ammoniated soap of fatty acids (Final-San-O)
Rate For control of small weeds 10% v/v solution; for control of perennials or established weeds 16.7% v/v solution.
Remarks Avoid contact with desirable vegetation. Disrupts cell membranes, causing leakage and symptoms of leaf burn.
Site of action Group 26: unknown
Chemical family Carboxylic acid
ammonium nonanoate (AXXE)
Rate 6 to 8% solution to control small annual weeds (<1 inch); 8 to 10% solution for burndown of annual weeds 1 to 4 inches tall; 10 to 13% for weeds larger than 4 inches tall; a 15% v/v solution for maximum vegetative burndown for control of perennials or dense weed growth.
Time Apply to thoroughly wet weed foliage as a directed spray around containers. Most effective a temperatures above 60º F.
Remarks Avoid contact with desirable vegetation. Disrupts cell membranes, causing leakage and symptoms of leaf burn.
Site of action Group 26: unknown
Chemical family Carboxylic acid
bentazon (Basagran herbicide)
Non bearing grapes in Idaho and Oregon only
Rate 0.75 to 1 lb ai/a (1.5 to 2 pints/a)
Time Spring to early summer, depending on growth stage of weeds.
Remarks Supplemental label (Arysta LifeSciences only) for nonbearing crops. Useful for suppression and control of yellow nutsedge, Canada thistle, and musk thistle. For Canada thistle apply 2 pints/a when plants are between 8 inches tall and bud stage. Apply a second application 10 to 14 days later if needed. For nutsedge, apply 1.5 to 2 pints/a when plants are 6 to 8 inches tall, and make a second application 7 to 10 days later if needed. Always add a crop oil concentrate. Use no more than 2 lb ai/a per year. Irrigate to make sure plants are actively growing before applying bentazon. Do not cultivate or mow for 5 days after application. Weeds growing under drought conditions may not be adequately controlled.
Caution Apply as a directed spray, away from the crop. Do not apply within one year of crop harvest.
Site of action Group 6: photosystem II inhibitor
Chemical family Benzothiadiazole
carfentrazone-ethyl (Aim EC)
Rate 0.016 to 0.031 lb ai/a (1 to 2 fl oz/a Aim EC)
Time Directed spray and with hooded sprayers within and between rows.
Remarks Preharvest interval is 3 days. Control is enhanced with COC (1%) or NIS (0.25%).
Caution Care must be taken not to allow spray mist to contact desirable fruit, foliage or green stem tissue. Can be used for control of suckers if tissue is young.
Site of action Group 14: inhibits protoporphyrinogen oxidase
Chemical family Triazinone
clove or clove leaf oil (Matratec)
Washington only
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 FIFRA 25(b) exempt pesticide. OMRI listed and WSDA approved herbicide for in-crop use. Apply before crop emerges, or between rows after emergence; avoid contact with desirable foliage. Directed sprays or hooded sprayers are recommended to protect desirable foliage. Works best on annual weeds less than 6 inches. Performance may be erratic depending on environmental conditions. Bright sunlight improves efficacy. No preharvest or reentry interval.
d-limonene (lemongrass oil) (Avenger AG)
Rate 14% dilution rate, 20% for spot treatment of difficult to control weeds.
Time Up to first fruit set, when weeds are less than 6 inches tall.
Remarks Broad-spectrum, nonselective contact herbicide that does not translocate. Spot treatments allowed in bearing crops up to 1 week before harvest. Do not exceed 8.5 gal/a per application in bearing crops. Most effective on annual weeds. OMRI listed, NOP compliant, and WSDA approved organic burndown herbicide for use in crop and noncrop sites. Foliage contacted by Avenger AG will be damaged. Directed sprays or hooded sprayers are recommended to protect desirable foliage. Coverage is very important. Carrier rates of 40 GPA or more are essential for good control. Leaf damage is visible within hours. Cool weather may slow activity. No reentry interval. This herbicide causes rapid wilting or necrosis of the leaves due to removal of waxy cuticle.
glufosinate ammonium (generic)
Rate 0.88 to 1.5 lb ai/a; (48 to 82 fl oz/a depending on weed size)
Time Apply to actively growing weeds as a directed spray or spot treatment according to weed growth stage.
Remarks Avoid drift to, or treatment of, desirable foliage or green bark during establishment year.
Caution Do not exceed 4.5 lb ai/a per 12-month season. Do not graze or apply within 14 days of harvest.
