.age

approximately

trained

present

products

AGRICULTURE

An

be

sugar

of

of

Botanist

summer

soils,

of

minimum.

Joaquin

all

characteristic,

being

a

little

the.control

the

of

found

intensification

the Supervisor BALL,'

over

effectively

control

can

been their

examples publication

effort

situation

to

their

needed

San

is

conditions

Weeds,"

S.

too

of

so

very

list

is

do

also

control

of

various

This

Assistant

Professor

W.

their realized.

Two The

With

Weeds,

1 •Field •Professor •

•A

•

cies

clean, duced control

is CALIFORNIA but complex fore organized fore ".1-dual productive on trol

This in have virus the

having

ently

but

names,

spreads

·upper

..matic

·"

•

•

,,

.~~

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-

l

';t

·-

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•.·.

ID.

.

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-;

.....

.

-·.

.

'·'·:~··

,,...,._,.

of of

of of

5 5

for for

to to

by by

on on

the the

one one

the the

an­

with with

life life

may may

with with

crop crop

their their

with with

and and

con­

plant plant

plant plant

loss loss

alfalfa alfalfa

many many

or or

elimi­

or or

loss loss

billion billion

growth. growth.

in in

infested infested

than than

falls· falls·

through through

of of

fact, fact,

obtained obtained

for for

power power

of of

whole-:a whole-:a

the the

When When

have have

the the

resUlt. resUlt.

the the

way way

California, California,

a a

because because

Weeds Weeds

In In

loss loss

of of

weeds. weeds.

three three

infested infested

weak weak

ways: ways:

injurious injurious

food food

infested infested

loss loss

health health

in in

as as

factor factor

which which

moisture, moisture,

alfalfa alfalfa

will will

one one

value value

heaviest heaviest

or or

by by

yields yields

the the

of of

undesirable. undesirable.

competition competition

tax tax

occur occur

in in

and and

most most

slow, slow,

products products

moisture, moisture,

plant plant

about about

weeds. weeds.

many many

the the

burning, burning,

available. available.

annual annual

a a

food, food,

matures. matures.

the the

in in

of of

weeds weeds

the the

country country for for

orchards orchards

the the

lower lower

limiting limiting weed weed

or or

levy, levy,

their their

crop crop

often often

grain.fields grain.fields but but

affected affected

example, example,

crop-producing crop-producing

production. production.

causes· causes·

$244. $244.

food food

by by

portion portion

to to

crop crop

by by

the the

reduclthe reduclthe

the the

plant plant

the the

shading shading

enda~ger enda~ger

destructive destructive

losses losses

at at

other other

average average

of of

of of

or or

For For

The The

keener keener

from from

the the

young young

weeds, weeds, many many

crop crop

said said

for for

industry industry

makes makes

or or

plant plant

its its

either either

may may

eliminates eliminates

failures failures

be be

involves involves consumption

inches, inches,

larger larger

water water

1927 1927

In In

cause cause

pests pests

for for

that that

it it

made made

cultivation cultivation

with with

usually usually

the the

Obviously, Obviously,

noticeably noticeably

and and

light. light. of of

in in

been been

through through

to to

the the

and and

before before

crops crops

few few

Light.-Probably Light.-Probably

may may

destroy destroy results results

crop crop

CONTROL CONTROL

is is

by by

by by

striking. striking.

usually usually

radish, radish,

that that

use use

limited limited

and and

human human

been been

Weeds Weeds

preparing preparing

have have

fun'gus fun'gus

often often

or or

and and

as as

and and

is is

estimated estimated

with with

supply supply

total total

the the

for for

has has

necessary necessary

of of

water water

WEED WEED

dollars, dollars,

wild wild

are are

grass, grass,

first first the stimulated. stimulated.

condition. condition.

and and

perhaps, perhaps, or or

just just

cost, cost,

Wisconsin Wisconsin

poisonous poisonous

agriculture agriculture

1920 1920

soil soil

exhausted exhausted

usually usually

States States

effects. effects.

removed removed

in in

cost cost

is is

Water, Water,

California, California,

labor labor

proportional proportional

compe.tition compe.tition

moisture, moisture,

quality quality

this this

land, land,

in in

is is

limited limited

on on

trees trees

the the

high high

seriously seriously

to to

are are

million million through through

the the

estimate estimate

yields yields

in in

been been

farm; farm;

their their

insects insects

cultivating cultivating

the the

of of

partly, partly,

soil soil

tax tax

at at

mustard, mustard,

this this

the the

least least

effect effect

land, land, Bermuda Bermuda

Food, Food,

no no

food, food,

except except United United

or or

soil. soil.

has has

per per

at at

sometimes sometimes

for for

or or

poor poor

sixty sixty

Indiana Indiana

the the

immediately immediately

weeds weeds

the the

only only

chiefly chiefly

wild wild

animals. animals.

the the

greatly greatly

share share

compete compete

of of

harbor harbor

are are

impair impair

increase increase

Plant Plant

plant plant

increase.the increase.the

annual annual

plants. plants.

in in

$210 $210

unirrigated unirrigated

of of

weeds weeds

which, which,

but but

are are

products products

the the

Though Though

especially especially

reduced, reduced,

but but

of of

and and

supply supply

irrigated irrigated

at at

reason reason

a;n a;n

of of

for for

foxtail foxtail

oats, oats,

must must

They They

agricultural agricultural

probably probably

They They

They They

They They

They They

They They

On On

Upon Upon

Loss Loss

man man

is is Weeds Weeds

6. 6.

5. 5.

many many

4. 4.

3. 3.

2. 2.

1. 1.

morning-glory, morning-glory,

plants plants

When When

with with

water; water;

growth growth

main main

foods, foods,

yields yields

wild wild

contribute contribute water water

production; production;

our our

crop crop

frequently frequently

crops crops

weeds, weeds,

weeds weeds

agriculture. agriculture.

minimum minimum

dollars. dollars.

it it

other, other, ·water. ·water.

of of

ec.onomic ec.onomic

products products

sumption. sumption.

. .

light. light.

of of

nation nation

1936) 1936)

97 97

to~ to~

4) 4)

ex­

are are

our our

Na­

not not

( (

(2) (2)

cost cost

and and

will will

may may

pre­

weed weed

their their

grow grow

crops crops

to to

three three

losses losses

circu­

waste waste

hoped hoped

of of

group group

[Cm. [Cm.

Opera­

control control

College College

are are

of of

of of

produc­

Depart­

and and

or or

of of

be be

artichoke artichoke

they they

with with

employed. employed.

character­

This This

the the

to to

universally universally

other other

eradication, eradication,

Trinity Trinity

control control

Agriculture Agriculture

We We

methods methods

many many

preparation preparation

The The

, ,

diseases, diseases,

annual annual

and and

is is

to to

California, California,

weed weed

in in

of of sequences, sequences,

items items

now now

principles principles

second. second.

perennials perennials

the the

difficult. difficult.

history history

it it

their their

crops crops

Service Service

which which

adequate adequate

According According

But But

the the

The The

growing growing

in in

such such

undoubtedly undoubtedly

weed weed

Valley. Valley.

animals, animals,

of of

one one

tried. tried. useful. useful.

in in

SERVICE SERVICE

thorn thorn

daily daily

the the

As As

methods methods

of of

animal animal

be be

complete complete

weeds weeds

any any

existence. existence.

in in

under under

areas. areas.

general general

summer summer

Klamath-weed-infested Klamath-weed-infested

usually usually

farmer, farmer,

would would

various various

weeds. weeds.

cropping cropping

losses losses

remedies remedies

(1) (1)

for for

that that

through through

unlike unlike

camel camel

Agriculture. Agriculture.

field. field.

important important problem problem

and and

is is

almost almost

phase phase

the the

the the

deep-rooted deep-rooted

Department Department

WEEDS WEEDS

The The

so so

Commerce, Commerce, the the

of of

on on

predatory predatory

epoch epoch

with with

eradication. eradication.

Agricultural Agricultural

human human

Sacrame~to Sacrame~to

this this

sufficiently sufficiently

however, however,

only only

on on

weeds weeds

simultaneous simultaneous

of of

first first

ExTEN8foN ExTEN8foN

much much

in in

this this weed weed

are are

infested infested

our our

pests: pests:

of of

BY BY

average average

Often, Often,

to to

an an

thirty thirty

in in

weeds weeds

the the

State State

conditions conditions

and and

methods, methods,

controlling controlling

so so

spend spend

the the

of of

combined combined

on on

and and

two two

the the

promising promising

been been

the the

battle battle

the the

of of

add add

devised. devised.

upper upper

projects projects

fact, fact,

weeds weeds

submitted submitted

a a

for for

the the

soil soil

should, should,

the the

ranked ranked

mark mark

listed listed

spring spring

vary vary

for for be be

of of

in in

and and

not not

some some

the the

Chamber Chamber

stay, stay,

often often

expense expense

allow allow

these these

work work

by by

promise promise

noxious noxious

The The

farm farm

Department Department

and and

of of

report report

rodents, rodents,

CAUSED CAUSED

weeds weeds to to

rules rules

Cultural Cultural

cited cited

·picture ·picture persistent. persistent.

to to

and and

agricultural agricultural

that that

least least have have

largely largely

total total

to to

exceed exceed

never never

erosion erosion

effects effects

AGRICULTURAL AGRICULTURAL

States States

questions questions

much much

State State

is is

species, species,

of of

here here

at at

loss. loss. and and

spread, spread,

cases cases

practical practical

County, County,

practical practical recent recent

the the

the the

completed, completed,

burden burden soil soil

climatic climatic

justified. justified.

insects, insects,

the the

a a

foothills foothills

to to

are are

winter winter

a a

organization organization

offer offer

supervised supervised

arbitrary arbitrary

establish.ed establish.ed

LOSSES LOSSES

continue continue

many many

requirements requirements

crops crops

United United

the the

methods methods

are are

most most

by by

and and

methods methods

most most

actual actual

the the

attempts attempts

(3) (3)

groups groups

times times

probably probably

and and

of of

investigational investigational

prompt prompt

we we

specific specific

all all

different different

what what

by by

or or

progress, progress,

farms; farms;

the the

same same

down down

the the

being being

considerably considerably

CALIFORNIA CALIFORNIA

costs costs

be be

allowed allowed

during during

the the

will will

some some

in in

Humboldt Humboldt

little little

four four

answer answer

shown shown

habits, habits,

The The

m"ay m"ay

many many

cultural cultural

lay lay

programs programs

If If

greatly, greatly,

perennials perennials

successfully successfully

This This

provided. provided.

of of

circular circular

now now

with with almost almost

.As .As

and and

realize realize

are are

Forest Forest

to to

diseases, diseases,

so so

must must

. .

and and

if if

weeds weeds

Committee, Committee,

initial initial

adequate adequate

be be

incur incur

of of

state state

should should

controlled controlled

.American .American

.Agriculture .Agriculture

weeds. weeds.

Eradication Eradication

This This

Few Few

pasturing pasturing

tional tional

tions tions

ranges ranges

4 4

high high

control. control. will, will,

thistle thistle

periments periments

the the

be be

noxious noxious

mea~mres mea~mres

and and

Obviously Obviously

rotation rotation

ready ready

that that gether gether

undoubtedly undoubtedly

of of

differ differ soon soon

istics istics

different different

of of

applicable applicable

There There

lar lar

plant plant

sented sented

weeds weeds

groups. groups.

from from ment ment

on on

tion tion . .

to to

is is

7 7

or or

the the

the the

the the

the the

of of

on on

the the

and and

the the

leaf leaf

skin skin

six­

State State

and and

leaf­

com­

build build

virus virus

to to

more more

diseases diseases

tomato tomato

weeds, weeds,

one one

lamb's­

only only

propa­

render render

fungus fungus

the the

Lactuca Lactuca

bug, bug,

lives lives

cabbage cabbage

beet beet

bug, bug,

the the

cites cites

infested infested

counties counties

vegetable vegetable

lettuee lettuee

beet beet

and and

19 19

especially especially

apple apple

aphid, aphid,

in in

the the

for for

8 8

pests pests

not not

leafhopper, leafhopper,

plant plant

to to

by by

1933. 1933.

harbor harbor

weed weed

of of

leafhopper, leafhopper,

will will

Harris Harris

presence presence

of of

in in

the the

the the

hay hay

of of

another another

California California

many many

the the

aid aid

aphid; aphid;

crops. crops.

bli~ht bli~ht

leafhopper, leafhopper,

many many

strawberry-root strawberry-root

the the

hosts hosts

hosts, hosts,

to to

by by

may may

melon melon

cabbage cabbage

insect insect

western western

grape grape

beetle, beetle,

grape grape

big-eyed big-eyed

thistle thistle

and and

by by

spread spread

be be

they they

Jimson Jimson

pests. pests.

the the

or or

spread spread

thistle. thistle.

:273-277. :273-277.

mildew mildew

beets, beets,

bean. bean.

fact, fact,

Lockwood

blackleg blackleg

the the

the the

harbor harbor

example, example,

flea flea

is is

peach peach

wild wild

destructive destructive

belonging belonging

to to

.. ..

aster aster

bug, bug,

in in

the the

example, example,

plants plants

to to

California California

sow sow

for for

22(6) 22(6)

Thus Thus

in in

weeds: weeds:

miner, miner,

insect insect

sugar-beet sugar-beet

sugar sugar

Russian Russian

mustards mustards

cotton cotton

commercial commercial

more more

reduced reduced

downy downy

in in

harlequin harlequin

important important

wild wild

weeds weeds

aphids; aphids;

thrips, thrips,

For For

green green

to to

also also

eausing eausing

potato potato

thistle thistle

plant plant

causing causing

of of

Bul. Bul.

known known

and and

to to

the the

and and

._Weeds ._Weeds

the the

. .

factor factor

example, example,

pests. pests.

wireworm, wireworm,

the the

The The

wild wild

clover, clover,

the the

the the

several several on

as as

but but

a a

Mo. Mo.

top top

worthless; worthless;

citrus citrus

thrips; thrips;

render render cultivated cultivated

weeds weeds

greatly greatly

as as

.moth; .moth;

for for

several several

several several

others. others.

present present

trash trash

weeds weeds

Pests Pests

of of

to to sour sour

and and

lettuce lettuce

CONTROL CONTROL

Russian Russian

be be

aphid, aphid, Agr. Agr.

the the scale, scale,

insect insect

pests pests

migrate migrate

on on

organism organism

spinach-leaf spinach-leaf

in in

tarnished tarnished

1933. 1933.

aphid, aphid,

they they

curly curly

organism organism

above, above,

of of

bean bean

destructive destructive

to to

Certain Certain

tiger tiger

cabbage. cabbage.

Weeds Weeds

than than

common common

and and

may may

live live

and and

hosts hosts

found found

of of

and and

sugar-beet sugar-beet

Dept. Dept.

such such

the the

the the

in in

plum plum

The The

yellows, yellows,

WEED WEED

many many

aphid, aphid,

F'ungits F'ungits

addition, addition,

relation relation

the the

practically practically

seeds seeds

prickly prickly

hosts hosts

to to

which which

melon melon

to to

cushion cushion

Stout. Stout.

Califm~nia Califm~nia

milling. milling.

the the

may may

In In

:279-:-282. :279-:-282.

beet beet

wild wild

be be

bacterial bacterial insect insect

crickets, crickets,

of of

been been

State State

or or

hibernate hibernate

and and

and and

The The

wheat wheat

L. L.

are are

weeds weeds

few few

aster aster

of of

mustard. mustard.

species species

species species

for for

mentioned mentioned

host host

an an

a a

G. G.

the the

of of

purse purse

that that

The The

clubroot clubroot

bug. bug.

on on

may may

has has

a a

22(6) 22(6)

field field

leaf-curl leaf-curl

from from

legumes; legumes;

cabbage cabbage

that that

plantain. plantain.

cottony cottony

enemies, enemies,

and and

young young

objectionable objectionable

as as

cotton cotton

Insect Insect

wild wild

unfit unfit

including including

species species

Bul. Bul.

the the

Even Even

Stewart. Stewart.

vine vine

species species

diseases diseases

value value

the the

California California

R., R.,

of of

several several

triplex triplex

beetle, beetle,

the the

wild wild virus virus

on on

act act

causes causes

diseases; diseases;

the the

fungus fungus

crop crop

leafhopper, leafhopper,

importation. importation.

A A

29 29

control. control.

Mo. Mo.

spread spread

cabbage cabbage

M. M.

insects insects

more more

a a

to to

numbers numbers

its its

leafhopper leafhopper

wheat wheat

the the

flea flea

and and

is is

its its

shepherd's shepherd's

leafhopper, leafhopper,

to to

will will

that that

aphid, aphid,

Rumex Rumex

and and

weeds. weeds.

by by

family, family,

list list

such such

leafhopper, leafhopper,

Agr. Agr.

aphid, aphid,

of of

are are

market market

virus virus

of of

apple apple

the the spider,

thrives thrives

puncture puncture

beet beet

bacterial bacterial

broad-leaved broad-leaved

Lockwood, Lockwood,

their their

California. California.

8 8

•Harris, •Harris,

Ha1·boring Ha1·boring

The The

sack sack

Dept. Dept.

in in

weevil, weevil,

the the

worm. worm.

banded banded

quarters quarters

-red -red

bean bean

clover clover

beetle beetle

weevil; weevil;

the the

up up

species species

harlequin harlequin

apple apple

following following

especially especially

hopper; hopper;

disease, disease,

the the

Stout' Stout'

more more

spotted spotted

posite posite

caused caused

also also

fungus fungus

some some difficult difficult

gating gating

and and

a a

certain certain

prohibit prohibit

with with

weeds weeds

1936] 1936]

I I

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} }

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··. ··.

.. ..

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~~· ~~·

r r

l: l:

E. E.

F F

i: i:

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to to

is is

in in

f'"l f'"l

for for

97.;~ 97.;~

for for

In In

and and

first first

ex­

the the

pri­

indi­

---

Some Some

and and

seed. seed.

many many

hand­

loss loss

weeds. weeds.

farm farm

lands lands

dealer dealer

mostly mostly

equip­

cereals cereals

the the

market­

produc­

[Cm. [Cm.

hay, hay,

of of

one-fifth one-fifth

of of

cultiva­

depress' depress'

subjected subjected

1,444,000 1,444,000

seeds seeds

the the

farmer farmer

-

prepara­

used used

the the

in in

the the

of of

weed weed

roadways, roadways,

expense expense

of of

money money

equipment equipment growth. growth.

California, California,

be be

include include

and and

with with

cotton, cotton,

already already

. .

least least

the the

the the

annual annual

equipment equipment

. .

annual annual

for for

weed weed

alfalfa alfalfa

with with

upon upon

about about

not not

at at

and and

as as

to to

and and

much much

$1,200,000. $1,200,000.

cultivated cultivated

consisting consisting

which which

are are

weed weed

must must

the the

corn, corn, of of

increase increase

public public

or, or,

is is

quantities quantities

do do

further further

ditches, ditches,

tax tax

purpose purpose

perennials perennials

on on

rioxfouEfweedS. rioxfouEfweedS.

of of

SERVI~ SERVI~

costly costly

. .

investment investment

origin. origin.

labor labor

implements implements

cent, cent,

price price

Oonsumption.-After Oonsumption.-After

ton, ton,

fu· fu·

crops crops

the the

Since Since

contamination contamination

tons tons

cro~s cro~s

harvesting harvesting

Weedy Weedy

crop crop

average average

weedy, weedy,

weeds, weeds,

a a

sole, sole,

weeds weeds

cereals cereals

more more

for for

other other

per per

down down

Further, Further,

be be

the the

the the

nor nor

involve involve

seed seed

high high

ton. ton.

install install

The The sorghum, sorghum,

more more

the the

however, however,

weedy weedy

. .

weeds weeds

to to

a a

of of

contaminated contaminated

with with

the the

California California

one one

In In

most most

value. value.

11,000 11,000

$1.50 $1.50

and and

annual annual

the the

which which

_or _or

of of

such)illage such)illage

not not

.. ..

enormous enormous

may may

approximately approximately

in in

objectionable objectionable

must must

·iixTENSION ·iixTENSION

are are

of of

areas, areas,

less less to to

/·'.;, /·'.;,

if if

•·I •·I

crops. crops.

of of

foul foul

over over

keeping keeping

is is

one one

an an value value

Products Products

liable liable

than than

with with

which which

figures, figures,

origin. origin.

rice rice

against against

is is relatively relatively

market market

crops-]ike crops-]ike

. .

the the

cost cost

the the

mallchv, mallchv,

constitutes·anotli.er constitutes·anotli.er to to

well well

·~re ·~re

value value

transported. transported. $2.50 $2.50

material material

discussion. discussion.

Millers Millers

extent extent

Equf/ment.-The Equf/ment.-The

contain contain

cereal cereal

Crop Crop

Products.-Weed Products.-Weed

more more

eradicating eradicating

of of

the the

cultivating cultivating

.· .·

and and

to to

in in

and and

usual.ly usual.ly

and and

These These

to to

cost cost

· ·

:~· :~·

weedy weedy

California California

( (

the the

principal, principal, and and

of of

weeds weeds

cultivated cultivated

weeds. weeds.

our our

possesses possesses

is is

and and

methods. methods.

check check

for for

need need

for for

other other

especially especially

California California

of of

in in

second second

summer summer

of of

contamination contamination

average average

in in

Farm Farm

wheat. wheat.

in in

the the

.A.Gil(cuLTURAL .A.Gil(cuLTURAL

$1.00 $1.00

to to

creeymg creeymg

the the

campaigns campaigns

in in

of of

dockage dockage

barley, barley,

of of

the the

and and

quality quality

one-twelfth one-twelfth

farm farm

The The

Labor Labor

and and

Preparing Preparing

therefore, therefore,

planting planting

on on

assumed assumed

cleaning cleaning

against against

against against

grown, grown,

reduction reduction

weed weed

reason reason

at at

of of

expense expense

annually. annually.

grown grown

handled handled

. .

found found

reasons reasons

from from

of of

near near

weeds weeds

of of

be be

control. control.

expensive expensive

. .

material material

as as

known known

oats, oats,

example example

ii.gr ii.gr

the the

seeds seeds

their their

be be

be be

every every

growth growth

orchards orchards

ain. ain.

processing, processing,

or or

by by

average average

part part

crops, crops,

I I

Quality Quality

of of

main main

industry industry

Cost Cost

crops crops

barley, barley,

· ·

·I ·I

may may

Cost Cost ct'.mtrol. ct'.mtrol.

