bensulide (Prefar 4-E)
Excluding horseradish
Rate 5 to 6 lb ai/A (5 to 6 quarts/A)
Time Apply before crop and weeds emerge, preferably soon after planting; follow with 1 inch of sprinkler irrigation.
Remarks For furrow irrigation, thoroughly saturate bed top. Sometimes the first flush of weeds must be controlled with cultivation before herbicide begins to control grass. Does not control nightshade.
Site of action Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family Organophosphorus
clomazone (Command 3ME)
Broccoli and cabbage only
Rate 0.25 lb ai/A (0.67 pints/A) on seeded cabbage; 0.25 to 0.49 lb ai/A (0.66 to 1.33 pints/A) on transplanted cabbage; 0.25 lb ai/A (0.67 pints/A) on transplanted broccoli).
Time Direct seeded cabbage: After planting, prior to emergence
Transplanted cabbage: Prior to transplanting
Transplant broccoli: Within 48 hr of transplanting
Remarks Before using: note crop-rotation restrictions, weeds controlled, and possible injury symptoms for several days after treatment or when applied to sandy soils. The ME formulation is designed to minimize volatilization, movement off site, and potential injury to adjacent fields and sites.
Rotational cropping precautions: all crops can be planted at 12 months after application. Other restrictions depend on crop, rate, region, and soil pH. Small grain cereals and corn may be sensitive to carryover residues. Cover crops may be planted anytime but stand reductions may occur in some areas. However, do not graze or harvest cover crops for food or feed planted less than 9 months after applications.
Caution Clomazone may persist in soil up to 16 months. Consult label on rotational crop guidelines before applying.
Site of action Group 13: inhibits DOXP synthase
Chemical family isoxazolidinone
dimethenamid-P (Outlook, Slider)
Horseradish only
Rate 0.56 to 0.84 lb ai/A (12 to 18 fl oz/A Outlook) on coarse soils and 0.84 to 0.98 lb ai/A (18 to 21 fl oz/A) in medium-textured or fine soils. May be applied in a single application. Do not exceed 21 fl oz/A per season.
Time Apply postemergence from the 2-leaf to 8-leaf stage of plant development.
Remarks Postemergence by ground, chemigation, aerial, or impregnated onto dry bulk fertilizer. Application must be to clean-tilled soil or with other herbicides that control emerged weeds. Make chemigation applications only through center pivot, lateral move, solid set, or hand move irrigation systems. Make applications in volume minimums of 0.33 to 0.67 inch of water, using the lower volume on coarser soils and the higher volume on finer soils. Applications in more than 1-inch volume may reduce weed control. Refer to the EPA-approved labels for specific application methods and requirements. Preharvest interval is 40 days.
Caution Replanting (recropping) of horseradish is not recommended if Outlook has been applied.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Chloroacetamide
linuron (Lorox 50DF)
Horseradish only
Rate Up to 1.5 lb ai/A (3 lb/A Lorox 50DF) depending on soil type
Time Apply as a dormant application, after planting horseradish or when plants are dormant and no leaves have emerged in the spring.
Remarks Both soil residual and contact weed control. Lorox must be activated within 2 weeks of application for optimum control with rain or irrigation of 0.5 inch or more. Add a surfactant to increase contact activity. Do not exceed a total of 3 lb Lorox/A.
Caution Do not apply through irrigation systems. Note ground and surface water advisories on main label. Toxic to fish and aquatic invertebrates. Do not apply directly to water or to areas where surface water is present or to intertidal areas below the mean high water mark.
Site of action Group 7: photosystem II inhibitor
Chemical family Urea
napropamide (Devrinol 50DF, Devrinol 2-XT)
Rate 1 to 2 lb ai/A (2 to 4 lb/A 50DF, 2 to 4 quarts/A 2-XT), depending on soil texture
Time Direct seeded and transplanted crops, preplant incorporated or as a surface spray after planting. For direct-seeded crops, apply to soil surface immediately after planting and sprinkler-irrigate within 24 hr to wet soil 1 to 2 inches deep, or mechanically incorporate not exceeding the seed depth.
Remarks Selectivity is based on placement above seed or transplant depth. Can be applied with shallow incorporation before transplanting seedlings. Rotational crops listed on the label require deep moldboard plowing. Inhibits root growth.
Caution Do not plant other crops until 12 months after application. Preharvest interval is 60 days.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Acetamide
oxyfluorfen (GoalTender, Goal 2XL or Galigan 2E)
Transplanted broccoli, cabbage, cauliflower
Rate 0.25 to 0.5 lb ai/A (1 to 2 pints/A product)
Time Apply soon after final soil preparation and before transplanting through the treated layer with minimal soil disturbance.
Remarks Select lower rate for coarse soils with less than 1% organic matter. Leaves that contact treated soil may be temporarily injured. Injury may be severe if transplants are stressed by temperature, disease, fertilizer salts, nematodes, insects, pesticides, and storage conditions or if planting small transplants grown in 1-inch cells. After transplanting, apply at least 0.25 inch overhead moisture. Plant only crops listed on the label within 10 months after treatment. Grazing crop residue of treated fields is prohibited.
Caution Late summer transplanted cauliflower is occasionally injured if weather becomes unseasonably hot after transplanting. Do not apply in the same season as Group 15 herbicides such as Dual Magnum as injury potential increases. Do not exceed 2 pints/A per season.
Site of action Group 14: protoporphyrinogen oxidase inhibitor
Chemical family Diphenylether
oxyfluorfen (GoalTender or Goal 2XL)
Horseradish only
Rate 0.5 lb ai/A (1 pint/A GoalTender); (2 pints/A Goal 2XL)
Time Apply after transplanting roots but before new shoots emerge. Plant tissue exposed at application will be injured.
Remarks Do not exceed 0.5 lb ai/A per year.
Caution Acts as a selective contact herbicide that disrupts cell membranes.
Site of action Group 14: protoporphyrinogen oxidase inhibitor
Chemical family Diphenylether
paraquat (Gramoxone; 2 lb paraquat cation/gal)
Rate 0.63 to 1 lb cation/A (2.0 to 4 pints/A)
Time Apply just before crop emerges to emerged weeds.
Remarks Prepare stale seed bed as far ahead as possible to encourage maximum weed emergence. Direct-seed or transplant with a minimum of disturbance. Add a nonionic surfactant or crop oil concentrate as specified on label; take care to avoid anionic formulations that may form insoluble precipitates in the tank.
Caution Restricted-use herbicide due to acute toxicity. For retail sale to and use only by certified applicators - not to be used by uncertified persons working under the supervision of a certified applicator. Do not ingest or inhale spray mist. Wear protective face shields, respirators, and clothing and personal protective equipment (PPE) as specified on label. Do not exceed two applications or 3 pints/A per season. Do not ingest or inhale spray mist. Applicators must wear long-sleeve shirt and long pants, shoes plus socks, protective eyewear, chemical-resistant gloves, and a NIOSH-approved particulate respirator or approved powered air-purifying respirator
Site of action Group 22: photosystem 1 electron diversion
Chemical family Bipyridilium
pendimethalin (Prowl H2O, AquaPen 3.8, Satellite Hydrocap)
Rate 0.475 to 1 lb ai/A (1 to 2.1 pints/A) depending on soil type.
Time Preplant surface before transplanting
Remarks Preemergent weed control; will not control emerged weeds. Labels differ slightly on allowed applications depending on crop group. In general, labeled uses are more restrictive for head and stem brassicas than leafy green brassicas. Pretransplant applications are allowed for brassica head and stem crops.
Caution Never apply preplant or post-plant surface to any direct-seeded brassica crops or severe injury may occur. Do not apply within 21 days of harvest and do not apply more than 1.05 quarts/year.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
S-metolachlor (Dual Magnum)
Oregon only, for direct-seeded turnip, rutabaga, radish and daikon radish only
Rate 0.64 lb ai/A (0.67 pints/A Dual Magnum)
Time Make a single broadcast application of Dual Magnum to soil surface after planting but before weeds or crop emerge. For effective weed control, s-metolachlor must be applied to clean-tilled soil.
