Legumes (Large-seeded) 

Dry beans are sensitive to weed competition. Weed growth reduces bean yields by competing for light, moisture, and nutrients. High weed populations also are likely to cause a buildup of disease and/or insect problems that may affect bean growth, development, and marketability. Weeds also increase harvest losses, reduce bean quality, and make seed cleaning more difficult and expensive.
Good seedbed preparation is essential to give dry beans a head start on weeds at planting time. Cultivating emerging weed seedlings between bean rows usually controls weeds adequately without using herbicides. However, weeds usually are not adequately controlled in the bean row; therefore, herbicides and tillage are usually necessary. Dry edible beans may be cultivated several times during the growing season to control weeds and maintain irrigation furrows; however, cultivation should be shallow to avoid damaging the bean’s shallow root system. Do not cultivate or harrow when bean foliage is wet because bacterial leaf diseases may be spread.

Dry Beans East of Cascades
Phaseolus spp. (field bean, kidney, lima, navy, and pinto)  
 Don Morishita
Revised December 3, 2008
BEANS, DRY—Annual Grass and Broadleaf Weeds
•  EPTC (Eptam)
dry beans only
Rate  3 to 4 lb ai/A (3.5 to 4.5 pints/A Eptam 7EC)
Time  Apply preplant to soil surface free from dew and other moisture, or as a directed spray at layby.
Remarks  Incorporate Eptam thoroughly into soil 2 to 3 inches deep immediately after applying. Eptam gives good general weed control for about 6 weeks as well as early-season control of hairy nightshade and suppression of yellow nutsedge and quackgrass. However, on some PNW fields, effective control may be shorter. These fields have a history of continued thiocarbamate herbicide use. Eptam also can be metered into furrow irrigation water before weeds emerge. Eptam may be tank-mixed with alachlor, ethalfluralin, metolachlor, pendimethalin, trifluralin, or halosulfuron. 
Caution  Do not apply before preirrigation. Do not apply to cowpeas, lima beans, garbanzo beans, soybeans, or other flat-podded beans. Do not feed bean hay, vines, or forage to livestock or graze livestock in treated bean fields within 45 days of application. Cold, wet soils after planting may delay crop maturity or reduce yields. Do not exceed 9 pints/A Eptam in one season.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Thiocarbamate
•  trifluralin (several trade names)
Rate  0.5 to 1 lb ai/A for dry beans (1 to 2 pints/A trifluralin 4EC); 0.5 to 0.75 lb ai/A for lima beans (1 to 1.5 pints/A trifluralin 4EC)
Time  Apply to dry soil and incorporate either in fall between October 15 and December 31 or just before planting in spring.
Remarks  Rate depends on soil type, amount of organic matter and rain. Incorporate thoroughly into soil 2 to 3 inches deep as soon as possible but no later than 24 hr after applying. Trifluralin may be tank-mixed with EPTC (but not on lima beans), alachlor, or metolachlor. Trifluralin is susceptible to photodegradation; incorporation soon after application is best.
Caution  Do not apply to soils that are wet, cloddy, or subject to prolonged flooding; poor weed control or crop injury may result. Do not plant sugar beets, red beets, corn, oats, or spinach for 12 mo after spring application. Plow 12 inches deep before planting sugar beets to prevent possible crop injury. Do not plant vegetable crops other than those listed on label within 5 mo after application.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
•  ethalfluralin (Sonalan)
Rate  0.56 to 1.69 lb ai/A (1.5 to 4.5 pints/A Sonalan 3EC)
Time  Apply to dry soil up to 3 weeks before planting and incorporate.
Remarks  Application rate depends on soil type, amount of organic matter, and whether nightshade is to be controlled. Incorporate herbicide uniformly into top 2 to 3 inches of soil within 2 days of application. To control nightshade, use higher rate and two incorporation passes. Ethalfluralin may be tank-mixed with EPTC (but not on lima beans), alachlor, or metolachlor.
Caution  Do not apply to soils that are wet, cloddy, or subject to prolonged flooding; poor weed control or crop injury may result. If crop fails, replant only crops listed on label. Do not plant sugar beets or red beets within 13 mo after applying 3 pints/A or more. If less than 3 pints/A were used, sugar beets and red beets may be planted 8 mo after application if field is moldboard-plowed at least 12 inches deep before planting. Do not cut for hay or forage livestock or graze.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
•  pendimethalin (Prowl EC or Prowl H2O)
Rate  Prowl 3.3EC—use 0.495 to 1.5 lb ai/A (1.2 to 3.6 pints/A) 
Prowl H2O 3.8AS—use 0.95 to 1.43 lb ai/A (2 to 3 pints/A)
Time  Apply and incorporate up to 60 days before planting.
