Download Chemical Recommendations for Noxious Weed Control

Chemical Recommendations for
Noxious Weed Control
The following information is provided only as a general guide to weed control. Size of
infestations, current or projected land use and site conditions will determine what herbicide
or other control method will best suit your needs.
For individualized plans, please consult the Noxious Weed Control Board or WSU
Cooperative Extension Agent in your area.
Always read and follow all label instructions on the
products you select and use!
HERBICIDES
Most of the products listed below are restricted in sizes of 1 gallon or larger; some will be
available in smaller containers. To purchase and apply restricted-use herbicides, a
pesticide license is required. Contact the WA Dept. of Ag. or the WSU Cooperative
Extension Office for information on how to obtain a license.
2,4-D: This product is sold under many names and formulations (Amine 4®, Hi-Dep®,
Weedar 64® etc). 2,4-D is a selective, broadleaf herbicide , its effect is all on the foliage.
Can be weak on bigger/older plants. Can help stop seed production when tank mixed with
a slower acting herbicide, such as Milestone or Tordon.
Aminopyralid: It is for use on broadleaf weeds, applied to foliage and then moves down
into the root system. This product can be sprayed up to the edge of water and also be used
on “seasonally dry” wetland. There are no grazing restrictions. The only brand name of
this product is Milestone®. One drawback is that it is not very effective for the control of
mustards or toadflax. This product has a very low use rate at a maximum rate of 7oz/acre.
Aminopyralid + 2,4-D: Forefront R&P® For use in range and grass pastures, CRP lands.
It controls a wide spectrum of broadleaf weeds faster than aminopyralid alone.
Aminopyralid + Metsulfuron: Opensight® For use in range and pastures, CRP lands,
and permanent grass pastures. The metsulfuron will aid in the control of mustards and
members of the borage family (tarweeds, etc.).
Dicamba: This is the active ingredient in Banvel® Clarity®, Diablo® among others. A
selective, broadleaf herbicide and can last 2-4 months in the soil. Most of its activity is
through the foliage but will provide some residual control of new seedlings. Usually
provides quick burn down of plants.
Dicamba + 2,4-D: This is a combination often recommended to landowners with noxious
weeds in pastures. Some of the trade names include Weedmaster®, Range Star®, and
Outlaw®. It controls a wide variety of broadleaf weeds.
Clopyralid: A broadleaf herbicide for use in pastures and non-crop areas. Transline® or
Spur ® is recommended when weeds are growing among conifers.
Clopyralid + 2,4-D: A mix for pasture and rangeland, Curtail® or Cutback® are very
effective for use on thistles and other broadleaf weeds.
Clopyralid + Triclopyr: Brazen® A herbicide for pastures, rangeland, CRP, road sides
and non-crop areas. (Redeem R&P is no longer available)
Chlorsulfuron: A selective broadleaf herbicide for use in non-crop settings. Telar® and
Glean® are trade names for this chemical. Effective on mustards.
Metsulfuron: Another broadleaf herbicide used for weed and brush control in pastures,
rangeland, and non-crop areas, trade names include Ally®, Escort® , Patriot®.
Effective on mustards.
Metsulfuron + 2,4-D, + Dicamba: Trade name is Cimarron Max® or an alternative is
to buy the Dicamba + 2,4-D mix (Weedmaster®, Outlaw®, etc.) and add metsulfuron
(Escort®). This is a very effective mix for a wide variety of weeds and brush. For use in
pasture, rangeland, and CRP areas. It will kill most annual grasses and can yellow or
temporarily stunt perennial grasses.
Picloram: Tordon® or Trooper® are some trade names -it is a long lasting herbicide for
broadleaf plants. A license is required to purchase this product in any amount. It is a
selective herbicide that will remain in the soil controlling broadleaf plants an average of 2-5
years depending on soil type. Picloram has both foliar and root activity. It should not be
used in sand or gravelly soils.
Glyphosate: Most commonly known as Roundup®, this active ingredient can be found in
many herbicides. Glyphosate only works on foliage and has no soil activity. Particular
caution should be used when applying glyphosate as it is non-selective (works on grasses
and broadleaf plants); leaving bare ground for new weeds to get established unless
reseeding is done.
*These are just a few of the many herbicides on the market today. We urge land
owners to do research on what is available and appropriate for their site as it changes
every year. The Pacific Northwest Weed Management Handbook has a much larger list
of herbicides and their recommendations. The book can be purchased through the WSU
Extension or accessed on line at http://weeds.ippc.orst.edu/pnw/weeds or find
herbicides and label information at www.cdms.net
Backpack Calibrations
(per 1 gallon of water)
2,4-D
2 oz
Hi-Dep
2 oz
WeedMaster
1 oz
Roundup
2 oz
Curtail
3 oz
Tordon
1oz
3-way mix per acre rate:
½ ounce Metsulfuron (Escort)
8 ounces Dicamba (Banvel)
1 quart 2,4-D
Updated 2/2014
Surfactants
Surfactants are an important key to maximizing an herbicide’s effectiveness.
