Author: Andrea Dailey
Last saved by: Jennifer

Weed Management in Vegetable Crops
Ed Peachey
Revised November 26, 2008

Annual weeds that grow and produce seed quickly, or perennials such as yellow nutsedge, Canada thistle, and field bindweed often dominate in cultivated fields. Routine cultural practices and repeated use of the same or similar herbicide enhances selection for resistant species or weed biotypes and can modify some microorganisms that degrade herbicides, resulting in shorter soil persistence and poor weed control.
Preventing weed shifts and introductions  Weeds that survive plowing, cultivation, repeated herbicide treatments, or other routine cultural practices must be eliminated before tolerant species or biotypes become established. Combine a variety of weed control practices or treatments, rotate practices and herbicides, spot-treat with registered herbicides, or remove weeds manually when they first appear.
Clean your equipment when moving from an infested field. Wild proso millet seed has been carried by harvest equipment, and puncturevine seeds are being transported from eastern Oregon and are becoming more common in the Willamette Valley. 
Weed management in annual cropping systems  Successful weed management in annual cropping systems requires a year-round approach, employing a combination of weed control practices and rotating them throughout several years. Developing these strategies requires knowledge of specific weeds that infest your land. Identify and map major weed species and infested patches within each field. With an established point of reference and occasional observations, you can evaluate weed shifts and adjust crop and weed management strategies before resistant weeds predominate.
Planning weed control options  After accurately identifying weeds, plan an efficient year-round weed and crop management program by listing previous rotations, possible herbicide residues, and effective controls for each weed. Consider the strengths and weaknesses of each control based on your experience, herbicide labels, and local experts, including pesticide dealers, consultants, and Extension agents. Evaluate the information carefully and select a field, soil conditions, weed infestations, and control methods that are compatible with the crop you intend to plant.
Field preparation and planting  Eliminate perennial weeds before planting by designing a selective control program in the previous crop or by controlling the weed during a temporary fallow period. Canada thistle, for example, can be controlled with wiper applications of glyphosate (Roundup) in certain crops if 10% or less of the acreage will be treated (see label). Soil fumigation also might be considered for high-value vegetables if potential losses from soilborne diseases, nematodes, or possibly perennial weeds such as yellow nutsedge would justify application costs. (See the current edition of the PNW Plant Disease Management Handbook for soil fumigation details and approved materials.)
During field preparation, destroy all weedy vegetation and prepare a reasonably smooth surface for uniform herbicide application. Wet soils or delayed applications after the last soil disturbance often result in erratic weed control
Effective use of preemergence herbicides  Three principles should guide the use of preemergence soil-applied herbicides.
1.	Apply the herbicide before the weed seed germinates. Many herbicides are not effective if applied after weed seeds germinate. The radicle of the seed emerges first and quickly grows down and away from herbicide-treated zone. If the herbicide is not active when the radicle emerges, the weed seedling may survive. Herbicides such as Dual (S-metolachlor), Outlook (dimethenamid-P),and Treflan (trifluralin)  provide very poor control if the weed seeds have germinated. This is not the case for all soil-applied herbicides, including Goal (oxyfluorfen) and Chateau (flumioxazin) ; but even in these cases, the smaller the seedling, the better the efficacy. To ensure proper preemergence herbicide efficacy, till the soil and apply and incorporate the herbicide before weed seeds have a chance to germinate.
2.	Activate the herbicide. Activation of soil-applied herbicides distributes the herbicide so that it comes in contact with the weed seed. Water usually works best to activate preemergence herbicides, but tillage is required in some situations, such as with Eptam (EPTC) because of herbicide volatility or because the herbicide is very insoluble and is difficult to incorporate with irrigation or rain (Treflan). Irrigation water or rain carries the herbicide down into the soil and distributes the herbicide throughout the soil. Most weed seeds germinate from 0.25- to 1-inch depths. If the herbicide is not in contact with the seed when it germinates, the first emerging root may get a foothold, and the seedling will survive.
In some cases, immediate activation of preemergence herbicide is counterproductive. For instance, Outlook can be applied post-emergence in corn. If the corn has been planted in moist soil, and irrigation has not been applied recently, few weed seeds will germinate until further irrigation is applied or rain falls. In this case, the herbicide may be most effective if activated with the next irrigation because this will delay weed seed germination until later in the growing season, enabling more crop competition and hopefully less weed seed production from those weeds that do escape. Some weeds will escape, however, and therein lies the tradeoff.
3.	Preserve the chemical barrier. Properly applied and activated herbicides present a barrier to weed seeds that they must escape if they are to produce weed seedlings. Too much irrigation water or rain on a soluble herbicide such as Dual or Eptam will destroy the chemical barrier because the herbicide gets washed too far down and becomes diluted at the soil surface. Incorporating the herbicide too deeply into the soil is another way to diminish the effective chemical barrier. Mechanical disturbance also can destroy this barrier and allow weed seedlings to escape. Goal), Cobra (lactofen), and Chateau are preemergence herbicides that kill some weeds by contact when weed seedlings grow into the chemical barrier at the soil surface. If the herbicide concentration is lessened at the soil surface because the surface layer has been moved (by cultivation, tillage, or foot traffic), the herbicide barrier will be broken or diminished and weed control will suffer.
Scouting  Evaluate the effectiveness of preplant or preemergence weed control treatments as you assess crop emergence, soil moisture, disease incidence, and other factors during the growing season. Note whether gravel or low spots may have caused abnormal weed control or possible crop injury. Map weed problem areas in fields, including patches of perennial weeds. Determine whether additional control measures such as cultivation, application, or spot-spraying of a postemergence herbicide, or hand-hoeing individual weeds, will be necessary to achieve a quality product at harvest yet minimize the chances of allowing a weed shift.