Remarks Special local needs indemnified label for turnip, rutabaga, radish, and Daikon radish (OR-060012). The label is available through the Syngenta website (https://www.syngenta-us.com/labels/indemnified-label-login) which must be accessed to digitally sign the indemnification agreement or product liability waiver. Make uniform applications in at least 15 gal/A water. A band application may also be used. Irrigate after application to activate the herbicide if rain is not expected.
Caution Excessive irrigation before the crop emerges may increase the risk of crop injury. Do not mechanically incorporate Dual Magnum. Do not use Dual Magnum if the planting operation creates a furrow or trough over the seed row into which rain or irrigation water will collect and thus concentrate the herbicide over the row. Do not use on coarse soils with less than 1.5% organic matter. Do not use on soils with greater than 10% OM. Do not exceed 0.67 pint/A Dual Magnum in any single application or in total per crop year. Preharvest interval is 60 days.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Chloroacetamide
S-metolachlor (Dual Magnum)
Oregon only, transplanted or established cabbage only, including Chinese (napa and bok choi)
Rate 0.48 to 1.27 lb ai/A (0.5 to 1.33 pints/A)
Time Prior to transplanting, or broadcast postemergence application within 48 hr after transplanting.
Remarks Special local needs indemnified label for cabbage (OR-070006). The label is available through the Syngenta Farm Assist website (https://www.syngenta-us.com/labels/indemnified-label-login), which must be accessed to digitally sign the indemnification agreement or product liability waiver.
Caution In general, the risk of crop injury from the use of Dual Magnum is lower for post-transplant than pre-transplant applications, and the risk of crop injury is lower with post-directed than from over-the-top post-transplanting applications. Applying Dual Magnum before bed formation may result in crop injury due to the incorporation and/or concentration of Dual Magnum directly near the transplanted crop's root system. Napa cabbage and bok choi are less tolerant to Dual Magnum. Preharvest interval is 60 days.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Chloroacetamide
sulfentrazone (Spartan 4F)
Cabbage and horseradish only, pre-transplant only
Rate Depends on soil type and pH. Use higher rates when soil pH is less than 7.0 and lower rates when pH is greater than 7.0.
Time Fall or early spring preplant surface or preplant-incorporated.
Remarks Apply in fall or spring from 60 days prior to and up to transplanting. Preplant incorporate to 2 inches.
Caution For use only by individuals or firms certified and or licensed as pesticide applicators. Do not use on soil with less than 1% OM. Observe rotational guidelines, which may be as long as 24 months for some crops
Site of action Group 14: protoporphyrinogen oxidase inhibitor
Chemical family Triazinone
sulfentrazone (Aquesta 4F, Willowood Sulfentrazone 4SC)
Rate Depends on soil type and pH. On coarse soils with less than 1% organic matter: apply 0.07 lb ai/A (2.25 fl oz/A). To fine soils with more than 3% OM: apply 0.375 lb ai/A (12 oz/A). Use higher rates when soil pH is less than 7.0, and lower rates when pH is greater than 7.0.
Time Apply in fall or spring up to transplanting, starting 60 days prior.
Remarks Labeled for use on several brassica crops including brassica head and stem (group 5-16) and brassica leafy green crops (Group 4-16B). Experience is lacking in the PNW for many of the uses allowed on these labels. Preplant incorporate to 2 inches or apply pretransplant surface. Surface applications provide better weed control if irrigation or rainfall is available to incorporate the herbicide.
Caution OSU research indicates severe injury potential if applied postplant surface to all direct-seeded brassica crops. Do not use on soil with less than 1% OM. Observe rotational guidelines, which may be up to 24 months for some crops including beets.
Site of action Group 14: protoporphyrinogen oxidase inhibitor
Chemical family Triazinone