Clethodim Herbicide

Clethodim is a selective, systemic herbicide primarily used for post-emergence control of annual and perennial grasses in a variety of broadleaf crops.

There are three types of this herbicide: Clethodim 2EC, Clethodim 2E, and Clethodim 70% MUP. The primary differences between them lie in their formulation, concentration, and intended use.

Clethodim 2EC

Formulation: “2EC” stands for 2 lbs. of active ingredient per gallon in an Emulsifiable Concentrate (EC) formulation.
Active ingredient concentration: Contains 26.4% clethodim.
Usage: A ready-to-use post-emergence herbicide for controlling grassy weeds in crops. It is a standard commercial formulation commonly used in agriculture.
Key Feature: The emulsifiable concentrate formulation allows the herbicide to mix readily with water and form a stable emulsion for application.

Clethodim 2E

Formulation: Similar to 2EC, the “2E” likely refers to 2 lbs. of active ingredient per gallon. It may also be an Emulsifiable (E) formulation.
Active ingredient concentration: Typically contains 26.4% clethodim, similar to 2EC.
Usage: Very similar to 2EC and used for controlling grassy weeds. The difference might be due to branding, minor formulation changes (like surfactants), or manufacturing details.
Key Feature: Like 2EC, 2E is tailored for efficient application on crops.

Clethodim 70% MUP (Manufacturing Use Product)

Formulation: “70% MUP” indicates 70% clethodim concentration, designed as a Manufacturing Use Product.
Purpose: Not a direct-use herbicide. Instead, MUP is a concentrated product intended for formulating other herbicides.
Usage: Used by manufacturers to create diluted, ready-to-use products like 2EC or 2E.
Key Feature: Extremely high concentration of clethodim, not suitable for direct field application without further processing or dilution.

Key Differences
Aspect	2EC	2E	70% MUP
Active Ingredient	~26.4% clethodim (2 lbs/gal)	~26.4% clethodim (2 lbs/gal)	70% clethodim
Formulation	Emulsifiable Concentrate (EC)	Emulsifiable formulation (E)	Manufacturing Use Product
Usage	Ready-to-use in fields	Ready-to-use in fields	Used for product formulation
Concentration Purpose	Application-level strength	Application-level strength	High concentration for formulation

The Active Ingredient

The active ingredient of this herbicide is a member of the cyclohexanedione (DIM) chemical family. It is a lipid synthesis inhibitor that specifically targets grassy weeds.

Weeds Controlled

This selective herbicide targets annual and perennial grassy weeds. It does not affect broadleaf weeds or sedges.