Postharvest control  Soon after harvest, destroy weeds and crop stubble to reduce pests and minimize weed seed production. Weed seed production is often at its peak when short-season crops such as beans are harvested in mid- to late summer. Harvest procedures do not always kill weeds, and seeds will continue to develop and mature. Steps to control weeds after harvest contribute to an overall weed management strategy that minimizes the amount of seed that will go back into the soil. If weeds are perennials, maintain optimum growing conditions so appropriate herbicides can be applied to actively growing weed foliage for maximum control. Consider factors such as application timing and weed growth stage, herbicide persistence in soil, crop rotations, and label restrictions for subsequent crops when selecting a postharvest herbicide for perennial weed control. After postharvest treatment, consider planting a rotation crop, such as winter grain or a small-grain cover crop, that requires significantly different cultural practices.
Warning  Using 2,4-D or similar materials on horticultural farms involves risk, not only to the crop to which it is applied but also to crops in nearby fields. However, in some instances, using 2,4-D will enhance weed control in horticultural cropping systems. Be careful to clean all 2,4-D from your equipment, or use separate sprayers before applying another product in other horticultural crops. Never use a volatile formulation of 2,4-D or similar material.
Herbicide persistence and crop rotations  Many herbicides used in vegetables persist or have residual activity in soil. Some of the longer rotational intervals are required following the use of Sandea (halosulfuron), Raptor (imazamox), and Impact (topramezone) herbicides. Brassica crops and sugar beets often are impacted by carryover from persistent herbicides. Overapplication or unusually dry or freezing weather may prolong herbicide persistence. If herbicides persist into the next crop cycle, those crops may be injured, or harmful residue might accumulate in the food product. Managing persistent herbicides requires careful planning of crop rotations according to waiting periods specified on the label.
Accuracy, precision, and food safety  Herbicides must be applied at the correct rate and time to selectively control weeds with minimal risk of injuring vegetables. If the label is not followed accurately, illegal pesticide residues may be found in harvested crops and cause the crop to be removed from the market. Risks of endangering the food supply with pesticide residues can occur when herbicides are applied without label approval for each crop, when excessive quantities are applied, or when harvest occurs before the preharvest interval expires. Avoid possible residues in edible crops by plowing the field if a mistake occurs involving a nonregistered pesticide, by verifying mathematical calculations with other knowledgeable persons to ensure accuracy, and by noting the preharvest interval at the time of application to ensure food quality standards are met or exceeded. 
Read the label and other information about properly applying and timing each herbicide. Suggested rates in this guide are stated as pounds active ingredient per acre (lb ai/A) or pounds acid equivalent per acre (lb ae/A). Many tank-mixes are listed on herbicide labels. Growers or applicators may accept liability and mix materials unless specifically denied on one of the labels. Select products that are compatible and complementary in their weed control. 
Important Preharvest Intervals (PHIs) for Vegetables 
Vegetable | Herbicide | PHI (days)
Beans | bentazon (Basagran) | 30
| clethodim ( (Select Max) | 30
| clomazone (Command) | 45 snap
| halosulfuron (Sandea) | 30
| imazamox (Raptor) | 0 for snap or dry
| lactofen (Cobra) | 55 snap Oregon only
| quizalofop P-ethyl (Assure II) | 15 snap; 30 dry; 60 lentils
| sethoxydim (Poast) | 15 snap; 30 dry
Beets, table | clethodim  (Select or Prism) | 30
| clopyralid (Stinger) | 45
| ethofumesate  (Nortron) | 30
| phenmedipham (Spin-Aid) | 60
| phenmedipham + desmedipham (Betamix) | 50
Broccoli, Brussels sprouts, cauliflower, leafy brassicas | clethodim (Prism or Select) | 14 leafy brassica crops; 30 others
| clopyralid (ClopyrAG) | 30
| S-metolachlor (Dual Magnum) | 60
| sethoxydim (Poast) | 30, 14 for leafy greens
Cabbage | clomazone (Command) | 45
| clethodim  (Prism or Select) | 30
Carrots | clethodim (Prism or Select) | 30
| ethofumesate  (Nortron) | 30
| fluazifop (Fusilade DX) | 45
| linuron  (Lorox) | 14
| metribuzin  (Sencor) | 60
| pendimethalin (Prowl) | 60
| sethoxydim (Poast) | 30
Celery | linuron  (Lorox) | 67
Corn, sweet | clopyralid (Stinger) | 30
| dimethenamid-P (Outlook) | 50
| foramsulfuron (Option) | 45
| fluroxypyr (Starane) | 31 ears; 47 forage
| S-metolachlor (Dual Magnum) | 30
| simazine | 45
| tembotrione (Laudis) | 45
| topramezone  (Impact) | 45
Cucurbit/vine crops (all) | clethodim  (Prism or Select) | 14
| clomazone (Command) | 45
| dimethenamid-P (Outlook) | 90 on Golden Delicious squash
| halosulfuron  (Sandea) | 30 squash, cucumber, and pumpkin; 57 melon
| sethoxydim (Poast) | 3 cantaloupe; 14 others
Garlic | bromoxynil (Buctril) | 112
| clethodim (Prism or Select) | 45
| dimethenamid-P (Outlook) | 30
| fluazifop (Fusilade DX) | 45
| oxyfluorfen (GoalTender) | 60
| pendimethalin (Prowl) | 45
| sethoxydim(Poast) | 30
Lettuce and leaf crops | clethodim  (Prism or Select) | 14
| fluazifop (Fusilade) | 28 endive
| pronamide (Kerb) | 55
| sethoxydim (Poast) | 15 leaf; 30 head
| triflusulfuron (UpBeet) | 60 for endive and chicory
Onion | clethodim (Select Max, Prism) | 45 bulb only
| dimethenamid-P  (Outlook) | 30
| ethofumesate  (Nortron) | 30
| fluazifop (Fusilade DX) | 45 bulb only
| oxyfluorfen (Goal) | 45 bulb only
| oxyfluorfen (GoalTender) | 60
| paraquat (Gramoxone Inteon) | 60
| sethoxydim (Poast) | 30
| trifluralin (Treflan) | 60 bulb only
Peas (green or English) | metribuzin (Sencor) | 50
| quizalofop P-ethyl (Assure II) | 30
Peppers, bell | pendimethalin (Prowl H_2O) | 70
| S-metolachlor (Dual Magnum) | 60
| sethoxydim (Poast) | 7
Rhubarb | clethodim (Select) | 30
| S-metolachlor (Dual Magnum) | 62
| mesotrione (Callisto) | 21
| pronamide (Kerb) | 38
| sethoxydim (Poast) | 30
Spinach | clethodim  (Prism or Select) | 14
| phenmedipham (Spin-Aid) | 40
| sethoxydim (Poast) | 15
Tomato, eggplant | clethodim (Prism or Select) | 20
| metribuzin (Sencor) | 7
| paraquat (Gramoxone Inteon) | 30 tomato
| pendimethalin (Prowl H_2O) | 70
| rimsulfuron (Matrix) | 45
| sethoxydim (Poast) | 20 tomato and eggplant
| S-metolachlor (Dual Magnum) | 90

