Spectrum B

Dow AgroSciences
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Spectrum Herbicide is a selective postemergence herbicide for the control of hard-to-kill annual broadleaved weeds such as chickweed and cleavers in spring wheat (including durum), winter wheat, spring barley (not underseeded with legumes), and oats. Spectrum Herbicide is mixed with water and applied as a uniform broadcast spray.
Spectrum Herbicide MUST be applied early postemergence, to the main flush of actively growing broadleaved weeds. Warm, moist growing conditions promote active weed growth and enhance the activity of Spectrum Herbicide by allowing maximum foliar uptake and contact activity. Weeds hardened off by cold weather or drought stress may not be adequately controlled or suppressed and re-growth may occur. For best results, ensure thorough spray coverage of target weeds. See “DIRECTIONS FOR USE” section of this label for complete use details.
Spectrum Herbicide stops growth of susceptible weeds rapidly. However, typical symptoms (discolouration) of dying weeds may not be noticeable for 1 to 2 weeks after application, depending upon growing conditions and weed susceptibility. Degree of control and duration of effect are dependent on weed sensitivity, weed size, crop competition, growing conditions at and following treatment, and spray coverage.


Spectrum Herbicide is a combination of Group 2 and Group 4 herbicides. Group 2 herbicides inhibit the production of the ALS enzyme in plants. This enzyme is essential for the production of certain amino acids which are essential for plant growth. Group 4 herbicides are synthetic auxins, which act at multiple sites in the plant to disrupt hormone balance and protein synthesis and thereby cause a variety of plant growth abnormalities.




Do not use in greenhouses.
Apply only when the potential for drift to areas of human habitation or areas of human activity (such as houses, cottages, schools and recreational areas) is minimal. Take into consideration wind speed, wind direction, temperature inversions, application equipment and sprayer settings.

Sensitive Plants
Do not apply Spectrum Herbicide directly to, or otherwise permit it to come in direct contact with susceptible crops or desirable plants including alfalfa, edible beans, canola, flowers and ornamentals, lentils, lettuce, peas, potatoes, radishes, soybeans, sugar beets, sunflowers, tomatoes or tobacco.

Non-Target Sites
Do not apply where proximity of susceptible crops or other desirable plants is likely to result in exposure to spray or spray drift. See Environmental Hazards section of the label.

Crop Rotation

Fields previously treated with Spectrum Herbicide can be seeded the following year to barley, canola, corn, field peas, flax, mustard (brown, oriental and/or yellow), oats, or wheat or fields can be summerfallowed. Seed only those crops listed above in the year following treatment. Do not seed to field peas for at least 10 months following treatment. Very dry soil conditions following application can result in a risk of injury to field peas grown in rotation. If severe drought conditions are experienced during the months of June to August inclusive in the year of application, delay seeding field peas an additional 12 months (total 22 months following application). Contact your local Dow AgroSciences Canada representative or retailer for more information before seeding field peas following drought conditions in the previous year.
This product has potential to leach. Do not apply excessive irrigation. Do not use in successive years at the same site.

Tank Mixtures

In some cases, tank mixing a pest control product with another pest control product or a fertilizer can result in biological effects that could include, but are not limited to: reduced pest efficacy or increased host crop injury. The user should contact Dow AgroSciences Canada Inc at 1-800-667-3852 or www.dowagro.ca for information before mixing any pesticide or fertilizer that is not specifically recommended on this label. The user assumes the risk of losses that result from the use of tank mixes that do not appear on this label or that are not specifically recommended by Dow AgroSciences Canada Inc.

Spray Equipment Precaution

Do not apply through any type of irrigation system.

Sprayer clean-out

To avoid injury to desirable plants, thoroughly clean equipment used to apply this product before re-use or using it to apply other chemicals.
1. Immediately after spraying, completely drain the sprayer tank. Any contamination on the outside of the spraying equipment should be removed by washing with clean water.
2. First rinse:
 Spray the inside of tank with clean water and fill the sprayer with at least one tenth of the spray tank volume.
 Agitate and circulate for 15 minutes, and flush through booms and hoses.
 Remove end caps or open ball valves on the ends of each boom section, and flush solution through the boom ends to ensure there is no spray solution trapped between the boom end and the nozzles.
 Drain tank completely.
3. Second rinse:
 Fill the tank with clean water.
 Add All Clear Spray Tank Decontaminator, or Clean-Out Spray Tank Cleaner, or 1 L of household ammonia (containing a minimum of 3 % ammonia) per 100 L of water, or similar tank cleaning agent as per manufacturer’s recommendations while filling the tank with clean water.
 Agitate and then flush the boom and hoses with the cleaning solution. Top up with water making sure the tank is completely full. Allow to stand for 15 minutes with agitation. Flush the solution out of the spray tank through the spray booms. Remove end caps or open ball valves on the ends of each boom section, and flush solution through the boom ends to ensure there is no spray solution trapped between the boom end and the nozzles.
 If possible, let the solution stand in the sprayer tank and booms for an extended period of time, overnight if possible.
 After flushing the boom and hoses, drain tank completely.
 Remove nozzles and screens and clean separately with a cleaning agent or an ammonia solution (100 mL in 10 L water).
4. Third rinse:
 Rinse the tank with clean water and flush through the boom and hoses using at least one tenth of the spray tank volume.
 Remove end caps or open ball valves on the ends of each boom section, and flush solution through the boom ends to ensure there is no spray solution trapped between the boom end and the nozzles.
 Drain tank completely.
Do not use ammonia with chlorine bleach. Using ammonia with chlorine bleach will release a gas with a musty chlorine odour which may cause eye, nose, throat, and lung irritation. Do not clean equipment in an enclosed area.

DIRECTIONS FOR USE – Spectrum Herbicide Applied Alone


Field sprayer application
DO NOT apply during periods of dead calm. Avoid application of this product when winds are gusty. DO NOT apply with spray droplets smaller than the American Society of Agricultural Engineers (ASAE) coarse classification. Boom height must be 60 cm or less above the crop or ground.

To reduce spray drift:

 Use low pressures (200 to 275 kPa)
 Use 100 L/ha of spray solution
 Spot treatments should only be applied with a calibrated boom to prevent over-application.

Preharvest/Grazing Restrictions

 Do not permit any grazing within 7 days after application.
 Do not harvest forage or cut hay within 7 days after application.
 Withdraw meat animals from treated fields at least 3 days before slaughter.
 Do not harvest the treated crop within 60 days after application.

Restricted Entry Interval (REI)

All crops – 12-hour REI


Spring wheat (including durum), winter wheat, spring barley and oats.

Rates of Application

The contents of this tank-mix co-package mixed with 800 L of water will treat 8 hectares.
For control of a wide spectrum of broadleaved weeds plus Canada thistle and perennial sowthistle. Apply a uniform spray containing 0.1 L of Spectrum A Herbicide and 1.5 L of Spectrum B Herbicide in a minimum of 100 L of water per hectare to thoroughly cover the weeds. Apply to actively growing spring wheat, barley and oats from the 2-6 leaf stage. Apply to winter wheat from tillering to just prior to flag leaf emergence. Apply when weeds are actively growing. Only weeds emerged at the time of treatment will be controlled. Best results are obtained from applications made to seedling weeds.
A maximum of one application per year.

Mixing Instructions

1. Fill sprayer tank 1/2 full of water.
2. Start sprayer tank agitation.
3. Add the required number of jugs of Spectrum A Herbicide.
4. Add the required number of jugs of Spectrum B Herbicide.
5. Complete filling the sprayer tank with sufficient water to spray 100 L of spray mixture per hectare
6. Follow sprayer directions and precautions as outlined above, especially when applying next to sensitive crops (e.g. canola and legumes).
7. Follow sprayer clean-up directions.
Note: Do not add a surfactant to this tank mixture.

Weeds Controlled or Suppressed

Weeds Controlled:
buckwheat wild, hempnettle, sowthistle perennial (top growth only)**, canola volunteer*, lamb’squarters, chickweed common, mustard wild, sowthistle annual, cleavers, narrow-leaved hawks beard (seedling to <20 cm) stinkweed, cow cockle, pigweed redroot, stork's-bill, dandelions (seedlings; over-wintered rosettes <15 cm), shepherd’s purse, thistle Canada, flixweed (spring rosettes only), smartweed
*Including Roundup Ready, Liberty-Link and Smart herbicide-tolerant canola varieties.
**Control not observed until a minimum of 40 days after treatment.
Weeds Suppressed:
dandelion (over-wintered rosettes >15 cm; mature plants), plantain (top growth)


Crops Registered
spring wheat (including durum) and spring barley

Do not apply these tank mixes to oats.
Tank mixtures of Spectrum Herbicide with other herbicides will provide control of broadleaved weeds and specified annual grasses. Apply when crop and weeds are actively growing. Only weeds emerged at the time of treatment will be controlled. Best results are obtained from applications made to seedling weeds. Follow all precautions, minimum interval to harvest and directions for use on the Spectrum Herbicide and tank-mix partner labels.

Mixing Instructions
1. Fill sprayer tank 1/2 full of water.
2. Start sprayer tank agitation.
3. Add tank mix partners in the proper order (see Notes 2 and 3 below) and continue to agitate.
4. Fill the sprayer tank with sufficient water to spray 100 L of spray mixture per hectare.
5. Follow sprayer directions and precautions as outlined above, especially when applying next to sensitive crops (e.g. canola and legumes).
6. Follow sprayer clean-up directions.

Note 1:
 Add only the adjuvant recommended. Follow tank-mix partner label for order
of mixing and for any specific mixing instructions.
Note 2: When using Assert 300 SC herbicide, add tank mix partners in the following order:
Spectrum A, Spray Water pH Adjuster, Assert 300 SC, Spectrum B.
Note 3: When using Everest 2.0 SC Herbicide add tank mix partners in the following order:
Everest 2.0 SC Herbicide, Spectrum A, Spectrum B, adjuvant. Vigorous agitation is required to dissolve Everest 2.0 SC Herbicide before adding other tank mix partners.

Tank-Mix Combinations with Spectrum Herbicide

Herbicide Tank Mix Partner: Assert 300 SC
Crops Registered: wheat (spring & durum), barley
Rate (Product/ha): 1.6 L
Adjuvant and Rate: Refer to the Assert 300 SC label
Additional Weeds Controlled: wild oat

Herbicide Tank Mix Partner: Everest 2.0 SC Herbicide♦†
Crops Registered: wheat (spring & durum)
Rate (Product/ha): 36-72 mL
Adjuvant and Rate: Non-ionic surfactant (see label) 0.25% v/v
Additional Weeds Controlled: wild oats and green foxtail

Herbicide Tank Mix Partner: Axial 100 EC Herbicide
Crops Registered: spring wheat and barley
Rate (Product/ha): 600 mL
Adjuvant and Rate: Adigor 700 mL/ha
Additional Weeds Controlled: wild oats, green foxtail††, yellow foxtail, volunteer oats, volunteer canary seed, proso millet, barnyard grass†††

Herbicide Tank Mix Partner: Simplicity™
Crops Registered: wheat (spring & durum)
Rate (Product/ha): 500 mL
Adjuvant and Rate: Not required
Additional Weeds Controlled: wild oat, barnyard grass, Japanese brome, yellow foxtail

♦ For conditions for when to use the higher rates, refer to the Everest 2.0 Herbicide label.
†Wheat (including durum) exposed to water-logged or saturated soils, or temperature extremes such as heat or freezing weather, or drought, low fertility or plant disease at application time could show unacceptable injury symptoms. Weed control may also be reduced by these same conditions.
††Suppression only of green foxtail.
†††A reduction in barnyard grass control may be observed when Axial 100EC Herbicide is tank mixed with Spectrum Herbicide.

NOTE TO USER: READ THE FOLLOWING BEFORE USING THIS PRODUCT FOR THE INDICATED SPECIAL USE APPLICATIONS: The DIRECTIONS FOR USE for this product for the use(s) described below were developed by persons other than Dow AgroSciences Canada Inc. and accepted for registration by Health Canada under the User Requested Minor Use Label Expansion program. Dow AgroSciences Canada Inc. itself makes no representation or warranty with respect to performance (efficacy) and/or crop tolerance (phytotoxicity) claims for this product when used on the crop(s) listed below.
Accordingly, the Buyer and User assumes all risks related to performance and crop tolerance arising, and agree to hold Dow AgroSciences Canada Inc. harmless from any claims based on efficacy and/or phytotoxicity in connection with the use(s) described on this label.


 Seedling and Established chewings fescue, creeping red fescue, crested wheat grass, hard fescue, hybrid brome grass, intermediate wheat grass, meadow brome grass, perennial rye grass, smooth brome grass, tall fescue, timothy.

Application rates (apply as a tank-mix only): Apply Spectrum A Herbicide at a rate of 0.1 L/ha. Apply Spectrum B Herbicide at a rate of 1.5 L/ha. Apply in a minimum spray volume of 100 L water/ha.
Apply one postemergent application when weeds are small and actively growing by ground application only. Do not cut treated fields for forage/hay or graze the treated grasses. Refer to the main Spectrum Herbicide label for additional details and instructions before using.


Use of the following spray methods or equipment DO NOT require a buffer zone: handheld or backpack sprayer and spot treatment.
The buffer zones specified in the table below are required between the point of direct application and the closest downwind edge of sensitive terrestrial habitats (such as grasslands, forested areas, shelter belts, woodlots, hedgerows, riparian areas and shrublands), sensitive freshwater habitats (such as lakes, rivers, sloughs, ponds, prairie potholes, creeks, marshes, streams, reservoirs and wetlands) and estuarine/marine habitats.

Buffer Zone Table

Method of application: Field sprayer
Crop: Cereals
Buffer Zones (metres) Required for the Protection of:
Freshwater Habitat of Depths:
Less than 1 m: 5
Greater than 1 m: 5
Estuarine/Marine Habitats of Depths:
Less than 1 m: 5
Greater than 1 m: 5
Terrestrial habitat: 30

NOTE: Applicators may recalculate a site-specific buffer zone by combining information on current weather conditions and spray configuration for the following applications: all airblast applications, and for field and aerial applications which specify the following droplet size category wording on the product label: ‘DO NOT apply with spray droplets smaller than the American Society of Agricultural Engineers (ASAE) [Fine or Medium or Coarse] classification.’ To access the Buffer Zone Calculator, please visit the Pest Management Regulatory Agency web site.
When a tank mixture is used, consult the labels of the tank-mix partners and observe the largest (most restrictive) buffer zone of the products involved in the tank mixture and apply using the coarsest spray (ASAE) category indicated on the label for those tank-mix partners.


For resistance management, please note that Spectrum Herbicide is both a Group 2 and a Group 4 herbicides. Any weed population may contain or develop plants naturally resistant to Spectrum Herbicide and to other Group 2 and/or to Group 4 herbicides. The resistant biotypes may dominate the weed population if these herbicides are used repeatedly in the same field. Other resistance mechanisms that are not linked to site of action, but specific for individual chemicals, such as enhanced metabolism, may also exist. Appropriate resistance management strategies should be followed.
To delay herbicide resistance:
Where possible, rotate the use of Spectrum Herbicide or other Group 2 or other Group 4 herbicide within a growing season (sequence) or among growing seasons with different herbicide groups that control the same weeds in a field.
Use tank mixtures with herbicides from a different group when such use is permitted. To delay resistance, the less resistance-prone partner should control the target weed(s) as effectively as the more resistance-prone partner.
Herbicide use should be based on an integrated weed management program that includes scouting, historical information related to herbicide use and crop rotation, and considers tillage (or other mechanical control methods), cultural (for example, higher crop seeding rates; precision fertilizer application method and timing to favour the crop and not the weeds), biological (weed-competitive crops or varieties) and other management practices.
Monitor weed populations after herbicide application for signs of resistance development (for example, only one weed species on the herbicide label not controlled). If resistance is suspected, prevent weed seed production in the affected area if possible by an alternative herbicide from a different group. Prevent movement of resistant weed seeds to other fields by cleaning harvesting and tillage equipment when moving between fields, and planting clean seed.
Have suspected resistant weed seeds tested by a qualified laboratory to confirm resistance and identify alternative herbicide options.
Contact your local extension specialist or certified crop advisors for any additional pesticide resistance-management and/or integrated weed-management recommendations for specific crops and weed biotypes.

NOTICE TO USER: This pest control product is to be used only in accordance with the directions on the label. It is an offence under the Pest Control Products Act to use this product in a way that is inconsistent with the directions on the label. The user assumes the risk to persons or property that arises from any such use of this product.

Registered for culturesRatePreharvest Interval
Winter wheat1.5 l60
Spring wheat1.5 l60
Spring barley1.5 l60
Winter oats1.5 l60
Spring oats1.5 l60