Site of action Group 10: glutamine synthase inhibitor
Chemical family Phosphinic acid
glyphosate (numerous products)
Rate 0.47 to 4.5 lb ai/a (11 oz to 3.3 quarts/a Roundup Power Max)
Time Select application equipment to prevent crop injury by directing spray, or use selective applicators.
Remarks Adjust concentration depending on equipment. See label for rate and time of application, especially for perennial weeds. Adding surfactant or mixing ammonium sulfate according to label may improve control of slightly stressed weeds.
Caution Do not let drift or mist contact green foliage or bark, suckers, or vines and renewals less than 3 years old. Preharvest interval is 14 days. If repeat applications are needed, do not exceed 8 lb ae/a per year. Repeated glyphosate applications have created resistant biotypes of ryegrass in Australian orchards. To avoid weed resistance, rotate and mix weed control practices.
Site of action Group 9: inhibits EPSP synthase
Chemical family None generally accepted
glyphosate (several products)
Rate 0.47 to 4.5 lb ai/a (11 oz to 3.3 quarts/a Roundup Power Max)
Time Wick-wiper: Mix 1 gal product with 2 gal water and apply to weeds.
Remarks Avoid contact with desirable vegetation. In severe infestations, reduce equipment ground speed, or apply in two directions to ensure contact with wiper. (See remarks above.)
Site of action Group 9: inhibits EPSP synthase
Chemical family None generally accepted
pelargonic acid (Scythe)
Rate 3 to 5% solution to control annual weeds, mosses and cryptogams; 5 to 7% solution for burndown of perennial herbaceous plants; 7 to 10% solution for maximum vegetative burndown, edging, or foliar trimming.
Time Apply to thoroughly wet weed foliage as a directed spray around containers. Most effective when temperature is above 65°F.
Remarks Avoid contact with desirable vegetation. Disrupts cell membranes, causing leakage and symptoms of leaf burn.
Site of action Group 26: unknown
Chemical family Carboxylic acid
pyraflufen (Venue)
Rate 0.0015 to 0.006 lb ai/a (1 to 4 fl oz product/a); 3 to 4 oz/a for sucker control.
Remarks Apply as a directed application to actively growing weeds less than 4 inches high, or rosettes less than 3 inches in diameter. Use lower rate for small weeds and higher rate for larger weeds. Do not exceed 6.8 fl oz/a or three applications per season. Allow at least 30 days between applications. Apply after harvest until bloom or in-season for sucker control. Mixing this herbicide with another herbicide increases the weed spectrum and is highly recommended. A spray tank adjuvant is recommended. No preharvest interval.
Caution This product is a contact, nonselective, broadleaf herbicide. Avoid contact with desirable foliage, green bark, or fruit.
Action in plant Inhibits protoporphyrinogen oxidase (PPO) that disrupts cell membranes.
Site of action Group 14: protoporphyrinogen oxidase inhibitor
Chemical family Phenylpyrazole
paraquat (Gramoxone Inteon)
Rate 0.625 to 1 lb ai/a (2.5 to 4 pints/a Gramoxone Inteon)
Time Apply as a directed shielded spray toward base of vines, when weeds are growing vigorously and new growth is 1 to 6 inches high or when sucker growth is no more than 8 inches.
Remarks Add a nonionic surfactant or crop oil concentrate according to label; avoid anionic formulations that react in the tank to form insoluble precipitates. Avoid windy conditions. Acts on contact; absorbs energy produced by photosynthesis forming peroxides that disrupt living cells. Five applications allowed per year. Treat when suckers are less than 8 inches long.
Caution Restricted-use herbicide. Do not ingest or inhale spray mist. Wear protective face shields, respirators, and clothing. Do not allow spray to contact green stem, fruit, or foliage.
Site of action Group 22: photosystem I electron diversion
Chemical family Bipyridilium
sethoxydim (Poast)
Rate 0 .19 to 0.47 lb ai/a (1 to 2.5 pints/a Poast)
Time Identify susceptible grasses and apply at optimum growth stage listed on the label.
Remarks Add 2 pints/a of a nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed by drought, high temperature, or low fertility. Resistant grasses include annual bluegrass and all fine fescues; quackgrass can be suppressed. Inhibits fatty acid production, cell membranes, and new growth.
Caution Preharvest interval is 50 days. Do not exceed 5 pints/a per season.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Aryloxyphenoxy propionate