Site Preparation, Stale Seedbeds, and Selective Postemergence Applications
Site preparation
•  soil fumigants
See the current edition of the PNW Plant Disease Management Handbook for application details and approved materials.
•  glyphosate (several product names)
Rate  Consult labels
Time  Apply to actively growing weeds with site preparation or preemergence to crops listed on label.
Remarks  See label for specific rates, application times, and perennial species controlled. Use higher rate if annual weeds are more than 6 inches tall. Inhibits three amino acids and protein synthesis.
Caution  Do not exceed 8 lb ai/A per year. Do not plant unlabeled crops within 12 mo after application.
Site of action  Group 9: inhibits EPSP synthase
Chemical family  None generally accepted
•  metham sodium (several brands)
Rate  63 to 317 lb ai/A (15 to 75 gal/A product)
Time  Apply preplant when conditions will enhance moving from liquid to gas phase in soil.
Remarks  Cultivate soil 7 to 10 inches deep before preparing a uniform seedbed using equipment that leaves a smooth surface. Soil moisture must be adequate for seed germination but below field capacity. Apply when temperatures exceed 50°F, with a boom mounted on the front of a rototiller. Incorporate 3 to 4 inches deep; seal surface of soil with a smooth roller power-driven to travel at same speed as tractor. Soil surface must be smooth without cracks where fumigant may escape.
Delay planting until soil is free of metham, usually 14 to 21 days. Plant radish seeds or transplant radish seedlings while protecting from wind and bright sun. Observe for 12 to 24 hours for wilting. Before planting, till the soil surface (3 to 4 inches) while breaking the compacted layer formed during incorporation of metham using a small shank within the seed row.
Caution  Wear protective face shields, respirators, and clothing. Metham sodium is dissolved in water for application. Activity depends on several soil factors that enhance conversion and movement from the liquid to gas phase. Avoid mixing soil from beneath the treated layer. Do not contaminate water, runoff water, or fish habitat. Disrupts cell membranes.
Stale seedbeds 
Several herbicides are registered for use in vegetable as burndown products in stale seedbed systems. Stale seedbeds sometimes are used for vegetable production when other selective weed control practices are limited or unavailable. Success depends on controlling the first flush of emerged weeds before planting or crop emergence, and on minimal soil disturbance, which reduces subsequent weed flushes while the crop establishes. After establishment, other weed control practices including cultivation or other herbicides can be used. Stale seedbed steps are:
1.	Prepare a seedbed, preferably 2 to 3 wk before planting, to achieve maximum weed seed germination near the soil surface. Soil temperatures and moisture must be reasonable, or results will be erratic.
2.	Plant the crop with minimum soil disturbance to avoid exposing new weed seed to favorable germinating conditions.
3.	Just before or after planting (depending on herbicide or strategy), but before crop emerges, treat the field by flaming or with herbicide to kill all germinated or exposed weeds.