·: ·:

grown, grown,

weed weed

CALIFORNIA. CALIFORNIA.

lands lands

tb.e tb.e

charged charged

an an

seed, seed,

brings brings

average average

may may

weed weed

affd affd

to1'.e~p to1'.e~p

and and

is is

must must

and and

one one

seed seed

estimated estimated

wheat, wheat,

too too

specifically specifically be be

seed seed

ThJ'm.·, ThJ'm.·,

rice, rice,

chargeable chargeable

these these

for for

morning-glory, morning-glory,

much much

an an

thet!nd thet!nd

reduces reduces

Almost Almost

weed weed excellent excellent

$40,000,000 $40,000,000

remove remove

is is

with with

of of

considerable considerable

such such

as as

alfalfa alfalfa

. .

costs costs

of of

waste waste

of of

is is

crop crop

been been

the.crop the.crop

fact, fact,

weed weed

Impaired Impaired

An An

Most Most

Increased Increased

Also Also

prevent prevent

Increased Increased

That That

the the

With With

cutting cutting

example, example,

crops crops

.of .of

residue residue should should

cated, cated,

ing ing

of of

tion tion

tons, tons,

ling ling

must must

that that

In In

removing removing

handling handling

such such

the the

marily marily

ment. ment.

and and

pended pended

about about

very very

has has

tion tion

vineyards vineyards

tion tion

income. income.

necessary necessary

beans beans

or or 6 6 ~,... i 0 8 CALIFORNIA AGRICULTURAL EXTENSION SERVICE [Cm. 97 1936] ~~ WEED CONTROL 9 sphinx, and the potato-tuper moth; several' species of plantain to the that had attended its development for ages. The pigweeds, thistles~morn­ rosy apple aphid, the cotton or melon aphid, the tarnished plant bug, the· :~ potato flea beetle, and the serpentine leaf miner; species of wild mus­ ing-glories, and others came with the .American farmer and ha.ve not tard, for a time at least, to the sugar-beet leafhopper, the grape leaf­ only persisted to tax his labors but thrived as in no other situation~In the deep alluvial soils and .temperate clinlate of Oalifornia ·many weed· hopper, black grass bug, the harlequin cabbage bug, and other injurious ,,:~ insects; wild morning-glory to many crop pests, including the common ••• species find better conditions than in their native lands. They have red spider, several species of thrips, the cotton or melon aphid, and the ~> tended, consequently, to drive out economic plants and have resisted the ' ~i control measures effective in the East and in Europe. ' soft brown scale; and lupine to the pod borer, so destructive to baby .· ·f lima beans. J. C. Elmore, of the United States Bureau of Entomology, b The introduction of new weeds has continued up to the present, and states that in the pepper-growing districts of southern California ap­ only constant vigilance can check their establishment and spread . .Arti­ proximately 85 per ·cent of the first weevil infestations in the spring jf choke thistle was first brought in as a vegetable, restricted to a few - ~~~;; originate from one species of nightshade (Solanum douglasii), which is gardens. Escaping, it has covered thousands of acres of valuable range a host to the pepper weevil, especially in winter. '!'his weed, therefore, land in Solano and other Bay counties, Camel thorn, an extremely per­ should be eradicated from areas devoted to pepper growing. Nematodes nicious weed, was first brought into a southern county, presumably from and grasshop:pers, destructive to many crop plants, live and multiply southwestern .Asia in Turkestan alfalfa seed. Fro~this small start it on weeds. Tho'.Ugh other examples might be cited, those given indicate spread to ten California counties, infesting approximately 600 acres . .At how weeds assist insect pests. In fact, if uneconomic plants could be present Marlahan mustard, or dyer's woad, a biennial weed from Europe, eliminated, some of our worst crop pests could be easily controlled. is confined to Scott Valley in Siskiyou County. Austrian field cress, a . Injury to Livestock and Human Beings.-Many domestic animals are perennial, also from Europe, is limited to a region at the headwaters of lost annually from weed poisoning. The most important poisonous wee~ the south fork of the Pit River in Modoc County. Many of the early in­ such as larkspur, water hemlock, whorled milkweed, Klamath weed, art~ festations were limited in area and, by proper handling, could have been death camas, occur-extensively on some rap.ges, under conditions d~ eliminated; but ignorance, indifference, neglect, or improper methods cult to control. On cultivated lands and in pastures seeded to cultivated have permitted most of them to spread, till today soDJ,eare beyond hope plants, many animals are lost through their owners' failure to eradicate of eradication. poisonous weeds. Certain species of lupine, poisonous when in seed, If an infestation involves a small patch of a very noxious weed, espe­ cially a new introduction, strenuous methods and considerable expense ~auseannual losses of sheep. The health of human beings may also be affected. Deaths occasionally are justified in preventing that weed from gaining a foothold. An ex­ occur from the eating of poisonous seeds, berries, or tubers. Poison oak pense that might be inordinate if required over a larger territory causes much suffering and distress, and many victims of hay fever can becomes, in such an emergency, highly practical. trace their aflliction t<::ithe pollen of weedy plants. To prevent the introduction and spread of new noxiorui we~dsin Cali~ fornia requires vigilaMe, not only by quarantine officials, county agri­ INTR01'UCTION AND SPREAD @F WEEDS cultural commissioners, and farm advisors, but also by growers. When Weeds as we know them today were no problem in the lives of early Cali­ new weeds are found, prompt and concerted action should be taken. If fornia settlers. They. were, with few exceptions, introduced into this eradication is too difficult for the individual, then county and state country with the settlers and their crops. To this day, in fact, specific should cooperate . .All infested areas should be adequately marked and crops tend to have their special pests; and, with the introduction of new ;I periodically inspected to insure complete eradication. crops, new weeds are certain to occur. Wild oats and many weedy range ' Impure Commercial Seeds.-Probably the most common and effective grasses, apparently, arrived with the Spanish invaders, probably in hay means of introducing weeds is the sale and distri"bution of impure com­ ·~ accompanying livestock. Some of these weedy annuals were so thrifty :l mercial seeds. Hoary-cress and Russian-knapweed infestations in many and so prolific in seeding that they have practically supplanted the native localities in California can be traced to impure Turkestan alfalfa seed vegetation of our foothill range areas. , ·i brought in during the World War. These two pests are now so widely With the westward march of intensive agriculture came the weed& ~ ~tributedthat there seeins to be little hope of eradicating them. , / During the winter of 1927-28 many consignments of Sudan grass seed

.. ·1,

\- - '

i i

i1 i1

oJ oJ

th th

hi~ hi~

soi soi

the the

11 11

de­

har har

ope ope

con: con:

cut cut

thei thei

and and

cars, cars,

grail grail law, law,

way, way,

trees, trees,

recen recen

on on

in in

infes­

prop­

of of

moved moved

Delta Delta

of of

having having

farmin farmin

and and

materi~ materi~

equally equally the the

loads loads

the the

Valley, Valley,

it it allowed allowed

the the

and and

Seedsme Seedsme

Cyperus Cyperus

screenin~ screenin~

seed seed

seed-cleau seed-cleau ( (

grinding grinding

the the

stock stock

is is

in· in·

clover clover

on on

eradicatinf eradicatinf

infestatiom infestatiom

are are

about about

later later

camel-thorn camel-thorn

this this

kinds kinds

within within

practices practices

construction. construction. sell sell

in in

distributed distributed

in in

along along

fine fine

out out

particularly particularly

several several

seed seed

vehicles; vehicles; adequate adequate

from from cleaning cleaning

scattered scattered from from

California California

All All sell sell

in in

through through

from from

and and

animals, animals,

grass grass

the the

Joaquin Joaquin

or or

bodies bodies

will will

and, and,

dairyman, dairyman,

streams. streams.

of of

thorn, thorn,

of of

scattering scattering

in in

not not

the the

1). 1).

often often

packing packing

spent spent

pound pound

California California

nut nut

them them

used used

San San

is is

farm, farm,

scattered scattered

by by

miles miles

seed seed

In In

One One

into into

accumulated, accumulated,

permit permit

of of

dealers dealers

the the

scattered scattered

to to

are are

per per

bedding bedding

(fig. (fig.

by by

pests pests

it it

potatoes potatoes

camel camel

tracts tracts

foreign foreign

to to

later later

wheels wheels

dissemination dissemination

burning burning

for for

airplanes. airplanes.

purchased purchased

in in

this this

screenings screenings

of of

are are

commercial commercial

south south

clean clean

dump dump

gravel gravel

present present

of of

farm farm

of of

often often

the the

seeds seeds

seed seed

seeds seeds

with with

implements; implements;

fed fed and and

some some

all all

nutlets nutlets

or or

many many

hay, hay,

Puncture-vine Puncture-vine

the the

were were

concern. concern.

dump dump

animals. animals.

region region

sow sow

or or who who

seeds seeds

marked marked

The The

are are

to to

driven driven

in in

be be

in in

He He

to to or or

Gravel.-Though Gravel.-Though

introduction introduction

digestive digestive

from from

kicking kicking

sufficient sufficient

weed weed

means means

Although Although

other other

be be

stockman stockman that that

to to

While While

sand, sand,

sand. sand.

farm farm

was was

CONTROL CONTROL

grave grave

unscrupulous unscrupulous

disposal disposal

89 89

the the

the the

spread spread

Almost Almost

and and

weed weed

dollars dollars

in in infested infested

are are

door door

lands. lands.

feed, feed,

weed weed

of of

cress. cress.

and and

out out

of of

weeds weeds

animals animals

and and

of of

other other

of of

later later

dirt, dirt,

Shafter Shafter

path path has has

automobiles automobiles

materials materials

attention attention

some some

for for

sheepmen, sheepmen,

of of

WEED WEED

in in front front

at at introducea introducea

of of

Another Another

problem. problem.

which which

trucks, trucks,

through through

to to

through through

hoary hoary

may may

carry carry

pasture pasture

a a

matter matter

Packing, Packing, labeling. labeling.

turned turned

of of

these these

the the

feet feet

gravel, gravel,

a a Their Their

prevalent prevalent

a a

and and

which which

Agriculture. Agriculture.

regarding regarding

tires tires

tolerance tolerance

often often

at at amounts amounts

fed fed

from from

Conveyance.-Weed Conveyance.-Weed

seed seed is is

in in

door door

may may

a a

grower's grower's cultivators, cultivators,

with with

growers growers

agricultural agricultural

any any

Hundreds Hundreds

the the

of of

not not

dangerous, dangerous,

planted planted

Feed, Feed,

procedure, procedure,

of of

are are

bodies bodies

hay hay

'·-

special special

seedlings. seedlings.

becomes becomes

the the

on on

thus thus

Screenings.-The Screenings.-The

our our

in in

weed weed

large large

unharmed unharmed

are are

back back

infestations. infestations.

rubber rubber

manure, manure,

of of

farmer farmer

cattle cattle

weed weed

foothills. foothills.

allows allows

plows, plows,

of of

of of

being being

The The

range. range.

animals animals

harvester, harvester,

a a

feedstuffs, feedstuffs,

of of

dirt dirt

legislation legislation

the the

to to the the

or or

proper proper

often often Means Means Weeds Weeds

pass pass

the the

loss loss seed seed

called called

the the

machinery machinery

Seeds Seeds

Sheep Sheep

transportation transportation

above above

his his

tolerances, tolerances,

without without

on on

protect protect

were were

to to

and and

the the

tell tell

clean clean Department Department

can can

contaminated contaminated

establishments establishments

only only

pieces. pieces.

to to

resultant resultant

passage passage

sheep sheep

instance, instance,

Disposal Disposal

camel-thorn camel-thorn

Other Other

various various

b.y b.y

Weed Weed

Federal Federal

range. range.

through through

worker worker

to to who who

disposal disposal

the the

mercial mercial

ing ing

combined combined

fields. fields.

vesting vesting

years, years, adhering adhering

mud mud

the the

own own

hay hay

of of

them them grazed grazed

seed seed

the the

scattering scattering

as as

During During

in in

offensive. offensive.

scribed scribed tations. tations.

alfalfa alfalfa certain certain

for for

erly erly

rofandus), rofandus),

a a

seed seed

State State

region region

1936] 1936]

( (

the the

ex­

the the

the the

un­

star star

97 97

knap­

illus­

by by

grades grades

Sudan Sudan

in in

the the

thistle, thistle,

State State

Johnson Johnson

Sudan Sudan

formed formed

creeping creeping [CIR. [CIR.

In In

through through

Johnson Johnson

indicating indicating

yellow. yellow.

contain contain

explains explains

bull bull

The The

noted noted

and and

of of

Russian Russian

Department Department

inferior inferior

morning-glory, morning-glory,

nutlets nutlets

examples examples are are

may may

prevalent prevalent

thistle, thistle,

seeds, seeds,

been been

imported imported

largely largely

Laboratory, Laboratory,

grass, grass,

too too

right, right,

impurities. impurities.

continued continued

seed seed

thistle, thistle,

SERVICE SERVICE

These These

grass, grass,

this this

barley barley

weed weed

sale sale

California. California.

involves involves

thistle. thistle.

all all

today. today.

of of

California California

Seed Seed

percentage percentage

in in

Russian Russian

star star

same same

recently recently

grass grass

are are

potato; potato;

morning-glory, morning-glory,

star star

alfalfa alfalfa

into into

a a

the the

the the

barnyard barnyard

has has

usually usually

these these

that that

Crops, Crops,

in in

barnyard barnyard

perennial. perennial.

by by

yellow yellow

Found Found

samples samples

EXTENSION EXTENSION

analysis. analysis.

grass, grass,

dodder, dodder,

California California

yellow yellow

potato. potato.

California California

of of

Johnson Johnson

uncontrolled uncontrolled

shipped shipped

a a

for for

were were

Field Field

in in

thistle, thistle,

of of

farmer farmer

cress. cress.

penetrating penetrating contain contain

and and

Laboratory, Laboratory,

noxious noxious

of of

grass, grass,

This This

increase increase

to to

were were

observed observed

typical typical

within within

Johnson Johnson

receipt receipt

seeds seeds weed

may may

grass grass

seeds seeds

dissemination dissemination

weeds weeds

this this

grass, grass,

Seed Seed

hoary hoary

blessed blessed

the the

rapid rapid

nut nut

were were

of of

water water

submitted submitted

morning-glory, morning-glory,

Bureau Bureau AGRICULTURAL AGRICULTURAL

farmer farmer

a a

of of

analysis. analysis.

weed weed

thistle, thistle,

wheat wheat and and

percentage percentage

weed weed

or or

of of

State State

noxious noxious

with with

Oklahoma Oklahoma

the the

seed seed

noxious noxious

of of

cases cases

for for

containing containing

of of

Johnson Johnson

and and

from from

star star the the

of of

high high

noted noted

and and

rhizome rhizome

to to

oats oats

other other

these these

acres acres of

common common

seed seed

infestations infestations

means means

The The

CALIFORNIA CALIFORNIA

barnyard barnyard

danger danger

thistle, thistle,

knapweed, knapweed,

beginning beginning

yellow yellow

samples samples

morning-glory, morning-glory,

of of

Texas Texas

and and

the the

submitted submitted

Seed Seed

of of

new new

commercial commercial

new new

1.-Left, 1.-Left,

the the

in in

in in

seed. seed.

seed seed

Laboratory Laboratory

A A

Though Though

According According

Fig. Fig.

Agriculture, Agriculture,

weed, weed,

thousands thousands

never never change change

Russian Russian

grass grass

grass. grass.

thistle, thistle,

Russian Russian

mallow, mallow,

seeds seeds

clean clean

trate trate

many many 1929 1929

grass grass

grass grass

Seed Seed

grown grown

10 10 ·of ·of ·

-

~ a

is

to.

or

1a-

the

For

ani­

irri­

over

they

been

rela­

than

root­

Cali­

over­

froJn

them.

many

seeds, in

weeds

differ­

enable

has.:idl:

cockle­

12-foot

is

willow,

catches

by

carried

species,

in

noxious

produce produce·

Johnson

a

pigweed,

and

becom~

bindweed, is

or

beings,

rainfall

often

prickles

Early

to often

with

that

these

weed

on

feared

to

thus vine,

survive

rapidly

season

tall

the

has

produce

roots

either

are be

spreading.

to

water;

thistles, Furthermore,

are

spreading

black

with

different

water,

of

to

point

weed-seed

by

vegetatively

human

necessarily'

on

known

hooked

section of

_

example,

infestations

enough

millions.

through

sow

organs

by

81 and

pests

where

or year;

or

156

but

weed.

way

puncture

pigweed,

cleanup

usually

more

for of

given

been

plant

in

morning-glory,

loaded attachments

have

a

means

man,

each these

seed

wind,

weed

nonirrigating

another

are

of

barbs

several

doorweed,

one

will float

of

dragged

of

total

have

dissemination

reproduces

in

by

grass,

by

noxious

may

the

by found effective

livestock

no

a

annuals

sandbur,

a

dandelioD.S,

or

prostrate undisturbed it heavily

cottony

passing

to

seeds

underground as

only

Most

elder, weed

weed

satisfactory

of

or·

number

some

important

Klamath

CONTROL

a

but

clothing

themselves

of

during

the

most

not

course,

infestation.

cultivation

Johnson

being

ditches

seeds

such

an

.

be dispersal

weed

become cultivators

very

increase.

common

Colorado,

of

may

the

and

be

have

of

Of

a

themselves

be marsh

rest

tumbleweeds

spread

The

not in

for

WEED

or

milkweeds,

or

and

with to

means

prolifically, poisonous

the

to

clean to

may

soon

spread

weeds

Many

a

banks,.apparently,

tall

mild,

is

period

may

feather-like

met the

reestablish perpetuation.

as

attach

and

sources

seeds

irrigation

portions

seeds

or conditions.

rapidly.

are

found

areas

of

In

known

of

thistles,

working

adapted

animals,

injury,

characteristics; Ditch about.

harrows,

perennials,

individual have

vegetative

observed

is

dandelion. must

and

the that

of

of

seeds;

24-hour are numerous

locality

perennials

were

parts,

spread

place.

a

effective

means

and

climatic of

winters

different

ditch.

often that

blown

operations

plows,

frequently

to

one

seeds

a wool

writers,

weeds

plant seeds

high.

similar

farmers.

numbers

as

lettuce

certain

and

beggar-ticks

so

be

weeds

or

the

and

million

Although waters

by the lamb's-quarters,

dock,

mechanical

irrigation

seeds

noxious

were

and

slow,

The

three

Undesirable niost

to during

have

from

place

Any

of a

where

carry

and

wild

of

soil

hair field,

Soine

The Annual The Cultural

them One 1936]

these pest. and those underground mals. ditch multiply must example, over gation bur, relatively thousands. causes weed only mud enormous from roadsides which ent fornia sedge, from the grass, tively stocks; may looked curled the

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of

of

81

45

at­

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.

sea­

oats

Ber­

Also

total such

sam­

agri­

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grass

plant

Asso­

them­

some­

seeds.

either

a

spread [Cm.97

having

spread

screen­ dodder

usually

Most

sample,

Russian

and

supervi­

they

and

man's

means

enormous

;

were

of

Nine run

screenings

not

heliotrope,

1,200.

weed grass

injury.

and

samples,

:

malice, county they

their

contained

do

Johnson

showed

11

different weeds.

alfalf_a-

establish

resist or

thistle,

seed by

been

pernicious

barley,

of sample,

material,

and

perfect

pound

produce

drought

wherever

;

seaside

visible

are

and

they

stream

destroy

dump

quantity

of

and

SERVICE

the

Johnson ;

had these

cat's-ear

they

milk

with

samples

Commissioners'

per

to

soil

seeds

in

and

9

they

few

more

11

Of

wheat,

information

collected

ground

down 18

and

areas

ignorance

the

Thirty-one

pound

No

sample, without

weeds. chicory,

seeds

methods plants

thistle,

large-seeded

in

found prevented

These the

known

from

wanted;

of

per

A

2,178,

EXTENSION

in

sow

seeds.

carried

·

some

8,175

relatively

and

not

objectionable

Also

been

averaged examined,

conditions;

following

thistle, through

ranges. process years

characteristics

Agricultural

seeds.

be

as

unground,

cultivated

temperature,

pound

grinding

seeds

law

Hammermill.

spiny

weed

to

weeds.

the

how for

thistle

333.

found to

sow

have

a

where

and

world,

per weed

screenings

weed

by

State of

high

high

344

contains

or

climatic

CHARACTERISTICS

samples live

species-mostly

summer

star

as

the of grinding

were

present

the

devised.

screenings River,

thistle,

vine

have grow

valleys

dodder thistle,

yielded

on

in and

AGRICULTURAL

frost,

perpetrated

mixed

of

may

be world ground the

the

to

plant

determine sow

not

presence

of

grinder

soil

yellow and

contained

species.

star

extent forbidden

WEED

field

weeds, the

hills

to

that do

numbers

screening

plants tend

all

the

could

be sorghum

establishments

survive species-mostly

all

puncture

the

in

882,

the

hills

type

But

weed

through of

Whether

mallow.

Sacramento

of

chicory,

different

to

yellow

seeds

effectively Committee

samples

they

varying

CALIFORNIA

screenings,

plants

may

bur

common

:

into

weeds

77

alfalfa ground

plant

should

of the

showed

commissioners, gone a pests. of

almost

were

how

attempted

countless seeds

possible. 27,

Seed

sample

as

grass,

and

occurred they

the

adjacent

under different

into

is

present

heliotrope.

45 from

creeping

native

cent

and the

irrigation.

16

One

Eighteen

Seed-cleaning The

'Of

Of

our acteristics tack; from grow numbers through per selves and actually

species,

different of present cultural ciation Samples muda contained ings by are was times areas practices sion ples morning-glory thistle and side spreading

12

· if

in

in

In

15

his

die

are

the

one.

pro­

they

soil­

Cali­ must

some

later

acid,

They

prac­

grow

inter­

crops.

where

shoots

mean8

would

should

second

should

of

during

spring,

provid­

usually

method

in

used

and

or

a

for

an

way,

for

soil

This

orchardist

plants California

germinate

invade

when

land.

the

groWth.

new

moisture

oil

are

exercised

often

plants

This

surrounding

of

in

weeds

in

this

seeding, the

the

land

spraying

up

that not

seeds,

free

be

throughout plowing

purpose

for

Such

effective,

the

practice

in

unprofitable

plan.

they

available.

orchards,

of

do produce

for

impossible

acid.

the

_winter

either

and

early usually

the

be

plowing.

layers

live

also

principally

send

in

land

from

and

annual

menace

winters

plowing

are

seed.

used

to

case

rosette-like

crop

may

crop

annuals

of

and

weedy

of

followed,

often

early

the

a

two-fold

will

common

a

-

seeds

fairly

a

used

may

mild

before

plants

is

sprays,

sulfll.ric

this

is

or

surface should

mowing

weeds

and

job

the

competition

spring;

perennials

Where

preparing

annuals,

as

and the

produce

soiling

as

The

In

also

however,

crop-rotation

production. the

and

control

a

fall

under

ripen

in

summer

leaving radish,

a

the

young it

forming good

section.

develop

iri.

produced,

serve

cost.

cultivation,

to

and

leaves

crop

procedure

the

such

a

similarly

in

in

severe

caution

program

annual

the

plowing

and

is

and

winter

during

CONTROL

a

The

noxious

and

wild

of

for

next

kept

in

check

are

often

they

plowed

seeds

methods,

lower

seed

operatio'ns

heavy

spray

covercrop

be

season,

to

If flower,

sheep

Great

pasturage.

California.

and

placed the

that

such

shallow

cultivation

Spring

and

the

controlled,·

WEED

is

minimum

times-a

or

start

prevent

the

in

for

_in

for

hazard

germinate

Such

production

checking

at

seeds

and

It

same

clean,

of

before

available,

Annuals favorable.

primarily

production

a

luxuriantly

effective

condition,

will

of

Where

lettuce

the

usually

selective

cattle

rapidly, careful

plowing.

spring,

the

detail

used

readily.

are

that

Shallow

several

seed.

not

a

allowing

is

usually

is

cereal axils

control

for

done

in

Two

undetected.

under

is is

grow

annuals

the

effectively

wild

by

winter; cereal

control.

grow

screenings

is

and

In

to

means

C'overcrop

in the

crop

between order

scatter.

as

thorough.

in

mowing

of feed

during

are

presents

the

winter.

in

in

vegetative often

method

best

they

water

repeated

extremely

annuals

turned

spread

season.

a

germinate

conditions

cereals,

sometimes

which

crops.

.and

such

summer

seeds

under both

flowers

be

the

be

described

second be

in

green

the

first

difficult

if buds

weeds

summer

of

valuable

and

to

of

will

are

always

be

a

planting

rainy

perpetuated

difference

spring

clean

shallow,

maturity

The

Annuals

Although

The

Winter

growing

tice

plowed are crop

viding the be and land

fornia, will should ing species, from be irrigation

fields

the should

these summer Plowing

the

more throughout have

during moisture winter the 1936] to

Rfford tilled

seeds

.they

f>

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,'.~

I

or of of

of

in

by

are

the

the

the

one

but

cul­

The

The

con­

soil. irri­

that

may

mus­

corn­

plow.;.

many

in

insure

Often,

atmos­

is

under­

[Cm.97

by

annual

certain

by

the

of

seed

habits

question.

to power a

have

field morning­

buried

indicated,

germinate

chickweed

themselves

in

soil

weeds.

growth

the

habits.

a

plowing,

lost.

attained

its

in

purse,

no

parts

adapting

practice.

Plowing

of

and

another

seeds

to

determine

be

ragweed,

and the

Annuals

them

brought

when

introduction

no

has

their

their

to

Thus

this

produce

seldom

undergo planted,

already

period

be

upon

crop

production

mostly

may

is

weed

encouraged

SERVICE in

the

years,

years.

is

a

as

for

crop.

dock,

root

propagate

related

where

5

years;

be

if

pigweed

conditions

shepherd's

rest

they

cultivation,

must

eliminated,

then

seed

5

follow

Having

be

others

labor

the

a to

the

crop

of

especially

many

the

by

If

they

1

course,

and

controlling

depends

CONTROL

always,

that

all.

the

germinate.

develop

widely,

may

and

to

may

over

the

year;

depths

should

must

Of

of

Prickly

seeds

largely

injure

after

mayweed,

conditions

EXTENSION

killed,

at

from

and

and

years,

and

considerably and

they

coats one

vary

years,

is

spread,

the

success

after

requiring

weed

seeding-which

seeds

WEED

for

destroyed

they

years.

of spraying.

then,

mallow

soil

problem,

root

infested

been

but

of

suddenly

them

where

weed

can

hard

these

differ

any

cocklebur,

methods

decrease.