Annual Grasses
Grass Species	Scientific Name	Weed* Height (inches)	Rate (fl. oz./acre)	High Rate⁽⁴⁾ (fl. oz./acre)
Barnyardgrass	Echinochloa crus-galli	2-8	6	8
Broadleaf Signalgrass	Brachiaria platyphylla	2-6	6	8
Brome, California	Bromus carinatus	2-6	6	8
Cheatgrass	Bromus secalinus	2-6	6	8
Downy Brome	Bromus tectorum	2-6	6	8
Ripgut Brome	Bromus diandrus	2-6	6	8
Canarygrass	Phalaris canariensis	1-4	6	8
Crabgrass, Hairy	Digitaria adscendens	2-6**	6	8
Crabgrass, Large	Digitaria sanguinalis	2-6**	6	8
Crabgrass, Smooth	Digitaria ischaemum	2-6**	6	8
Crabgrass, Southern	Digitaria ciliaris	2-6**	6	8
Crowfootgrass	Dactyloctenium aegyptium	2-6**	6	8
Fall Panicum	Panicum dichotomiflorum	2-8	6	8
Field Sandbur	Cenchrus incertus	2-6	6	8
Foxtail, Giant	Setaria faberi	2-12	6	8
Foxtail, Green	Setaria viridis	2-8	6	8
Foxtail, Yellow	Setaria glauca	2-8	6	8
Goosegrass	Eleusine indica	2-6**	6	8
Itchgrass	Rottboellia exaltata	2-6	6	8
Junglerice	Echinochloa colona	2-6	6	8
Lovegrass (Stinkgrass)	Eragrostis cilianensis	2-6	6	8
Rabbitsfootgrass	Polypogon monspeliensis	1-4	6	8
Red Rice	Oryza sativa	1-3	6	8
Ryegrass, Hardy	Lolium remotum	2-6	6	8
Ryegrass, Italian	Lolium multiflorum	2-6	6	8
Seedling Johnsongrass	Sorghum halepense	4-10	6	8
Shattercane	Sorghum bicolor	6-18	6	8
Southwestern Cupgrass	Eriochlola gracillis	2-6	6	8
Sprangletop, Amazon	Leptochloa panicoides	2-6	6	8
Sprangletop, Bearded	Leptochloa fascicularis	2-6	6	8
Sprangletop, Mexican	Leptochloa uninervia	2-6	6	8
Sprangletop, Red	Leptochloa filiformis	2-6	6	8
Texas Panicum	Panicum texanum	2-6	6	8
Volunteer Barley	Hordeum vulgare	2-6	6	8
Volunteer Oats	Avena sativa	2-6	6	8
Volunteer Rye	Secale cereale	2-6	6	8
Volunteer Wheat	Triticum aestivum	2-6	6	8
Volunteer Corn	Zea mays	4-12	4	6
Volunteer Corn (S.R.)	Zea mays	4-12	8 (suppression only)	N/A
Volunteer Grain Sorghum	Sorghum bicolor	8-12	6	8
Wild Oats	Aven fatua	2-6	6	8
Wild Proso Millet	Panicum miliaceum	2-10	6	8
Witchgrass	Panicum capillare	2-8	6	8
Woolly Cupgrass	Eriochloa villosa	2-8	6	8

*Typically occurs between the 3-leaf stage and tillering.

**Refers to the extent of lateral growth.

⁽¹⁾ Volunteer corn resistant to sethoxydim.

⁽²⁾ Includes volunteer corn with traits like Roundup Ready®, Liberty Link®, and IMI-CORN®.

⁽³⁾ For cereal grains (e.g., wheat) interseeded for crop establishment or planted as windbreaks, the minimum application rate of CLETHODIM 2E for control is 8 fl. oz./A.

⁽⁴⁾ In specific geographic areas, environmental conditions, or cropping scenarios where higher rates are known to be more effective, CLETHODIM 2E can be applied at rates between 8 and 16 fl. oz./A for adequate control of annual grasses. For crops such as asparagus, carrot, cranberry, cucurbits, flax, fruiting vegetables (excluding tomato), garden beet, green onion, head and stem brassica vegetables, herbs, hops, leaf petioles, leafy brassica greens, leafy greens, non-bearing food crops, root vegetables, safflower, sesame, and strawberry, the maximum rate per application is 8 fl. oz./A. For canola or mustard seed, do not exceed 6 fl. oz./A per application.

How Does It Work

It has a systemic action.

The herbicide is absorbed through the leaves of the weeds and then moves throughout the plant via the phloem, concentrating in growing points such as root tips and shoots.

Once inside the plant, it disrupts lipid biosynthesis, leading to cell membrane disintegration and, ultimately, plant death.

Timeline of Action and Visible Effects

You can see the first signs of this herbicide working within 7 to 14 days.

In grassy weeds, some signs include a loss of vigor and slowed growth. Younger plants may start turning yellow or brown initially, and over time, the rest of the leaves will gradually collapse.

Where to Apply

Clethodim herbicide can be applied in various agricultural and non-crop settings:

Agricultural Crops

Agricultural Crops
Alfalfa	Asparagus	Beans, Dry	Beans, Succulent
Beet, Garden	Brassica Vegetables	Canola	Carrot
Clover	Cotton	Cranberry	Cucumber
Flax	Herbs	Hops	Leafy Greens
Leafy Brassica	Mustard Seed	Onions	Peanuts
Potato	Soybeans	Strawberry	Sugar Beet
Sunflower	Sweet Potato, Yam	Tomato	Tuberous Vegetables
Squash	Melons

Non-Crop Areas

When it comes to non-crop areas, you can use it in places like rights-of-way, including railroads, highways, roads, dividers, and medians. It’s also suitable for pipelines, public utility lines, pumping stations, transformer stations, and substations.