•  flaming
Use liquid propane or similar fuel-burning equipment to quickly sear weeds. Use the thumb pressure test to determine effectiveness: press a weed leaf between thumb and forefinger; if the leaf collapses and a thumb print remains, sufficient heat was applied to kill the leaves. There may be no other noticeable change in the plant. The objective is to disrupt cell membranes, not char the plant.
•  paraquat (Gramoxone Max) or
•  diquat (Reglone)
Rate  Consult label
Time  Apply during or after planting but before crop emerges.
Remarks  Use paraquat if grasses are present. Add a nonionic surfactant or crop oil concentrate according to label specifications; take care to avoid anionic formulations that react in the tank to form insoluble precipitates. Exposed crop plants will be killed. Acts as contact; absorbs energy produced by photosynthesis, forming peroxides that disrupt living cells.
Caution  Paraquat is a restricted-use pesticide. Do not ingest or inhale spray mist. Wearing protective face shields, respirators, and clothing is advised. Do not apply preplant or preemergence to soils lacking clay minerals, such as peat, muck, pure sand, or artificial planting media.
Paraquat can be used in these crops (not an exhaustive list): beans, lima and snap;  broccoli; cabbage; cabbage, Chinese; cantaloupe; carrots; cauliflower; collards; corn, sweet; cucumber; eggplant; garlic; lettuce; melons, musk; onions, green and dry bulb; peas; peppers; squash; tomatoes; turnips; watermelon. 
Site of action  (both) Group 22: photosystem I electron diversion
Chemical family  (both) Bipyridilium
•  glyphosate
Rate  0.5 to 2 lb ae/A
Timing  Apply to seedbeds before or shortly after the crop is planted or emerges.
Remarks  Refer to the table “Registered Uses of Glyphosate” in this chapter for general guidelines; read the label carefully to determine proper timing and which product can be applied to each crop.
Caution  Some crops may be injured by glyphosate if the soil is extremely sandy, or if the planter did not properly close the seed row. Do not allow glyphosate to contact seeds or any part of the seedling, as crop failure will result.
Site of action  Group 9: inhibits EPSP synthase
Chemical family  None generally accepted
Selective Postemergence Applications (postemergence-directed, shielded or hooded sprayers, harvest aids) 
•  carfentrazone (Aim)
Rate  0.33 to 0.66 oz/A; label allows up to 2 fl oz/A
Time  Preemergence or any time during the crop growing season to control weeds in row-middles or to burn down unwanted crop vegetation (e.g., in hops).
Remarks  The EPA classifies carfentrazone as a low-risk herbicide, and it is therefore registered on many crops as a post directed-application. Refer to the table “Registered Uses of Aim” in this chapter for registered uses of this herbicide in the Pacific Northwest.
Caution  This herbicide is not selective in broadleaf vegetable crops, and crop will be injured any time the spray contacts plant tissue.
Spray equipment clean-out  Aim herbicide is active at very low rates; ensure that spray tanks are thoroughly cleaned before pesticides are applied to other crops. Clean the spray tank as soon after use as possible with recommended cleaning procedures on the label. For more information on cleaning spray tanks, see http://hort.oregonstate.edu/files/Faculty_Staff/On_Campus/peacheye/PeacheyTankCleaningFactSheetv9.pdf
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Triazinone
•  clove leaf oil (Matran EC) 
Rate  5 to 8% dilution in 25 to 100 gal of water, depending on weed size, temperature, and sunlight intensity.
Time  Before weeds are 6 inches tall.
Remarks  OMRI-listed and WSDA-approved herbicide for in-crop use. Apply before crop emergence, or between rows after emergence, avoiding contact with desirable foliage. Directed sprays or hooded sprayers are recommended. Works best on annual weeds less than 6 inches. Performance may be erratic depending on environmental conditions. Bright sunlight improves efficacy. No preharvest interval or reentry interval.
•  glyphosate (Roundup, Touchdown, and many others)
Rate  0.5 to 2 lb ae/A
Timing  Apply to seedbeds before or shortly after the crop is planted or emerges.
Remarks Refer to the table “Registered Uses of Glyphosate” in this chapter for general guidelines and read the label carefully to determine proper timing and which product can be applied to each crop. 
Caution  Glyphosate may injure some crops if the soil is extremely sandy, or if the planter did not properly close the seed row. Do not let glyphosate contact seeds or any part of the seedling, as crop failure will result.
Site of action  Group 9: inhibits EPSP synthase
Chemical family  None generally accepted
•  lemon grass oil (Green Match EX)
Rate  7 to 15% depending on weed size and species.
Time  When weeds are less than 6 inches tall.
Remarks  OMRI-listed, NOP-compliant, and WSDA-approved organic burndown herbicide for use in crop and noncrop sites. Foliage contacted by Green Match will be damaged. Directed sprays or hooded sprayers are recommended.  Coverage is very important. Leaf damage is visible within hours. Cool weather may slow activity. No reentry interval. Fast wilting or necrosis of the leaves due to removal of waxy cuticle
•  paraquat (Gramoxone Max) or
•  diquat (Reglone)
Rate  Consult label
Time  Many crops and situations, including weed control in row middles after crop establishment; consult labels.
Remarks  Apply between rows in vegetable crops. Use paraquat if grasses are present. Add a nonionic surfactant or crop oil concentrate as label specifies. Take care to avoid anionic formulations that react in the tank to form insoluble precipitates. Exposed crop plants may be killed if these herbicides contact sufficient living tissue. 
Caution  Paraquat is a restricted-use pesticide. Do not ingest or inhale spray mist. Wearing protective face shields, respirators, and clothing is advised. Both herbicides act on contact; they absorb energy produced by photosynthesis, forming peroxides that disrupt living cells.
Site of action  (both) Group 22: photosystem I electron diversion
Chemical family  (both) Bipyridilium