30 OF

or

soon

areas

where

such

often

the

pigweed,

has

first

shown,

area plantain,

the

live

or

seedlings,

may

of

all

series

in

before

more;

they

have

for

vitality

cheaply

than

to

Since

a

top

by

the

entirely,

placing

or

The

and

germination.

apparently

have

surface,

AGRICULTURAL

free

annuals

grass,

surface

in

pigweed,

and

weeds

prevention

burning,

vine,

the

years

before

gradually

their

more

which

plants

germination;

controlling

over

the

suited

needed

the

oats,

down

years

shed,

tall

of

neighboring. in

for

differ.

is

for

before

to

under,

for

will

to

Obviously,

once

winter

easily

pigeon

PRINCIPLES

25

germination

best

situation.

die

are

retain

wild

young

relatively

live

oats,

increases

used

thus

are

from

reinfestation

puncture

reproduction.

and

CALIFORNIA

and,

experiments

the

seeds

means

live

decay them

The

the

cultivation

object-the

alone.

then

prevented

cultivating,

they

by

to

seeds

been

may

attack

wild

of

As

unsuited

by

practices

and

large

cheat,

of

or judgment

seed is

operations

seeds

of

purslane,

of

stages

population

weed

and

survive

methods

brings

year

long

soil.

seeds·

fact,

Many A.nnuals.---Annual

Summer

Sound ground

The

the tural by annuals turn once glory amount mowing, gation cockle, mode weed growth chemicals; ing control methods

principal phere killing

rejuvenation. has weed early the tard, may sistently seeds

favorable.

in

followed

14

-Others,-like 17

to

if to by

the

I;f or

in­

old

the

pre­

these have

there

as each seed.

such

hoary seed­ need

pieces, is burn­

vigor peren­ under­ of

and

plants

because

be

soil.

already several

through

of

attached

of

or

mowing, First, difficult.

case

rhizomes)

the similar Jmapweed. roots

the

after hazard

into

the

or

plants grass,

or

cultivations

seed

must stand

growth,

cultivation,

WEEDS control more

bulbous example, vigor

weeds,

smothering,

conditions either

spread

weakly

sprays,

distances

two

from such

grass.

to

structures

scattered plants,

from top in broken

greater mature, for

Russian involved.

methods

the

of

the by

plants

but

Morning-glory

much

Johnson of .

nut

spraying

existing

and

are type the rootstocks

shallow

All, cultivations

are ( use

and other common

old more

contact

natural

are

rootS

limit

and

or

stage

Morning-glory nut-like often the perennial

grasses; nutrients

that

early

loose

cultivation,

the

four

may prevent

or the with

appreciable with

becomes developing plant. removal stems Some

are

PERENNIAL

or

difficult gras8es, by

if

to thistle,

become

Under

perennials. garlic, roots.

one

for

the problems

bunch to common

five-leaf except

Plowing themselves.

of bulbs Second,

but

mineral after.

land

CONTROL

soil.

most

to

wild either

organs

Probably

seedlings bunch

by

two established

spraying

crown. seedlings most

the requirements

the Canada

seed; by

two

competition certain eradication

the

allowed

cultivation. in

killed.

important

WEED easily dragged

certain

situation,

stubble underground the

annuals,

are

and onion,

2), by

seedlings If

of by

eradicated.

the penetrating

be

stages,

limited, weeds, like and

perpetuate

horizontally are

and purpose.

rejuvenating the

deep for

and or

unirrigated be in

is

kill more Certain

CONTROLLING

to

reproduce (:fig. wild

ollly

seed,

of of land.

perennial

on

eradicating

and reproductive seed formation.

this must

Among

feet

seedling habit,

creeping crowns are will

deeply OF

system,

or

water, spread water,

20 reinfestation

perennials much

by plowing factors

ability

soil

the

perennial

the

blossoming plant seed.

it Their inches

described

or

capable

effective. have root controlled ripening

3

irrigated

over spraying or prevent

propagate

only perennials the plants mustplants is

by

the

enough,

their these under

be

of

on

to

perennial

by well. are oxygen, but

in accomplish during as in California

of

creeping

from not makes a

morning-glory

mother

spread

as and

piece well-developed already METHODS of reproduce handling fibrous found

controlling

may

early

way

soil

a will

combating depth one a

well

The

the

Bulbous

In

a

In

1936J or is perennials dandelion, each

they as cress, These ground been'

to the seeds nials In check present

established those volved Mowing ing followed .vented best done lings

to assume methods irrigation any J>lants sunlight; immersion

"'"'

_;:~-:'·

a

to

re­

sow the

-

pur­

roots cheat,

three

treat­

[Cm.97

repro-

group.

· have

control.

or

summer.

of

the live

which

being

dandelion,

spring

for

through

tumbleweed,

grass.

easiest way

rootstoeks

chess

the

second

and important

methods

The

crab

annuals,

underground like

stages.

SERVICE

dodder, the biennials,

radish,

passing

examples

or

gras8,

endeavor

perennials,

by

roots

and

like

their

and

seed

early freezing winters

wild few,

the

are

vine, to

failure, also

years,

taproot,

of

of

distinct

are

plant.

but their

two

barnyard

soil

EXTENSION

mean annuals

weeds

in

large

cocklebur, painstaking

controlled

the

for

seed

a

producing

mustards,

puncture according

regions

form a

in

inay

with

are by

purse,

them year.

biennials

in

are

and

not

either

morning-glory

kill

ollly

delay first

do They

classes,

True

thistle,

sunflower,

the

systematic, troublesome

form weed lives

not

have the

is to

AGRICULTURAL

of

distribution

contrasted annuals

annuals

time;

three and shepherd's

state.

as the

most

thistle,

are

rosette

burdock.

biennials

weeds

Russian spread

into

during

biennial this

oats,

proper star

in

low

the

and

and perennials that group,

fall

methods

a

California

CALIFORNIA

made

wild

the

annual

in

2.-Showing this

habit

at

more

of

yellow

thistle in

weeds

simple

special or

being Fig.

year

California

done

Common

stems.

Biennials.-A star

Perennials.-The

Perennials The

pigweeds, lamb's-quarters,

dispose be 15 thistle,

first In Many biennial le ment quire Plants or years duction: 1936] 18 CALIFORNIA AGRICULTURAL EXTENSION SERVICE [Cm.97 WEED CONTROL 19 of the· plant is reduced; and if any one is rendered permanently un­ were usually eradicated. This method has been used rather' extensively available, the plant must ultimately die. with camel thorn and hoary cress (fig. 3) and Yields excellent results in In addition, the perennial plant goes through a more or less normal sandy.soils. In heavy soils flooding has not been so satisfactory. annual cycle of vegetation, reproduction, storage, and dormancy; and White horse nettle occurring in several of the camel-thorn areas has any disturbance of this cycle lowers its vigor. A plant may be induced, been killed in nearly every instance. In Stanislaus County a 13-acre area furthermore, under certain limited conditions, to take up a chemical of Russian knapweed, flooded for 60 days, was ·completely killed. In through cut or injured tops; the poison is then translocated to the roots, killing all tissue with which it comes in contact. And finally a plant, under other conditfons, may absorb toxic chemicals from the soil and die when these accumulate sufficiently. With these points in mind pres­ ent methods for controlling perennial weeds will be discussed. Clean Cultivation.-!£ a perennial plant is not allowed to send leaves up into the sunlight and air, food manufacture is prevented, and the roots are killed. This principle underlies the old practice of clean culti­ vation. Although excellent in some places, this method has drawbacks in California. On our deep alluvial soils the roots of such perennials as morning-glory are so extensive that two or more years are often required for depletion of food reserves. In unirrigated soils, as the soil moisture runs low the roots tend to become dormant; thus their food consumption is reduced, and their life prolonged. This difficulty may be overcome by occasional irrigation where possible. Any seeds formed on the infestation may later be brought to the surface and in certain crops, such as cereals, may reinfest the areas. In fact, cultivation tends to spread the seed so Fig. 3.-An area in Imperial County, infested with hoary cress, that if reinfestation occurs the areas are larger than ever. A clean culti­ . flooded to eradicate the weed. vation program, once inaugurated, involves watching the areas closely several other places knapweed has given the same response. Occasionally for years after the old plants are gone. In California the .actual areas of submergence for three to five weeks has given satisfactory control. infestation should be kept free of crops during the first year of cultiva­ As results of flooding have varied on different soils, soil type is evi­ tion, because it is almost impossible to keep down gro-w1!haround crop dently a factor. Flooding is effective only where the area is completely plants. immersed for the whole time of treatment. Many failures have resulted In dry-land areas, summer fallowing not only disturbs the roots to the from allowing the water level to lower so that regrowth occurred. Not depth of plowing but, if followed by a weed-cutting program, accom­ all weeds react in the same way to flooding an~our information is not plishes the same result as clean cultivation when conscientiously carried yet complete enough to warrant general recommendations. out. Although pasturing of fallowed land tends to check such perennials As flooding kills plants by excluding the air, it is effective only when as morning-glory, it does not appreciably reduce the stand. the plant is covered and the roots completely surrounded with water. Flooding.-_A practice increasingly popular in California for con­ Under certain soil conditions some plants apparently become dormant trolling perennial weeds is flooding. This is accomplished by surround­ and thus, through lowered oxygen consumption, are enabled to survive. ing the areas with dikes and covering them with 6 to 10 inches of water '"".\ Cropping Methods.-In several cases recently noted in California, for several weeks in the summer. The infested area should be plowed d;, morning-glory, creeping mallow, and other perennial weeds have dis­ before immersing, and no growth should be allowed to appear above .'~) appeared in certain crops. After the serious outbreak of curly top in the the water. ~~'' sugar-beet area of the Salinas Valley ·in 1925, lettuce culture was in-,

Flooding :first attracted attention when areas infested with morning­ l~~- augurated; within three years the ext~ntand vigor of morning-glory in­ glory and other noxious perennials were planted to rice. Such weeds festation markedly decreased. Two y~arsago the Agronomy Division at

------~ '- --·------11 20 CALIFORNIA AGRICULTURAL EXTENSION SERVICE [Cm. 97 1936] WEED CONTROL 21 the University Farm, Davis, found that morning-glory had almost dis­ weeds. Although it does not provide so much shade nor such keen root appeared certain of their .~lfalfaplots .. A series plots plowed in of alfalfa competition, it may be grown on a wide variety of soi.IS not suited for in 1934 proved to be almost free of this pest, although the area had been alfalfa. It may take longer, but it should eventually give the same heavily infested four years previously when it was planted. A grain­ results. . sorghum crop grown there during the summer of 1934 was practically In addition to these two legumes, several combination$ will be tested free of weeds. Encouraged by these results the Agronomy Division, for their value in weed control. Most of them consist of an annual legume which had previously spent hundreds of dollars annually in spraying and a nonleguminous truck or field crop. Crop rotation has not been and hoeing morning-glory, has initiated a 5 to 6-year plan of crop sufficiently stressed in this state, where large areas of the most fertile rotation, with alfalfa serving the dual role of legume for soil improve­ lands are still under a system of bonanza farming. ment and competitor for weed control. Smothering.-The control of perennials by smothering with straw, Studies now under way explain the effectiveness of alfalfa as a. weed­ manure, or: paper, though not practicable for large infestations, may be control crop under California conditions. Though no definite report is successful on small patches. Weeds with indeterminate growth, like yet possible, several factors are apparently involved in this response. In morning-glory, are extremely difficult to keep under cover. On others the first place, alfalfa grows vigorously and competes effectively with the more easily managed, like Bermuda· and Johnson grass and Russian weed for soil moisture and nutrients. Aboveground it shades the sun­ knapweed, smothering has proved successful. If continued long enough, loving morning-glory. Furthermore, takes the available nitrates from it it should be effective on any plant that can be successfully covered. the soil rapidly in the spring and then utilizes nitrogen fixed by the Smother crops are not so generally useful in California as elsewhere. bacteria in its root nodules. Thus it can maintain a low nitrate level in Millet, Sudan grass, sweet clover, sunflowers, rape, rye, and sorghums, the soil and yet thrive in competition with a nonlegume. By the second unless combined with some other agency, can do little except· hold the crop in the summer following spring plantiilg.. of alfalfa ·at Davis, the weed in check. Any crop that offers competition, however, tends to re­ morning-glory becomes spindling and light green, evidencing nitrogen duce the vigor of perennial weeds and to check their spread; and it is deficiency. This condition progresses throughout the season and, al­ always advisable, if nothing else can be done, to plant one of the crops though less apparent in the first crop of the following season, becomes just listed rather than let noxious weeds thrive undisturbed. very pronounced during the second summer. Meanwhile, if the alfalfa is vigorous, the stand of morning-glory becomes notably weaker and METHODS OF CHEMICAL WEED CONTROL thinner. By the third season only a fraction of the original infestation Within the past few years, progress has been made in chemical weed con­ remains and by the fourth is practically gone. Finally, morning-glory it trol. Not only have new chemicals been added to the list of herbicides, likes to grow vigorously without competition in the spring, blossom, but research has increased our knowledge of the reagents previously fruit, and mature seed during the summer; and then, with the depletion used. Although no revolutionary methods have been introduced, recent of soil moisture, die down and go into dormancy until the next spring. information permits a much more intelligent appli~tionof chemicals When this cycle is disturbed the plant suffers. In both lettuce and alfalfa than was possible in the past. .. ·· · - culture, in addition to frequent cutting, which tends to keep the plant The types of herbicides being used with success in California are as vegetative, the soil is kept moist, inducing continued growth. This long follows: vegetative period reduces starch reserves in the roots to a minimum and Contact Herbicides.-These chemicals kill only the tissues to which then fails to provide for replenishment. The roots consequently start they are applied. They include oils, dilute sulfuric acid, dilute sodium the winter in a depleted condition and fail to survive, especially if the arsenite, 2 per cent sodium chlorate, iron sulfate, copper sulfate, and rainy season is long and wet. Apparently, then, several factors operate sodium metaborate. They are used principally on annual weeds to pre­ in this cropping method; and when they favor the crop in comparison vent seeding, to reduce fire hazard, and to destroy weeds which harbor with the weed, excellent results are obtained. The benefits are three­ insect pests and plant diseases. · . fold: not only are the weeds eliminated, but the soil is improved in fer­ Selective Sprays.-These solutions, applied to mixed vegetation, kill tility and physical condition, and a valuable crop is prpduced. the broad-leaved annuals having exposed growing points but do not Besides alfalfa, ladino clover offers some promise as ·a control c~opfor seriously affect cereals and grasses. Dilute sulfuric acid, iron, copper, 1936] WEED CONTROL 23 22 CALIFORNIA AGRICULTURAL EXTENSION SERVICE [Cm.97 and ammonium sulfate solutions are the most important. Although SEASONAL CONTROL OF WEEDS IN UNCROPPED AREAS Kainite and calcium cyanamide are used as dusts for the same purpose, Under this heading will be considered the contact sprays used princi­ the fertilizing elements that they carry are not usually required in Cali­ pally on annual weeds, as contrasted with. the more permanent method fornia soils ; they cannot, therefore, be generally recommended. } of soil sterilization. One should note at the outset that, wherever possible, Translocated Sprays.-These sprays not only affect the tissues to mechanical means rather than chemical are more economical for con­ which they are applied but, under certain rather specific conditions, are trolling annual weeds. This matter will be further considered in a later carried through the conducting system of the plant deep into the roots section. On some areas, however, chemicals can be used economically ; or rootstocks. For this purpose a solution containing 1h per cent arsenic and there is then considerable question as to the most suitable reagent. trioxide in the form of sodium arsenite and 5 per cent sulfuric acid by The principal agencies now engaged in seasonal control of weeds in weight has been found most satisfactory. Other chemicals that will have California are the railroads and the State Highway Commission. Broadly the same effect on plants are arsenic acid, arsenic trichloride, and sodium spe'aking-, their purpose is threefold: fire prevention, pest control, and chlorate. Translocated sprays are used on certain deep-rooted perennials. :-·,. elimination of unsightly weed growth. l\iany farmers and industrial or­ Temporary Soil Sterilants.-Sodium chlorate applied in the fall or ganizations have followed their example and adopted their methods. early winter, either dry or in solution, will be leached into the soil by Although these activities have served as a country-wide demonstration rains. After plant roots have absorbed a sufficient quantity of this com­ of the effectiveness and practicability of chemical weed control, improve­ pound, the entire root system may be killed. By decomposition and leach­ ments in method could probably be made at the present time. ing, the chemical is gradually lost from the soil, so that in time crops Oils.-The Highway Commission has used Diesel oil almost exclu­ may be grown. The success of a given treatment depends upon factors sively in its control program. This material, being relatively cheap in to be discussed later in detail. California, can.be applied at a cost of 5 to 6 cents per gallon. Application Carbon disulfide injected into the soil and sealed in by a compact or rates vary from 300 to 500 gallons or more per acre, according to the moist soil la:yer will volatilize and fill the air spaces with a vapor poison­ height and density of the vegetation. The oils have sometimes been used ous to plant roots. It diffuses, usually in 3 to 6 weeks, leaving the soil at the time of burning the dead vegetation. Oil that penetrates the seed unaffected for subsequent crops. • coat almost invariably kills seeds. . Relatively Permanent Soil Sterilants.-These chemicals, applied di­ The cost of such treatment is not prohibitive and, m view of the prop­ rectly to the soil, render it sterile for several years. They act as poisons, erty saved, has been thoroughly justified. In some seasons, however, late killing the emerging seedlings. Among them sodium arsenite, arsenic spring rains stimulate a second crop of weeds on the sprayed areas and trioxide, sodium chlorate, and various sodium borates are the most prom­ two or more applications become necessary. Diesel oil, furthermore, has ising. They are used on ditchbanks, roadsides, fence lines, and other little cumulative effect and must be used every year. For these reasons waste areas to prevent all plant growth. t4e method of chemical soil sterilization could perhaps well be applied to As shown by the discussion of weed characteristics, there can be no this problem of roadside weed control, at least in regions where climatic universal method of controlling these pests. Methods must be adapted and soil factors would favor effective results. to the specific weeds and to the attendant conditions as these factors ;.1 Diesel oil is, at best, strictly a contact killer. It spreads very well on relate to the problem at hand. In any intelligent practice the properties all vegetation and is particularly effective on grasses. It kills most of the weed and their relation to the environment largely determine the rapidly during hot weather and, if properly applied, will destroy all reagent to be used and the method of application. General recommenda­ vegetation down to the ground level. tions, therefore, must be interpreted and amended. Their use should be For a comparison of oils and mechanical methods in the control of tempered with judgment and, possible, based upon local experience. if roadside weeds, see page 49. With these points in mind, the various methods for using herbicides Sulfuric A.cid.-The increasing use of Diesel oil as fuel and the at­ in practical weed control will be discussed in detail. t_· tendant rise in price make it advisable to consider a substitute. In this field dilute sulfuric acid seems to offer the greatest possibilities. 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sprayers sprayers

acid acid

1.064. 1.064.

equipment equipment

and and

obtained obtained

suction suction

measured measured

nature. nature.

has has acre

approximating approximating

per per

about about

and and

arranged arranged

gives gives

of of

the the

brass brass

boom boom

right right

be be

Amsinckia, Amsinckia,

are are

the the

a a

size size

principally principally

so so

corrosion corrosion

per per this this

solution. solution.

of of

solution solution

mentioned mentioned

sulfuric sulfuric

the the

the the

in in costs costs

drifting drifting

orchard orchard

of of

are are

the the

may may

A A

the the

at at

Control Control

as as

pounds pounds

clovers, clovers,

nozzles nozzles

used used

little little

gravity gravity

parts parts

results results

of of

dilute dilute

radish, radish,

approximately approximately

gallons gallons

15 15

through through

5). 5).

AGRICULTURAL AGRICULTURAL

union union

strip strip

boom boom

upon upon

of of

the the

All All

a a

and and

acid acid the

best best

angles angles

was was

standard standard

130 130

(fig. (fig.

wild wild

the the

equipment equipment

at at

by by

thistles, thistles,

though though

equipment equipment

specific specific

gravity gravity

of of

undesirable undesirable

effect effect

discharged discharged

on on

treatments. treatments.

cost cost

a a

brass, brass,

the the

prices prices

largely largely

held held

high high

596.) 596.)

Many Many

unsprayed unsprayed

inch inch

into into

method method

of of rate rate

distributed distributed

coverage. coverage.

aeid aeid

CALIFORNIA CALIFORNIA

different different

has has

a a

against against

is is

species, species,

total total

causes causes

such such

speeific speeific

The The

Bul. Bul.

6.-The 6.-The

method, method,

run. run.

nozzles nozzles

cost cost

this this

are are

C C

With With

approximately approximately

the the

at at

inches inches

present present

the the

washer washer

the the

from from

depends depends

of of

square square

Fig. Fig.

7 7

The The

25° 25°

acid acid

(From (From

This This

wheat. wheat.

At At

little little

ejector ejector

With With

to to

effective effective

acre, acre,

ations. ations. Atriplex Atriplex

tion tion

pressure pressure

per per

at at

gives gives

weighs weighs

tion tion

weight weight

4 4

followed followed

at at

season's season's

the the

twice twice

satisfactory satisfactory

zles. zles.

nickel nickel

26 26 the the

to to

29 29 acre acre

time. time.

250 250

this this

time time

per per

the the

maximum maximum

about about

twice twice

in in

camel camel

:filling :filling

second second

a a

of of

left left

gallons gallons

with with

lower, lower,

about about

are are

application application

250 250

provide provide

jar; jar;

of of

sprayed sprayed

treatment treatment

first first

plants plants

and and

the the

covered covered

in in

results results

rate rate

in in

the the

be be

a a

The The

at at

minutes, minutes,

plant plant

can can

gives gives

solution solution

method" method"

40 40

the the

solution. solution.

to to

of of

the the

"jar "jar CONTROL CONTROL

and and

satisfactory satisfactory

sprayed sprayed

20 20

top top

the the

be be

arsenic arsenic

of of

of of

For For

the the

WEED WEED

hours. hours.

cent cent

use use

conserve conserve

coverage coverage

morning-glory morning-glory

should should

48 48

acre. acre.

per per

of of

To To

to to

interval interval

inserting inserting

a a 1

24 24

per per

areas areas

an an

stand stand

for for

with with

maximum maximum

7.-Showing 7.-Showing

the the

Upper, Upper,

after after

jar jar

spray spray

required. required.

Fig. Fig.

is is

of of

solution solution

the the

thorn. thorn.

average average

insures insures

then, then,

The The

This This

and and

penetration, penetration,

amount amount

gallons gallons

1936) 1936)

a a

of of

15 15

is is

in­

the the

be be

the the

de­

by by

obc obc

the the

the the

irri­

and and

the the

inad­

Only Only

next next

to to

dark dark

must must

With With

being being

roots. roots.

roots. roots.

which which

water water

spray­

is is

growth growth

and and

notably notably

growth. growth.

(Cm.97 (Cm.97

will will

insure insure

1933-34, 1933-34,

move move

solution solution

arsenical arsenical

into into

moriling­

moisture moisture

shoots shoots

the the

the the

unusually unusually

August August

to to

subsequent subsequent

during during

after after

to to

Where Where

of of

mature mature

end end

feet, feet,

the the

condition condition

these these

before before

been been

and and

distribution distribution

normal normal

followed, followed,

plants. plants.

probably probably

all all

soil soil

enhanced enhanced

acid acid

3 3

heayy heayy

addition, addition,

followed followed

to to

growth, growth,

into into

the the

deficit deficit

maturity. maturity.

be be

a a

free free

arsenic; arsenic;

be be

used used

its its

the the

diffuse diffuse

on on

has has

the the

times times

are are

before before

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In In

therefore, therefore,

during during

done. done.

is is

of of

furthermore furthermore

is is

top top

the the than

before before

of of applied applied

growth growth

SERVICE SERVICE

Among Among

be be

down down

will will

1932-33 1932-33

spring spring

moisture moisture further further

drawninto drawninto

or or

limiting, limiting,

be be

successful. successful.

act act

during during

with with

should should

available available

cannot cannot

less less

done done

of of

state state

growth growth

produce produce

be be

be be

rainfall rainfall

results results

moisture moisture

several several

sufficient sufficient

the the

ample ample

plants plants

to to

sprayings, sprayings,

soil soil

summer summer

method, method,

supply supply

be be

can can

the the

to to

spring spring

low, low,

plan plan

of of

in in

plan plan

all all

poison poison

water. water.

carried carried

end end

irrigation irrigation

the the

factors. factors.

can can

also also

even even

the the

should should

the the

mentioned. mentioned.

The The

best best

results results

of growth of of growth of

sp:i:aying sp:i:aying

be be

growth growth

not not

the the

This This

of of

becomes becomes

winters winters

this this

an an

until until

this this

arsenical arsenical

and and

an an

EXTENSION EXTENSION

this this

having having

and and

thoroughness thoroughness

will will

the the

the the

the the

is is

when when

separate separate

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type type

the the

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spray spray

moisture moisture growth growth

chemical chemical

roots. roots.