Remarks  Application rate depends on soil type and amount of organic matter. Incorporate into soil 1 to 2 inches deep within 7 days of application. Refer to label for suitable incorporation equipment. Pendimethalin may be tank-mixed with EPTC (but not on lima beans) or metolachlor.
Caution  Cold, wet soils after planting may delay crop maturity or reduce yields. Do not apply after planting; crop may be injured. If crop is lost, crops labeled for preplant-incorporated pendimethalin may be replanted. Winter wheat and winter barley can be planted 120 days after applying. Do not plant red beets, sugar beets, or spinach for 12 mo after applying pendimethalin, and plow 12 inches deep before planting. Do not feed bean hay or vines to livestock or graze livestock in treated fields.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
•  alachlor (Micro-Tech)
Rate  2.5 to 3 lb ai/A (5 to 6 pints/A Micro-Tech); 2 to 3 lb ai/A (4 to 6 pints/A Micro-Tech 4MT for lima beans)
Time  Apply and incorporate within 7 days prior to planting dry or lima beans or within 5 days after planting lima beans.
Remarks  Application rate depends on soil type, weed species, and weed density. Incorporate alachlor within 8 hours after application into the top 1 to 2 inches of soil with equipment that ensures thorough soil mixing. Alachlor controls nightshade and yellow nutsedge effectively in the early part of the growing season. On dry beans, alachlor may be tank-mixed with EPTC, ethalfluralin, or trifluralin.
Caution  A restricted-use herbicide. Cold, wet soils after planting may delay crop maturity or reduce yields. Do not apply to dry beans after planting or crop may be injured. Do not feed forage or hay from treated crop to livestock.
Site of action  Group 15: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Chloroacetamide
•  imazamox (Raptor)
dry beans only
Rate  0.031 lb ae/A (4 oz/A Raptor 1SC)
Time  Apply postemergence to dry beans with at least one full, expanded trifoliate leaf and before bloom.
Remarks  Weed control may be improved by adding 12 to 15 lb ammonium sulfate or 2.5 gal liquid fertilizer (28% or 32% N) per 100 gal spray solution. If using crop oil concentrate or nonionic surfactant, Basagran must be added at 6 to 16 oz/A. Rezult herbicide can be substituted for Basagran. Raptor applications must be made before dry peas and dry beans bloom.
Caution  Do not apply Raptor to chickpeas (garbanzo beans), fresh limas, or lentils. Some varieties of edible legumes are more sensitive to Raptor, and Raptor may delay crop maturity. Adding nitrogen-based fertilizer or adjuvants may increase crop response. See label for crop rotation guidelines. Recommended rotation interval of 18 mo for potato and 26 mo for sugar beets.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor 
Chemical family  Imidazolinone
•  imazethapyr (Pursuit)
lima beans, chickpeas (garbonzo beans), and lentils only
Rate  0.047 lb ai/A (1.08 oz/A Pursuit 70DG or 3 fl oz/A Pursuit 2LC)
Time  Apply preplant incorporated within 30 days before planting.
Remarks  Registered for use only in certain Oregon, Washington, and Idaho counties; see current label for appropriate use areas. Wheat may be planted 4 mo after applying. Barley may be planted 9.5 mo after applying. In no-till and minimum-tillage systems, Pursuit may be applied in the fall prior to spring planting. Rainfall is required for incorporation and activation. If applied in the fall, wait until 4-inch soil depth is less than 55º F
Caution  Do not incorporate deeper than 3 inches. See label for crop rotation guidelines. Do not feed treated forage, hay, or straw to livestock.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor 
Chemical family  Imidazolinone
•  dimethenamid-P (Outlook)
dry bean classes such as small whites, navy, black turtle soup, pink, pinto, great northern, red Mexican, red kidney, and cranberry
Rate  0.375 to 0.98 lb ai/A (8 to 21 fl oz/A Outlook 6EC)
Time  Apply preplant surface, preplant incorporated, preemergence, or early postemergence (first to third trifoliate leaves).
Remarks  May be applied only preplant surface or preemergence to chickpeas (garbanzo beans) and lentils. Will not control emerged weeds. Application rate depends on soil type and organic-matter content. Reduced rates, 8 to 16 fl oz/A, can be used where partial control or reduced length of residual control is required. For early preplant applications, use 21 fl oz/A. Incorporate 1 to 2 inches deep. Under furrow irrigation, apply and incorporate before planting. May be tank-mixed with other dry-bean herbicides (refer to label for specific uses). May be applied through most sprinkler irrigation systems. Outlook applied postemergence may occasionally cause some temporary leaf spotting or browning.