Registered (R) Uses of Glyphosate 
DTP: lay out in landscape; delete this red text   (note key to crops on next page)

Vegetable crops 
(see key)

Chemical fallow

Preplant fallow beds

Preplant

Before 
transplanting vegetables

Pre-emergence

At planting

Hooded sprayers in row middles

Shielded sprayers in row middles

Wiper applications in row middles

Post-harvest-directed applications

Over-the-top wiper application

Brassica vegetables ^a | R | R | R | R | R | R | R | R | R | |
Bulb vegetables ^b | R | R | R | R | R | R | R | R | R | |
Cucurbit vegetables and fruit ^c | R | R | Cantaloupe, Casaba, Crenshaw, Cucumber, Gherkin, Gourds, Honeydew, Honey ball, Mango melons, Melons (all) Muskmelon, Persian Melon, Pumpkin, Squash (winter and summer) and Watermelon—allow 3 days between application and planting | R | Touchdown (Syngenta) allowed postplant | Touchdown (Syngenta) allowed postplant | R | R | R | |
Leafy vegetables ^d | R | R | Watercress—allow 3 days between application and planting | | | | R | R | R | |
Fruiting vegetables ^e | R | R | Eggplant, Ground cherry, Pepino, Pepper (bell, chili, cooking, pimento, sweet)—allow 3 days between application and planting; | if more than 3 days | | | Tomato: not recom-mended | Tomato: not recom-mended | R | |
Legume vegetables ^f | R | R | R | R | R | R | R | R | R | |
Root and tuber vegetables ^g | R | R | R | R | R | R | R | R | R | Non-bearing ginseng only; no contact with plant 1 yr before harvest | Rutabagas only; 14 days between application and harvest