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cultivated cultivated

available available

several several

during during

deplete deplete

the the

acid acid

should should

when when

killed. killed.

sap, sap,

of of

is is

reach reach

summer summer

the the

tissue tissue

two two

the the

to to

the the

application application

has has

plants plants

soil soil

with with

soil soil

July. July.

should should

arsenic, arsenic,

been been

foliage foliage

moisture moisture

the the

been been

to to

time time

the the

and and

in in

mature, mature,

Davis, Davis,

effectiveness effectiveness

seasons seasons

by by

upon upon

During During

Only Only

the the

and and

flush flush

of of

permeable, permeable,

that that

applications applications

the the

early early

to to

upon upon

water water

undisturbed undisturbed

California California

at at

in in

had had arsenical arsenical

allow allow

has has

any any

early early

the the

to to

so so

with with

with with

tissues tissues

mature mature

of of

foliage foliage

Spraying Spraying

tends tends

to to

the the AGRICULTURAL AGRICULTURAL

first first

at at

When When

or or

reached reached

soil soil

acid acid

to to

more more

contains contains

grow grow

depend depend

and and

superficially superficially

is is

mature mature

growth growth

absorbed absorbed

the the

night night

index index

weather. weather.

allowed allowed

or or

central central

to to

depends depends

The The

rendered rendered

plant plant

the the

green green

to to

treatment. treatment.

application application

fall fall

deficient deficient

June June

penetration penetration

power power

mixing mixing

at at

treated treated

irrigation irrigation

foliage foliage

growth growth

in in

only only

satisfactory. satisfactory.

or or

in in

one one water-conducting water-conducting

best best

depleted. depleted.

its its

and and

the the

irrigated irrigated

available, available,

system system

later later

water water

was was

leaves; leaves;

solution solution

moisture. moisture.

top top

the the

lush, lush,

total total

and, and,

windy windy

done done

morning-glory morning-glory

CALIFORNIA CALIFORNIA

of of

the the less less

be be

in in

sparse. sparse.

largely largely

condition condition

morning-glory morning-glory

allowed allowed allowing allowing

were were

abundant abundant

unless unless

The The

allowed allowed

not not

plants plants

or or

with with

be be

and and

the the

root root

with with

on on

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by by

high high

large large

of of

into into

was was

spray spray

summer summer

this this

may may

tissue tissue

been been

on on

summarize: summarize:

satisfactory satisfactory

spraying spraying

been been

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dry, dry,

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depth depth

rainfall rainfall

plants; plants;

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the the

Success Success

practically practically

To To

deficient deficient

roots roots

summers summers

glory glory

visable visable

the the

gation gation

have have sure sure

uniform, uniform,

ceases, ceases,

when when

the the

summer summer

notes notes

sprayed. sprayed.

and and

then then

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tained tained

morning-glory morning-glory

hot, hot,

is is

have have

in in

morning morning

making making

dries dries

have have

ing ing

water-supplying water-supplying

satisfied satisfied

de:ti.ciency de:ti.ciency

into into

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If If killed killed

rapidly rapidly

forced forced 28 28 .

a

a

31

to

of

15

ap­

the for by

the

free side

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100-

small

it

stock at

out weigh

undis­

When

kept

arsenic

a sodium

sodium

in

arsenic.

pounds

stirring piece

add using

doubled the

trioxide, opening

as solution

becomes

be_redis­

solution. of

solution,

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consider­

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mounting

well,

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end A

20

of

rapidly.

Continue

weight

trioxide

entirely conveniently

the satisfactory

the

batch, by times.

can

Weigh

using time,

this

large

mixed can one

For

add

save a mix

a

remains by

be a

forming

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are against pound A

3

of

boiling

in through

It

pounds

By rapidly;

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pounds dissolved,

of

water. and

made

pounds 5

2

and

dissolve can 1,4

that

If a

that

arsenic

When

so

they

bucket.

between be use. As 20

water,

80

heat

prepare and

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capacity.

gallons

to

rockers. solution,

mixed

with

drum, the more

cent

can

weight

pounds

water 3

cent

until To out

withdrawing 8olntion.-Equipment

evaporate.

of

shown

will

drum

water.

in and

or arsenic

the

the

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by

of

heat,

to

covered

quantities

completely

per

of

oxide)

few per

a time

additions. to

ready

and

the

make

a molasses

a gallon.

wooden.

have any

condition, gallons'

lye) Stock

acre remaining it

into

1h

50

goes

are bottom lumps

Weigh

it

5

parts container

add at or

To of

of

opening.

mixture

CONTROL parts now cheesecloth

the

larger

4

the

gallons

dry

the

3

soda allowed the

opening

upon

evolving

is the

to

least add 3 or

of

top

between

ceases, half rocking

arsenious ends.

thoroughly,

if

The

pounds

valve acid.

arsenic

about

the chemicals add

even the

at to

and

contains

WEED from

violent,

hold

the 30

soda, by

solution

of

chemicals the

stir

react, the

in

lye. well

for one-half gate the

to

about

against screen

pounds

Quantities add

warms,

for

a

Keep

solution

boiling

arsenic, the

can

pour Mix

stock

16

sulfuric

and

composed

Mix prepare

add

contain

horizontally

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used crystallize water, or

and

becomes

of

is

against

chemicals cover a

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stock adding

hydroxide,

in

water.

solution can cent

white

mashed be

and

chemicals When

a

When

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,

top

solution

sprayer,

of will

3

must

stock

the drum

be all

thoroughly, for arsenic

Solution.-Experiments of be

0

per one

boiling on

or

the

2

This

can

bucket

the boiling

more

pounds

is (NaOH,

oil

stock

but 5

weighed hydroxide.

solution

water

a

sodium the

This

boiling.

the

as

If

through

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violently

of

allow

160 add

in

of

solution.

should

by approximately and

Spray

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pounds solution

off

screen knapsack

stock

loosening

weeks

time.

arsenic

a

60

the

loosen

sodium

Enough

the

Preparation

part

The 50-gallon

1936]

The

1 proportions

mixed

amount trioxide hydroxide to pounds proaches

arsenite.

in wire remaining while stir, solved few

cheesecloth. mixing in a solved bottom There

of splashes trioxide;

the draw sugar violent,

out gallon able

weighs spray weight

for

97 5 1

is

on

31

It

are

best

foli:

cent

that

of

of

some

pres­ over, than

indi­

gives solu­

water

alkali

equip­ entire

[Cm.

might

water. related

arsenic

it

page

the

on sulfuric

solution

its

plant per

they

all

excellent been chemical

or

compared livestock,

Although

arsenical,

a

the bent

permeable

on

and

weeds

applied.

the

spray

satisfactory

applications infestations

as dosage a 1

to

killing

successful

acid, one

that

and

this

effective

a

method

on

nettle, have until

useful acid

and

Where

with

in

and beds. if

spraying

where

cress,

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probably

application

less

at

most

the make simply

tissue

called,

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the

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an

rendered

given,

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horse

is described arsenic

To case,

the scattered

even of

system

are no

useful

it

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by

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hoary

Proper

form

covered

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solution

in

arsenical has

and

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indications

as

prepared

are

to

storage

effective this

nonpoisonous

root

give white

Success

also

strawberry

Solution.-The

this

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and

increased is

is

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weight.

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.

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or

killed

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EXTENSION

on

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gallons.

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7),

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method

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the

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Stock

conditions,

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first treatment.

stock

penetrates

into

If

knapweed,

spray

results

well 250 cylinder

abundant

roots.

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chlorate morning-glory, the

draw

concentrated

method

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of soil

The

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gardens

to

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occurs

can

there

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a

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practicable

all

of

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tops

method

arsenical drawn on in

second

their

better

The

in

having

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Russian Arsenical "dipping"

three

translocated

has plants

sodium tin

the

the expensive.

Under

morning-glory. morning-glory,

acid solution,

or

AGRICULTURAL

it or

as

As

obtained

chlorate. or on

the

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usually

Even

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variable

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situation

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through

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negligible

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cent when

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add

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per and

thus

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glass

much

per

satisfied.

in

been method

described omitted,

weeds.

detrimental;

CALIFORNIA

a

the camel

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1

heavy

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structure;

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be

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be killed. results

woody

use

in

sulfuric

on

chem"lcals

all This

not

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have

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results

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gallons

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is

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favorable translocated

is

interconnected

used on

some

cent

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350 the

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a 100

A perennial

Other

Preparation

30

act of age ment alkali on to

with response. perennials. ence acid containing forced deficiency arsenic to by treated are

system results vidual less effective mallow. of

trichloride, arsenic more per as besides pound

gives find

consists

tion .

to

to of at

or of 33

In

the the the

one

will

con­

This soils

com-·

Yolo.

show

of rain­

1,000

water

series,

by

Plants

a use degree

injury

enough

as heavily

toxicity failures

peats

chlorate

chlorate

from

herbicide may

ability chlorates.

In

to variety in

shows

important over

weathered California

the

as eradicated

clays

determina­

weeds,

response a more the

depth

certain

moisture.

by

we

when species.

in

soil,

in

a

comes

old and

of

Among

series,

are

results.

toxicities

soils

prescribing

such

the

final

cases, applied soil

to

water.

even controlled that

adobe

contact

soils.

and,

successful

respect

in

resprout

another soil

loam his

work

is of soils

a

and low

of

noxious

injury

strongest

a

treating

many

and

is

was West.

with

and

the

to chlorate,

other

grades. resistant

will

moisture

killed

with In

matter,

clay

the

Yolo

soils

differences

with

storms,

the of toxicities; show

in In

alluvial

a

tissue

many

be inches

California

Recent

the

plant clays

within

of chemical;

determined freely

In

find

toxicity

have

considered

explains

progress

killed. accurately

Others

plants

certain

acre.

root

die.

to

organic

textural

distribution

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must

lowest

effects be

recent

primary

through in

in

sprayed

between

are heavy move

Where

in

or

several

surface

die. per

in

involved

regions and

6 the

susceptibility

sure

including

CONTROL

parasitic

of

survive.

not

chlorate toxicity

must

River

control

seems.that,

absorb high probably

fertile

previously

coarser stem

vertical

they

When

interpret

specific

arid

tissues

are still

with

chlorate

their to

show

and

does

one is

sicken

factors the upon now WEED required. chlorate

of the

others, has

the

in certain Soils

it survey

apparent

differences lowest

situation. Extremely

it

factor

plants

a

evaporation

more level,

highly

these

in

in

killed.

he morning-glory

depth

use

was

they

cannot

failed

origin

type

still the

them

of that

the

one

very

main for

soil.

the the

clays.

rule.

resprout

Sacramento

he

the

sodium

recent

in

chlorate, so

is

susceptibility made,

that

soil

of

and

the easily

have

in

underground

experiments

of A.

higher the inherent

ground

This unless

Davis,

to

into

first of

the

will

recent

amount

reported,

and above,

particular

This

been

vestiges

it

furthermore,

In are

showing

treatments of

the the

those

the

acre

and

injury,

sodium

runs

this

from

species'

or

any

factor all

; chemical

not

at

from water-laid

crown;

going

to

accumulated,

pounds

needed. through

opportunity

of highest.

leached

soils

soils per

with

or

Although for or

off

with

influence

plants feet

12

this

chlorate,

be

widely,

briefly

described

have

when

the

4

toxicities. determined

double chlorate

been

problem.

of

with

been

control

cut

one instance

chlorate

A.s

Before

The

a

Another

1936]

has

or chlorate Many regenerate has plants stump of only mechanical In sider pounds differ problem dosage use of factor. tions alluvial soils exception high

leached general, parable retain is retain_ semipeats

has would

least fall with

clay,

is it

97

in of

rig

the are the the ap­

con­

acid

with

Best

open

solu­

these stock

Even

much

finely infes-

cover­ in of When

severe

is

(CIR.

bucket

way rate serious

gallons

soil..

a

calcium

an

sulfuric

as

into a

dividing such they

however,

spray

stock in

in

the

Keep

the

solid

the

300

If

by

proprietary

there

cause contact

water

it

substance, and

the

Sulfuric cause

acid

to

of

Keep

to

three

nozzles.

clothing.

The

If

in

applying

of

complete

(approximately (approximately

on

contact

as

nonpoisonous,

constantly.

The

will

the

application

250

may

acre

under.

usually gained

all

apparent,

SERVICE least

increase

through

and

mixing

come

of

more

them.

poisonous.

hot, concentrated

cotton

be

spilling.

fumes.

chlorate is at

per if

to

later.

and clothing. gallons pour

pounds

after

pounds

crystalline

Chipman

of

8

avoid

available

that

confused

house,

96 and

gives agitating plowed

relatively

may

side

40

used ruin

mixing

dense,

or becoming

week

with between

dissolve

gallons

pour sodium

white

into

be one

arsenic

avoiding

in

EXTENSION

sores;

is

much

extremely acid,

will pounds extremely

solution,

a

clothes discussed

TREATMENTS

to conditions,

applications lot supply

of

solu..tion

nozzles

slowly

is

One

500

It

Though

air,

slopping

or

may be

1%

open

disked,

been

advantage

minutes

rapidly

being SOIL

add carries

most

pressure

in

Keep spray

fixed

unusually

solution

least

or

soda)

caution salt.

open solution

will

acid

sulfuric face,

40

it

is arsenic

A.void

plants. at chlorate,

have

separate

will

chemical mixture

the

Some

to

as

the

100-gallon with livestock.

cuts

pour

of

under

a

burned,

table

a

20 more spray

two

up in

of AGRICULT~AL to

and

kills

arsenic

which

pounds'.

solution,

hands,

(baking

is

spatters.

be

large

extreme foliage

of

Soluble

well,

For

the

out:fit control

made.

stirring.

out

thoroughly,

mto

low,

100

smoke,

TEMPORARY

action,

of and

unlike

the

stock

be

soda

wash

burns

any

may

is

stir

to mixing

concentrated

making

boiling

hazard,

or the

boom weed of

application. chlorate

not application

apply.

the

acid

of

75 all poisonous

interval

A.

In agitate

on CALIFORNIA

from

constant

of

fire

The is

poisoning.

solutions

severe "Atlacide" weeds

rapidly should

an

and Do

wind

hand

treatment cent

a

avoid

Chiorate.-Sodium.

principal

form

solution,

using

follow

sodium

the

tank,

and

with

per

mix,

with

heats the

cause immediately gallons)

spray

than

temperature

total

spray.

5

gallon)

possible.

bicarbonate

Precautions.-Use Arsenic Workers

container. 1h tion and divided the results penetration. age the of poisoning. obtainable burns the 2~ tation, as the burned, 32 each will spray herbicide plications and which arsenic Sodium siderable solutions. acid, spray water involves chloride.

that

.

. ;

35

be

or

on

be

!£ by

soil

an

the

and

not the not

con­

out­

con­

days being

solu­

clean

safest water distri­

cotton if

equip­ and straw

two

As

sulfur,

absorb dangers

prepar­

for the washed

in of

minimize and

as; or.

does

l£

otherwise

The spilled

in

should

should

be to afternoon

the

straight

with

violence or

or they

Spray

several from

eliminated

materials to

chlorate

such

once employed

uniform

the

containers.

the

bucket chemical

inside

they

barns,

material.

be hose for

as tends

gunpowder, for completed,

loss A

great

for

oxygen. solution

a

for

should rinsed.out

containers

chlorates.

contact For this

combustible.

Chlorate

and spray

or

can

are

on be

metal dry,

fire. the in

of

the

accident. accidentally or

with

black

used

machine with washed

stand unloading,

provided material,

of

burning

in

to

can put using

sounded

off

to

boots,

kept

highly

wooden

that when

and danger

the

in spilling dry

case

burns

spray outbuildings,

employed,

sulfur, be

serious pair pair

supplies so

a

been

solution

in

It

a

if

penetration.

operations example,

organfo the evening. simil~r

properties than This

flood

washed

or one

rubber

dry alone

avoid

from

thoroughly

allowed

store in

CONTROL

to

becomes

loading for

preferably have be

the applied

hand

should

to

be

and the

and soil-treatment methodsoil-treatment body.

chlorate painted

noon

at

combustible better

be ignited.

work

prevent

prompt away

even

out,

mixture Moreover,

not

is

spraying

and W:1IBD

the they crystals the At added

a

the washed

barrel, during

should

care

containers, are

water not

well

chlorates.

and

may operator's

should and

on

extinguisher. as

be

easily

warnings

dried

any remember

insure

taken

after

purchased

use

for

sacks

since

with the forms

use

dry

solutions

fire

to

be

and blaze

Though

be chlorates. it

and

overalls. in wooden chlorate, Metals spray

a chlorate

assistance

to

on fire, particularly

Wooden

should

used

occur A

of

mix

the should machinery chemical

all

of

after

preferably straw,

chlorates, water. are equipment near had.

water

solution,

dry

or

should evening.

carry

can wood.

or

the one stored sulfur

handle

should

turn, be

of

case being

pairs to

chlorate.

emptied

smothered, allowed

Sodium

water.

with

to

together,

in

the

is remove

In solution.

spray spray

can be and

should

sulfur, inflammable every

is

two

trucks, wood,

to

are should

caution

chlorates

handling

extinguish

precaution,

with gallon

when

before hazard,

the

pair,

thoroughly

sodium

Pre~autions.-Many

allowed

applying Men

In

As

Accidents

Keep

Chlorates

1936]

per treatments bution of the cautious.

cloth, highly cannot policy tainers.

more may ment ing

floors, drenched great

taining in

clothing side water having be

this

washed saturate

chlorate out tion, filled extra

stacks. shipped

97

at

In

the the the (1) All

dis­ dis­

few

per­

con­ tem­

with bare

cress

same little rains

made

rapid

water

where

in

a differ­

humid

[CIR.

expert

a

depend

loam

the solution chlorate

methods of leaching in

summer,

Whereas and the

to

these

of irrigation

transloca­

conditions

the

during hazardous. during

hoary case

the

In

west, winter

As

is

susceptibility in methods: part, which

clay.

sandy

irrigation.

sometimes chlorate

procedure frequently

a after

local

this convenience. gallons the the sodium For shown,

applied

roots

represents Where considerable

engaged

3

of

applications

amount of two,

moisture

however, of

has In In

by

it

during SERVICE

Davis.

in

adobe

absorption, been

the the enough.

of

have treatment

dosages plays

by Fresno species'

and

feasible

under proper at with

first

of

killing,

dosage.

by

of in large

has

not

in

moist and

Davis

successful

soil

by formulated pounds

chlorate.

matter

the a

clay

subject,

dosages.

at

leaching chlorate. used applied results tbree foods a

root

of

are

largely

were grass

and

by

be

by are sterilization more

EXTENSION

;

general

rod

concentration Montezuma than

Yolo

and

land soils

a

or toxicity

straight experiments

in

translocation absorption

followed

variations

mainly

a

organic

residual application type on

heat, indicate the

must

universally

trial-and-error one

As utmost care.

concentration pounds more

better

lethal

square

for of

where followed 8

no Bermuda to

(2)

methods a

rid a

soil

confused by

with

where

conditioned

be morning-glory per to

with enough

be

affecting are

recommendations for determining absorption

is

much

extreme becomes and

The

even

summer chlorate

longer.

soil;

been

treatment

killed

spring

can

method,

not

AGRICULTURAL For chlorates to

way

used sections

depleted

or the above,

satisfactory provide

and the

for

the

and

has soil. experiments

would

rapid the

pounds soil

equivalent

be

worth

factors

6 of to

conditions. situation, recommendation

method 3 there

were

are

chlorate,

be soils.

a the is

experienced figure. were

easiest to

of

years listed

humid

from issue

conditions

soil

aim is

the must season

during

~here

available,

square rod

then, experimentation according they

the

pounds spring

during

the

the of

decomposition

CALIFORNIA

from

is

pounds heavy

reliable

should

three Because

dry

type

; 4

In

per California, poundS soil-treatment significance not

8

(3)

average numerous

complex method growth adapted

is

on formula 4

and

when

West part show,

proper

is

for

In

methods

only

rainfall, in

difficulty

so experience the be

water

the

of absorption Yolo

spraying old solution

soil

little

good

the

a

Chlorate

The

In Evidently,

In the a

pounds

perature. the little with water cretion East. sisted cussed, in 34 fall winter; tion period and three absorption soil upon ences and chlorates. must The is minimum in 2 Turlock, is locality advice. figures local has the first centration a

a 4

a

in

37 is

all

on do

fol­

the

soil

to

at

will

the

effec­

small

2

be

prep-

If, in

with

appli­

air,

kills

deeper,

there

effect

the

with

any it

the

If effective recommen­

container, to

applicator

from

conditions,

holes

than

a prevents them applied

in

tractor,

that

sealed.

usually apply

loss,

filled

The

cover

be

to

mechanical

be

to over

with

which

can

show

amount

pouring

average

heavier

making

The

extremely go

to

important.

soil,

and

high

exercised

mechanical factors.

should

to

excessive

by is

and caterpillar

should

a

the

be

thoroughly

is

a

being

soil necessary

seems

equipped

disulfide. sufficient

is

by rows

holes soil by

have

therefore

liquid

it

in

areas

prevent

chemical

is should

the

compacts the

which fumes,

sufficiently

the

to

carbon

CONTROL

application

the

susceptibility

drawn

minutes-under

and

subsoiler

care in

the are

small

of

then

done

which disulfide

crowns 20

staggered

weeds.

soil

influenced

moisture,

apply

fumes.

applied,

in

in

mass

WEED

is

applying

and

the

areas,

is

been

sealed

roller species'

depth

soil

in

because

soil

then carbon

way

treating

assurance. has

su_rface 3-standard

and

and with

disulfide

The

of

application

large

of

used heavy

pe~ennial

hour.

a

inches,

and This machine, chemical

a

each

disulfide occur

of

the of

6

soil

chemical of surface

work

treated

per

by

hole.

the

in

carbon

hoe

of

the the

contact

may

toxicity

rates tamped. the of

of apart

over

method

noxious

or

acre

reasonable

as

carbon

each

in fittings.

to

lack

into

into

of not

followed

as

treatment one

of 9.-Equipment

consisting drum

escape

soon

with is into usual and

inches

moisture

growth within of manufacturers

cutter

a of

the

8)

As Fig.

carefully

18 come

Experimental

The

ready cator

The

In

\936] rate

injected

roots eradicating tiveness dations variations lowed

weed

ounces (fig. soil ample depth account

crown not kill. and

valves,

a apply

I

I I r

i

~

a

97

If

with Used

be

When [Cm.

vapor­

chlorate

not

the

hazardous

air.

temporary

capac­

contact

a

that

industries.

readily

chemicals

less

as

Along

than

it should

the

Drum

close

SERVICE

and in

used

in

other

be

remember

liquid,

disulfide.

heavier

hazard.

and

chemical.

can

necessary is

fire

the

a

should constantly chemical,

carbon

that

volatile

EXTENSION. fungicides,

care

which

gasoline for

one

the

dry,

and

the

carrying

clear,

gas,

and

handled

than A

chemical

tube when

disulfide. a

applicator

is

toxic

use.

AGRICULTURAL

precautions,

herbicides,

insecticides

carbon

disulfide.

presents,

dangerous

of their

as

atmosphere;

subsoiler

these

to

extremely

sack,

the

carbon

more

each

effective

pounds farm

8.-Mechanical

is

an

of

CALIFORNIA

the

llO

chemical compounds

550

Disulfide.-Another

are

from

the

of

Fig.

are

drawback give

shank ity,

on

emphasizing

many

to

fiber

sterilant

In

Carbon

36. moisture the sprays

daily

than chlorates izes serious soil 39

re­

the

upon the

rate

a

depends

all on

surface

at

inches

64

held

depends

of

16

sodium

remove

effective

Three-foot

also

applied

to

with

it

heavy.

been

Passage

ditch.

whereas

failed

arsenic are

soils; has

treated

concentration

soils,

soils

The

been

field,

grass leaching.

of

heavier

to

cement-lined

the

CONTROL.

have

a

In the

applicat~ons

on

studied.

in

ditch

columns

Bermuda

WEED

resistant

loam.

the soils to

heavy-textured

where

of

all 3-foot

rod highest

fairly and

sterilization

of sandy

side

is

higher

being

soil

each square

through

Fresno

being medium

on

the

per

·property

type,

in

Fig.10.-Soil

water

from

strips from arsenite.

soil

of it

dosage,

pounds

common

4

Arsenic

1936]

upon a the

inches

arsenic moved of

I

I

I I I l i

.1 l

.• .i

,.,. '.! 't

_,;

.

:~.,.

.

..,

·r:'I

97

is

it

of

be 8

is in

In

of at

per

In

the

par-

good

ores

grass as

most soon ..

areas

show air, effec­

[Cm. Treat­

and

chemi­ seems of a

usually

may

canvas. ingress

is

is

are

relation pounds

$250

form

degree

steriliza­

field-plot

4

inefficient

sprinkling

The

to

with loam most arsenite clays

results. soils

waste borate

This the

the

desirable. In

applied

crops

soil by means escape, by

damp

California,

in

drums

possible

Bermuda is

expense.

amount

$200

higher

over

types, concentration

chemical

in

not

adobe

persistent

mixed

that as sandy

a time.

fertjle

used

proved cases SERVICE sodium

with

the certain

highly

this

so soil excellent

make it of

The

will from

chemical. The high

is

Empty

. applied

has

application.

such with

of found

when controlled

and

more growth

offers

these in

chemical Considering

use

even

steady, mechanical

the

of

will Fresno

soil. cost

it gives

rod,

In

care;

appears vapor clays.

the

of

the

the soils

of

by

rapidly and,

the

on and

weed

form

being range

covering

will

EXTENSION

successfully

and soil, rapidly on arsenite

the disulfide

which with all

soil

and

chlorate,

method

labor. after type

square

heavy

now perennials,

the

of wide

been

that

districts

organic

above 9) in

the importance.

the

the

hoe handled

per

quickly

are effective

so

sodium

available carbon

required;

in

has

application decrease

by

STERILIZATION

be and

handled sodium hours. (fig.

plowing and

is as

inflammable fairly least

diseases, and

to an

wet

and

control

_ spray. SteriTunt.-In agriculture

through the

a

be

24

is

or

work

in

leaving weeds

recommended

rod

soils

of

AGRICULTURAL to and trioxide

SOIL

described

soil

Soi7, kept

plants. of

plant

cannot

dosage

disulfide agricultural

this affected rolling

a sprays however, least Over

must proved

shallow-rooted

to be

increasing trioxide,

the vapor

soils

as applied at

prior

by complete the and

arsenic

of is disking square drawback

For usually of

that

arsenic has

alluvial

to clay.

of again

for

is

translocated liquid soil carbon

which, soil of

per

contact

is sandy

a

equipment

being

arsenic

on CALIFORNIA

areas furthermore,

advantage

important

insects

the areas

rod the disulfide

species, Yolo The control

recent

intensification Arsenite

shallow

dangerous.

surface

to

unavailable with

of grass, and

left

of the

than

principal a

arsenite, all light, on

; using

advisable.

pounds

pounds small

more the retention areas,

pest according

the be

toxicity

2 in

though

promise.

of 8 nut covering.should toxicities,

has

square

fertile

The

Carbon On

on noxious weeds

our

Sodium

The

38

means aration sealing

ments acre, cal

grown control explosive. ticularly and it The

must

With

state, of in many methods tion tive, offer

toxic soils, high

tests, ·of pounds the sodium per least .highly rendered iE a

4j is

of

a

In

soi; an­ be

no­

any

may may many and

soil early

in

milk, plan body. sodium recom­ that than burn­ ditch fallen. kill

out.

over

heavy

hazard.

doctor.

chronic

dosage sodium the

the relative

making

remainder on a becomes made the should

poison a In

hazardous.

also petroleum

and vegetation, the

This in

eggs, of have

by sprays

destroy of

arsenic is

the contacts scanty

total has enough to

into

with

solution arsenic used pointed soil

with

urination, free

schoolgrounds,

rain

take

year.

consult white

used growth the of economical

be

with

with of immediately. set pain, rainfall.

white

increase

bare

of land be

been

and

arsenic will sterilize first be

and arsenical

posted

symptoms

repeated

this with particularly

may

and

the absorbed soil, treatment arsenite and

dry

burning

has

vegetation arsenic,

part is permanence may be

doctor of inches the chlorate-will to

pharmacologist,

will for

amounts roads

the it

a

of owned with dry suspected, lips

a vegetative type this

intestinal

when The

the follow still to

poison

chlorate

arsenic

green more scanty are apply by

applying sodium

skin, it Cail

soil arsenic to The

should and small

for during permanent public applied or to the

using

before CONTROL of

of

the 2

contact is

be as

with

then

of upon

privately the arsenic avoid appearance

directly before

areas

diarrhea,

required.

more poisonous

swallowing sterilization rainfall,

retain

to with arsenic.

until eyelids, prepared localities

weakness, 011

symptoms such WEED and

vomiting. winter

be

but are and- nature

ways slow soil should

method

perennials, may ingestion light largely

it chemical:

in

treated highly sterilization late applied

away

white skin, other taken these

form

the areas cause of

rains

arsenic

vomiting,

weeds places, unavoidable

be

should If this sterilization are In the

All be

with accidental

Sterilants.-Whiie

used

muscular of give dry which

a kept

and possible

It chemicals

in

Another poisonous

of

use

depends

cause

may to precautions, treatment. repeated waste

livestock are

the Soil many

regions

exposed solution

years. two

It nausea, Where

the first useful fail. dead,

should

who case of

in

growth.

follow

are may solutions

mouth,

or the to

are other are

all added livestock In .

which

quantities

to killing

more

all contact disturbance. by in

care rash. and after

solution

deeper-rooted

form extremely

by

treatment

thereafter. following protect

or alive a there accidental applications and

and

nonpoisonous

period

large

the void There the avoid flour urine. soils

The

The

A two

Arsenical

1936) The

chlorat~ sterilization. Nonpoisonous particularly of nuals arsenic in vaseline) mended beginning

second the To winter, appreciable tices, Special

either heeded (

cause occur,

Symptoms ing and

long poisoning, intestinal

banks

safety, where chlorate clay for annual excessive.

,,

97

it it

be

in

of

be is

to to

first

in

of tri­ the

to

rod,

from and

sandy load­

[Cm.. stock had

stock year condi­

steady

to enough known white

avail­

the made

may

volume

arsenic

solution gallons. of sodium

as loss

localities,

equal the

it or

successive type

3 soil, first reason.

therefore

of

solution dilution

arsenic equipment

arsenic because solution square intermittent

of

proper

after considered

Fresno of

tons

inches.

the than application soil

top pounds

climatic

drier

four_ and solution

4 becomes 4 seems

be per

this

arsenic cent other

on

Although stock

fact, of to 16 by

terms

with

In as stock

the

SERVICE excessive to more trioxide its Light,

required

convenient

of top

showed

effectively

In pounds

per in

rod any stock

of

volume during or must 10). on

be and up 8 soluble

a particular stock intermittently

so type

the enough

50

soil any arsenite

from pounds

soils.

many for

Though

in

soil heavy,

to

adapted 4

out (fig.

will the to fell total any time less

as

and the is the

dosage

make factor inches square

of a

be the

it

determined

solution.

nearly

for EXTENSION on for half-gallon

applications. for

12 that

to is arsenic

the in

however, years a per can approximately

than

water equipment This much

proportions sterilized fluctuate

that of mixture.

must pounds is confined containing

dosage

up

purchased

the rainfall

is

Tests

on This from limits

:5 measuring

sterilize four

year, man not

the

be basis, annual with

1 few fact sterilant was Sterilant.-Arsenic

formula

weighs effective

applied by lasting arsenic depth a application a

not it for and

rod. factor

water leach

one

wide

a loam.

the the reason,

Where may be chemical. solution of

called,

light the Soil

to steel-drum

work,

second

to rainfall should soil

does

than a volume more

AGRICULTURAL

diluted made

by usual with

the

by

a this of Yolo it sterile the may

the

solution away is square plants; arsenite as stock

soil making

it and types. time be

Yolo on

the

on between

soil sterilization

arsenite pounds more

By

soil

facilities,

For seems

important

per

general

soil

4

With be, if this This the

wash

effects

it may not for commonly reason avoided

affect moving For

the

sandy to

water,

sodium

continuously~ factors for In 31. The solution prepared to be Arsenic is in varied

the not diluting as vA_LIFORNIA

but

day.

sodium this

of. to

the

plots,

application it would

be pounds

during soil

killer,"

flooding.

stock arsenic weight

in may

page will emptying soil

and per well

rains. arsenite

For

in as

application.

this

or field White

rendered

applied the by on solubility,

as fell the may

effective

heavy

its

and economical.

gallons

application. in In

"weed

Although

conditions.

low

satisfactory Dry

Fresno present

winter loam rain been

less interpreting rainfa)l rains

sodium tions leaching one years. as economically given ing solution oxide for a solution Since gallon, 2% recommended water or trioxide environmental arsenic, arsenite. after able effectiveness its more -

in

in

43

in-

the

can

sul­

For cor­

All

may

Ver­

with with

open

since

Such these

years

tested

found

.chlor­

power

In

chemi­

31 known

special

!'..elated

its sodium

content

Though

orchard

or

chlorate

the be cent

no

handle be control

the

and fitted

fitted usually

FOB

three

and

ruined. of

page barreltypes

sterilization.

to

their

per

nature.

spray. Many

sodium .machine.

be instance

often and

have be

and

5

on

weed reduces

by

cylinders; sodium

readily. equipment,

soil

should and

about

ordinary

roadsides control 12).

usually

will

may

their

adulterating

they spray

~ay

every

for

sprayer

in

solution,

difficult ·

to given

it

leach are or

for

(fig.

corrosive

they

greatly

solution

CHEMICALS

weed

contains

available,

They

chemical

spraying

not

translocated

materials so

almost

with

containing

in. . determined

for

jobs

introduced

are

of These

a

pressure

basis their

bronze-lined

arsenite

is

In handled

it

treatment

wheelbarrow

did

formula

persistent

diluting

it.

as ·knapsack

truck;

to

extremely these

arsenite

lined

be·

this any

proportion

men

solution

East

a

in

for equipment

large soil

have

the

of

less

The sold.

and

arsenite

means

value

in

.APPLYING

on

CONTROL

on

mixtures mixture

CONTROL In

sodium

the

two

simple for

may with

killer.

by

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IN

was

have

place

11). spray

boom pumps

sodium

weed work.

in

oil,

it

quantities.

a should

whose

according chlorate The

ineffective

any

expensive,· WEED sodium

for

weed where chlorate.

WEED

in

(fig.

effective and

·

up

acid, of

is

a

of

applied

killers" suitable

applied

-m:ounted

logical

chemical Diesel comparison

properties.

pump

as

reported

proprietary built the

be

proprietary

diaphragm-pump

than .

arsenical

arsenic,

user proposed

no

groups

proved sodium as

better

work

and a

REQUIRED

By

solutions

by

saving. this

it

The

of

"weed be making

case

the

the expensive.

workers,

available

may

been

are is most

acid

two

than

other

toxic

spot to in

inclusion

to

no

to

satisfactory

pump

that

not

herbicides, liquids

tests

eradication,

the

worthless

dioxide, herbicidal

In e~ched

have

and is

into less arsenite for

Chloron,

the

trioxide.

cost

used

is

and

our arsenical

solution

sprayer

orchards

be

was

appears EQUIPMENT

action

The

percentage

type

equipment. operations

excessively

guns acid, considerable

In

(fi.gs.13and14).

in

proved

common

according

it

marked

field,

sodium

content.

divided all-bronze

barberry

be

the

arsenite

Calcium

Ethylene

Atlacide

Many

Although

.

·

1936J trol. There California. soil more expensive

to in ago, the ate are, cals value. are of always to The sures be noncorrosive

chlorate rosive porcelain small morel used orchard an hand furic equipments field spray

.

.

97

in

by

for

are ore

soil are

pro­ best The

and

than con-

bare

com­ com­ been

hand

other

crude·

chlor­

(Cm.

sodium

against known.

sodium pounds

fixed

the

last Certain

of

the mixture

nuts Used

Judging

with

graveled

excellent

involved.

the

as

be of

chemicals. 16

weed

not·so

treatment.

to times,

than

on

boron

boron

35. dosages hand,

satisfactory on

Kramer

to

form

been to and

On

already

forms

of

them.

for

4

orchards.

gives

solubility

Hours toxic

other

and

existed.

it

page of

toxicity arsenic.

pound

very

other

ore three

as

chlorate long

though

winter

have

sterilizing

various

1 SERVICE

brjefiy.

near

chemical

on of

arsenic.

grapes,

effective

lower

species. the

persistent

these

at

and

available the tendency danger

has the the

rates

or

a

application

form

a

satisfaction

of

/

Oii.

used

at an

demand of

advocated

useful

is

listed sodium roadsides.

the

Kramer

/l

simple

commercial

more

fruits,

in

soils solubility.

be

have

Colemanite a

vegetation,

retention,

the or or

dry

plants,

the control

during

heavy

or

sensitive

containing

been

considered

variations in

chlorate

power most

by

chlorate if

minimum

EXTENSION

soil

usually

not

of

and

approximately

of

only rapidly.

be

This

lower

dry

effective

are

borates

the

is

weed

The

drawback

wide

than

with

single

considerable

its list present, they

not

plants

deciduous

concerning in Applied

will

precautions as

type

killing HERBICIDES in

valuable

a

the

mixture should avoided

recently

of

at

hazard

most

rather supplied

water.

to the

Colemanite,

a

borax

it

the

same

be

with

ores soil

mixture

compounds

be

Its.one

used

has

the

the tested

schoolgrounds,

fruits,

to

makes the form

intense

proposed.

chlorate expect OTHER

expensive

that retained

AGRICULT~AL

is .sounded this

used

often

market

because borax,

within

treatments danger

to

moving

been

c.ould

borate

the boron

observe

be

be

ornamental

are

less

not

of

citrus sterilization. areas,

others

no

of

can

the

arsenite.

susceptibility

anhydrous of

boron

is

and

of

Using

come

can

arsenic,

but minimum

lack have

sodium

on

experiment.s, soil

according

few

to

annual

a

much

thiocyanate

subject

a

should certain

frequently

probably ; to

unavailable

should

also effects

pounds

for

there to

not

however,

Colemanite

CALIFORNIA

with they

parking

valuable

are rod,

sodium

with 8

weeding

above pound,

are

an

species'

but

toxicity

are

and

as

or

to

varieties

to

One

chlorate, in years used,

for

ores

and

and

chemicals

production

sensitive

where

tests,

and economical.

The

warning

ones

should,

reduces

leaching square

soil

in

so

Borax

Borates

According

Although

A

Ammonium

42 the nounced ate. sodium chlorate Pound the Combined borate

type per sterilants. chlorate results. more combination One several soil from pounds pounds are all drives common ornamentals

hand, mentioned hoeing

new Many themselves, discussed,

.

·

45 45

strip strip

a a

nozzle. nozzle.

roads. roads.

54.) 54.)

spray spray

along along

multiple multiple

Cir. Cir.

Will Will

work work

with with

54.) 54.)

Ext. Ext.

spot spot

Cir. Cir.

hose hose

spraying. spraying.

for for

of of

(From (From

Ext. Ext.

54.) 54.)

lines lines

Cir. Cir.

roadside roadside

adapted adapted

gallons. gallons.

.(From .(From

CONTROL CONTROL

. .

Ext. Ext.

for for

900 900

hose hose

of of

built built

WEED WEED

two two showing

(From (From

equipment equipment

rig, rig,

rig, rig,

lines lines

Capacity, Capacity,

spray spray

Two Two

spray spray

spray spray

wide. wide.

feet feet

15 15

13.-Power 13.-Power

1~.-Power 1~.-Power

Fig.14.-Power Fig.14.-Power

Fig. Fig.

Fig. Fig.

1936) 1936)

I I

t t

l l

1 1

22-

gage gage

[Cm.97 [Cm.97

valve, valve,

pressure pressure

The The

SERVICE SERVICE

Brown Brown pop

work. work.

with with

weed weed

for for

EXTENSION EXTENSION

equipped equipped

nozzle, nozzle,

sprayer; sprayer;

Chipman Chipman

spraying. spraying.

AGRICULTURAL AGRICULTURAL

knapsack knapsack

and and

ordinary ordinary

for for

extension, extension,

CALIFORNIA CALIFORNIA

needed needed

brass brass

Fig.11.-Vermorel Fig.11.-Vermorel

not not

is is

ineh ineh 44 44 47 to to

is

on

are

here

ad-

lots.

cul­

This

and, along con­

must even

adja­ road­

found

is

plows

subject

gained.

or

ground ,

effort

to produc­ suppose

chemical

related related be

Joaquin or

·

discussion character­ technique, banks,

detail here

.

weed seeds infestations pests

the vacant

been been or along

problems

uncultivated weeks;

seed

the

San

on

on

disks

tractor

weed

The

has effects more of

of

ditch

from

the a

special

numbers of these

as on

in concerted predominate. destruction mature left

before with

and

in

on conditions

roadside with

of

presented a

erroneously

cultural statement:

of

and

special period

where great may

danger

control. frequently,

of early

are control.

never

a

from it perennial-may

in resulting

AREAS Some weeds

studied sections

of_

requiring all

annuals

solution,

unless too seed

from

of areas

farmers

and and

the

connection

in profusion driveways, have over

following cultivation

been

All

rule,

their blown flower, Commissioner

benefits in

effective

flower in fields

a

problems

the

and

and in

CONTROL

PROBLEMS

farming. problem p~oblems

situation when Often in are

practicability as have

clean

seeding the seed.

consult

be

most flowers localities, winters,

biennial, Consequently,

the

UNCROPPED

grow

toward

these to

uncropped to

the

control

weed but, makes

and

farmed

seeds

WEED when

and

gain

of

IN

special all

mowed mild

Others

other form line. moved,

or

in· a

mature

roadsides,

irrigation

to

farms. orchards.

weed Agricultural

weeds SPECIAL to prevented.

reader agriculture be

aiming are

disks,

appear

and areas;

simplify

special

or

of

growth mowed be

and

they

the

can

WEEDS number rows, plants plants cheapest

their

to

ground they

may

control

soils

state,

expect are the

A

is

for

demqnstrated

many the tractor

:fields

common represents

classes-annual,

crops

the

fence Control.-On the Mahoney, before

of

entire Many California investigation.

plant

has weed

has all well

somewhat

not

give

fertile

principles

information, plants each

E. to

cannot

of near

of be

prevent

the seeding

noncultivated

elsewhere,

implements who

along

Then

past.

the if

means

arid A; to

elsewhere.

surrounding

such

cut

or

deep,

speciality cultivated

should

is if

species

usually

by scientific

destroyed

these would

dry. Weeds

Mechanical

Mr.

1936)

California

by our our peculiar to than with Although it istics presented. Throughout Growers levees, methodS made areas

in fact be sides to cent that

tion although when

visable tivating

will County,

trol

,-,~-~

97

It

of

the

the

the

dry

boom

even

boom Davis

rate

plots Com­ [Cm. neces­ equip­

brass; nozzle steady in They

. a

a

spread equip­

at

a carbon various a an

obtained

of from

uniform

All arid spreader

produced

consists

Mfg.

of spraying."

a

deliver

be

for

will

made

be

and particularly

It

satisfactory

be

special years

water,

applying

Since

time satisfactory.

may

material. plumbing

not

weed

disks

that Friend

suffice. can

the were

for

necessary; inch.

and

supplying

SERVICE

coverage. fan.

to three fairly

should company.or

and nozzles this

the

obtaining of

were·

proper nozzles

rate drill proved

calibrated

application

of the for

acid,

acid by

machine-drawn in

this

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lawn-fertilizer

square

the

of

changes

has

spray

improved

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method

field

been

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adapted uniform

on

rent

Similar

from acid.

nozzles

absolutely

4) capable of per equipment a

plumbing

EXTENSION mixing

delivery

The

framework

sulfuric

fertilizer

was

slight ground

was

rig

fig. have

areas and sprea4

not large

All these

for

giving dilute the

advice

study

hand, manufactured

or

experienced

the

any

special

pipe

pounds

and

a and

cost

and

is

purchased manufacturers

California.

dilute

California.

the

spray by desired

and nozzles.

no

to larger

was offer

but 25, ground. be

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60°

by the

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Alto,

Jose,

any

of

machine.

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also

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AGRICULTURAL

nominal best,

treated (page

San

in Palo

present

boom ordinary ''Hummer," a solution, devoted to that evenly

sloping

and

is

difficulty

manufacturers,

They

somewhat spray Co.,

at in

at material. corroded spraying potatoes ordinary

acid, as so

the

spread on

through. been

any

used

pressure

too,

fan-shaped of been the

chemicals,

before both small-scale designed

sterilization York, spray

a the

to for

the For Mfg. this

Company,

areas. sizes

by

offers

at

though to have

has amounts

for of

the

disks termed

flat,

soil

CALIFORNIA

New for rapidly

been

made

it essential

Bean a

used

uniform

is

in

far

drill especially the areas.

is especially

corroding equipment a

time

fit

used, has

larger

water

corrosive

attached

of plumbing, nozzle, Chemical

market John

mentioned

at

to

supplied

of pipe

thus

be

for

Gasport,

applying

necessary small the

been hand For

delivers

Some

container As

The

Equipment application

46 brass equipment

without "This ment can

flow a for

sary steel

commonly It uniform, coverage design spray

~~ standard

chemicals

the used

ior has coverage,

disulfide

sell ment of

pany, Chipman from a

by

49

as

wet

the per

and

this

from

gen­

line,

$7.57

roads

facili­

control after in

a

given

To

of

shown

to burning.

to

cents

applied

be

gallon coverage is

automobiles

done Joaquin

wider

weed

72

cost

unusually

.

and

treatment

equipment,

improved

property

alone.

per

work.

first required

the

San

an thanks

to and was oil

oil

removed

'being

·

of

the should

of

·be

oiling

thriftiness.

vastly

cents large

average discarded

the

for

labor

cost in

complete

4

of

been

e:ffectiveness

an

of

some

started,

at for

been

disking roadside, the

shoulder

cans,

with at

strip

a Its on

that should

denotes

protection Because have

then

was cost '.

has

roadsides.

tin

mile

strip road

_ 1935 15.

Mahoney.) and

fire

line. of experience

second for with

8-foot and

along reach

.

in

used, work

E. per

roads

consideration

eradicator,

disked for the from to eyesores

May

per if

A. piles 5-foot

the

twice,

fence

our added

high,

disking.

on

countryside

by

disking

disked

of CONTROL

$75.00 Here weed

mile

the other

each

firebreak

twice,

and for the

of

disked when

a

equipment

a

was disked

roadside

of finishing difficult

sprays,

and and

of For

inches

Unsightly

mile cost

than

the

were

WEED

disked

originated make were and cheapest

$24.00 roads

condition

road

the per

few

4

areas

less

to

(Photograph practical.

made.

conditions These

fences,

a our

the treat

were

fires

cost

the

roads

be

approximately

appearance $7.57

To county used

viewpoint.

no

were

of

depreciation

acid.

roadsides only is

of of

compare

roads

cost

County.

would

may

roadside

February control,

is

possibly

year

to

weeds.

of the

between

disk

miles

of cost

general

considerably

rounds

miles added

of broken-down oil,

of

burning.

acre,

last weed is

well would

Control.-On

be

487

miles The

sulfuric 670

nine per

and starting be

growth actual

cost

methods

that

of

parts,

growing

Many from Diesel

as

183

growth

must

an

and

1935,

16), the

disking,

This

fact

might

total disking.

their

improvement

gallons

Fig.16.-The

In

Aside

apply

highway-maintenance many in

oils

A. Chemical

It

(fig.

1936] the annuals spring, 8econd

a

and per.mile. tate as.

mile. To 300 eral amount

application as against

chemical to when

-

~:

:i:

,.,,;

in

97

of

of

pur-.

are

been

and

not

first

imple- road­

miles

work

grow­

depart­

[Cm.

winter

burned spring

are

the Russian

districts

six

have

additional

caterpillar

grow

151

County. generally the

species

the

This

a and and

of

of

primary tractors When

of on

after

accomplished.

eradication

weeds may

disks

oil,

three

the

other the after

weeds with

total

tires.

winter the Joaquin

of made

a been of vine

and

are

with

interest

SERVICE started

many the

protection. 1931,

noxious

San established.operation

was

has

growth

infestations

purpose the

of

burning.

had an

and fire

control

making

tractors

under

purchase sprayed

primarily other highway-maintenance

puncture

this

- automobile

starts

and for

Since

prevention now disking the

disking,

spring

the which

grass,

Manteca-Ripon-Escalon

by turn and

is was for

seen,

more

fire

eradication

where to

eliminates

EXTENSION the Mahoney.)

which

county

oiling be

the

lands.

after

that

vine disking second

two permit

used in

E.

disks and or

of

in

the

A

much

control

annuals, to

vine,

being

A. contemplated,

Bermuda

not easily scattered

harbor

and then

by

cost

is

pests by

a

down 15).

line

farmer's

roadside

started

work.

can

disked weed

roadside

and

p-qncture

the

one

object

grass,

When

aroused, the summer Since

(fig. weed

satisfactory

up puncture

make first

season

fence

tractors

keeps

were

on

than and same

of

under, so

lll}lin

where AGRICULTURAL

the

been

of

disk. was

mature.

roadside

1936

the

with also

Johnson over

the

control.

picked (Photograph

roads has

office

lower

of

especially

the

burs prevalent turned

miles places. roadsides

be

Control proved

offset

of

blow

is

this weed

districts,

however,

to for

are the

road-maintenance roads

much thistle, control season, demand

roadsides

control

has

such

by weeds, and

is

miles purpose vine

of

5-foot Weedy

in the

CALIFOR..VIA puncture-vine-infested

star

County.

grain

disks

these

a weed other

removing

in

one

weed work before

cost

244

annuals in

roadside creep

many

in

vine.

and

weed-free, problem,

are and

disking

The The

original yellow unobserved,

for

early

puncture

growing

that

Joaquin

1935, are

spring

Roadside The

adjoining

gathered

Fig.15.-A The destroy

In

Roadside

Farmers

done

serious

San poses.

tractor purchased, ment. tractors

ments employed '48 puncture reseed sides or and where to

treatment. thistle, weeds ers Farmers found

a is 51 to

in

of

the on

the in­

was

free the

the

and

cost fre­ con­

star·

espe­ areas

wild

such

as most

buy­

being years

weeds

banl!:s which

growth

Sacra­

taken).

Univer­ of

and

of

the in

are without of

sections.

from

from

canal

the

means land They well banks food,

gophers

the and

yellow weeds

sowing;

as

on

land;

this especially

ditch Thistles, animals for

keeping on seeds

weight mustard,

kept

morning-glory

sheep-days, Sheep many the

and

ranch,

plant

practice unsightly occur. district

increase potent

-Burning

Napa of no of of

the as

culture.

in

has to consumption. keep the

1931

before

the canal

except of

3,929

the state

seed.

it

number,

In

way difficult

other i·apidly,

days,

labor.

weeds such

in

only

grazing.

occur 9

the Fields.-A.side

particular weeds,

it In species weight ranch

common fiddleneck.

unirrigated

weed moisture,

17).

two

by Grazing

of and not perennials

remove

and

ultimate

grazed or in cleaned.

on trouble

the

of

neighboring

is FIELDS

This

occur, to spread

cleaning irrigation

from

for are

Grain

conditions is a

(fig.

for

many.

Fieids.-A.mong thistle,

was (during time several

addition, some

making or

gain

in

being Farm. economical

the region

much growth

that

grown CONTROL of

One animals are field, source levees 1934. In main crop

throughout

there

from

GRAIN moves

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canal Grain

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the fields

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fields.

WEED preparing without yield. grain

saving

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spread

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recommended

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area

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1933

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the

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district the parts and

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grain

grain

California rarely

effective started with

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WEEDS

this

purpose.

annuals,

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the

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harvester

Occurring

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fields

thistle

this reduce qnce.

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hazard.

successive 1932, infest

spikeweed,

with to

and been

considerable The tocalote

they

taken the sheep-days,

cleaning,

winter covered

grain

mallow,

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sow weed-free irrigation weight

fire or

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grain of Weeds that custom four has

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with

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weeds

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Grazing.-A.

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Most Common

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Annual

1936]

methods and treated down cially of work. sity grazed 765 total past No clean, were The kind, sist weeds, light, of common radish, as Napa thistle and quently natural spreading ing other ascertaining fested .men

.

97

In

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EXTENSION

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CALIFORNIA year,

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Fig.

practice

Where weed method by

Burning.-Since

Burning

50 can tender.

the year after

most spraying growth, weeds

smaller scribed cal Though ticularly

of that required. tical 53

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comes

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the

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stubble

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methods.

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WEED

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Fig.18.-Equipment

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Perennial Perennials Russian

knives weeds or

1936] dle-western tard varying not was with spray

acid for will because and spread growth perennials, grain spread from tempt Where

97

in

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radish,

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SERVICE the This

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plowing

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EXTENSION

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the

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Fields.-Control and

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not subsequent

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Occasional

order cutting A

In Chemical

52 land tard, at do harvesting

maturity grain fairly seeds This from results lowed March, be the ever, namely, eradicating three easily fiddleneck, may until three turned seeded. implements desirable, · sprout although in tions

stimulate though more

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55 55

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Going Going

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place place

rapidly rapidly

growth growth

to to or or

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years. years.

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method. method.

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than than

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3 3

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hay hay

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CONTROL CONTROL

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starts starts

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WEED WEED

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February February

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SERVICE SERVICE

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IN IN

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Establishment Establishment

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AGRICULTURAL AGRICULTURAL

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CALIFORNIA CALIFORNIA

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(1) (1)

54 54

treatment treatment

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sprayed sprayed

seed, seed,

spreading. spreading.

will will

choke choke

mainly mainly

nials nials

mustard, mustard,

growth growth

that that

Of Of

seeded seeded may

moisture, moisture,

grass, grass,

able able

knapweed knapweed

mentioned mentioned

eral eral

that that

prey prey

marily marily

ceding ceding

and and

Sudan Sudan

an an

to to weeks weeks

with with

ing, ing,

important· important·

to to

in in

in in readily readily .

a in

57 to

is

or

on to for or the In

be

The

and

em­ and

soils and

vine­

than

farm­

as

Eng­

clean

meth­

annual added

been

or

soil.

allowed because

in

cases crops weeds may

have

endanger

· employed

yields

probably

be·

cultivation allowed

dangerous

thistle

grass, orchard

as not

orchard

the

their· destroyed

injured. particularly

bad be

have careless

an and

vineyard orchards

may too

an other

certain

be be

has

shallower cases

nutrients

a well

of

In in

remove in

resulted orchards

in

annuals is and

and

as hand, measure

Russian not

also to in moisture, with

fact,

orchards, consequently soil wisely stirring

has

changed such

Bermuda

as

to

may,

Hendrickson

irrigation

to orchard, to will In Such growth

in

weeds

years

seed provide may

only other

and

tillage of

evidence

states,

headway

·even

rotate

and such orchard in. VINEYARDS and

the

crops;

saving

be 1930. they evil.

that

the

into

weed conserve

they

to and

and

reinfestation. ; may

gain

should

plants water

several

pests on

not AND materially needed

to

attempted

knapweed,

injurious eastern

disked to

more

Essentials attributed

come

is for

and for

given however, CONTROL

50:1-24. which

or

or past

may

the

be pests.

have

which

alfalfa cultivating however,

Veihmeyer have

very alfalfa harmless in

fungus

are

Cir.

of

In old the neighboring

of

as

Considerable

unmitigated

can covercrops the Russian allowed

out,

WEED the under

of

and Ser.

watched

Perennials,

ORCHARDS

as

annuals, be an

up

allowed to seriously

year hosts

Areas Hendrickson.

unnecessary

cultivation

proved that nitrates, covercrops

stations

a

vineyards

IN during

Ext. be so therefore,

cress,

not

purpose relatively

periods.

of

as

stands insect

plowed plow

fields. A.H. pointed

weed

that

and

plots. not cultivations

imperative.

always Agr.

to

be

competition, be

carefully though

long stands and

the employed

infestation

hoary

is

increase

Pernicious sh9uld

WEEDS

though

young in J., compete

be harbor growers,

be for sometimes they years.

no

weed experiment should F. must

depletion important

even

In employed

should

untilled removal

but orchards seed. cause management

frequent infestation. cultivated nor California are It has

may

conclusion

destroy

fruit often

grow

the

in three

are

but of

unanimous. should show most

to

soil

and

into to

less

procedure

nor sod soil. way, their the or thistle,

remove

scythe.

of

covercrops,

The Veihmeyer,

Different to

Many

the

ohnsori grass,

Weeds orchards.

1936]

or this 11

spots best two

Weeds ing, weeds come star yards, as adjacent morning-glory, J vineyard source is phasized.n tilled factor fact, almost ods weeds much ~ormerly. vineyard make land,

through to

vineyards, cultivation, of needed

97

is

to

re­

to

un­ in for

the

on

or

grass,

grass weeds many until spe­ The

[CIR.

injure

may

eradi­ little

prev­

left all

the

oil

treat­

alfalfa

seeding

in

to

lighter mower extract­

parasite seasons

widening

Bermuda

seeding.

of

necessitate remedy parasites.

and greatly

such seed.

does

usually

cultivation

by

water the most

troublesome, apt the preparation of which roots but with

the

it

up

ever The themselves again prevalent before

of and in

alfalfa

treatment the Bermuda it successfully are plant

pernicious

irrigation. in

and several

with

time

seed, alfalfa

being to is

it areas

SERVICE

September,

a

permits

field entirely

practical

in for eradicate

correction attach The before

conditions plow exposed

with

or They

at the

plowed species, mowing

grass growth Appearing

to

typical

or to

with further

that dodder spreads

infestations

infestation,

apparently

grow the conditions. only

soil frequent

soon is

whole

it

the

are

One

than elapse

weeds. abundant

crab the

of fields

one

moist. bad

but

the deeply reappears.

stems. impurity Rotation the and

best August they

local

EXTENSION troublesome infested

as

small-seeded

be unsuccessful, vines

spraying

without the be

as a

compete an

in rotation, its

Attempts off

need

the

occur. and

should

by reduces the as

dodders

practice

most of

left procedure

been years. such

into

can

cut produces alfalfa; occupy badly

beginnings

crop die, spreading unfavorable

eradicate should

From

seed-borne leafless be

should

under years

is pest

of best continually

to others

it

have of

cutting. plowing

better may Bermuda stand.

many

field

greatly

dodder,

is lessen the

a.-The roots crop fields, small which

economically; host. attack is

it the

where

only

it

annuals, per AGRICULTURAL the to

three of weed should preferably alf in

yellow, for

when emphasized

elongation carefully

such soil

danger the

introduced

also

remedy or their

is

This

Alf

From shallow the

the years of

soil alfalfa although

field necessary the fields examples

the

alfalfa, less

summer spots, is in

cultivation

will

best removed being

then Two species from

in

winter, by few summer the

moisture the injuring

of

An

state.

the always

condition, After a dodder good seeds, remedied,

be cultivation;

appearing irrigations

in

grass The

lJALIFORNIA burning.

where

the usually

in

and Weeds

only the

early crops.

soil and are plant;

plants involves

summer

-yield

of pest. various

of from

perish,

destruction California, or after and it three rapidly spreading

easily

nearly reason

only

repays

seriously viable

cannot food

until

vegetation, the rotation.

in or

the the

alfalfa.

for the

and

fall

heavy are future nourishment

are

Most

alfalfa this

Bermuda

alfalfa,

Parasitic

Of

therefore,

Dodders

iJO

occur therefore, two the by favorable sections 1)-reas duce plant grass crop rarely cate Bermuda dry

late for to and Starting ing the spreads rapidly

plants,

alent

native damage.

cies

For parasite, remain

is, ones kerosene, ment, ,

is

as

59

the

fre­

The

it

For sul­ and

tea­

pre­

soon may

area

soon

rules

weed roots

seeds,

a

to

inches

is

should

thrifty annual

it carbon

applied such

organic

of manure

success.

are

constant sulfuric

removed 3

needs of

All

nutrients

nutrients

so

fairly

occasional

a

cottonseed

places lawns. is

be

established oil,

sod

or and

but

whole of

weed ammonium

the

they

sulfate

the

is about

be

such Certain

as

an

They

or

of

of

sound.

lawn

the

adapted

the

California.

chisel. If

Dandelions ammonium

needs

must

for

in

varying and many

viability

leaches

oils,

organic

Diesel

killed

depth

of

problems, in be

such

surface or

the

iron

free

In

a arsenite

should lawn. is

those

of

the

The

lawn

with

pests

therefore

lawn

foothold.

leaf the

dandelions,

a

rotted. again.

treated

as

the

keep

must

ammonium

a

other

sulfate, spud,

provide

turf

spring

of

from

to

thoroughly materials

well-established watering

ou

are

With

kerosene,

to

these

sodium

well

or fertilizer

depletion manure,

Mowing

is

weeds

the

much grow

be

less

iron

depleted

provided.

purpose.

healthy

lasting

knife,

secure

dosage

the

of

to

season,

induce

however,

condition

too

shoots

These a

and

heavy been

plantains,

and

weeds to best, so

of lawn

lawn. ample

this

If

in

the fall The

of

up

organic

a CONTROL

not of

clea1iand

gasoline, area clippings

amply

has

the

be

herbicide.

not

become

seelllS

able

for

combating

of

laWn

arsenite,

only

it

be

it well-rotted

guano.

the

Somewhat of

sprout close.

growing

in

send

does

with

are

if

other

against

small

weed-free

of

or

WEED

Frequent during

conditions,

growth care

grass reseeding.

to

a

too

a

number

weeds

along-bladed

the should

will

drops

type

leave

pests,

used

relatively

thrifty

should

the

sodium in

compound.

made material some

used

the

and

not

used

are to occasionally

a

meal,

favored.

grade

the

few

with

are

be

large they

excess. sufficient. practice

undoubtedly of

proper

however,

use

known

in

best

destroyed

A

a

but

insect

is

during Usually acid, lawn

are

been

best

toxic

in

favorable

or

in

invade

only

favors

and

is

a

watering

and

may good blood

this

or

the

to

roots

nutrients

been

are

not practice

view

of

or A

and

have

most

plant

effects,

methods

removed fertilizing other

weeds

Where

regular first,

able

the obtained, meal,

and occasionally

but

appear sulfuric or

required. the

soil

have

Its per

followed

removed manure

Plant

Where

sufficient.

question

from

any

diseases

Two

be

is

are

and

The

stimulation

over.

fish

in be

the

be

in

orily

treatments or

annual

are require

perennial

grass

used.

pulled

Irrigation more.

Under

undoubtedly

Weeds

Chemicals

1936]

weeds maintenance battle.

lawn. quent must the that and the becoming

from grasses. hidden vented. fertilization. fungus is

seeds cannot meal, quick

sparingly be be materials.

must

plantain

or Spot disulfide, weed

fate, acid

sulfate spoonful grows may

.

is

97 is

as

of

to

in

be

by

sec­

cau­

and

first

plow

diffi­ they Any

they

grass

pests. char­ lawn

vines,

intro­

[Cm.

stems,

plants

purest

speed­

serious

spread

thrifty

the

Usually

seasons. spotted

of

either the

taken burning. a

greens

neighbor­

should

are

Except grass

lawn have

patches

Spreading

and

orchards

while most

of

see

trees,

be

kept

they and

applied

short

special

growth, and

fungus

is

golf

young

in to

the

is

removed.

or

competition

several

be

best

or seeds

trouble.

it

mixture

small

oil,

weeds

top

the

becomes solution,

and

chickweed,

out

weeds

are

of

very if

have planted

threaten

locality.

for them

or

SERVICE the

chicory.

fertilizer

to

should

clover,

soil,

give

the

injury

must

weed

insect

help

the

perennials,

Diesel roots and

spite GREENS

have the bur lawns

with

crowd care

newly

all, lawns

weeds

to

of

growth

cultivation

vines.

often

dissemination,

a

in formed,

all

in

variety

of

arsenical

Common

at in

many

knotweed,

fertilizing,

remove

with and

carefully

or

eliminate

in

without

will

other

bed

purse, GOLF

applicable

either

that The to

weed

EXTENSION been

seed

to

acid

nitrogenous

bed used

and

climate madder,

dangerous

weeds

is

over

so

extreme

and

spread trees

seed

grass,

of of

Often

has surface

if

orchards

AND

of

pernicious

The

surface.

appear

time

concerned,

They

when

and

seed

in

spraying field

the

orchards

and

area

these

the

moist

turf

seeding.

the

troublesome

harbor

in inju~e

are

of

by

shepherd's

outset, established, best

soil is

means

when

mowing,

the

of

for

weeds

topics.

control

particularly

grow Bermuda LAWNS

are

near

solid

disulfide,

available.

the

soil the

near

used The

cutting.

is

a

application

AGRICULTURAL

weeds to

time the

killed

IN

~eeds necessary

work

to

be

the

At that become

morning-glory

buttercup,

regular

be seed grass,

blackberries

seriously

as method

the plantain,

the

specific

leaves

turf.

excellent

Once

to

moisture, well-prepared light

and

of

even

carbon

them

may at

a it.

a preparation

of

runners

method far

while

or

may crab the

may

weeds

WEEDS frequent soil Wild

above-named in

perhaps

adapted

when these

and

their

or

as

the

control jars,

difficult. jar

lawn

creeping

soils,

CALIFORNIA

plants,

the

for are:

enable the

allowed control

of they ruin

a

watering,

in

and and

and

well

dandelion, lawn

pulled

lawn-grass

of rosettes

of if

growth

invading

The

the

or

fo~ established.

be the

be

of that

into

during

the

covering

in

oxalis,

fertile

weeds

are:

chlorates

top any

eradication

grass fields,

cheapest

young.

proper soil. rootstocks

grub

Evidently, For

them,

Many

If Because

spray

58 advisable

a competitor or

tions The ing the The morning-glory. or The tiously

plant grade exceedingly duced

should very by made become the

acters culty type forming by lawn well,

should spurge. of eventually are a

to

61 be of

is

re­

un­

for

few the this pic­

this and that and

culti­ prob­

pulls head­

a

is

can an water chemi­ weeds.

are

water.

In

in harbor

gained several

is

unlined

freed the

laterals. uniform For

the mechani­

It found

including

it allowed

with

structure, the

of

in the water

equipment

of

soils, has they

there

illustrates

engineer

used

is

If

leaves tractor

been

far

of use withiri. of

main

type. accumulating

cases

passed. system

line

each re8tricted

treatment from usually under are 19

in

to

This

tlie

soils is

has

a used

this

shown

at

controlling

the flow thus summer.

certain

such is

are of·the

up

year

appear.

Wooley, soil in oil,

water surface siphon

in frequently,

growth extent

infestations

(not

In

all

over free water.

Figure

district

California

F.

forturiately, the

disk seriously deVices, a alluvial the successfully

the

on

control

in

structure whole

required. the

undisked some

line. disk is However, W.

water plants

Diesel arsenite on this

WATERWAYS year's methods

following for

severe the going

to ditches, . and

neeessary.

effective

the if

after inverted the

used

in left best the hoeing.

Mr. below

recent

and lifting by which, In is

flow

new

the as

drink

float

be with each

water

AND

open

on

hoeing are and by

use CONTROL The draws or the

recover.

and

the the

of the of

can hand

reseed the

down

importance of

again District, no

discussed

man as laterals kept

which

heavier-

mechanical

However,

day during

are. hand mud

a

cleaning

and of

and

rapidly, throughout

a

until perennial surface

WEED cement-lined

any reseeding.

spraying

are

above work

tractor

grasses Dl':rCBES the

designed

The been

the in

of

the

means

are of

localities.

by economical

in

areas

Then

lowered

IN in

the

digging animals

sod,

equipment

outlets

water

Varions by

have feet

.Along spread arsenite.

lawn .

Irrigation

ditch

few

of

the are

years. ditches

and

weed

all dosages the

requires

been

seedli:ngs,

a dragging,

of

killed mechanical

preceding

best. pernicious and

rooted

carry

up

gangs the

equipment however, outlets

banks

WEEDS

careful minimum soil, the and

be has piece square disks

sodium

the

only structure.

a are poisoning

dig miles which

the

several other

by

grow most the

floating

peremiial seems

kill one the

year size any few reinfests can of

in

of Stanislaus ditch which excessive to

to Sterilants." disking, a the

weeds.

or

a

with

to special

sod it for

in

of

in the

this of and of

which many and only

and raises

of each

that best

weeds

sterilants,

pest. only

"Soil treatment

West

control

passing

Ditches

The

foothold

1936]

over eradicated spread which sightly ably vations the

weeds ing Soil cal ditches

quired plowing, cal piece the district reason shape In inches ture) ahead, way reducing covers times devoid plants Such upon dredging

hyacinth, a

spraying possibility

.·.:i.;."·

in it

of

of be

the

im­ the re­

an­

will

per­

with free plow lays that

from

lawn

leave

prac­

of the

in [Cm.97

chemi­

inches, carbon lawns. enable plants

Young enough sprink­ rate

eastern no several

or and

grass infested

roots

applica­

severely

affected,

be

a

of knapsack The

If

18

should of will

plant nodes, the

prevent·

a which at

six and

the

soon can,

with leached

to solution

which

to replaced

disulfide pounds spade

more to

the merely reestablish

clothing.

in winter.

be

heavily

12 area. should

small

seed

to

with successful

gallons broad-leaved

California

at

by severely Bermuda on

soil

11;2

distance

of the

SERVICE addition

spray

is four and

of

Warning

in made

applying chlorate may

a

tubers

each

lawn dandelions. recovers 11;2 ·suffer

carbon

detected

and

in the and

Mountain

been

sterilization.

the be

been

sprinkling

treated reserves

of if

up freely one

old

seed well,

kill applied

depth

From

1awn applied

weeds of

soon

and

and

has

survive

the

a control eradicate about

sodium an its

it

fertilization

curbs, be

dissolving food

have

the

Rocky

to

to to roots

best to

grass,

should

garden

abundance EXTENSION

vapors

Use

other

by over digging in application.

is

sprayings; and with gallon

may

up fertilize together,

temporary surface.

underground an

Then vitriol) broad-leaved, the heavy

used by

It

corrosive a weeds

weeds

laterally, completely treating and

injured, which fall

effort first one unable

throwing

dug

walks in to

fewer canvas

lawn canvas. work

be

keep

the been ordinary lawn

the

Bermuda give

treatments, small, the for lawn, are weeds, forms being green

be

prepared

a: of

chemical water.

mist, a

in

To an wet respray.

of wet

reseeded. chickweeds

It

is also Every of growth has difficult

in may ·or annual with

strongly

will

in of

with until they

cement AGRICULTURAL

of the is fine

forms

means

This

rod. required

hours. and yards and

dandelions, weeds,

with several

with

should may

a a

most rod

procedure it

roots

and

it

spring, 24

are

killed spraying

gallon solution .As

the

disulfide The

area

limits

of spreads

creeping

the .

best

watching.

grass

.. the

(copperas sulfate

grass, .After destroyed

square greens. infestation watered

square

of established

it a

individuals .

having

seeded,

buildings, square

unrolling

in

the

vegetatively.

the fails, each

mature, out the

40

be season CALIFORNIA fertilized,

the to

spray brass are

one

iron dandelions golf on

covering depleted

usually

two

has period per

in Carbon

small to grass

is Once

infested of

damage this

one

of a other grass, sulfate

rule, not

it

they rake again

The

A constant are

and

are that about a

Bermuda

If

in

the beyond spread

becoming

the soil.

stains as

the

up,

.As addition

Iron chlorate, to

.Although Oxalis

Crab

pounds

ljl) with before it lawn. well new lawns ling mediately disulfide escaping, cal, control chemical states. cover sprayer tions usually should manent dandelions than given weeds nuals rust In feet it appears. from ticed. 3 of appear quires

a a

A A

in in

one one

in in

with with

63 63

then then

inex­

tules tules

effect effect

year, year,

even­

This This

even even

opera­

some­

using using

weak­

effective, effective,

and and operation operation

disk disk

and and

it it

first first

by by

most most

but, but,

summer. summer.

The The

ditches ditches

has has

for for

be be

in in

growing growing

illustrated illustrated

the the

the the

to to

ditches. ditches.

the the

offset offset

frequent; frequent;

team, team,

now now

permanent permanent

in in

cattails cattails

larger larger

weeds. weeds.

Willamette-Ersted Willamette-Ersted

District District

direction direction

one one

order order

Weeds Weeds

no no

less less

a a

material, material,

On On

the the

the the

during during

pulling. pulling.

herbicides; herbicides;

tules tules

persistently, persistently,

In In

one one

be be probably probably

equipment equipment

has has

of of

eradicated eradicated

or or

Killefer Killefer

with with

in in

is is

with with

parts. parts.

and and

with with

keep keep

bank. bank.

equipment equipment

Irrigation Irrigation times times

the the

may may

not not

but but

cost. cost.

40 40

llh-inch llh-inch

to to

This This stems stems

applied applied

ditch ditch

cattails. cattails.

ditches. ditches.

6-foot 6-foot

The The

or or

each each

if if used used

low low

dragged dragged

a a

the the

dredging dredging

1 1

the the

Turlock Turlock

cattails cattails

several several

and and

on on

though though

be be

chain. chain.

has has

eradicate eradicate

of of

the the

very very

thus, thus,

CONTROL CONTROL

and and

beneficial beneficial

than than

to to

drainage drainage

from from

a a

treatments treatments

ditches. ditches.

can can

done done

the the necessary necessary

tules tules underground underground

by by

is is

down down

Caterpillar Caterpillar

horse horse

at at

weeds, weeds, is is

of of

be be

breaking breaking

the the

bottom bottom

used used

District District

one one

WEED WEED

later later

winch winch

made made

as as

width width

cleaning cleaning

end end growth; growth;

The The

cheaper cheaper

and and

difficult difficult

clean clean

spring spring kill kill

must must the the

in in

drainage drainage

the the

keeping keeping

plants. plants.

be be

top top

links links

often often

each each

controlling controlling

the the

over over

in in

having having

feet feet

kept kept

ditch. ditch.

towing towing

the the

that that

along along

as as

on on

may may

in in

is is

for for

10 10

Irrigation Irrigation

with with

of of

and and

so so

the the

Diesel-powered Diesel-powered

to to

dragging dragging

cleaning cleaning

destroy destroy

20.-Equipment 20.-Equipment

apparently apparently

a a

ultimately ultimately

power power

bending bending

ditch ditch

up up

effective effective

roots roots

for for

the the

of of

are are

method method

dragged dragged

Fig. Fig.

does does

required required

repeated repeated

Turlock Turlock

cleaning cleaning

20 20

may may

the the

chemicals chemicals

the the

is is

thus thus

is is

it it

clogging clogging

stretcher stretcher

is is

been been

weakened weakened

drag-chain, drag-chain,

The The

and and

Ditches Ditches

water water

such such

A A

"Hyster" "Hyster"

consists consists

figure figure

upon upon

single single

however, however,

pensive pensive

team team

long long

tually tually are are

tion tion

from from

back, back,

chain chain

times times

so, so, the the

ens ens

1936] 1936] stocks, stocks,

97 97

and and

has has

root-

been been

[Cm. [Cm.

cattail, cattail,

and and

the the

particular particular

view view

have have

second, second,

sprays sprays

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laterals. laterals.

roots roots

the the

lower lower

These These

used used

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The The

ditches ditches

on on

SERVICE SERVICE

disk disk

chemical chemical

twice twice

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raised. raised.

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penetrate penetrate

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year, year,

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careful careful

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disk disk

EXTENSION EXTENSION

does does

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machine machine

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ditches ditches

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times times

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show show

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obstacle obstacle

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AGRICULTURAL AGRICULTURAL

weed. weed.

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views views

method method

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water water

passing passing

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oil, oil,

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attempted. attempted.

it it

Stanislaus Stanislaus

upper upper

CALIFORNIA CALIFORNIA

perennial perennial

Fig.19.-Three Fig.19.-Three

yellow yellow

with with

twice twice

were were

been been

shows shows

The The

West West

or or

and and

Common Common

ditches ditches

once once

sprayed sprayed

62 62

seldom seldom tule, tule, a

as or 65

of

up

In

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4

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seed a

adjacent

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irrigation

cattails pests by as

type, problem;

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weeks

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CONTROL

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other

nut-like

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moderately

rice

be

seed

rice. of cattails

grass," repeated

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rapidly

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three that of aboveground plowing, likewise, thorough

and

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is

land.

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time

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practiced.

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stand

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none

water heavy

of they

Thus

fully

spring

rice, the

growth

only

by

cultivation As

The spreading

Cattails,

unused satisfactory

Destruction

New

1936] mon broadcast before "white apparently the from germinate common the the monly is tatively equally reproduction field stand, land, heavy control s:gring fact a growth; during by and ment trolled been liminary important troduced and or seed.

it

is

to

ac­

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so

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rice

it

and from cat­

also rice

their

[Cm.97 where in an

from com-

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water

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removal seeded, rice

cattail,

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spreads

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gather

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AGRICULTURAL

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fields ones there quires

seeds rapidly. time weedy

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67

the

the

per

Ac­

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in

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the

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soil

than

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solution

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WEEDS

all

Considering 2

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the

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CONTROL

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WEED

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treatment

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the

of

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at arsenic is

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instance,

level

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of

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the

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growth

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experiments early 41.

chemical

after

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the cost

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elsewhere.

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in the

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access

Although

Experience In

Another

Stump excessively

feet

1936] developed cially of reason during may trees rainfall is 8 reduces chemical; ments, and cording

most value labor, killing arsenite nominal below cent Often livestock, with arsenic. appearing 32, 35,

control under have grow localities

,

97

of

or of

at­

in­

the

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and

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on

purple policy. ranges

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species Among

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domain

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by

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SERVICE

large

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Forest

them.

invaders.

enormous.

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of

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the

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Many once

EXTENSION

usually slow

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value

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out

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the

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serious fluctuations

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WEEDS

that

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annuals.

feed

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of

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regardless

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to check

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FIREBREAKS

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AGRICULTURAL

introduced

of

weeds,

learn

The

effort

seeds

thistle.

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or

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of

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Klamath

numbers

seeds

state,

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competitive the

to

menace

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weed

cover

KEEPING

cattle

tends

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milk

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compared

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CALIFORNIA

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shown

the

to

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should

therefore

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fire with California prevention

Since

Although

Considering

The

worth.

bound

66

ditch

in

water, have infestations. with ranges Although tend the tempts these star valley variation These vasions

tinct

value, range

restricted is of

appear and species

stricted is are who

seed methods

its As a

to 69

no

in of

of

the pe­

the

the

and

but ·

days after with seed

lower them

estab­

open,

inter­ of culti­

When

winter germi­

viable season

should end

rest

greater at Alfalf;i. have

from

200

manure. maturity

of by

period~ cut

estimated used,

the

cent more the

make destroying

vine,

not

difficulty same closely

presented

for

be

be

prevent further

blossoming

hightempera­ or to days rest and

of

after

per

destroyed,

the contains

incubation, to

has

after

therefore, 10 with

mesh

was amount 90 before

the decomposition may

dropped, percentage

incubated may

of materials. artificial vine

rather

a

days from gerlllination.

but

water were of

apparently

made puncture

for seeds. the period

of

only

than method has

10

than completed

burs in

for seed

enough

days process, large control

relatively steam

season,

picked by

bulky the

rate;

3 checks a

rest

tests

stack less period not effect

at

through sure to a

than live puncture more

are

plant

In kill

often

a

sample. germination tested but growing

seed making

first induced under the the

current

cases,

the normal

responsible

ordinary

accelerated, overnight with be of affected not from picked burs

and

the passed a done the

days.

compost same

CONTROL

temperature is

being is on the or

requires

is

sound if

at the

incubated

control 10 the pest is in most

puncture-vine

rate maturity,

of the

the growth,

Burs

could made

by

in

or

soaked germination of

germinate, seed

within of

the

meal infested of

torch

mean the place WEED processes

with reference

remains. before Burs

of

decomposed to

was to remain after

Burs

within manure are

is refuse was,

brief. the rapid test

the

killed temperature milled to

take

weed seed

rate apparently

where Vine.-To test

of

gerlllination

satisfactory

tests.

is

a nor and

burs

interior viability

failed very

rapid. months A

products

will

hay,

seasons

germination

are

after

is

is milling especially infested

germinated the organic

of

viable the

days

six

from

sufficiently higher plant

between

season puncture-vine

of germinated physiological

If

seed.

the a

in no 90

districts more

permitted

seed

germination

Puncture

burs ripening,

not

the

containing

all in

rains, or the other least in the influence; or

laboratory infested cutting Heat

of

of

if

If matured,

blossoming

inch,

at 60 of problem,

seeds was

by relation

germination approximate when

2 one

treatment fall

showed and and

of

viable

but

germination from

%

burs natural

first

number

held inspection.

The more.

During

Apparently

The

The Composting

Control

laboratory

J.93tij

tion, apparent lished tures temperatures. rainfall. maturity time nated blossollling. riod before be total practically the the or tested the ruption by the a acceptable difficult meal seed; than puncture-vine Though

straw exterior vation formation.

97

of

the Al­ in­

any also au­

Con­

con­

few

pro­

prob­ cor­ Sta.

may

soil­ badly [Cm.

only Com­

is given

weed. years

When

and

condi­

it less

the addition highest infested

reduced.

averaged livestock

along was the too

Exp.

very

sprouted travel.

germina-

Weed first puncture­ disease almost this in

or

of in mechanical

eight

germinates Though

others

was of

of but A and

of

of on by .Agr.

·first

being favorable for

when

the

.Agricultural more costs season railroads,

apparently rate

injures quantities.

SERVICE and

a 1903 crop

expended ·

feeding burs. usually

is

nonirrigated the the considered

those

chemicals,

automobile

each of

considerably sprouted products.

grazing

presented.

dissemination, vine

the California Deputy

thin.

longevity

matured appeared of since thus

made

for principally "Principles u by

of

with

and

been operating

Under

production

growth

products, acGOmpanied

from seed increase

worn

counties

temperature

number

warmest,

J!iXTENSION subject

uppermost infested

Johnson,

Highways,

land

no undiminished or plants

have milk

Having means and amount VINEu, caused

increase puncture California.

section consists counties

of few the contact.

rains for puncture-vine and

of in

of

in total

California spraying

were

in

as

a

Seed.-The

in the

seasonal the increased

of

off vine in livestock which total

bur,

for crops in

The

Ethelbert vine

belief, a

value earlier. June to temperature.

particular

on

season

The with temperatures fall

the with

principal summer Division in

markets number

Mr. comes

moisture

California

to

PUNCTURE construction the

reported and

and

known

A\i.H:IUULTURAL mostly it of plot

except

by

animals, each the

various

high

years

is in puncture puncture

appropriations A injury total

State

quantities general years

said observed.

season. by May

rapidly

1925, present

himself by been

and

seed

The

Whereas

been the the

Puncture-Vine which

diminished is

are

some

light

plot

1932,

prepared

control,

favorable of moisture direct large

has by

Africa

of

annually,

rather known. done when

same

limitation County. several

about

seed considering have at

with of spread one

was

cows

VA.LIU'V.a..L'i

sprout sufficiently

soil

those 1932. animals,

cent persons crops,

not

vine it Since

the

Ethelbert. on

and to to given For one

South is

to

by of familiarize tires

conditions.

rare, Orange cases

per effort

15

seasons

with damage

before object section when

$160,000

introduced in

but

except than

90 containing

seed

are

Beginning 528:1-42.

expenditures

The

This

July Germination

those

should trol"

Puncture ably railroads, though carried other u certed infested. "'Johnson,

about to dividuals.

duction injuries products, thentic hay hay Contrary

· sheep tires continued vine more germinate first; related

tions by in months

moisture missioner,

:Bui. 71 is

be

be

at­

are

but and de­ also

and and

cent,

used

Poor crop­ many store

must

often estab­ culti­

faith­ morn­ depth

dep~hs

can varied

smoth­ shoots

special second

method soil. is

may

cultiva­ soil,

failures. per

at

for from compared

A

and

the plants

roots,

treatment. indifferent

week; the of

received

pest

43

death. work

with considerable

arvensis)

on

three several soil cultivation Davis, become in under a

moist to the

many

has

one

the small implements

the buried intervals, with eradicate

and leaves

material), of at or material

in in

by

the depth

is used cultivations

has

economical to do

with

Cultivation, only and

the

41,

seed

than

in

prevented.

or two

to

show,

established tried, food depends

food starved

by

effect way incomplete

dormant

manufacture 27,

been

only

definite

rapid, prevent

ways.

the and Convolvulus are of or

more

the nonliving· success (

been_ at this often

ordinary

lain but embedded to

loose

attempts species, soon

perennials

be

have must be

observations

morning-glory

viability reserve in if reserve most

applicable

light the has also

parts weed-cut

and

with some

to is

undo will

torn several of

morning-glory satisfactory

destroy the

experiments. be

careless

or the to

in failure related

best, may,

CONTROL

leaves

that

have cultivate

with

spread With

retains

As to

to numerous at

parts money.

only

useful, to germinations until

· growth

must

crop herbicides surface

eradicating Where seed amount

reach

the met

exterminated,

is

green morning-glory

closely

according

WEED

not

and are,

are

in a

attacked completely material

leaf the

field underground

:flooding

distances but

when

the intervals cannot

from

devised. have

wild no

probably showed

years.

shoots

must

of with the conditions.

smother attributed

been

and food

labor,

the

chemical

on

until

small

20 attributable August, a seed. cultivation heat,

been

methods

season, underground a new seed methods be one completely procedure

or has

years,

principle

by inches

local trials

often and

data

and no

yet

the

with

The in after C1.1,ltivation.-The

can 42 inches,

even recurrence such best Morning-Glory.-Although

of time, cultivation infestation; _

considerable

these

6

usually sufficient

many

how almost

has summer

of Pasturing by

that

continue growth

July by

for

spread

and

to but

development for certain or The seed.

All

frequent. new

for

so therefore, are ;

to

4 the

root (either

a Just

results methods,

the 22, new

is prevent underlying the

of

available,

8, control in

Morning-glory the Control cultivation;

Morning-glory more Control

During

1936] mature carried start with

years. Though of respectively, lished, not also tention of checked expenditure ering results. ping combined. success conditions. ing-glory Poor The that rule up results veloping, in vations. enough fully. of perhaps tion during be

:

'11

of

too

the·

the oil. It

the cut

an

be has

and

the

and

was

that

V.IA. pest punc­ weed

punc-

l from makes

where there­ vege­

the kill

abun­

cracked sprout­

cereals

pest

of far, seed.

shallow

bearing

to when in

form, this be, in because

field

stems

structures the

so

important

and serious

quickly a

this which established. completeness

and destroy

these spread

considered

county

disturbing chemical penetrate

perennial in

vines

burs

barley California water

growth water a is the and,

known most can

most

will

root

cent,

is

in ~J!ilt.V.l\..I~ purpose

the

on from

affords the and produced

drag the burs.

cent every become are plants

cheap starts aromatic the

necessarily

controlling encourage

land pest with

per

the

without

it

to

of

main

the

the

5 per

seed fact

underground subterranean

not any

for

conditions,

the before being for

wheat which

in

treatment to on 75 farming

infests the

its or

chemicals depends thus prevent

farming

that

is

2

products to may

of

choicest

and -~.1..&:J.l""'(i;:t..lVJ."'l

to

oil

area present,

used so

seed,

irrigation

of

and 50 ·

of these

and

from if

seeds

Ordinarily From undoubtedly

today, our

Grain proportion

several

favorable satisfactorily years with The previous

uncleaned

deposited

small seed

range widely year

presence appear, implements,

size. morning-glory a

high of seeds, surface, recommended

spread more. petroleum

chemicals frequent

to

soil.

early

Its

spray the under

its

invades circle.

and or

the the

containing by

the are

seed infestation

MORNING-GLORY

destroying without it. farming.

or

the

California

It emulsify infestation. the Although tillage

plants

--~------with

to From produce

quantity year in

sowing in will, remove

cost, kill feet the

in

certain

of

in

in

to to

the morning-glory, within poor

spray

to to

oil the

20 Morning-Glory.-Morning-glory

the ----

low come a plants

depose

from

of

through

crown; summer, by

only young area of methods

oil of plant

on of

lies

of by weed

to its wild

satisfactory

sterilized

its spread

extensive. the the ability

expensive.

and everwidening increases similarity the

or

field is

green stages. use and

shoots

with remaining be is

a

of

growth its an plants, too

2),

the

of oil

all efforts dissemination. impossible

caused

opportunity the content

rapid

distance

below

indication new

in

widens of following its may

Whenever treat During in seeds

all over of a root and

and rapidly

(fig. pernicious

vine.

Its effectiveness an

common

of

availability,

just

coverage to

Diesel

Soil The

Characteristics

almost

The

burning slow ture-vine seeds its oils, asphalt possible The of ture

First, vines. off ing killer. The most agriculture defied fore, renews

roots rapidly seed. probably is because excellent

soil laterals, tatively dance,

means spread

· .73

can

blade

control.

The

·

256.)

256.)

control

Cir.

Cir.

morning-glory

for.

(From

(From

used·

morning-glory

CONTROL

seat.

for

the

weeder,

WEED

blacksmith.

used

a

from

by

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raised

Made

be

22.-Three-horse

Fig.

23.-Two-horse

Fig.

1936]

to

of

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is

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feet

Under

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SERVICE of

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and the When in

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in

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blacksmith.

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plants

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18

stops

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EXTENSION spring

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256.)

least

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eternal

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If

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AGRICULTURAL

surface,

suitable Yolo

depth

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that (figs.

a

soil,

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morning-glory

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soils should

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farmers on

down

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most

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21.-0ne-horse

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Fig.

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CALIFORNIA

shallow

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however,

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than

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the

On

latter soil

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plants

easily

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days.

the

cutting

Davis, field,

The

72

from 12 and winter. development

ing-glory mer At and On

eradication

straight-blade condition. and provided more the

the success ,

-

75

is

of

in

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of

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more

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method.

8

more

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as

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in

to become

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cropping

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the

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Plants

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carried

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than

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GRASS

than

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the

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their

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·

full

·Johnson

CONTROL

burned

results was

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grass

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of chlorate

Sudan

been

rootstocks

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the instead

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average or

first

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rows

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all

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areas

cheaper, promising.

grass

the found,

contain

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if

WEED

better

condition

if

pest JOHNSON Sudan

of

been

The

spread

are

cultivation, good

upon

plants

having

are

fence

used a prolific

most

Seed

pound

mowed·

small

dry control.

the

the

to

Johnson

a

in

is

1

as

be Careful much

this,

from well. dosage

conditions.·

be

is

method

On

Johnson

probably

introduced

ones

infestations

the

confused do

largely

possibly

soil,

rod

examined

as infestations; State

It

is

methods portions

herbicides

penetrated

appear roots soil

such may

The spray not

ln.

with

spread To

first

has

oil

Cultivation,

oil

the

where

for

good

seed

heavy

often

fine

small

large-scale

and burned.

disulfide.

pests.

preventing

stems

from

cheaper

square

practical

thus

is a

the stand

areas, seed.

depends

a

on

should in be

grass,

and

winter.

fact, for chemical cases

different

chlorate

Diesel

as

to

chlorates

by

per

areas, distinguished

time

grass

and

weed

and

differ

also

In

or chlorate)

carbon days, unfavorable

thinned may

few

the

employed. is early

a

less

solution containing

Many

Johnson

1936) justified

effective

factory liable feasible

Johnson derground

worst be spread accessible fested parts

top" in

In mer

and

dry, sprayings moisture

ent, cium A

applied

Sodium

the chlorates

pounds allowed

they

with

fests. Sudan

readily which

soil,

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·

97

to

in

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by

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and

the the

are

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well

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have

with days from

effec­

them

light

morn­ eradi­

of

[Cm.

means neces­

use morn­

eradi­

two

kept

may

90

.on

without

warrant

30).

meager;

methods chemical

to

be to

have time

arsenical

on

is

paper

vigor

used

to

vines

conditions

for

is

smothering

to

plants,

to

by eradicating

chemical

in area

proved

alfalfa,

and

renders

60

the

however,

tar

in

27

One

the

because 38.

smother of

or

morning-glory

would plant field likely effective

the

been

of

smothering

at as

the

has

to

for

to

obtained

is

it

completely obtained

points

succeed

manure,

of

known

weed

of the

the

SERVICE

the

by

27

nature

has be

to

most

reflooded

(pages

reduced

soil,

means

such

not

if

success

are

the

and

prevent

stand

involved

these

cultivation-namely,

so

available,

the

cheap, The

chlorates.

Efforts

lapped, eradicate

the

to

environmental

pages

then

of

cultivation

in

be chemical

likely

that

forcing

cannot

conditions

to

in

G."

submerged

condition now

straw

on

section apparently

and

as

and

before

though flooding

by

and

absorption

prove

and

varying

any

will

EXTENSION as

M.

thus materials, promising most

shoots.

are

vigorous the

and

of

principle

of

shows

a

properly

on some

same given results

carefully

morning-glory, years

a

environment

"K.

with

such and

new

starts

attempts

reduce,

The

previous

of control,

abundant

are

plentiful the

followed

diked

leaves,

Chemicals and

a

good

offers

probably

arsenicals,

met

is

is

method

flooding growth,

watch

used,

paper,.

used

be

in

are

several

environmental

physiological

name

of

run

the application

to.control layers.

tar green greatly

knowledge

Experience have

morning-glory

for

from

alfalfa,

before

AGRICULTURAL

growth

must

the

water

to

crops seeds

of

developing

.substances,

should widely herbicides

the

of

long

of

trade

germination disulfide,

yet,

will stage

used

as

herbicides

materials proper

one

in

single

completely.

and

years,

explained

the

grown

the

the

use

of

stated

morning-glory

Though

results

the

most

the

these and Where

No

as

Chemicals.-The

Where

be

in until

Even as such

when organic

five

herbicides

soil,

to of

of use

areas, Smothering.-Nonliving

carbon

The

between

Best

formation

or

UALIFORNIA

best

can

under

dry

material

by will conditions

with

failed.

the

the with

infestations

with

and

morning-glory. are

is

knowledge

out

soils.

results.

the

to

small

success,

applied.

failed.

four

of

chemicals

manure,

crops

is

the 'fhe

weeks.

chemical

for

for

morning-glory

plant

attention

.

certain

plant, absorption. reserve

midsummer. Control control.

Cropping.-Of sandy

Flooding.-In

application Control

The

Though

marketed

"/4

growing straw generally the tive prevent

its watered, ing-glory

formly cate, alfalfa other unprofitable. treatment,

of variaWe trial. in allowed

or three with

sufficient the

for ing-glory but

sary is of due morning-glory,

nature cate

spray in

is

a;ll

in

by

al­

of

of

at

set

77

be­

and

The

over­

to

War

more

than

more

to

causes

lawn­

about

condi­

spray

follow­

greatly

survive

we'ed

results.

readily effective

or

spent

displace

made

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is

control

and

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even

tools. readily"

is

is

to

fails

spring

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methods

this

World penetration.

and

attention

to

become·

pounds

certain

are

usually

when

seed

of

salt

the rainfall

chemicals

open

The

the

arsenical

pounds

other

satisfactory,

10

California

well

often

alfalfa

of

in

common 4

money

known

plants

to

promising·

The

often

not

it

in

a

present

in

annually.

serioris

stems

under

of

which

method. depth

Acid

cultivating

is

the

many

do

.

promise

been

during

At

injury.

pest.

early

the

Much

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Common

given

by of

the

this

amount

canals

and

that

Valley

has

here.

with

reasonably

germinate

seed

crop

by

the

repeated

given

state.

very

impurity

prevented.

cutting,

.Although

chlorate,

have

susceptible

serious

.

be

appears

extent.

33,

cress

than will

carried

an

a

heads

deserves

the

apply

underground

great

.Applications

Pajaro

thus

check

CRESS

cress.

have

as

waterway.

alfalfa

be

.

hand

proved

drainage

however,

of

more

determines

are

is

first

CONTROL

proved

Its

in

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must

page

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that

to

the

Sodium

is

rapid

chlorate

by

encroachment

Hoary

soils

has

WILLOWS

of

and

on

to

works

has

in

hoary

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and

parts

held

wind

parts

results

whatever.

produced May.

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HOARY

less

impure

qu~ntities-approximately

WEED

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cup-shaped

chlorate

be

perennials

crops.

by

if

of

failed.

originally:

morning-glory

of

tried

cress

year

fair

sodium

one

in

machinery,

levees,

threatens

many

value

the

of

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is

capacity

knapweed

disulfide

last

especially

Gradually seed

explained

crop

in

conditions.

appeared

come

of

adobe-clay

and

next

been

perennial

under

and

hoary

and sufficient feed

the

somewhat

a

invariably

As

and

dispersal

on

those

the

brought

32)

is

is

underground

in are born are

ditches,

good

no

by

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sometimes

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for

carbon

whic_h

a

Russian

willows.

willows,

harvesting

rod

carrying

to

adverse

of

morning-glory

Importations

the

than

knapweed

has

also

and

rapidly

has

seed

ready

stand

cress

winter.

cereals

seeds

by

localities

far,

of

It

it

the

application

mentioned

infestations

27

with

cress,

by

seed,

in

applied

has

wild.

cultivation

matures

seed.

seems

the

under

banks

square

the

early

some

Chemicals

Thus

Hoary

thicker

Russian

when

a

reduce The

controlling

grown

clean

ing In

per tions,

the

though

(pages

alfalfa.

even

persistent

viable often

grass

1901, started spreading Hoary

either

Apparently Californians,

control

nation

collected

maturity;

cause

1936]

portions

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?:

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roots

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impure

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spread

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Merced

arsenic

the

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Johnson

disulfide

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$250

hours

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seeds

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in

of

fact

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these

48

of

and

methods

As

state.

a

innumerable

in

in

,

Madera,

some

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flooding

to

of

1912

season's

shoots

County;

nearly

confined

originated

feet

Carbon

where

distances

the

that

or

plants

36

treated

A

and

is

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arsenic

grade,

underground

solution

12

areas.

then

Being

SERVICE

new

.

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the

flooding

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growing

Kern.

by

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than

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in

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especially

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per

shoots

plants

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throughout When

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California, counties.

Kings,

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spread

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EXTENSION much

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year,

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growing

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new

the

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placed

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carbon

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isolated

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O.AMEL

plants

land

spreads

seed

single

10,000 railroad

on

plant,

that

plants

proved

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may

average

an

solution,

these

results

a

with

in

RUSSIAN

and

it

similar

The

which

Riverside,

AGRICULTURAL

introduced

the

in the

the

in

an

On

these

where

that

best

Turkestan

shoots

Angeles,

plants

flooding.

at

was

very

results,

all

satisfactory,

either

method

cress,

infested

similar

arsenic

feet

tried

occurs

or

to

or

strenuously

random

that

also

method,

roots

Los

semiwoody

comparatively

40

flooding.

through

animals,

this

that

at

I;mperial,

a

these

stock.

first

with

now

pweed

counties

to Evidently

but

been

seed

jar

hoary

CALIFORNIA

by

of

roadbeds.

under

by

wholly

in

counties

treated.

of

treated

of

solidly

moved

25

was

ten

proved

kna

or

perennial,

has

and

disulfide

thorny,

Tulare,

The

cost and

thorn,

used.

one

develops

treated.

it

growing

selected

view

been

treated killed,

the

has

areas

Kern

. were

prove

definitely

be

rather

railway

the

The

In

This

browsed In

treatment grass, carbon and

acre. Russian widely nicious

sugar-beet

were jars

when

ence

to

roots of were were

ing trioxide, not

of

water.

have method, not

laterally

Camel movement

is

76 tain weed, seeds, Diego, spring. 8

of

be

for

an

79

has

its

to

but

Ex­

still

More

were

more ;·and

seed­

most

4

chlor­ weed,

germi­

inches

by

vigor­

test

is

pounds

prevent

experi­

control

avoided,

of

Control

problem.

chlorate

chemical

5

County.

form

4

generally

out

two

will prob­

.

New

should

value,

plots

be

its

afterward,

of

with

to

have

amount

to

and

eradication.

this

results

there

be

any

re~ults.

Reinfestation

2

·

Cruz limited

42),

the

growing

Klamath

of

sterilization

crowd

this

present

within

can

study

be

tends to tends

forage

counties. occurs

Agricultural

upon

pound

spring.

should

on

soil.

insure

to

plants

should

clean.

to

from. 1

that

however,

It

growth,

(page

to

Santa

Applications

ever

as

comprehensive

even

experience

results

so

the

excellent

lacks

coast

equivalent

used

soil

a

in

given

comparable

an

way,

ranges

complete

in

rainfall

perennial,

of

material

probably

is

be

remain

project

receive

reinfested

points,

weed.

only

gave

from

following

for

and

enough

California

north

this

summer.

plants

chlorate

optimum lasting

densely

plants.

be

established

clean

this

yet

more

surface

given

will

form

not

in

the

may

will

control.

field

so the

the

the

to

for

Bay

the

commonly

cattle.

1935,

It

a

the

it

most

by

than

in the

can

animals

the

that

precipitation

lasting

deposited

judging

Applications

all

Klamath

have

CONTROL

required

areas

in

before

so

and

pest,

the

kill

most

significant

grows

not

1934

is

probably

Applied

during

grass

shallow-rooted

desirable.

when

rod

to

established

taken

and,

chemical

firmly

infested

ranges.

in

report

southward

this

are

these

of

is

grazing

few

increase

and seeds

killing

rod

Francisco

conditions

useful.

sheep

WEED

in

will

seasonal all

February,

feet

has

season,

our

of

A

do

by

of

3

all

for

from

more

required

in

previously

highly

chemical

produced

of

spring controlling

square

San

far

the

very

stand

to

moist

total

spread

present;

areas

definite

be

can

relatively

in

returns

killed square

system

treatment.

in

so

chlorate

of

1

rod

the are

has

without time

be

the a

per

fixed

stock

weed.

seed

established

breeds

of

the 3

of

No

the

is

is

interested the

per

will

of

has in

were

0

root

heavy

rather

available

annuals

2

grass

this

to

the

seriousness.

north

a

which

away

further

earlier

from

of

square

as

As

rod

should

In

past,

valuable

chemical

weed

disseminated

on

arsenite

after

effects

those

chlorate,

height

certain

which

the

its

Station

of

therefore,

with

per a

pounds

to

and

the

applied

to

work,

and

any

The

however, subject

3

seed

however,

common

county

to

territory

le;iched

prove

applied

in years.

eradication.

movements

square

to

more

All

Sodium

rainfall

Borax,

best

If

the

Noting

toxic

Klamath

·Sodium

All

from

recurrence

two nated;

or

tested

tests, recommended.

pounds

ably

when been

up

ates

years.

covered

per

is of

lings,

herbicides helpful

mental

and

periment

of is

ously interconnected

methods,

Although requirement

much

1936]

every

'~~

r•/

a

97

by

in­

the

ap­

the

has

dry

and

and

suc­

con­

that

part

Two

have

each with

were

grass

of

south,

that

of

nearly

(CIR. recom­

willow

to

system

so

central

system.

to

method.

cups and

common

effective.

is

chlorates

in

size.

states

the

intertilled

necessary.

fairly

the

A

The

eradication

followed

winter

thick

some

in

root

two

recorded

treated best

the

in

effective encouraging,

solution,

heat

willows

an

was

so

to

Bermuda

were rotation

on

pounds

attempts

the

required

or

occurs

the

a

alfalfa,

first

acres.

eastern

early

infests

proved

northwestern

been

sterilization

grass are

in

is

it

where

area,

varied

SERVICE

plants

One

250

stumps.

of

are

its

kill

proved

in

complete

arsenic

summer,

the

on

soil,

January,

one

withstand 38),

cut

have

lawn

has

will

the

several

cowpeas,

100,000

after

pests.

Wherever

shading,

cent

plants

to

cases

in

into

willows

applied

In

generally in

the

penetration

in

applications

seeding

instances

or

and

made

sometimes

effective.

(page

California

chlorates

per

the

to

dry

containers

soils.

years

EXTENSION

some

worst

dense

weed

used.

few

willows

clumps WEED

root

of

GRASS

In

ability

have

were

water.

very

in

grass

rather

is a 1

heavy 50

a

of

treatments

present

our

the

a

is

Its

pasture

individual

of

noncultivated

follow-up

Large

section

necessary-about

sandy

of

and

and

a In

applied

Usually

applied

now or

is

Idaho.

dcy-plowing

using

the

approximately

on

Klamath

as

within Sudan

the~·

unsuccessfully

spray,

is

withstand

one

pulling

individual

rod,

acre.

XLAMATH

of

areas

gallon

it

as

EERMUDA

salt

it

others,

and

and

but

disulfide

applications

cultivation

results.

cultivation soils

and

over

occasional

of

a

been

used

AGRICULTURAL

observations

in

included.

the

willows.

California.

preceding

chlorates

the

cannot

to foliage

such

method,

as

these

noticeable,

to

be

a

of

roadsides,

tractor

of

square

of

makes

a

clean

especially

The thick,

by

have

roots

grain

sandy_

Heavy

Europe,

carbon

jar

Oregon,

spread

can

widely

as

tons

obscure;

crop

Though

frequent

grass

the

from

by

of

and

the

a

is

parts

clump 20

introduction

cover

banks,

to

has

satisfactory

some

The

chlorate

rather

areas

however,

CALIFORNIA.

this

arid

or

distinctly

districts

failed.

of

tried

it

grass;

weed.

of

In

plant

obtained.

chemicals

conditions

spread

As

promising,

eradicated

was

described in

branches

ditch

case,

around

rod,

was

fairly

followed

rotation

small

have

been

ground

some

includes

as

pounds

this

mode

southern

been

now

Washington,

California

4 this

Many

On

In

pound

Crop

pearance

The roadside of

mended. harrowing in crop,

infests that soil, cessful. trol proved most

Bermuda

and

has

jected

summer given to

In

economical.

growth several

has 1

largely

have plants

78 average-sized

solid

square

·

· 1936] WEED CONTROL 81 80 c CALIFORNIA AGRICULTURAL EXTENSION SERVICE [Cm.97 sulfuric acid have been tried as herbicides, the most practical method of and a control program once inaugurated on a given range should be eradication is grubbing. Individual, scattered plants may be removed followed out rigidly until all infestations are ~radicated.More work with a grub-hoe (fig. 24) ; and heavy infestations are plowed out with a must be done before any suggestions can be made as to control on large special tractor-drawn implement equipped with a heavy blade (fig. 25). infested areas. In such cases, obviously, chemicaIS are out of the ques­ · The cost of this latter operation h8:8 averaged from $8 to $10 per acre, tion, for they would cost many times the value of the land.

Fig. 24.-Removing the seed stalks of artichoke thistle.

POISON OA.X Fig. 25.-Equipment used in plowing out artichoke thistle. - . Small infestations of poison oak can be grubbed out by an individual according to tJ:\e roughness of the area. If the weeds are growing on who is immune. In some cases fair results have followed spraying with slopes too steep to plow, treatment with oil is the cheapest control Diesel oil. One spraying usually kills the top growth; and although method. Just before the growth of the seed stalk, about % pint of Diesel there may be some regrowth later in the season, as a rule a second_spray­ oil is applied to the crown of each plant. The cost of this treatment varies ing eradicates most of the plants. If regrowth follows, a third spraying greatly with the terrain and the degree of infestation. with oil may be necessary. Oil applied to the stumps of cut plants is also effective. REGULATORY PHASES OF WEED CONTROL.. A little .chlorate solution (see page 32) applied around the roots of each plant will usually give a satisfactory kill. Roots of other plants When, despite general recognition that a particular agricultural pest needs control or _eradication, a few persons neglect their responsibility interlaced with the poison oak will be killed also. If poison~akplants are burned, care should be taken to keep out of the smoke, which carries and do not take the advisable steps, there arises a demand for laws and the volatile oil that causes injury. regulations to compel the negligent to cooperate. Laws for weed control when necessary should meet three needs: (1) ARTICHOKE THISTLE they should prevent introduction of any new and seriously noxious weed This weed has infested approximately 70,000 acres of grazing land in pests; (2) they should authorize responsible official agencies to eradi­ Solano County. Scattered areas occur in Contra Costa, Alameda, Napa, cate any new or limited infestations; and (3) they should provide for and Orange counties. Particularly in the Bay region, environmental the abatement of any noxious weeds against which there is continual conditions favor its rapid spread. A tall perennial from a rather shallow .. This section was prepared by W. 0. Jacobsen, Supervisor of Rodent and Weed crown, it produces an abundance of seeds. Although oils, chlorates, and Control, State Department of Agriculture, Sacramento. of

in to 83 to

it as

be or

the

the

the de­ the The the

pre- this

then seed

state

ship­

really after deter­

in (Sec­

noted.

or

of a) on to in

can insects,

make the

Agricul­

been instances the

anything

However,

authority

problem

term hold,

involved

their

pest-abate­

if

of eradication

infestations

weeds intrastate

116,

seeds

to has another segregated with

Director, is

mainly

Code

crushing,

the most

cleaned

infested

this same Director

for in

that injurious

is commissioner

in Weeds.-( or the previously and are the

applicable

procedures area bailee

or

the

the

it

laws,

is if general

limited

shipments. by

inspection. weed what

"pest" provisions relative moving

noxious

or

115, infested

since

authority They on

needs

substantiate state

against

be

until that The

released.

and

available Noxious

provides

cleaning

upon

106,

is to weed reflects

to

Agricultural

the

be

of owner

only

gives

a it weed-free

actually

three by are

alternative

agricultural

limited of concerned with interstate

California

105, destination,

as the

able Code shipments

be

the

proclaimed Code

is

understand may Department introduced

in the

the

at

in

that Code

operative.

of

to

The

be

provided

Code

seeds

Spread just

CONTROL to

the

authorities

encountered

county

inspection

clean~g.

locality

now

notify

to will newly

which

is eradication and

district event

generally

(Sections weed

found

determination or

pests

involved hours,

the

however,

shipment

authority

WEED

for

for

upon for of

Code.) the

after

the

Infestations.-(a) shall

occurrence of

provisions

48

Agricultural

Agricultural

or

apparently the

weed

this Those officers

following in responsive Agricultural

county available

into Agricultural

available

of the

the of

animals

released. found area are be weeds

eliminate

the

the weed-pest-infested

release commodity

capable

kinds

of commodity is of

the

within

be

of Limited Introduction advisable

common use agricultural.pests.

of

is

pest

eradication,

can

it

of may

the

Agriculture.

of

of 125 treatment any evidence 124

another

wh~ch the or

Code, 128 are or Agricultural satisfaction

actually

may

nuisances. The

a

specific regulatory commissioner

of

permit authority

transport,

in other

serious

not by

they

weed-free

country

by but

the

are

to

to where

introduction return

any

and

,

rejection

will notice,

to

Section pest

Section

proceedings. consignee

public control control Section

how diseases The

Code.) more

Prevent to infestation

of

the provisions

129-138,

the

shipment

Director be

d)

e)

There

(b) To (c) foreign

the any

(

(

the

Eradication

1936)

to weed means, minations coUrt Agricultural weed show quarantine

vent plant if the tural weed · pertains for section

originating or of agricultural ment destroyed written premises "pest" the

seeds unlawful clared. ment procedure of tions .

97 is

be

as is

to

the· not

the

will

any need with

to

par­

were 1929 accu­ seeds

neces­ weeds shrub

grass. detri­ diver­ [Cm.

cover­ appar­

weeds. of

by a

weeds?

hazard,

such

develop

was

or and Code."') taken

declares for

the

of

the

constitute

definition

cases the as

it beneficial.

some

Agriculture, not

seems

wide dangerous,

undesirable

of this such

if

may

of

broadened

noxious or for

take

of diseases plant passed and Code

importations Johnson be,

"noxious"

noxious

were California study;

sound

with usually and

If sources should

A

to

enactment a

weedy,

not

was

as the

role

continuous SERVICE of dodder

was

stowaways

such

has

plant

a

knapweed state;

do

apt

the they

acquiring purposes

Agricultural were was

be the

noxious, in against whether

establishment

far,

recognition

is

weed Department

outside

of

the

and

years country nations, added.

to which

affecting

measure

a

with

say

or So What 100, to for

attention.

control

of

'.A

With

consider

weeds

seeds

forage of

State

is, Russian ignore

took

decide abnormally sure been

pests

other

to pests

.EXTENSION

means

look introductions.

directed field

Federal faced

(Sec.

necessities

weed we

might

considered of are even

and weed

recalcitrants that is.this:

is

federal

county.

order,

measures have

If

from

or be

preventive industry insect

of we

must

plant provided.

or

become

California

another. a fertile

the

definition

life"

iS

a

agriculture. "pest." weeds

thorn

to which

as

ultimately

the

apparently authority

practical

important new

a

could

affecting

to the field claimed category environment.

specifically

state

however, by

were

of

suppression.

country

the offers and

agriculture injurious

AGRICULTURAL tolerance authorities shipments

regulatory must camel has the

one law very

the point

covercrops.

new was

course, plantings, weed

ornamental a fonn

against

1933,

agricultural a

vegetable

soil of in new

of

as

inspection

through

weed

Of

seed

a operations that

in in for and first of

have This quarantine

concern, is court and

the

holdings

of

in

and every

original

enacted specific

way Should that

definition

detrimental

to

Another

the

that

pest

pamphlet the American harboring

1903 ever

stock. allowing

Code the form not

value

belongs

plant

land weed.

vAlJUfUIUHA the

in

detailed the

first in desirable

phase in

more of

of commercial

transfer of

evils.

seeds

warfare

climate

cope.

in ignored in weed

shows tendencies

shall to

to "any

precede

weed immediate one

in or

to large

be

immigrants

then

steps.

unless

weeds

we

planting

noxious modified,

policy only

to

active Published

Certainly

Our detrimental, a

Apparently Obviously, primary

"'

o" or a sary the are should not ent and which plant noxious seemingly mulated History and land gences When necessary difficult legislature

reasonably crop Since mental Hence, of plants legislature Agricultural include or included Undoubtedly, ticular Sacramento.

.l or

an

85 en­ the

the 920 the

sec­

nui-

shlp­ coop­ guid­ from

Code

public to viable

to

in assists

jointly

for encour­ ditches

associa- tending

and

directed

"that

the

Improve-

one 911

intensified regulatory

regulatory

plant regulations

public vital and

jurisdiction thereunder. are

unless such enforcement.

for

made·

or

being

countries; eradication

in state; is

response our

even

aid

the

Highways with

authority manner to

primary and

materially

Code

District

to from to been Agricillture,

and

is federal

against users

(Sections

services and

weeds

since of

stated further, time

improvement sueh

that control foreign

Lackillg

the

water certain of

there

seed. having

subject

administered

and, inaugurated

federal

utility their

of of connection Code

Streets .some

from weed

Irrigation

application •. improved not of

investigation. in

applicable in

in.jurious information

of tolerance, Agricultural

both cleanup.

new

proceed, the

are users impure elaborately

seed of Department

their

general

the

share with to proYision researeh

'in of

the

needs references,

effectively

CONTROL

the sound

weed namely, and of laws,

organization measures

the

in

infestation;

Code.) witk

which seeds stations, full

of

States introduction

and of Agricultural

a for basic provisions

an found the

of

special upon permissible of

importance

WEED

allowed

specific. the one a planting

be

burdened commercial law

fully

control; defined a.ccord is

ditches

of as important the start of

to Code.) United

conceived

devote

the provisions be

inspection be purposes. as

regulatory

officers,

notice

Highways is

of

above

and

the few experiment of

weed

costs. may can

not welZ

responsible

authorizes

a

seed general as dissemination

and prevention

the

subdivision,

sections introduction

the tkorougk cannot control" imported

in

through seed and

state how

to

canals the are still the

in

them

in such

inspection for elimination the

which

officials authority

of commissioner is abatement to they

Agricultural

affecting

all,

Streets are weed-control

recognition "weed weed enforcement with

work

the weeds of application

and

political seed

"Maintenance" There the

case matter

Act,

27,

of for

the making

agencies

prevent

any No (e) Above (d) the There Specific The Incidental

ance control age proper se;,,timent erating forcement measures, (Sec. to ments improvement toward by ondary noxious ment primarily inclusive, measures and them, responsible tions pest-abatement of service 1936] in includes si;inces.

·

'

(

'

~

'

} ~ .J

•

97

to

if

in­ in

or

138

make ap­

com­

gen-

lines

'

[Cm.

agree­

with weed

to owner

federal are

"pest"

and agricul­ (Sub­ public

also applica­

The a authority. commis­

·

the

the

129

is requiring is eradication

and the generally

is directed proclamation or the annual

agricultural jurisdiction

Agricultural

weeds recalcitrants

supervisors, is

to abatement, inclusive,

weeds.

the serious

Code.)

This

quarantine law

or the of proceeded

particular agricultural

state. commissioner

state, with

108, cooperative

SERVICE 158 destroy notices

wherein

Code.) property for to a sections by

board,

such

be

county

to

or the eradication

Pests.-(a)

abatement

of

into noxious

post

(Sec. special of the

authority boards

particular owners

may 155

dangerous of

Code,

a of

official, to

notices

property.

officer,

subject private declare included to cost of

weed-free-area

particularly

Weed control special

then .Agricultural enter

a This

seed.

as on the

agricultural a

EXTENSION

pests

the of landowners effect phase

other

may ordinances. in

spread. costs Agricultural areas other

on of sections

circu.mscribed him,

in

property may

authorize county

powers of even

subdivision abatement

34,

is the Code.) and

be with authorized This

abatement Code.) by

destruction

mature Against lien

county

or

some

is Agricultural

subject eradicate, a (Sec.159, named

of county county may

or act, programs

proceed,

and up.

or the

1929.)

a to the (Sec.

done of

the the which to

eradicating controlled to

of

negligent for provisions, political weed is infestation

of

Code.) itself of or

not AGRICULTURAL thorn. Political a

contracts clean service permanent prevention

Agriculture necessary, notice

fails

sidewalks

Code

supervisors are If Procedut:e

any becoming of

if

area notified to

or Agricultural cress Statutes

of

the

board supervisors passage

or

Forestry, the

into is of authority supervisors

the

camel provide

limited owned

California. authority weed-control of can, for

time. of the

purpose 149, there owner 457, the of field

general to

of 4041.11,

board of

this

of provisions owner, propagate

by

enter

has

streets

the pest the

CALIFORNIA

to perm.it required to boards

the posting .Agricultural

weed-free Director

(Sec.

the to

board Abatement area Board property

given

governing If where publicly

general eradication be

section provide for

Under

section

by is specified

through

upori The w~ed

to

Austrian The with A

(Chapter An

in The 159a, a

industry

3,

The and officer governing

Under

eradication c)

d) abatement

must (b)

con,tinue ( (

(e) unlawful paid designated (f) "pests." where aid (g)

County

General bill. infested

the the (b) 84

it to (Sec. (c) the

ments agencies tural missioners of

jurious to Code.)

eral inclusive, of within commissioner not ble effect who plicable of

growing

nuisance. the

sion abatement. by

tax authority section exercised

·'

~-'Ill ~-'Ill

......

. .

: :

a a '

or or

is is

spp. spp.

so so

97 97

spp. spp.

be be

for for

De­

the the

the the

any any

in in

minus minus

they they

intybus intybus

hispida hispida

cloth, cloth,

arvense arvense

airoides airoides

Sacra­

latifolia latifolia

are are

secalinus, secalinus,

secalinus secalinus

height, height,

[CIR. [CIR.

In In

canadense canadense

Or Or

portion portion

between between

used used

camelorum camelorum

or or

envelope envelope

families, families,

agencies agencies

program program

State State

Zanceolatum Zanceolatum

a a

helpful helpful

specimen. specimen.

its its

cannot cannot

identifica­

Stellaria Stellaria

individual individual

be be

or or

a a

mailed mailed

Arctium Arctium

an an

carrots, carrots,

Typha Typha

Berkeley; Berkeley;

Cirsium Cirsium

REFERRED REFERRED

best best

Bromus Bromus

Bromus Bromus

and and

for for

structures structures

Medicago Medicago

. .

in in

other other

.Hypochaeris .Hypochaeris

the the

Alhagi Alhagi

in in

Also Also

. .

Control, Control,

Cichorium Cichorium

growers growers

cotton cotton

_ _

they they

Sporobolus Sporobolus

and and

Xanthium Xanthium

and and

. .

Cirsium Cirsium

the the

In In

necessary. necessary.

cannot cannot

by by

wrapping. wrapping.

Advisor; Advisor;

dry dry

following following

......

SERVICE SERVICE

including including

plant plant

it it

that that

be be

fruits, fruits,

weeds, weeds,

moist moist

Weed Weed

in in

.....

plan plan

......

......

......

newspaper, newspaper,

......

......

the the

WEEDS WEEDS

included included

all all

of of

......

California, California,

to to

specimens specimens

paper paper

that that

......

Farm Farm

thistle thistle

and and

...... • ...... •

......

and and

of of

may may

weed, weed,

grass grass

of of

be be

placed placed

of of sent sent

thorn thorn

......

mustards mustards

of of

......

OF OF

thistle thistle

cardboard, cardboard,

clover clover

paper, paper,

packed, packed,

identification. identification.

the the

order order

weed weed

for for

any any

the the

identification. identification.

heavy heavy

EXTENSION EXTENSION

Chickweed Chickweed

Chicory Chicory

Cocklebur Cocklebur

Cat's-ear Cat's-ear

Cattail Cattail

Cheat Cheat

Canada Canada Davis. Davis.

Chess Chess

Bur Bur

Bunch Bunch

Bull Bull

Burdock Burdock

Camel Camel

of of

an an

in in

IDENTIFICATION IDENTIFICATION

in in

County County

to to

flowers, flowers,

Rodent Rodent

CIRCULAR CIRCULAR

simply simply

as as

or or

moist moist

condition condition

for for

possible, possible,

grows. grows.

of of

poorly poorly

structures structures

classification classification

NAMES NAMES

specimens specimens

in in

if if

thicknesses thicknesses

leaves, leaves,

weed weed

habit habit

send send

it it

University University

box box

FOR FOR

Farm, Farm,

so so

corrugated corrugated

such such

poor poor

a a

as as

making making

spp. spp.

spp. spp.

to to

THIS THIS

leaves, leaves,

with with

major major

needed needed

or or

in in

weed weed

in in Material Material

latifolia latifolia

soft soft

IN IN

Bureau Bureau

dactyZon dactyZon

crusgalZi crusgalZi

frondosa frondosa

which which

scolymus scolymus

such such

austriaca austriaca

The The

well well

always, always,

several several

specific specific

growth growth

hederacea hederacea

benedictus benedictus

deal deal

wrapped wrapped

Botany, Botany,

convolvulus convolvulus

occidentaZis occidentaZis

AGRICULTURAL AGRICULTURAL

or or

plants, plants,

identification identification

in in

doubt, doubt,

Bromus Bromus

as as

WEEDS WEEDS

TO TO

Commissioner; Commissioner;

the the

often often

the the

of of

be be

Sida Sida

useful useful

Un~versity Un~versity

Amsinckia Amsinckia

in in

of of

not not

underground underground

Plantago Plantago

. .

Bidens Bidens

. .

for for

under under

enclosed enclosed

Cynara Cynara

Jloripa Jloripa

. .

of of

Cnicus Cnicus

SCIENTIFIC SCIENTIFIC

Cynodon Cynodon

should should

..

frequently frequently

.. ..

Sagittaria Sagittaria

Scirpus Scirpus

condition. condition.

paper paper

between between

. .

the the

know know

incomplete, incomplete,

arrives arrives

Very Very

does does

......

Echinochloa Echinochloa

most most

certainty. certainty.

flowers flowers

and and

when when

Polygonum Polygonum

.. ..

are are

......

should should

Agriculture, Agriculture,

cress cress

......

so so

......

dry dry

......

Botany, Botany,

AND AND

......

the the

families families

CALIFORNIA CALIFORNIA

system system

SENDING SENDING

......

of of

plantain plantain

......

with with

thistle thistle

of of

grass grass

should should

blotter blotter

grass grass

moss, moss,

field field

Agricultural Agricultural

specimens specimens

conditions conditions

pressed pressed

Department Department

grasses, grasses,

usually usually

are are

fruits fruits

......

thistle thistle

description description

circular circular

control. control.

grass grass

include include

mallow mallow

root root

of of

bindweed bindweed

be be

as as

One One

the the

its its

certain certain

box, box,

moist moist

this this

Send Send

Specimens Specimens

the the

encouraged, encouraged,

brief brief

Blnek Blnek

Bermuda Bermuda Broad-leaf Broad-leaf

Buckthorn Buckthorn Blessed Blessed

Brome Brome

Bulrush Bulrush

Beggar-ticks Beggar-ticks

Barnyard Barnyard

Austrian Austrian

COMMON COMMON

Alkali Alkali

Artichoke Artichoke

Arrowhead Arrowhead

Division Division

mento; mento;

County County

partment partment

determination. determination.

or or

thoroughly thoroughly

or or

folds folds may may

and and

a a

event, event,

flowers flowers

In In

mature mature

such such

of of

identified identified

framentary, framentary,

for for

is is

As As

ti<:m. ti<:m.

86 86

- ' '