Caution  Outlook is not registered for use in succulent beans or cowpeas. Ask seed supplier about your dry bean variety’s tolerance to Outlook before applying. Growth may be temporarily suppressed if heavy rain falls or soil is saturated for long periods during bean germination or early seedling development. Avoid incorporating more than 1 or 2 inches; weed control may be reduced and/or the crop injured.
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family  Chloroacetamide
•  S-metolachlor (Dual Magnum)
Rate  0.96 to 1.9 lb ai/A (1 to 2 pints/A Dual II Magnum 7.64EC)
Time  Apply preplant incorporated or preemergence.
Remarks  Application rate depends on soil type and amount of organic matter. Incorporation into top 2 inches of soil is required. Under furrow irrigation, apply and incorporate before planting. When applied through center-pivot irrigation systems, apply proper rate in 0.5 to 1 inch of water (depending on soil type). Preplant-incorporated treatments will control yellow nutsedge. Metolachlor may be tank-mixed with EPTC (but not on lima beans), ethalfluralin, or trifluralin.
Caution  Crops may be injured if soil moisture is abnormally high during early crop development. If crop fails, beans, corn, potatoes, or safflower may be planted. Do not plant small grains for 4.5 mo after treatment. Corn, potatoes, safflower, pod crops, root crops, barley, oats, rye, or wheat may be planted the spring after treatment. All other rotation crops may be planted 18 mo later. Do not cut for hay within 120 days; residues may be illegal.
Site of action  Group 15: inhibits very long chain fatty acid synthesis
Chemical family  Chloroacetamide
•  halosulfuron (Sandea)
Rate  0.375 to 0.75 oz ai/A (0.5 to 1 oz/A Sandea 75DF)
Time  Apply preemergence (after planting but prior to soil cracking). Or, apply between crop rows for nutsedge and broadleaf weeds, but avoid contact with the planted crop.
Remarks  Use lower rate on lighter texture soil with low organic matter. Use only up to 0.66 oz/A preemergence.
Caution  Do not apply more than 1 oz/A per crop cycle or 2 oz/A per 12-mo period. Refer to label for rotational crop restrictions.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor 
Chemical family  Imidazolinone
•  paraquat (Gramoxone Inteon)
Rate  0.3 to 0.5 lb ai/A (1.2 to 2 pints/A Gramoxone Inteon 2SL)
Time  Apply when crop is mature and at least 80% of pods are yellowing and mostly ripe and no more than 40% (bush type) or 30% (vine type) leaves are green.
Remarks  Add nonionic surfactant at 1 quart/100 gal water. For vining type beans or bush beans with lush growth, use the highest rate. May also be applied as a split application.
Caution  A restricted-use pesticide.
Site of action  Group 22: photosystem I electron diversion 
Chemical family  Bipyridilium
•  glyphosate (several trade names)
Rate  0.375 to 1.125 lb ae/A
Time  Apply to weeds in proper growth stage before planting or before beans emerge.
Remarks  Be aware that glyphosate is formulated as 3, 3.7, and 4.5 lb ae/gal. Take care to ensure using the correct amount of herbicide. Use highest rates on field bindweed. Delay applying to allow maximum weed emergence but apply before beans emerge. Herbicide will not control weeds that emerge after application. Rain within 6 hr after application may reduce effectiveness of some brands. Some products require the addition of a nonionic surfactant. Be sure to check the label.
Caution  Glyphosate applied after crop emerges will injure or kill the crop. Do not apply if weed is stressed by drought, weather, or maturity. Do not plant subsequent crops other than those on label for 30 days after applying. Do not feed or forage treated crops within 8 wk after applying.
Site of action  Group 9: inhibits EPSP synthase 
Chemical family  None generally accepted 
•  DCPA (Dacthal)
Rate  4.5 to 10.5 lb ai/A (6 to 14 lb/A Dacthal W-75)
Time  At seeding time, within 3 days after cultivation.
Remarks  Label tells crops that may be planted after DCPA-treated crop. Must be incorporated mechanically or by rain or sprinkler irrigation. Do not feed livestock on forage or hay.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  None generally accepted.
BEANS, DRY—Annual Grass
•  sethoxydim (Poast)
dry beans only
Rate  0.187 to 0.48 lb ai/A (1 to 2.5 pints/A Poast 1.5EC)
Time  Apply to actively growing grasses at grass growth stage indicated on label.
Remarks  Always add a nonphytotoxic crop oil concentrate to the spray tank at 2 pints/A. Sethoxydim is most effective on actively growing grasses that are not stressed. Will not control annual bluegrass or any of the fine fescues. Sethoxydim is not registered for use on lima beans.
Caution  Control often is erratic if grasses are stressed by drought, insect damage, extreme temperatures, or herbicide injury. Do not apply within 30 days of dry bean harvest or within 15 days of harvest of succulent beans. Do not exceed 0.96 lb ai/A (4 pints/A Poast) during the season. 
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor 
Chemical family  Cyclohexanedione
BEANS, DRY—Annual and Perennial Grasses
Postemergence
•  quizalofop P-ethyl  (Assure II or Targa)
dry beans only
Rate  0.034 to 0.08 lb ai/A (5 to 12 fl oz/A Assure II 0.88EC or Targa 0.88EC)
Time  Postemergence to grasses. See label for details.
Remarks  Controls annual and perennial grasses. Always use either a nonionic surfactant at 1 quart/100 gal water or a petroleum-based crop oil at 4 gal/100 gal water. Do not apply if rain is expected within 1 hr of application.
Caution  Do not exceed 24 fl oz/A per season. Do not feed vines or hay. Preharvest interval is 30 days.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor 
Chemical family  Aryloxyphenoxy propionate
•  clethodim (Select)
dry beans only
Rate  0.063 to 0.25 lb ai/A (4 to 16 fl oz/A Select 2EC)
Time  Apply to actively growing grasses 1 to 8 inches tall (generally three-leaf to tillering).
Remarks  Apply when the first grass-weed species in a mixed grass-weed population reaches the recommended growth stage for treatment. Always use crop oil concentrate at 1% v/v. An additional 1 to 2 quarts/A liquid fertilizer (28% or 32% N) or 2.5 to 4 lb AMS fertilizer may be added to enhance grass control. Do not apply if rain is expected within 1 hr of application. See label for tank-mixing with broadleaf herbicides. Select is not registered for use in lima beans.
Caution  Do not apply within 30 days of harvesting or cutting beans.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Cyclohexanedione
BEANS, DRY—Annual Broadleaf Weeds and Sedges
•  bentazon (Basagran)
Rate  0.5 to 1 lb ai/A (1 to 2 pints/A Basagran 4SC)
Time  Apply postemergence to actively growing weeds in the two- to ten-leaf stage of growth (refer to label). Beans must have first trifoliate leaf fully extended.
Remarks  Controls certain annual broadleaf weeds, including nightshade and cocklebur. Can control Canada thistle and yellow nutsedge with two applications 7 to 10 days apart. Does not control grasses. Irrigation may be needed before application to ensure weeds are growing actively.
Caution  Bean leaves may temporarily yellow, bronze, or speckle under some conditions. Do not apply in cool weather (days below 75°F and nights below 55°F for 2 to 5 days) or weed control will be poor. Do not apply to stressed beans or to garbanzo beans. Do not exceed 2 lb ai/A in one season. Do not apply if rain is expected within 8 hr. Do not cultivate within 5 days before or after application. Do not apply to dry or succulent beans within 30 days of harvest.
Site of action  Group 6: photosystem II inhibitor 
Chemical family  Benzothiadiazole
BEANS, DRY—Harvest Aid
•  paraquat (Gramoxone Inteon)
Rate  0.3 to 0.5 lb ai/A (1.2 to 2 pints/A Gramoxone Inteon 2SL)
Time  Apply when crop is mature: at least 80% of pods yellowing and mostly ripe and no more than 40% (bush-type) or 30% (vine-type) of leaves still green.
Remarks  Apply in 20 to 40 gal/A of water by ground or in at least 5 gal by air. Add a nonionic surfactant at 1 quart/100 gal spray mix. For vining or bush beans with lush and vigorous growth, use a single application at the higher rate. May also be a split application.
Caution  A restricted-use herbicide. Do not use on fava beans or faba beans. Do not exceed two applications or 0.47 lb ai/A (2 pints/A) per year. Follow all safety precautions on label. Do not harvest within 7 days.
Site of action  Group 22: photosystem I electron diversion 
Chemical family  Bipyridilium 
BEANS, DRY—Quackgrass
•  glyphosate (several trade names 
Rate  0.75 to 2.25 lb ae/A 
Time  Apply to quackgrass 8 to 12 inches tall before planting or bean emergence.
Remarks  Be aware that glyphosate is formulated as 3, 3.7, and 4.5 lb lb ae/gal. Take care to ensure using the correct amount of herbicide. Delay applying to allow maximum weed emergence, but apply before beans emerge. Use low rate for fall application, higher rates (2 to 3 quarts/A) in spring. Wait 3 or more days after applying before tilling. Herbicide will not control weeds that emerge after applying. Rain within 6 hours may reduce effectiveness of some brands. Some products require adding a nonionic surfactant; be sure to check the label. Control weed escapes in following years.
Caution  Do not till before applying. Glyphosate applied after crop emerges will injure or kill crop. Do not apply to quackgrass stressed by drought, weather, or maturity. Do not plant crops other than those listed on label for 1 yr after application. Do not feed or forage treated crops within 8 wk after application.
Site of action  Group 9: inhibits EPSP synthase 
Chemical family  None generally accepted

Herbicide Effectiveness on Weeds in Dry Beans
   
      Weed Species	Preemergence		Postemergence	
	alachlor
(Micro-Tech)	dimethenamid
(Outlook)	EPTC
(Eptam)	ethalfluralin
(Sonalan)	metolachlor
(Dual)	pendimethalin
(Prowl)	trifluralin
(Treflan)		bentazon
(Basagran)	glyphosate
(Roundup)	imazamox
(Raptor)	quizalofop 
(Assure II)	sethoxydim 
(Poast)	
Annual Grass
Barnyardgrass	
E	
E	
E	
E	
E	
E	
E		
P	
E	
G	
E	
E	
Foxtail, green 	E	E	E	E	E	E	E		P	E	G	E	E	
Grain, volunteer	P	F	E	F-G	P	F	F-G		P	E	G	E	E	
Oat, wild	P	F	G	G	P	F	F		P	E	G	E	E	
Proso millet, wild	F-G	F-G	G	—	F	F-G	—		P	E	G	E	E	
Sandbur, field	F-G	F	F-G	G	F	G	G		P	E	G	E	E	
Witchgrass	G	G	G	—	E	G-E	—		P	E	G	E	E	
Annual Broadleaf
Buckwheat, wild	
P-F	
F	
F	
G	
P-F	
P-F	
G		
G-E	
G-E	
F	
P	
P	
Cocklebur, common	P	P	P	P	P	F	P		E	E	E	P	P	
Dodder, field	P	—	P	P-F	P	F	P-F		P	G	F	P	P	
Knotweed, prostrate	F	F-G	F-G	G	F	G	G		P	G-E	F-G	P	P	
Kochia	F	F	F	G-E	F	G-E	G-E		F-G	G-E	G	P	P	
Lambsquarters	F-G	F-G	F-G	E	F-G	E	E		F	E	G	P	P	
Mallow, common	P-F	F	P	P	P-F	P	P		F-G	E	F	P	P	
Nightshade, hairy	G	E	G	F	F-G	P-F	P-F		F-G	E	E	P	P	
Pigweed, redroot	E	E	G	E	G-E	E	E		F	E	E	P	P	
Puncturevine	P	G-E	F	G-E	P	F	G-E		P	E	E	P	P	
Purslane, common	F	F-G	F-G	E	F	E	E		G-E	E	E	P	P	
Sowthistle, annual	F-G	—	G-E	P	F	P-F	F		—	E	F	P	P	
Sunflower, common	P	P	P	P	P	P	P		G-E	E	E	P	P	
Thistle, Russian	P	F	P	F	P	F	F		—	G-E	F-G	P	P	
Perennial Weed
Bindweed, field	
P	
P	
P	
P	
P	
P	
P		
P	
F-G	
F	
P	
P	
Nutsedge, yellow	F-G	F-G	E	P	G	P	P		F-G	F	P-F	P	P	
Sowthistle, perennial	P	—	—	—	P	P	—		—	F	P	P	P	
Thistle, Canada	P	P	P	P	P	P	P		P	G-E	P	P	P	
Quackgrass	P	F	F-G	P	P	P	P		P	G-E	P-F	G	F	
Crop Safety
Tolerance	
G	
G	
G-E	
E	
G	
E	
E		
G	
P	
G	
E	
E	
Carryover 1	2–3	3–6	1–2	2–6	2–4	3–6	3–12		0	0	3–26	4	1–4	
E = excellent          G = good           F = fair          P = poor        — = no information
1 Number of months after application to plant an unlabeled crop. 

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