Key to Crops in the Table of Registered Uses of Glyphosate
^a Broccoli, Chinese broccoli (gai lon), Broccoli raab (rapini), Brussels sprouts, Cabbage, Chinese cabbage (bok choy), Chinese cabbage (napa), Chinese mustard cabbage (gai choy), Cauliflower, Cavalo broccoli, Collards, Kale, Kohlrabi, Mizuna, Mustard greens, Mustard spinach, Rape greens
^b Garlic, Great-headed garlic, Leek, Onion (dry bulb and green), Welsh Onion, Shallot.
^c Chayote (fruit), Chinese waRgourd (Chinese preserving melon), Citron melon, Cucumber, Gherkin, Edible gourd (includes hyotan, cucuzza, hechima, Chinese okra), Melons (aIl), Momordica spp. (includes balsam apple, balsam pear, bittermelon, Chinese cucumber), Muskmelon (includes cantaloupe, casaba, crenshaw melon, golden pershaw melon, honeydew melon, honey ball melon, mango melon, Persian melon, pineapple melon, Santa Claus melon, snake melon), Pumpkin, Summer squash (includes crookneck squash, scallop squash, straightneck squash, vegetable marrow, zucchini), Winter squash (includes butternut squash, calabaza, hubbard squash, acorn squash, spaghetti squash), Watermelon. 
^d Amaranth (Chinese spinach), Arugula (roquette), Beet greens, Cardoon, Celery, Chinese celery, Celtuce, Chaya, Chervil, Edible-leaved chrysanthemum, Garland chrysanthemum, Corn salad, Cress (garden and upland), Dandelion, Dock (sorrel), Dokudami, Endive (escarole), Florence fennel, Gow kee, Lettuce (head and leaf), Orach, Parsley, Purslane (garden and winter), Radicchio (red chicory), Rhubarb, Spinach, New Zealand spinach, Vine spinach, Swiss chard, Watercress (upland), Water spinach
^e Eggplant, Groundcherry (Physalis spp), Pepino, Pepper (includes bell pepper, chili pepper, cooking pepper, pimento, sweet pepper), Tomatillo, Tomato.
^f Bean (Lupinus: includes grain lupin, sweet lupin, white lupin, and white sweet lupin), Bean (Phaseolus: includes field bean, kidney bean, lima bean, navy bean, pinto bean, runner bean, snap bean, tepary bean, war bean), Bean (Vigna: includes adzuki bean, asparagus bean, blackeyed pea, catjang, Chinese longbean, cowpea, crowder pea, moth bean, mung bean, rice bean, southern pea, urd bean, yardlong bean), Broad bean (fava), Chickpea (garbanzo), Guar, Jackbean, Lablab bean, Lentil, Pea (Pisum: includes dwarf pea, edible-podded pea, English pea, field pea, garden pea, green pea, snowpea, sugar snap pea), Pigeon pea, Soybean (immature seed), Sword bean.
^g Arracacha, Arrowroot, Chinese artichoke, Jerusalem artichoke, Beet (garden), Burdock, Canna, Carrot, Cassava (bitter and sweet), Celeriac, Chayote (root), Chervil (turnip-rooted), Chicory, Chufa, Dasheen (taro), Galangal, Ginger, Ginseng, Horseradish, Leren, kava (turnip-rooted), Parsley (turnip-rooted), Parsnip, Potato, Radish, Oriental radish, Rutabaga, Salsify, Black salsify, Spanish salsify, Skirret, Sweet potato, Tanier, Turmeric, Turnip, Wasabi, Yacon, Yam bean, True yam.
Registered Uses of Aim Herbicide in Food Crops 

Crop, Crop Group, 
and Crop Subgroup

Crops

Approved 
Applications^1

Aim EC
Maximum Use Rate 
per Season^2

| | | fl oz/A | lb ai/A
Vegetable, root (Subgroups 1A and 1B) | Beet; Carrot; Ginger; Horseradish; Parsnip; Potato; Potato, sweet; Radish; Sugar beet; Yam; Turnip | H | 6.1 | 0.096
Vegetable, leaves (Group 2) | Beet; Carrot; Radish; Sugar beet; Turnip tops; Chicory | H | |
Vegetable, bulb (Group 3) | Chive; Garlic; Leek; Onion; Onion, dry bulb; Shallot | H | |
Vegetable, leafy (Group 4) | Arugula; Celery; Cress; Endive; Fennel; Lettuce, head and leaf; Parsley; Purslane; Radicchio; Rhubarb; Spinach; Swiss chard | H | |
Vegetable, brassica (Group 5) | Broccoli; Brussels sprout; Cabbage; Cauliflower; Collards; Kale; Kohlrabi; Greens; Mustard greens; Mustard spinach | H | |
Vegetable, legume (Group 6) | Bean, kidney; Bean, lima; Bean, pinto; Bean, snap; Bean, wax; Chickpea; Edamame; Lentil; Pea, blackeyed; Pea, edible; Pea, succulent-shelled; Soybean | BPT-1; H, HA | |
Vegetable, foliage of legume (Group 7) | Bean; Cowpea; Catjang; Edamame; Guar; Lentil; Lupine; Pea | H, HA | |
Vegetable, fruiting; Okra (Group 8) | Eggplant; Groundcherry; Pepper (bell, chili, cooking, pimento, sweet); Pepino; Tomatillo; Tomato | BPT1 (transplants only), H | |
Vegetable, cucurbit (Group 9) | Cantaloupe; Cucumber; Gherkin; Muskmelon; Pumpkin; Squash, summer and winter; Watermelon | BPT1 (transplants only), H | |
Herbs and Spices (Group 19) | Basil, fresh and dried; Chive; Cinnamon; Clove; Dill; Fennel; Nutmeg; Parsley; Pepper, black and white; Rosemary; Vanilla | H | |
Bushberry (13B) | Blueberry, high- and lowbush; Currant; Elderberry; Gooseberry; Huckleberry | D, BD | |
Seed crops | Rapeseed; Mustard; Flax; Sunflower; Safflower; Crambe; Borage | H | |
Strawberry | | H | |
Horseradish | | H | |
Vegetable, tuberous and corm (Subgroups1C and 1D) | Arracacha; Arrowroot; Artichoke, Chinese; Artichoke, Jerusalem; Canna, edible; Cassava, bitter and sweet; Chayote root; Chufa; Dasheen (taro); Ginger; Leren; Potato; Potato, sweet; Tanier; Turmeric; Yam bean; Yam, true | H | 11.6 | 0.181
Caneberry (Subgroup 13A) | Blackberry; Loganberry; Raspberry, red and black cultivars and/or hybrids of these | H, D^3, DD | 25.6 | 0.40
Pome fruit (Group 11) | Apple; Crabapple, Loquat, Mayhaw, Pear; Pear, oriental; Quince | H | 7.9 | 0.124
Stone fruit (Group 12) | Apricot; Cherry, sweet and tart; Nectarine; Peach; Plum; Plum, chickasaw, damson, Japanese); Plumcot; Prune | H | 7.9 | 0.124
Tree nut (Group 14) | Almond; Beech nut; Brazil nut; Butternut; Cashew; Chestnut; Chinquapin; Filbert (hazelnut)^5; Hickory nut; Macadamia nut (bush nut); Pecan; Pistachio; Walnut, black and English | H | 7.9 | 0.124
Corn, sweet and field | | H, B, D^4 | 2.0 | 0.031
Hops | | H, D^5 | 7.6 | 0.12
Grape | | H, D^5 | 7.9 | 0.124
Potato | | H, HA | 11.6 | 0.181
^1 Approved applications: B = broadcast; BPT1= burndown 1 day before planting; BPT-1= burndown 1 day after planting; BD = broadcast dormant; D = directed, nondormant crop; DD = directed dormant crop; H = hooded in row middles; HA = harvest aid.
^2 The total allowable usage includes all applications made to the field per calendar year. This includes fallow treatments, burndown treatments, and all in-season treatments, including harvest aid.
^3 Primocane suppression.
^4 Use directed applications for corn that is at growth stage V8 or greater.
^5 Control of suckers at base of plant.