Surfactants are formulated to improve the performance of herbicides in spray solutions.
They do this by modifying one or more of the following:
1. Mixing (emulsifying and dispersing oil and water-soluble particles)
2. Coverage (spreading and wetting leaves)
3. Spray retention (sticking to the leaves)
4. Absorption (penetrating properties)
There are 5 classes of surfactants: nonionic, crop oil concentrates, nitrogen-surfactant
blends, esterified seed oils, and organo-silicone surfactants.
Not all herbicides behave the same on or in the plant. Most labels will recommend the
type of surfactant that is best for that particular herbicide. Also there must be
consideration of plant characteristics of whatever plant you are spraying, such as waxy
leaves, plant hairs, lack of leaves, and leaf arrangement.
Environmental conditions must also be a consideration. When there is high humidity
and moisture, plants tend to have thin relatively permeable cuticles making it easier for the
herbicide to penetrate the plants. When there is lower humidity the plant cuticles are
thicker and harder to penetrate. During low humidity periods crop oil concentrates and
esterified seed oils can pass through the cuticles better than nonionic surfactants.
If the label calls for 1 quart of
surfactant per 100 gallons; the
equation would be
32(converting quart to ounces)
divided by 100.
Answer = .32 oz per gal.
So multiply .32 X number of
gallons of water you are using.
If the label calls for a .5% solution;
Multiply the gallons of water you are using
by .005 (converting .5% into a decimal)
Using 3 gallons as an example
3 × .005 = .015 gal
Then multiply by 128 to convert to ounces
(128 oz in a gallon)
.015 × 128 = 1.9 oz for the 3 gallons
HERBICIDE MIXING ORDER
Unless the label states otherwise, add the herbicide to the water or fertilizer in the
following order:
1. wettable powders or dispersible granules
2. flowable or aqueous liquids (solutions)
3. emulsifiable concentrates
4. crop oil concentrates
Spray tanks should be at least half filled with the carrier (water or fertilizer) before the
herbicides are added. If the mixture foams excessively, separates, or becomes syrupy,
do not apply. Tank mixes usually require constant agitation and should be applied
promptly.
WEED
Bull, Musk,
Plumeless,
and Scotch
thistles
Canada thistle
Dalmatian or
yellow
toadflax
Russian
knapweed
Fiddleneck
tarweeds,
Bugloss &
other borage
family
GROWTH
CYCLE
Biennial
Perennial
Annual,
biennial &
perennial
Hawkweeds
Perennial
Knapweeds
including
yellow
starthistle
Biennial &
Perennial
Kochia-
EARLY
SPRING
MIDSUMMER
When plants start
actively growing
Curtail®
Brazen®
Tordon®
Weedmaster®
Milestone®
Herbicide treatment
at this time is not as
effective
Bud to bloom
3-way mix*
Telar®
Brazen®
Escort + 2,4-D
Same
herbicides for
fall rosette
treatment
Curtail®
Brazen®
Tordon®
Weedmaster®
Milestone®
Telar®
Effective but
should be done
before plants
flower
Same
herbicides:
Apply after
first frost
Banvel®
Curtail®
Brazen®
Milestone®
Weedmaster®
Milestone®
Curtail®
Brazen®
Weedmaster®
Roundup®
Same herbicides:
Apply before
flowering
Mustardsincluding
hoary
alyssum
Escort or 3-way*
Annuals &
Weedmaster®
Biennials
Telar®
Brazen®
If spot spraying
Rush
Perennial
plants can be
skeletonweed
difficult to see early
in the year
Perennial
3-way mix*
Weedmaster®
St Johnswort
Tordon®+ 2,4-D
Milestone
Reminder: 3-way mix is Metsulfuron, Dicamba,
Updated 2/2014
Rosettes/
Perennials
Same herbicides:
Apply before
plants flower
Herbicide treatment
at this time is not as
effective
Annual- but seeds keep
germinating into the fall season.
Better control when it is small.
FALL
Same
herbicides:
Apply to
perennials &
fall rosettes
Plants are hard
to find but it
may be
effective
Same
herbicides for
fall rosette
treatment
Weedmaster®
Vista®
Roundup®-Big plants may develop
resistance.
Same herbicides:
Same herb. for
Apply before
rosette
flowering
treatment
Tordon®+ 2,4-D
Milestone®
3-way mix*
Same
herbicides for
fall rosette
treatment
Not as
effective in the
fall
3-way mix*
Weedmaster®
Tordon®+ 2,4-D
Milestone
& 2,4-D aka Cimarron Max®