Additionally, it can be used around airports, electric utilities, commercial buildings, factories, storage yards, rail yards, fence lines, parkways, post-harvest fields, under greenhouse benches, and around golf courses.

Non-Bearing Food Crops

Non-bearing food crops
Common Name	Scientific Name
Apples	Malus spp.
Berries	Vaccinium spp., Rubus spp.
Cherry, Sweet	Prunus avium
Citrus Fruits	Citrus spp.
Grapes	Vitis spp.
Olives	Olea spp.
Peach	Prunus persica
Pears	Pyrus communis
Prunes	Prunus spp.
Stone Fruits	Prunus spp.
Strawberries	Fragaria spp.
Tree Nuts
Almond	Prunus dulcis
Filbert	Corylus maxima
Pecan	Carya illinoinensis
Pistachio	Pistacia vera
Walnut	Juglans spp.

Do not spray directly on the foliage of these crops. Instead, focus the application at the base of the plants where grassy weeds are present.

Conifer Trees

Conifer trees
Common Name	Scientific Name
Arborvitae, American	Thula occidentalis
Cedars	Cedrus spp.
Cypress	Taxodium spp.
Douglas Fir	Pseudotsuga menziesii
Firs	Abies spp.
Hemlock, Canadian/Eastern	Tsuga canadensis
Hemlock, Western	Tsuga heterophylla
Pines	Pinus spp.
Spruces	Picea spp.
Yew	Taxus spp.

Do not use it in forests. It is intended for use only in Christmas tree farms, conifer nurseries, and conifer plantations.

Application Rates by Crop Type

The application rate of Clethodim varies depending on the specific crop being treated.

Each crop has its own recommended rate to ensure effective weed control while minimizing the risk of crop injury.

Below, you’ll find the crops grouped by their corresponding application rates to help you determine the right usage for your needs. Always follow the product label for safe and effective application.

Application Rates for each crop
6-8 fl. oz./A	4-6 fl. oz./A	6-16 fl. oz./A
Beet, Garden Brassica Vegetables (e.g., Broccoli, Cabbage, Cauliflower, Brussels Sprouts) Carrot Cranberry Cucurbits (e.g., Cantaloupes, Pumpkins, Squash, Watermelon) Fruiting Vegetables (e.g., Eggplant, Peppers, Groundcherry, Tomatillo) Herbs (e.g., Basil, Dill, Rosemary, Sage, Mint) Hops Leafy Petioles (e.g., Celery, Swiss Chard, Rhubarb) Leafy Brassica Greens (e.g., Kale, Collards, Mustard Greens) Mustard Seed Onions Onions, Green Asparagus Flax Sesame Radish Safflower Strawberry	Canola (e.g., applied before bolting; crop injury possible during bloom)	Alfalfa Clover (grown in Idaho, Oregon, and Washington) Cotton Legume Vegetables, Edible-Podded (e.g., Beans: Snap, Wax, Lima; Peas: Snow, Sugar Snap) Mint Pea, Dry Peas, Succulent (e.g., Garden Peas, English Peas) Peanut (including Perennial) Potato Root Vegetables (e.g., Chicory, Ginseng, Horseradish, Turnip) Soybean Sugar Beet Sunflower Sweet Potato and Yam Tuberous and Corm Vegetables (e.g., Artichoke, Cassava, Ginger) Tomato Fallow Land Non-Bearing Food Crops Ornamentals

When to apply it

You should apply it after the grasses have started growing and are active.

This is during:

Spring (March to May): For cool-season weeds that germinate in early spring.
Summer (June to August): For warm-season weeds that thrive in hot weather.
Fall (September to November): For perennial weeds preparing for dormancy and for targeting late-season weeds.

You need to follow the rate recommendations provided on the label. Do not spray on grasses that are stressed due to lack of water or cold temperatures, as the herbicide may not work effectively. Avoid treating grasses that have grown beyond the recommended stages, as control may be less effective.

If you’re in a dry area where irrigation is used to supplement rainfall, apply the herbicide within 7 days after watering.

In these conditions, a second application is often more effective for controlling perennial grasses than a single treatment. The second spray should be applied 2 to 3 weeks after new grass growth starts and while it is actively growing.

Don’t apply it if it’s expected to rain within one hour of spraying, as this could reduce its effectiveness.

Tank Mixes

Clethodim herbicide can be tank-mixed with other herbicides, depending on the crop you are treating and the type of weeds you want to control.

This allows for a more effective approach to managing both grasses and broadleaf weeds in a single application, provided you follow the label instructions for each product.

Apply the tank mix only to grass and broadleaf weeds that are actively growing and at the height or growth stage recommended on the labels.

Always read the label. The most restrictive instructions on any product label used in a tank mix must be followed.

For alfalfa, this herbicide can be tank mixed with 2,4-DB, Pursuit, or Buctril.
For canola, it can be combined with Liberty herbicide.
For cotton, you can tank mix it with Cobra or MSMA herbicides.
In BXN cotton, Clethodim can be used with Buctril 4EC. For emerged grasses in cotton, it can be applied as a broadcast application alongside glyphosate.
For dry beans and succulent beans, Basagran is an effective tank mix option.
For flax, you can tank mix it with Bronate, Buctril, or Rhonox.
For soybean, recommended tank mix partners include Cobra, 2,4-D, Basagran, Blazer, Flexstar, Pursuit, Classic 25, Synchrony, and Frontrow.
In peanut, Storm, Blazer, and Basagran are good tank mix options.
For sugar beet, you can tank mix it with Spur.

Be aware that tank mixing may sometimes reduce grass control. If grasses regrow or new ones emerge, apply clethodim 2E again as directed in the size and rate tables.

Prevent the tank mix from misting, dripping, or drifting onto desirable plants or crops. Even small amounts of drift can cause significant harm.

Adjuvants

This herbicide can be combined with adjuvants or crop oils to enhance its effectiveness against weeds and grasses.

Adjuvants help the herbicide spread more evenly, stick to plant surfaces, and penetrate the leaves for better absorption.

Adjuvant or Crop Oil Concentrate Recommendations
Crop	Adjuvant Recommendations
Alfalfa, Cotton, Dry Bean, Dry Pea, Edible Podded Legume Vegetables, Peanuts (including perennial), Potato, Soybeans, Succulent Bean & Pea, Sugar Beet, Sunflower	Always use a crop oil concentrate at 1 qt./A for ground applications or 1% v/v (minimum of 1 pt./A) for aerial applications. You can also add 1 to 2 qts./A of liquid fertilizer (like 10-34-0, 28%N, or 32%N) or 2.5 to 4 lbs./A of spray-grade ammonium sulfate (AMS). Adding AMS improves control of tough grasses like quackgrass, johnsongrass, red rice, wild oats, volunteer cereals, and volunteer corn.
Asparagus, Canola, Carrot, Clover, Cranberry, Cucurbits, Flax, Fruiting Vegetables (except tomato), Garden Beet, Garlic, Head & Stem Brassica Vegetables, Herbs, Hops, Leaf Petioles, Leafy Brassica Greens, Leafy Greens, Mint, Mustard Seed, Onions (dry and green bulbs), Root Vegetables, Safflower, Sesame, Shallots, Strawberry, Sweet Potato (including Yam), Tomato	Always use a crop oil concentrate at 1% v/v in the spray mixture unless the tank mix label says otherwise. Liquid fertilizer is not recommended for these crops.
Ornamental Plants, Non-Bearing Food Crops	Use a non-ionic surfactant with at least 80% active ingredient at a rate of 1 pt. per 50 gallons (0.25% v/v). Crop oil concentrate is not recommended because it may harm flowers and leaves.
Conifer Trees, Fallow Land (and other non-producing agricultural areas), and Non-Crop or Non-Planted Areas	Always use a crop oil concentrate with at least 15% emulsifier at 1% v/v (minimum of 1 pt./A) in the spray mixture.