Crop Rotation Intervals (months) for Common Soil-active Herbicides Used in Vegetables and Other Rotational Crops
 DTP: lay out in landscape; delete this red text     (also see footnotes, next page)
Herbicide | Beans (snap) | Beets (table) | Broccoli, Cauliflower & Cabbage | Carrot | Collards | Corn (sweet) | Cucumbers | Eggplants | Lettuce | Onions & Leeks | Peas | Peppers | Pumpkins & Squash | Spinach | Swiss chard | Tomato | Cereals
Accent | 10 | 10/18^1 | 10 /18^1 | 10 /18^1 | 10/18^1 | 10 | 10/18^1 | 10/18^1 | 10/18^1 | 10/18^1 | 10 | 10/18^1 | 10/18^1 | 10/18^1 | 10/18^1 | 10/18^1 | NSP^2
Assure | 0 | 0 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 0 | 4 | 4 | 4 | - | 4 | -
Buctril | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
Callisto | 18 | 18 | 18 | 18 | 18 | 0 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 3
Command | 0/9 | 16 | 9/16^3 | 16 | 16 | 9/12^4 | 0/9^5 | 16 | 16 | 16 | 0/9 | 0/9^6 | 0/9^7 | 16 | 16 | 9/12^8 | 12/16^9
Curbit | - | 8/13^10 | - | - | - | - | 0 | - | - | - | - | - | 0 | 8/13^11 | - | - | 8^12
Dacthal | 8 | 8 | 0 | 8 | 0 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 0 | 8 | 8
Dual Magnum | 0 | 0 | NSP^13 | NSP | NSP | 0 | NSP | NSP | NSP | NSP | 0 | NSP | NSP | NSP | NSP | 0 | 4.5
Eptam | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0
Goal | 2 | 2/3^14 | 4 | 3 | 4 | 10 | 3/4^15 | 4 | 3/4^15 | 6 | 2 | 3/4^15 | 3/4^15 | 4 | 4 | 1/4^16 | 10
Impact | 18 | 18 | 18 | 18 | 18 | 0 | 18 | 18 | 18 | 18 | 9 | 18 | 18 | 18 | 18 | 18 | 3
Lorox | 12 | 12 | 12 | 0 | 12 | 0 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12
Nortron | 6/12^17 | 0 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 6/12^17 | 0/12^17
Outlook | FS^18 | FS | FS | FS | FS | FS | FS | FS | FS | FS | FS | FS | FS | FS | FS | FS | 0/4^19
Prefar | 4^20 | - | 0 | 0 | 0 | 4^20 | 0 | 0 | 0 | 4^20, ^21 | 4^20 | 0 | 0 | 4 | 4^20 | - | 4^20
Prowl | 0 | 12/14^22 | NS/24^23 | NS/24^23 | NS/24^23 | NS/24^23 | NS/24^23 | NS/24^18 | NS/24^23 | NS/24^23 | 0 | NS/24^23 | NS/24^23 | NS/24^23 | NS/24^23 | NS/24^23 | NS/24^23
Pursuit | 4 | 40 | 40 | 40 | 40 | 18 | 40 | 40 | 18 | 40 | 4 | 40 | 40 | 40 | 40 | 40 | 4/10^24
Pyramin | FS^18 | 0 | FS | FS | FS | FS | FS | FS | FS | FS | FS | FS | FS | FS | - | FS | -
Raptor | 0 | 26 | 18 | 18 | 18 | 8.5 | 18 | 18 | 9 | 9 | 0 | 18 | 9 | 18 | 18 | 18 | 3/4/18^25
Sandea | 9 | 24 | 18 | 15 | 18 | 3 | 9 | 12 | 18 | 18 | 9 | 10 | 9 | 24 | - | 8 | 2
Sencor | 12 | 18 | 12 | 0 | 12 | 4 | 12 | 12 | 12 | 12 | 8 | 12 | 12 | 12 | 12 | 4 | 4
Spartan | 12 | 36 | 12 | 12 | 12 | 18 | 12 | 12 | 12 | 12 | 0/2^26 | 12 | 12 | 12 | 12 | 12 | 4/12^27
Spin-Aid | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4
Stinger | 12 | 0 | 12 | 18 | 0 | 0 | 12 | 12 | 18 | 12 | 18 | 12 | 12 | 0 | 12 | 18 | 12
Treflan | 0 | 12/14^28 | 0 | 0 | 0 | 5 | 5 | 5 | 5 | 5 | - | 0/5^29 | 5 | 12/14^28 | 5 | 0/5^29 | 12/14^30

