Armezon™ Herbicide
Technical Information Brochure
Tough on Weeds. Safe on Corn.
contents
1 Introduction
2 Physical and Chemical Properties
3 Mode of Action
4 Formulation and Use
5 Resistance Management
6 Weeds Controlled by Armezon™ Herbicide
8 Toxicological and Environmental Profile
10 Safety, Stewardship and First Aid Measures
Introduction
Developed by BASF, Armezon™ herbicide is a highly flexible
postemergence solution for corn growers, providing excellent control
of tough broadleaf weeds and grasses to help protect yield potential.
This broad-spectrum herbicide has a wide postemergence application
window and ultra-low use rate for improved operational efficiency.
Topramezone, the active ingredient in Armezon, is a pyrazolone, a unique subclass
of the HPPD-inhibiting herbicides. Armezon’s unique chemistry offers highly effective,
consistent control of key broadleaf weeds and grasses, including those that have
developed resistance to glyphosate, triazines, PPO- and ALS-inhibitors.
Field trials have demonstrated that Armezon offers excellent selectivity to all types of
corn, even specialty corn varieties that are sensitive to other herbicides.
Key Features and Benefits:
n B
road-spectrum foliar control of annual grasses and broadleaf weeds
above:
n S
afe for use on all field and speciality corn regardless of trait, even sensitive varieties
Armezon-sensitive weeds turn
of popcorn, seed corn and sweet corn
white, called “bleaching” due
to loss of pigmentation.
n Wide postemergence application window to give growers application flexibility
n HPPD site of action offers an additional tool for weed resistance management
n Low active ingredient use rates for convenient handling and low
environmental exposure
n E
xcellent compatibility with other herbicides (e.g., dimethenamid-p, pendimethalin,
dicamba or triazines)
A R M E Z O N
H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E 1
physical and chemical properties
2
Code name
BAS 670H Active ingredientTopramezone
Chemical family Pyrazolone
Chemical name (IUPAC)
(3-(4,5-dihydro-isoxazol-3-yl)-4-methanesulfonyl-2-
methylphenyl)-(5-hydroxyl-1-methyl-1H-pyrazol
4-yl methanone) Molecular formula
C16H17N3O5S
Molecular mass 363.39
Melting point 220.9-222.2°C; 99.8% Appearance
White crystalline solid; 99.8% Vapor pressure <1x10E-12; 20°C; 99.7%
<1x10E-12; 25°C; 99.7% Solubility in water 510 mg/L at 20°C (pH 3.1); 99.7% Solubility in Dichloromethane 25-29 g/L; DMF 114-133 g/L; acetone
organic solvents
<10 g/L; acetonitrile <10 g/L; ethylacetate <10 g/L; toluene
<10 g/L; methanol <10 g/L; 2-propanol <10 g/L;
n-heptane <10 g/L; 1-octanol <10 g/L
All at 20°C; 99.9%
Partition coefficient - 0.81 pH 4 at 20°C; 99.9%
(log Pow)
- 1.52 pH 7 at 20°C; 99.9%
- 2.34 pH 9 at 20°C; 99.9%
Solo formulation
A.I. content and 336 g ae/liter (2.8 lbs ae/gal)
formulation type SC (suspension concentrate)
A R M E Z O N H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E
Armezon™ herbicide is a potent inhibitor of HPPD (4-hydroxyphenylpyruvate dioxygenase,
an enzyme in the plastoquinone biosynthetic pathway), and indirectly the carotenoid
biosynthetic pathway. As a result, oxidative degradation of chlorophyll occurs, leading
to pronounced whitening or “bleaching” of sensitive weeds. These bleaching effects will
be visible on new growth within five days of treatment. Ultimately, growth is inhibited.
Under the influence of light, chlorotic tissues become necrotic, and sensitive plants usually
die within 7-14 days after treatment.
Selectivity
Armezon Herbicide
Metabolism-Based
Selectivity
Field Corn
Radioactivity (% of total)
Mode of Action
Because corn rapidly metabolizes Armezon to non-active substances, the herbicide
regardless of trait and variety. Corn tolerance to Armezon is also based on a lower
sensitivity of the enzymatic target. In vitro assays show that Armezon exhibits a 10-fold
higher inhibitory activity of the HPPD enzyme in giant foxtail (Seteria faberi) than in corn.
Crop response (transient bleaching) from postemergence applications may occur under
extremely wet and/or cold weather conditions or when the crop is suffering from stress.
These effects are temporary. The plant quickly outgrows these effects and develops
49% 51%
14%
24
48
Time after treatment (hours)
Giant Foxtail
Radioactivity (% of total)
has excellent selectivity in field corn (grain, silage and seed), sweet corn, and popcorn,
86%
93%
79%
21%
7%
48
24
Time after treatment (hours)
normally with no affect on yield potential.
Radioactivity (% of total)
Black Nightshade
86%
76%
24%
14%
48
24
Time after treatment (hours)
Topramezone
Inactive metabolites
above:
Orange bars show very rapid
metabolism of topramezone
in corn varieties compared to
sensitive weeds. BASF lab
study 2004.
A R M E Z O N
H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E 3
T R E AT E D
LEAF
Absorption and Translocation
Armezon™ herbicide is translocated systemically throughout the plant. When Armezon
is used postemergence, susceptible weeds take up the herbicide through the treated
foliage and cease growth soon after application. Adjuvants enhance leaf absorption and
distribution of Armezon.
Formulation and Use
T R E AT E D
LEAF
Armezon is formulated as a suspension concentrate (2.8 lbs ae/gal).
Application
Armezon can be used postemergence in a total post or sequential preemergence/
above:
postemergence system. It will typically be tank mixed with atrazine and/or glyphosate
Leaf uptake and translocation
for a broader spectrum of postemergence weed control. Mixtures with a residual
of Armezon at 48 hours after
herbicide such as dimethenamid-p or pendimethalin are recommended for early
treatment in black nightshade
(Solanum nigrum) and giant
foxtail (Setaria faberi). Blue color
demonstrates translocation
postemergence applications.
Optimum postemergence activity of Armezon requires the addition of adjuvants such
outside treated leaf. BASF lab
as crop oil concentrate (COC) or methylated seed oil (MSO) plus ammonium sulfate (AMS)
study 2004.
or urea ammonium nitrate (UAN). For best performance use MSO except in cases where a
specific tank-mix partner prohibits use.
Young and actively growing weeds are more susceptible to Armezon applications
compared to weeds in advanced growth stages. Foliar uptake of Armezon may be
slowed down when used under cold and/or dry weather conditions, which may reduce
the speed and overall level of control.
Compatibility with Other Herbicides
Armezon is compatible with other herbicides either as a tank mixture or as part of a
sequential weed management program.
Armezon is compatible with all classes of insecticides either as a tank mixture or as
part of a sequential program.
Tank mixtures with strobilurin-based fungicides may result in temporary crop response
(chlorosis, whitening, and/or necrosis). Subsequent growth is typically unaffected.
Refer to individual product labels for precautionary statements, restrictions, rates and
approved uses.
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A R M E Z O N H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E
Mixing Order
Mix Armezon™ herbicide thoroughly in container before dispensing.
Liquid fertilizer as a carrier for postemergence applications of Armezon is not
recommended. Use only water as a carrier.
n W
ater - Fill the spray tank 1/2 to 3/4 full with clean water and start agitation.
n A
rmezon - Add required amount to spray tank while agitating.
n A
fter the Armezon has visibly dispersed, add spray additives and fill the remainder of
the tank with water.
Tank Mix Preparation
When tank mixing Armezon with recommended herbicides, add the other herbicides and
2011 University of
Tennessee Field Trial –
8 Days After Treatment
Confirmed glyphosateresistant Palmer amaranth
(Amaranthus palmeri)
other components in the following order while agitating:
n W
ater - Fill the spray tank 1/2 to 3/4 full with clean water.
n S
oluble packet products - Mix thoroughly.
n W
ater-dispersible products (such as suspension concentrates [SC; Armezon],
suspo-emulsions, wettable powders [WP], dispersible granules [DG], dry flowables
[DF], or liquid flowable [LF] formulations) - Mix thoroughly.
n E
mulsifiable concentrate (EC) products
n S
pray adjuvants
n W
ater - While agitating, fill the remainder of the tank with water.
Minimum Time From Application to Planting of Following Crops
Application rates and timing can affect subsequent crops. Refer to country specific
product labeling for details.
Resistance Management
Resistance to HPPD inhibitor herbicides are known to exist. Always use good resistance
management practices including, but not limited to, tank mixtures and/or rotation
with herbicides that have a different site of action, crop rotation, and mechanical weed
above top:
Glyphosate + NIS + AMS
control. Repeated applications of a single site of action in a weed management program
increase the probability of selecting for naturally occurring biotypes with less susceptibility
above bottom:
Armezon (0.75 fl oz /A) +
or tolerance.
atrazine (1 pt/A) + glyphosate
As an HPPD inhibitor, Armezon herbicide is effective against broadleaf weeds and grasses
+ COC + AMS
that have developed resistance to herbicides such as glyphosate, triazines, PPO- and
ALS-inhibitors.
A R M E Z O N
H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E 5
Weeds Controlled by Armezon™ Herbicide
Postemergence applications of Armezon in the US have demonstrated control or
suppression of the following annual grasses and broadleaf weeds:
Scientific Name
Bayer Code
Common Name
Grasses
Brachiaria platyphylla DIGSS
Crabgrass spp.
Echinochloa crus-galli
ECHCG
Barnyardgrass
Eleusine indica
ELEIN
Goosegrass
Eriochloa villosa
ERBVI
Woolly cupgrass
Panicum dichotomiflorum
PANDI
Fall panicum
Panicum miliaceum
PANMI
Wild proso millet
Pennisetum glaucum
PESGL
Yellow foxtail
Setaria spp.
SETSS
Foxtail spp.
Sorghum bicolor
SORVU
Shattercane
Sorghum halepense
SORHA
Johnsongrass
above:
excellent control of tough
broadleaf weeds and grasses.
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Broadleaf signalgrass Digitaria spp.
Armezon herbicide provides
BRAPP
A R M E Z O N H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E
Scientific Name
Bayer Code
Common Name
Abutilon theophrasti
ABUTH
Velvetleaf
Amaranthus palmeri
AMAPA
Palmer amaranth
Amaranthus spp.
AMASS
Pigweed spp.,
Waterhemp spp.
Ambrosia spp.
AMBSS
Ragweed spp.
Anoda cristata ANVCR Spurred anoda Brassica spp.
BRASS
Mustard spp.
Capsella bursa-pastoris CAPBP Shepherd’s-purse Cassia tora
CASTO
Sicklepod
Conyza canadensis
ERICA
Horseweed (marestail)
Chenopodium album
CHEAL
Common lambsquarters
Armezon™ herbicide
Datura stramonium
DATST
Jimsonweed
controls annual grasses and
Galinsoga ciliata
GASCI
Hairy galinsoga
Helianthus annuus
HELAN
Common sunflower
Hibiscus trionum
HIBTR
Venice mallow
Kochia scoparia
KCHSC
Kochia
Lamium amplexicaule
LAMAM
Henbit
Latuca serriola
LACSE
Prickly lettuce
Polygonum spp.
POLSS
Smartweed
Richardia scabra
RCHSC
Florida pusley
Salsola iberica
SASKR
Russian thistle
Sicyos angulatus
SIYAN
Burcucumber
Sida spinosa
SIDSP
Prickly sida
Sinapis arvensis
SINAR
Wild mustard
Solanum spp.
SOLSS
Nightshade spp.
Stellaria media
STEME
Common chickweed
Xanthium strumarium
XANST
Common cocklebur
Broadleaf Weeds
A R M E Z O N
above:
broadleaf weeds including
Amaranthus spp.
H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E 7
Toxicological and Environmental Profile
Topramezone, the active ingredient in Armezon™ herbicide, does not demonstrate
genotoxic, carcinogenic or neurotoxic potential and has no effect on fertility. Some
evidence of developmental toxicity was observed in animal studies but only at doses that
are significantly higher than those used for risk assessments.
The residues present in corn are below the determination limit of 0.01 mg/kg grain or
silage, and do not raise a concern to consumers.
The ecotoxicity profile of topramezone is favorable and does not raise a concern to
the environment.
Mammilian Toxicology
Species
Rat Study
Oral
Effect Level
LD50 > 2,000 mg/kg bw Rat Acute dermal LD50 > 2,000 mg/kg bw Rat Acute inhalation
LC50 = > 5 mg/L
Rabbit Skin irritation
Not irritating
Rabbit
Eye irritation
Not irritating
Guinea pig
Skin sensitization
Not sensitizing (maxim test)
Ames test
Mutagenicity
Negative
Study
Effect Level
Toxicity to Avian Species
Species
Bobwhite quail
C. virginianus Birds, acute oral
LD50 > 2,000 mg a.s./kg bw
NOEL > 2,000 mg a.s./kg bw Toxicity to Freshwater and Estuarine Organisms
Species
Rainbow trout
Orcorhynchus mykiss 8
Study
Fish, acute
Effect Level
Static, 96h LC50 > 100 mg/ L
Bluegill
L. macrochirus Fish, acute Static, 96h LC50 > 250 mg/ L
Rainbow trout
Orcorhynchus mykiss Fish, early life stage
Flow-through
96d NOEC = 3.2 mg/L
Daphnia
Daphnia magna Water flea, acute
Static, 96h LC50 > 100 mg/ L
Daphnia
Daphnia magna
Water flea, acute
Reproduction, semi-static,
21d NOEC = 50 mg/L
Green algae
Pseudokirchneriella
subcapitata
Algae
Static, 96h EbC50 =17.2 mg/L
A R M E Z O N H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E
Toxicity to Earthworms
Species
Earthworm
Eisenia foetida Study
Earthworm, acute
Effect Level
LC50 > 1,000 mg/kg
(dry soil weight)
Earthworm
Eisenia foetida
Earthworm, acute
NOEC = 2.96.3 mg/kg
Study
Effect Level
Toxicity to Honeybees
Species
Honeybee
Apis mellifera
Acute oral
Honeybee
Apis mellifera
Acute contact
LD50 > 72.05 µg/bee LD50 > 100.00 µg/bee
Effect on Natural Resources
Soil: Neither topramezone nor its metabolites are stable in an active soil environment.
Water: Applied according to the label recommendation, topramezone and its metabolites
are degradable in natural water bodies and are within the regulatory thresholds.
Air: Volatilization studies from plant and soil surfaces showed a very low potential for
topramezone to be displaced into the atmosphere.
A R M E Z O N
H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E 9
Safety, Stewardship and First Aid Measures
Hazards to Humans and Domestic Animals
Caution: Causes moderate eye irritation. Avoid contact with skin, eyes, or clothing.
Harmful if swallowed or absorbed through the skin. Wash thoroughly with soap and water
after handling.
Personal Protective Equipment (PPE)
Some materials that are chemically resistant to this product are listed below. If you want
more options, follow the instructions for Category A on an EPA chemical resistance
category selection chart.
Applicators and other handlers must wear:
n L
ong-sleeved shirt and long pants
n C
hemical resistant gloves Category A
n S
hoes plus socks
Discard clothing and other absorbent materials that have been drenched or heavily
contaminated with this product’s concentrate. DO NOT reuse them. Follow manufacturer’s
instructions for cleaning and maintaining PPE. If no such instructions for washables exist,
use detergent and hot water. Keep and wash PPE separately from other laundry.
User Safety Recommendations
Users should:
n W
ash hands before eating, drinking, chewing gum, using tobacco, or using the toilet.
n R
emove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly and
put on clean clothing.
n R
emove PPE immediately after handling this product. Wash the outside of gloves
before removing. As soon as possible, wash thoroughly and change into clean clothing.
Storage Notes
For topramezone, the shelf-life study in original containers confirmed excellent storage
stability for 24 months.
Topramezone is non-explosive and neither the active ingredient nor the co-formulants have
any oxidizing potential.
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A R M E Z O N H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E
Cleaning Spray Equipment
To avoid injury to sensitive crops, drain and clean application equipment thoroughly using a
strong detergent or commercial sprayer cleaner according to the manufacturer’s directions.
Triple rinse the equipment before and after applying this product.
First Aid
If in eyes:
n H
old eyes open and rinse slowly and gently with water for 15 to 20 minutes.
n R
emove contact lenses, if present, after first 5 minutes; then continue rinsing eyes.
n C
all a poison control center or doctor for treatment advice.
If swallowed:
n C
all a poison control center or doctor immediately for treatment advice.
n S
ip a glass of water if able to swallow.
n D
O NOT induce vomiting unless told to do so by a poison control center or doctor.
n D
O NOT give anything by mouth to an unconscious person.
If on skin or clothing:
n T
ake off contaminated clothing.
n R
inse skin immediately with plenty of water for 15 to 20 minutes.
n C
all a poison control center or doctor for treatment advice.
Hotline Number
Have the product container or label with you when calling a poison control center or doctor
or going for treatment. You may also contact BASF Corporation for emergency medical
treatment information: 1-800-832-HELP (4357).
A R M E Z O N
H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E 11
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A R M E Z O N H E R B I C I D E T E C H N I C A L I N F O R M AT I O N B R O C H U R E
BASF Agricultural Products
26 Davis Drive
Research Triangle Park, NC 27709
USA
+1 919-547-2000
www.agro.basf.com
Armezon is a trademark of BASF.
© 2011 BASF Corporation
All Rights Reserved.
APN-12-23-A-DEW-002 December 2011