Mixing Instructions

Add half of the required water to the spray tank and start the agitation.
Add the required amount of Clethodim and mix thoroughly to ensure it is evenly dispersed in the water.
Add the required amount of the tank mix partner (if applicable) and continue mixing to achieve a uniform solution.

Perform a Jar Test: Before mixing, use a jar test to ensure the herbicide and other components are compatible. This helps prevent clumping or separation during application.

Add the required amount of crop oil concentrate (COC) and/or nitrogen fertilizer, as specified on the label.
Add the remaining water to the tank while maintaining agitation until the tank is full.
Ensure agitation is maintained throughout the application process to keep the mixture consistent and effective.

How to apply it

Wear the right personal protective equipment (PPE). Put on gloves, long-sleeved clothing, protective goggles, and a mask to protect your skin, eyes, and lungs from exposure.
Check the weather. Make sure no rain is expected for at least 1 hour after application. Avoid spraying on windy days to prevent drift onto non-target areas.

Temperatures must be between 60°F and 85°F (15°C to 29°C) for most herbicides.

Prepare and inspect your equipment. Check your sprayer for any leaks or malfunctions.
Prepare the herbicide mixture. Read the product label carefully for the recommended mixing rates and application instructions. Mix the herbicide with water or other additives, as specified, in a well-ventilated area.
Select the right timing. Apply the herbicide during the active growth stage of weeds for the best results. Morning or evening applications are often ideal to reduce evaporation and maximize absorption.
Target the weeds directly. Apply the herbicide at the base of the plants where weeds are growing, especially for non-bearing crops. Avoid spraying directly onto the foliage of sensitive crops.
Watch for signs of effectiveness, such as reduced vigor and yellowing of weeds, within 7–14 days.
Clean the quipment after use. Rinse the sprayer and nozzles thoroughly with water to prevent residue buildup.

Restrictions and Limitations

Mixing with Other Herbicides: Avoid using post-emergence broadleaf herbicides within a day of applying CLETHODIM 2E, as this can reduce its ability to control grass.
Vegetable Seed Crops: This herbicide is not recommended for vegetables grown for seed unless specific instructions are provided.
Avoid Overuse: Using more than the recommended amounts can damage your crops.
Practices for Perennial Grass Control: If you’re targeting perennial grasses, till the soil first to break up rhizomes or stolons and encourage uniform weed growth. For no-till systems, expect to apply this herbicide at least twice per season.
Sensitive Crops: Grass crops like corn, rice, and turf are very sensitive to this herbicide.
Specialty Varieties: If you’re using this on specialty vegetable crops, test a small area first to check for any leaf speckling or stunting.
Wind Precautions: Don’t spray when winds are over 10 MPH or gusty. Be extra cautious if there are sensitive crops nearby.
Stay Close to Target Plants: Apply the spray as close to the weeds as possible to ensure good coverage while minimizing drift.

Specific Crop Limits: Some crops, like asparagus, leafy greens, herbs, and strawberries, should not receive more than 8 fl. oz./acre per application. For canola or mustard seed, don’t exceed 6 fl. oz./acre per application.

For canola, don’t use more than 6 fl. oz./acre per season.

For clover, flax, mustard seed, and radish, the limit is 16 fl. oz./acre per season.

For other crops, the maximum is 32 fl. oz./acre per season. However, on Long Island, New York, the limit is 16 fl. oz./acre per season.

EPA Registration Number

This herbicide has the following EPA registration numbers:

Clethodim 2E: EPA Reg. No. 42750-72
Clethodim 2EC: EPA Reg. No. 38167-39.
Clethodim 70% MUP Herbicide: EPA Reg. No. 91813-68.