Aim, Basagran Gramoxone, Poast, Ro-Neet, Roundup, Select, and Touchdown: No rotation restrictions listed for these crops.
^1 pH < 6.5 = 18 mo
^2 NSP = next spring
^3 cabbage 9 mo if transplanted; 16 mo for all direct-seeded brassica crops or >2 pints/A
^4 corn is 9 mo if <2.67 pints/A; 12 mo if >2.67 pints/A
^5 0 mo if <1.3 pints/A; 9 mo if >2 pints/A
^6 9 mo at 1.25 lb ai/A
^7 pumpkins, 0 mo if <1.3 pints/A; winter squash, 0 mo if <2 pints/A; other cucurbits = 9 mo
^8 direct-seeded tomato is 12 mo
^9 wheat 12 mo., all others 16 mo
^10 8 mo if >1.3 pints/A
^11 13 mo if >3 pints/A; 8 mo if <3 pints/A and moldboard plowed
^12 oats
^13 NSP = next spring
^14 3 mo if >1 pint/A
^15 4 mo if >1 pint/A
^16 transplanted, 1 mo; seeded, 2 mo at 1 pint/A, 4 mo >1 pint/A
^17 12 mo if >12 oz; 0 mo for ryegrass
^18 FS = following spring
^19 0 mo for sorghum
^20 4 mo; soil must be tilled to 4 inches
^21 4 mo on dry bulb in Willamette Valley, with soil tilled to 4 inches; 0 mo in other areas
^22 12 mo after spring application; 14 mo after fall application
^23 NS (next spring crop) if <2 lb ai/A; otherwise, 24 mo
^24 4 mo for wheat and rye; 10 mo for barley
^25 3 mo for wheat; 4 mo for rye; 9–18 mo for barley depending on rainfall and pH
^26 0 mo for dry shell peas
^27 4 mo for wheat
^28 12 mo after spring application; 14 mo after fall application
^29  5 mo before seeding; 0 mo before transplanting
^30 12 mo after spring application; 14 mo after fall application for cereals and grasses

Artichokes (Globe) 
Ed Peachey
Reviewed November 26, 2008
ARTICHOKES—Established Plantings	
•  napropamide (Devrinol 50DF)
Rate  4 lb ai/A (8 lb/A)
Time  Apply before weed emergence within established crop only.
Remarks  Irrigation, rain, or shallow incorporation (2 to 4 inches) is recommended within 2 wk after application in November through February, or within 24 hr when applied March through October. Performance is reduced if plant residues are on soil surface. Inhibits root growth.
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family  Acetamide
•  oxyfluorfen (Goal 2xL)
Rate  1 to 1.5 lb ai/A (4 to 6 pints/A)
Time  Apply as a directed treatment or during midsummer dormant and renovation period, either preemergence or early postemergence as a single treatment or in split applications 8 to 10 weeks apart. Acts as a contact, either directly on broadleaf weeds or at soil surface as weeds emerge.
Caution  Do not exceed 6 pints/A per year. Preharvest interval is 5 days. 
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Diphenylether 
•  sethoxydim (Poast)
Rate  0.47 lb ai/A (2.5 pints/A)
Time  Apply to actively growing grasses. Always add crop oil concentrate.
Remarks  May be applied by air. Feeding restriction. 
Caution  Do not exceed 5 pints/A per year. Preharvest interval is 7 days.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione