Toxic weeds may be found in pastures and hayfields throughout Georgia. The toxins can persist in many species even after they are baled as hay or baleage. In addition, toxic plant species often include trees and shrubs along fencelines.
This resource can help you identify the most common toxic weed species on your farm and what symptoms to watch for in grazing livestock. If you suspect that your animal has consumed a toxic plant species, please contact your local veterinarian for an official diagnosis and treatment.
Black Cherry (Prunus serotina)
Description
Black cherry is a deciduous hardwood tree or shrub that is commonly found along fencerows and roadsides. The leaves are described as elliptical with fine-toothed margins and are arranged in an alternate pattern (Figure 1, left). The leaf size is variable, 2.5 to 5 in. long and 1 to 2 in. wide. Flowers of black cherry are small and white and form drooping clusters. The flowers will form little red to black fruits as they mature (Figure 1, right).
Toxicity and Symptoms
Ruminant animals (e.g., cattle, sheep, and goats) are most affected, but horses may also be impacted. The toxicity comes from cyanide poisoning. Hydrocyanic acid is found in wilted leaves, often from fallen trees. The bark and twigs may also contain these compounds.
Animals may show symptoms within 15 to 30 min after consuming the material and will likely die within 1 hr. Only 1 to 5 lb of the material will be toxic to cattle, and only 3 to 12 oz will be toxic to small ruminants. Specific symptoms include:
- Difficulty breathing
- Anxious behavior
- Staggering, collapse, or convulsions
- Bright red in mucous membranes and blood
- Death
Black Locust (Robinia pseudoacacia)
Description
Black locust is commonly found in or along edges of pastures and fields. This is a medium-sized deciduous hardwood tree that reaches 40–100 ft tall at maturity. The leaves are defined as alternate and pinnately compound with a pair of thorns at the base of each compound (Figure 2, left). The flowers are showy, white, very fragrant, and droop (Figure 2, right).
Toxicity and Symptoms
All animals are susceptible to poisoning from black locust, but horses are the most susceptible. The toxicity comes from glycoside robitin poisoning following the animal ingesting roots, bark, sprouts, or seed pods. The toxic level of consumption is unclear. Specific symptoms include:
- Depression
- Loss of appetite
- Weakness or posterior (hips, hind legs) paralysis
- Dilated pupils
- Irregular pulse or heart rate
- Difficulty breathing
- Bloody diarrhea
Brackenfern (Pteridium aquilinum)
Description
Brackenfern is commonly found in drier fields and roadsides. This perennial fern grows up to 3 ft tall (Figure 3). Fronds are the leaf like part of the fern. These become leathery as they mature and can be described as coarse. Individual leaves are triangular (Figure 3). New fronds arise from creeping underground rhizomes.
Toxicity and Symptoms
All animals are susceptible to poisoning from brackenfern, but horses are the most susceptible. All portions of the plant are toxic, whether green or dried for hay. The plant contains the toxic enzyme thiaminase. The toxicity level reported in literature is variable, but as little as 3% of the diet can be fatal. Specific symptoms are species dependent.
Symptoms in Horses:
- Lack coordination, often standing with legs spread apart as if they are bracing
- Arched back and neck.
- Fever up to 104 °F
- Head pressing against objects
- Muscle spasms
- Death
Symptoms in Cattle:
- Difficult and loud breathing
- Bloody manure or urine
- Excessive bleeding from minor injuries (e.g., fly bites)
Symptoms in Sheep and Goats:
- Blindness
Buttercup (Ranunculus spp.)
Description
Buttercups are cool season broadleaf weeds and may be annual, biennial, or perennial depending upon the species. Regardless, they are common throughout the Southeastern US, preferring relatively wet areas. Buttercup can be prostrate or erect, growing up to 2 ft tall. The leaves are described as alternate, simple, and can be lobed or divided (Figure 4, left). The flowers are yellow and usually contain 5 petals (Figure 4, right).
Toxicity and Symptoms
Buttercup is toxic to all classes of livestock. These plants are unpalatable and usually avoided unless forage is limited. The stem and leaves contain an irritant oil called protoanemonin. The plant is more toxic when it is flowering than when it is vegetative. Generally, large quantities of the material must be consumed before toxicity occurs. Symptoms include:
- Stomach pain
- Severe diarrhea
- Convulsions
- Death
- Milk from lactating cows will be bitter and may be reddish in color
Castor Bean (Ricinus communis)
Description
Castor bean is a large warm season broadleaf annual weed but may be an evergreen perennial in cooler locations. It was a popular ornamental plant that has now invaded agricultural areas. The leaves are described as alternate, up to 16 in. long, palmately lobed, and serrated with gland-tipped teeth (Figure 5, left). The seed capsules are shiny, speckled with brown, and may look like a tick. Three seeds are contained within each capsule (Figure 5, right).
Toxicity and Symptoms
Horses and pigs are the most susceptible to poisoning, but all livestock can show symptoms. All parts of the plant contain the toxic compound, ricin. The seeds are the most toxic part of the plant. Symptoms are most likely to appear in the spring and summer. Symptoms appear several hours to days after consuming the toxin and will depend on the amount consumed. Consuming as little as 0.1% of body weight can be toxic.
- Stomach pain
- Violent purgation (straining and bloody diarrhea)
- Weakness
- Shaking
- Lack of coordination
Chinaberry (Melia azedarach)
Description
Chinaberry is a fast-growing deciduous tree that was once commonly used as an ornamental species but has now invaded agricultural areas. This small to medium-sized tree can reach 30 to 50 ft tall at maturity. Its leaves are defined as alternate, deciduous, and bipinnately compound with deeply toothed leaflets at the margins (Figure 6, left). Its flowers are white with 5 petals (Figure 6, right). The fruit are greenish yellow to yellow-tan and are ½ in. in diameter.
Toxicity and Symptoms
Pigs and sheep are most often affected, and symptoms will occur after consuming 0.5% or more of the animal’s body weight. Goats and cattle are also affected but greater amounts must be consumed before symptoms appear. The fruits are the most toxic part, but the leaves, bark, and flowers are also mildly toxic. The toxicity comes from tetranortriterpene neurotoxins, typically in the fall or winter. Symptoms include:
- Stomach irritation
- Vomiting
- Bloody diarrhea
- Paralysis
- Irregular breathing
- Respiratory distress (difficulty breathing)
Common Cocklebur (Xanthium strumarium)
Description
Common cocklebur is a warm season annual broadleaf weed found throughout the southeast US in fields and roadsides that receive full sunlight. This branching annual can grow 1 to 3 ft tall. The leaves are described as alternate, simple, coarsely pubescent, shallowly lobed (Figure 7, left). It produces ½- to 1-in.-long fruits that are broadly cylindrical and covered in hooked spines (Figure 7, right).
Toxicity and Symptoms
Toxicity is most often observed in pigs because they root up and ingest young plants in the springtime. Toxicity is rare in other classes of livestock. The main toxin is glycoside carboxyatractyloside which is concentrated in the seeds and seedlings. Only 3 lb of seeds consumed per 1,000 lb of body weight will be toxic. The mature plant is less toxic, where 7.5 lb of plant material consumed per 1,000 lb of body weight will be toxic. Symptoms include:
- Vomiting
- Stomach irritation with occasional diarrhea
- Muscle spasms
- Convulsions
Dallisgrass (Paspalum dilatatum)
Description
Dallisgrass is a warm season perennial grass common throughout forage systems in Georgia. It forms clumps that spread and outcompete desirable species. The seedhead is the most distinctive feature with 3 to 6 drooping spikes (Figure 8, left). The dallisgrass ergot (Claviceps paspali) is a fungus found on dallisgrass seedheads. The fungal mass (ergot body) grows in place of a seed. It starts as round mass that is tan to fluorescent orange in color. Then will shrink and turn black with maturity (Figure 8, right).
Toxicity and Symptoms
All grazing animals are affected by the toxic compound, paspalitrems. This compound is found only in the seedheads affected with the ergot. Symptoms may occur as soon as 3 days after consuming the affected materials. The toxic level of consumption is unclear. Specific symptoms include:
- Lack of coordination (often called staggers)
- Trembling
- Collapse
- Deaths are rare but may result from injury during staggering or collapse
Ground Cherry (Physalis spp.)
Description
There are several species of ground cherry that consist of both warm season annual and perennial broadleaf weeds. Plants are branched and spread at the top (Figure 17). Their leaves are defined as alternate, simple, and can be smooth margined or irregularly toothed. The flowers are funnel-shaped, and yellow (Figure 9, left). The fruits are yellow with red to purple berries surrounded by a light brown to yellow papery sack (Figure 9, right).
Toxicity and Symptoms
All grazing animals are susceptible to the solanine and other solanidine alkaloids. These toxins are concentrated in immature berries and leaves. The toxic level of consumption is unclear. Symptoms include:
- Excess salivation (slobbering)
- Shortness of breath
- Weakness
- Trembling (may lead to paralysis)
- Bloody diarrhea
- Vomiting
- Collapse
- Death
Hemp Dogbane (Apocynum cannabinum)
Description
Hemp dogbane is a warm season perennial broadleaf weed. The leaves are described as opposite and simple with smooth margins (Figure 10, left). Flowers are small, bell-shaped, and may be white to light pink in color (Figure 10, right). The fruits consist of two long, slender pods filled with lots of silky-haired seeds.
Toxicity and Symptoms
All grazing animals are susceptible to the toxic resins and cardiac glycosides, including cimarin. All parts of the plant contain these toxins, including both fresh and dry material. Death will occur within 6 to 12 hr after animals consume ½ oz of the plant material. Specific symptoms include:
- Dilated pupils (black center of eye)
- Weakness and convulsions
- Vomiting
- Blue coloration of mucous membranes
- Rapid pulse or heart rate
- Heart stress
- Death
Horsenettle (Solanum carolinense)
Description
Horsenettle is a warm season perennial broadleaf found throughout the Southeastern US. This species is challenging to control because it is rhizomatous. Mature plants will reach ½ to 1 ½ ft tall. The leaves are described as alternate, simple, and irregularly pinnately lobed (Figure 11, left). The stems are covered in small thorns and flowers are white to purple (Figure 11, right). The green fruits will turn yellow as they mature, resembling a small tomato (Figure 11, right).
Toxicity and Symptoms
All grazing animals are susceptible to toxicity from solanine and other solanidine alkaloids. All parts of the plant are toxic. The toxins are concentrated in the fruits and toxicity increases with maturity. As little as 4 oz per 1,000 lb of bodyweight may be toxic and 8 oz per 1,000 lb of bodyweight may be lethal. Symptoms include:
- Excess salivation (slobbering)
- Bloody diarrhea or urine
- Shortness of breath
- Weakness
- Trembling
- Progressive paralysis and collapse
- Death
Jimsonweed (Datura stramonium)
Description
Jimsonweed is a warm season annual broadleaf weed that may be found throughout the farm and can grow to several feet tall. The leaves are described as long, smooth, and irregularly wavy or toothed (Figure 12, left). The leaves have a unique or foul smell when crushed. It produces large, white to lavender flowers and spiny fruit capsules with many black, shiny seeds (Figure 12, right).
Toxicity and Symptoms
All livestock are susceptible to the toxins, but cattle and pigs are most affected. The toxic chemicals contained within the plant are the tropane alkaloids atropine, hyoscyamine, and scopolamine. All parts of the plant are toxic, whether green or dry but the seeds are the most poisonous. Nearly any level of consumption is lethal to pigs while cattle may be able to withstand up to 14 oz per 1,000 lbs. of bodyweight. Symptoms include:
- Weak, rapid pulse and heart rate
- Dilated pupils (black center of eye)
- Dry mouth (excessive thirst)
- Incoordination
- Convulsions
- Coma
Johnsongrass (Sorghum halepense)
Description
Johnsongrass is a nonnative, but common perennial warm season grass that can grow up to 8 in. tall. Its leaves may be up to 3 in. long and 2 in. wide. The broad loosely panicled seedhead is brown to purple and can reach 18 in. wide (Figure 13, left). Johnsongrass spreads readily through underground rhizomes (Figure 13, right).
Toxicity and Symptoms
Ruminants are more likely to be affected by toxicity than horses or pigs. Johnsongrass contains hydrocyanic acid (also called prussic acid). The concentration in the plant increases with plant stress including drought, frost, or herbicide activity. Johnsongrass with more than 500 parts per million hydrocyanic acid in dried material will be fatal. Animals may show symptoms within 15 to 30 min after consuming the toxic material and may die within the hour. Symptoms include:
- Difficulty breathing
- Anxious behavior
- Staggering, collapse, and convulsions before death.
- Mucous membranes and the blood are bright red in color.
Use in Forage Systems
Johnsongrass may be considered a desirable forage in pasture-based livestock systems or for use in baleage. It can be safely consumed by livestock when it is not currently under or immediately following a plant stress event. Please consult with your County Extension Agent if you are unsure of the safety in grazing or harvesting johnsongrass on your farm.
Milkweeds (Asclepias spp.)
Description
There are multiple species of milkweeds found throughout the South. These are erect growing, warm season perennial broadleaf weeds. One of their most characteristic identifying features is white, milky sap originating from stems and roots. The leaves are described as simple and opposite, whorled or alternate (Figure 14, left). Milkweeds’ flowers are in dense, showy clusters of flowers that will vary in color (Figure 14, right). The seed pods will contain many seeds that are topped with white, silky hairs for dispersal by wind at maturity.
Toxicity and Symptoms
All animals are susceptible to the steroid glycosides and toxic resinous substances. These toxins are present in all plant parts and remain toxic in dry material. The toxic level of consumption is unclear. Symptoms include:
- Staggering
- Convulsions
- Dilated pupils (black center of eye)
- Weak, rapid pulse or heart rate
- Labored breathing
- Bloating
- Coma
- Death
Oleander (Nerium oleander)
Description
Oleander is a warm season perennial shrub found throughout the Coastal Plains. These shrubs are used as an ornamental and can grow anywhere between 4 to 30 in. tall (Figure 15, left). The leaves may be defined as opposite or whorled, evergreen, and leathery in texture. The flowers are variable in color, showy, fragrant, and produced in large clusters (Figure 15, right).
Toxicity
All animals are susceptible to the digitoxin-type glycosides (oleandroside, nerioside, and others). The toxins are present in all parts of the plant and remain toxic in dry material. These species are very toxic. Less than 4 to 5 lb per 1,000 lb of body weight can be lethal. Symptoms include:
- Severe stomach pain
- Vomiting
- Diarrhea
- Increased pulse or heart rate
- Weakness
- Death
Perilla Mint (Perilla frutescens)
Description
Perilla mint is found throughout many areas of the farm primarily in disturbed areas and long woodland edges or fencerows. This warm season annual broadleaf herb can grow to reach ½ to 2 in. tall. The leaves are defined as opposite, ovate, coarsely serrate, and purple or green in color (Figure 16, left). The leaves have a strong mint smell when crushed. Stems are four-sided and described as freely branched. Flowers are small, white to purple, and grow at the tips of the stems (Figure 16, right).
Toxicity and Symptoms
Cattle and horses will be most affected, but symptoms can be observed in other grazing livestock. The toxin is a furan (perilla ketone) and is present in all parts of the plant, whether green or dry. Most livestock losses will occur in late summer through fall, which coincides with flowering and seed production. The amount of plant material that must be consumed to cause toxicity is unclear. Symptoms will occur 2 to 10 days after exposure.
- Labored, difficult breathing
- Inflammation and fluid in lungs
- Stretch neck and lowered head
- Reluctance to move
- Death
- Birth defects when contaminated material consumed early in gestation
Poison Hemlock (Conium maculatum)
Description
Poison hemlock is a warm season biennial broadleaf weed found throughout the region, especially in moist areas. Leaves are highly branched and look like the common herb, parsley (Figure 17, left). The leaves have a unique smell when crushed that is earthy and may be similar to parsnips (root vegetable). It has hollow spotted stems and can reach up to 7 in. tall. The flowers are white and arranged in clusters (Figure 17, right).
Toxicity and Symptoms
All animals are susceptible to the piperidine alkaloids. All vegetative plant parts and fruit are toxic, but the leaves are the most dangerous in the springtime and the fruits are more dangerous in the fall. Symptoms may appear suddenly or within a few days of consuming even limited amounts (ounces) of the material. Symptoms include:
- Dilated pupils (center of eyes)
- Weakness
- Staggering while walking
- Trembling and jerking motions, may progress to convulsions
- Slow pulse, may progress to rapid pulse or heart rate
- Slow, irregular breathing
- Death from respiratory (breathing) failure
- Chronic ingestion may lead to abnormal fetal (i.e., calf, foal) development
Pokeweed (Phytolacca americana)
Description
Pokeweed is common around fencerows and roadsides on farms. This warm season, perennial broadleaf weed can grow up to 9 in. tall. The leaves are alternate, lanceolate, and light green in color. Stems are fleshy and smooth and may be green to red or purple (Figure 18, left). Pokeweed seedheads are drooping clusters with white to purplish flowers. Ripe fruits are black, round, and juicy (Figure 18, right).
Toxicity and Symptoms
Most animals can be impacted by the toxins, which include oxalic acid, saponin, and alkaloids. These toxins are present in all parts of the plant, but the roots are the most toxic. The toxic level of consumption is unclear. Necropsies may show inflammation of the stomach linings, bleeding from mucous membranes, and a dark liver. Symptoms include:
- Vomiting
- Stomach pain
- Bloody diarrhea
- Convulsions
- Death from respiratory (lung) failure
Rhododendrons and Azaleas (Rhododendron spp.)
Description
Rhododendrons and azaleas are popular perennial ornamental shrubs in the Southeastern US that may invade pastures. There are wild ecotypes found in mountainous areas, in semi-shaded understories, and along waterways. These may grow as dense shrubs or small trees, typically reaching 3 to 10 in. tall. The leaves are defined as alternate, leathery texture, lanceolate to elliptic, and may be evergreen or deciduous depending on species (Figure 19, left). The seedheads are showy and grow in clusters of white, red, pink, or purple flowers (Figure 19, right).
Toxicity and Symptoms
Ruminant animals (cattle, sheep, goats, etc.) are more commonly affected by this toxicity. Horses and pigs can also be impacted but are less likely to consume the material. The toxin, andromedotoxin, is present in all parts of the plant. Poisoning can occur when only 0.02% of the animal’s body weight is consumed. Symptoms include:
- Bloating
- Salivation (slobbering)
- Stomach pain (straining)
- Vomiting
- Weakness can progress to staggering and collapse
Sesbanias (Sesbania spp.)
Description
Sesbanias are tall-growing, annual warm season legumes that are most often found throughout the Coastal Plains. Leaves are pinnately compound and alternate (Figure 20, left). The stems may be woody at the base. Flowers are yellow, often streaked with purple, and are arranged in clusters (Figure 20, right). The seedpods are linear and contain 30 to 40 seeds that will disburse when mature and dry.
Toxicity and Symptoms
All animals are believed to be susceptible to toxicity by the saponic glycoside. All parts of the plant are toxic, but the seeds are most toxic. Unfortunately, animals may selectively graze the seedpods. The toxic level of consumption is unclear, but it is considered highly toxic as death can occur within hours. Necropsies may show seeds in the stomach and severe inflammation in the stomach and intestines. Symptoms are variable but may include:
- Rapid pulse or heart rate
- Shallow breathing
- Stiff gait (walking)
- Walking with arched back
- Diarrhea
- Death
Sicklepod (Senna obtusifolia) and Coffeeweed (Senna occidentalis)
Description
Sicklepod and coffeeweed are warm season annual legumes that are found throughout the southeastern US. Leaves are described as alternate, pinnately compound with 4-6 obovate leaflets (Figure 21, left). Both grow to 1 to 2 in. tall. Flowers are yellow and the plant will form 4- to 8-in.-long sickle-shaped pods (Figure 21, right).
Toxicity and Symptoms
All livestock are susceptible to the toxins which include anthraquinones, emodin glycosides, toxalbumins, and alkaloids. The leaves and stems are toxic, even when dried. The seeds are the most toxic part of the plant. Animals usually avoid this weed unless forage is restricted. The toxic level of consumption is unclear, but it is considered highly toxic as death can occur within 12 hr.
- Diarrhea
- Lack of appetite
- Lethargic (no energy, very tired)
- Weakness
- Tremors
- Dark colored urine
- Death
Sneezeweed (Helenium spp.)
Description
Sneezeweed includes both warm season annual and perennial broadleaf species that grow up to 3 ft tall (Figure 22). Autumn sneezeweed is more common in Piedmont and Mountains of Georgia, while bitter sneezeweed is more common in the Lower Piedmont and Coastal Plains of the state. The leaves are described as narrow, alternate, and simple. The flowers have yellow centers and petals (Figure 22).
Toxicity and Symptoms
All livestock can be affected, but sheep are most often impacted by the toxins, lactone and phenol. These toxins can be found in all parts of the plant, whether green or dry. Toxicity can occur when only 0.25% of the animal’s body weight is consumed. Symptoms include:
- Dullness
- Trembling
- Restlessness
- Stiff gait (walking)
- Salvation (slobbering)
- Weakness
- Severe vomiting may lead to pneumonia
Additional Species for Consideration
The list of weed species addressed in this bulletin does not include all toxic species that you may encounter throughout the state. For example, there are many ornamental species that may spread out of landscaped areas or may be found in wildlife habitats. Furthermore, livestock may accidently access these types of plants if the animals wander outside of their fenced areas.
These species include, but are not limited to, those in the list below. These species have been identified by county Extension agents around Georgia but are yet not considered common threats to forage-based livestock operations.
- Buckeye (Aesculus glabra)
- Daffodils (Narcissus)
- Heliotropes (Heliotropium sp.)
- Ragworts (Jacobaea vulgaris)
- Rattlebox (Crotalaria sp.)
- Red Maple (Acer rubrum)
- Sweetclover (Melilotus sp.)
- Wild mustards (Brassica sp.)
In addition, there are many common weed species that naturally accumulate high levels of nitrates. More information on nitrate toxicity can be found in Extension expert resource C 915, Nitrate Toxicity. High nitrate levels may occur following fertilizer application, variable weather conditions, and plant stress events.
The most common forbs that will accumulate nitrates are listed here.
- Cudweeds (Gnaphalium sp.)
- Docks (Rumex sp.)
- Horsenettle
- Jimsonweed
- Lambsquarter (Chenopodium album L.)
- Nightshades (Solanaceae sp.)
- Pigweeds (Amaranthus sp.)
Integrated Weed Management of Toxic Weed Species
It is important to use an integrated weed management plan for long term control of these species listed in this bulletin. Mechanical and cultural control can be critical components of these plans that improve the efficacy of herbicide applications. These strategies encourage desirable species in the forage canopy and reduce the need for continued herbicide use in the future. Regardless of the chosen control strategy, grazing animals should be removed from the area during treatment. Do not allow animals to return to the affected area until all toxic plant material is removed, dead, or decomposed and they can no longer ingest.
Mechanical Control
Regular mowing before seed maturity may decrease stem diameter, help deplete root carbohydrate reserves, and limit spread of the weed seeds. Mowing after seed maturity will increase the number of plants through seed disbursement.
Cultural Control
Improved cultural management of the pasture or hayfield can limit opportunities for these weed species to invade forage systems. Improved management practices to consider are:
- Recognize and correct nutrient deficiencies in the soil through soil testing and adherence to sampling recommendations
- Correct soil pH following soil testing and sampling recommendations
- Increase grazing or harvest height to 3 in. for bermudagrass, 3 in. for bahiagrass, and 4 in. for tall fescue
- Minimize soil disturbance by discontinuing vertical tillage or aeration
- Improve soil drainage by clearing drainage ditches or installing drainage systems
Each of these management practices will help promote growth and persistence of the desirable forage species. This should result in improved ground coverage which will increase competition for weeds that may try to encroach into your pasture or hayfield. Open gaps in the forage canopy will enable invasion of undesirable weed species.
Chemical Control
Chemical control options are often limited in forage systems, especially in tall fescue or bahiagrass stands. Herbicide options are detailed for grass (Table 1), annual broadleaf (Table 2), biennial or perennial broadleaf (Table 3), and shrub or tree species (Table 4).
Not all products are safe for broadcast use or provide selective control of weeds in all pasture types (Table 5). Unfortunately, only nonselective herbicides are available in some situations. These should be used for spot treatments only to minimize the injury to desirable forages (Table 5).
Tables: Herbicides
| Active ingredient1 | Dallisgrass | Johnsongrass |
|---|---|---|
| 2,4-D | ||
| 2,4-D + Rinskor (florpyrauxifen-benzyl) | ||
| Aminopyralid | ||
| Aminopyralid + 2,4-D | ||
| Aminopyralid + Metsulfuron-methyl | ||
| Aminopyralid + Rinskor (florpyrauxifen-benzyl) | ||
| Dicamba | ||
| Dicamba + 2,4-D | ||
| Glyphosate | Excellent | Excellent |
| Hexazinone | ||
| Imazapic | Fair | Fair to good |
| Metsulfuron-methyl | ||
| Metsulfuron-methyl + Dicamba + 2,4-D | ||
| Metsulfuron-methyl + Chlorsulfuron | ||
| Metsulfuron-methyl + Nicosulfuron | Good to excellent | |
| Paraquat | ||
| Picloram + 2,4-D | ||
| Picloram + Fluroxypyr | ||
| Sulfosulfuron | Excellent | |
| Tebuthiuron | ||
| Triclopyr | ||
| Triclopyr + 2,4-D | ||
| Triclopyr + Fluroxypyr | ||
| 1 Not all products are safe for use in or provide selective control of weeds in all pasture types. Please see table 5 for more information. Note. No rating indicates poor efficacy, and the active ingredient should not be used for this species. | ||
| Active ingredient1 | Cocklebur | Ground cherry | Jimsonweed | Perilla mint | Pokeweed | Sesbania | Sicklepod |
|---|---|---|---|---|---|---|---|
| 2,4-D | Good | Excellent | Fair | Fair | Good | Fair | Good |
| 2,4-D + Rinskor (florpyrauxifen-benzyl) | Excellent | Excellent | Good | Good | Good | Good | Good |
| Aminopyralid | Good | Good | Excellent | Excellent | Good | Excellent | Excellent |
| Aminopyralid + 2,4-D | Excellent | Excellent | Excellent | Excellent | Good | Excellent | Excellent |
| Aminopyralid + Metsulfuron-methyl | Excellent | Excellent | Good | Excellent | Excellent | Excellent | Excellent |
| Aminopyralid + Rinskor (florpyrauxifen-benzyl) | Excellent | Excellent | Excellent | Excellent | Excellent | Excellent | Excellent |
| Dicamba | Good | Good | Fair to good | Good | Fair | Excellent | |
| Dicamba + 2,4-D | Excellent | Fair to good | Good | Excellent | |||
| Glyphosate | Excellent | Excellent | Excellent | ||||
| Hexazinone | Excellent | ||||||
| Imazapic | Good | ||||||
| Metsulfuron-methyl | Good | Fair | Fair | Fair | Good | Good | |
| Metsulfuron-methyl + Dicamba + 2,4-D | Good | Good | Good | Good | Good | Good | Good |
| Metsulfuron-methyl + Chlorsulfuron | Excellent | Good | Fair | Good | Good | Good | |
| Metsulfuron-methyl + Nicosulfuron | Good | Fair | Fair | Fair | Fair | Excellent | |
| Paraquat | |||||||
| Picloram + 2,4-D | Good | Good | Excellent | Excellent | Excellent | Excellent | Excellent |
| Picloram + Fluroxypyr | Good | Good | Good to excellent | Good | Good | Excellent | Excellent |
| Sulfosulfuron | |||||||
| Tebuthiuron | |||||||
| Triclopyr | Good | Good | Fair | Fair to good | Fair to good | Good | Good |
| Triclopyr + 2,4-D | Excellent | Excellent | Fair to good | Fair to good | Good | Good | Good |
| Triclopyr + Fluroxypyr | Good | Good | Fair | Good | Fair to good | Good | Good |
| 1 Not all products are safe for use in or provide selective control of weeds in all pasture types. Please see table 5 for more information. Note. No rating indicates poor efficacy, and the active ingredient should not be used for this species. | |||||||
| Active ingredient1 | Brackenfern | Buttercup | Hemp dogbane | Horsenettle | Milkweed | Poison hemlock | Sneezeweed |
|---|---|---|---|---|---|---|---|
| 2,4-D | Excellent | Fair to good | Fair | Fair | Good | Excellent | |
| 2,4-D + Rinskor (florpyrauxifen-benzyl) | Excellent | Fair to good | Fair | Fair | Excellent | Excellent | |
| Aminopyralid | Excellent | Fair | Excellent | Fair | Good | Excellent | |
| Aminopyralid + 2,4-D | Excellent | Fair to good | Excellent | Fair to good | Good | Excellent | |
| Aminopyralid + Metsulfuron-methyl | Good | Good to excellent | Fair to good | Excellent | Fair to good | Good | Excellent |
| Aminopyralid + Rinskor (florpyrauxifen-benzyl) | Excellent | Fair to good | Excellent | Fair | Excellent | Excellent | |
| Dicamba | Good | Excellent | Good | Fair | Good | ||
| Dicamba + 2,4-D | Excellent | Fair to good | Excellent | ||||
| Glyphosate | Excellent | Excellent | Excellent | ||||
| Hexazinone | Good | ||||||
| Imazapic | |||||||
| Metsulfuron-methyl | Good | Excellent | Fair | Good | |||
| Metsulfuron-methyl + Dicamba + 2,4-D | Good | Excellent | Good | Good | Good | Good | |
| Metsulfuron-methyl + Chlorsulfuron | Good | Excellent | Fair | Good | |||
| Metsulfuron-methyl + Nicosulfuron | Good | Good | |||||
| Paraquat | Good | ||||||
| Picloram + 2,4-D | Excellent | Fair | Good to excellent | Fair to good | Good | Excellent | |
| Picloram + Fluroxypyr | Excellent | Good | Excellent | Good to excellent | Good | Excellent | |
| Sulfosulfuron | |||||||
| Tebuthiuron | Good | ||||||
| Triclopyr | Fair to good | Good | Good | Fair to good | Good | Good | Good |
| Triclopyr + 2,4-D | Fair | Excellent | Fair to good | Fair to good | Good | Good | Good |
| Triclopyr + Fluroxypyr | Fair to good | Excellent | Excellent | Fair to good | Good to excellent | Good | Good |
| 1 Not all products are safe for use in or provide selective control of weeds in all pasture types. Please see table 5 for more information. Note. No rating indicates poor efficacy, and the active ingredient should not be used for this species. | |||||||
| Active ingredient1 | Black cherry | Black locust | Castor bean | Chinaberry | Oleander | Rhododendrons |
|---|---|---|---|---|---|---|
| 2,4-D | Excellent | Good | Good | |||
| 2,4-D + Rinskor (florpyrauxifen-benzyl) | ||||||
| Aminopyralid | Good | |||||
| Aminopyralid + 2,4-D | Good | |||||
| Aminopyralid + Metsulfuron-methyl | Good | |||||
| Aminopyralid + Rinskor (florpyrauxifen-benzyl) | Good | |||||
| Dicamba | Good | Good | ||||
| Dicamba + 2,4-D | Excellent | Excellent | ||||
| Glyphosate | Excellent | Excellent | Excellent | Excellent | Excellent | |
| Hexazinone | Excellent | Good | ||||
| Imazapic | ||||||
| Metsulfuron-methyl | Good | Good | ||||
| Metsulfuron-methyl + Dicamba + 2,4-D | ||||||
| Metsulfuron-methyl + Chlorsulfuron | ||||||
| Metsulfuron-methyl + Nicosulfuron | ||||||
| Paraquat | ||||||
| Picloram + 2,4-D | ||||||
| Picloram + Fluroxypyr | Good | |||||
| Sulfosulfuron | ||||||
| Tebuthiuron | Good | Good | ||||
| Triclopyr | Good | Excellent | Good | Good | Good | |
| Triclopyr + 2,4-D | Good | |||||
| Triclopyr + Fluroxypyr | Good | Excellent | ||||
| 1 Not all products are safe for use in or provide selective control of weeds in all pasture types. Please see Table 5 for more information. Note. No rating indicates poor efficacy, and the active ingredient should not be used for this species. | ||||||
| Active ingredient | Tall fescue | Bermudagrass | Bahiagrass | Spot-treat only1 |
|---|---|---|---|---|
| 2,4-D | ✓ | ✓ | ✓ | |
| 2,4-D + Rinskor (florpyrauxifen-benzyl) | ✓ | ✓ | ✓ | |
| Aminopyralid | ✓ | ✓ | ✓ | |
| Aminopyralid + 2,4-D | ✓ | ✓ | ✓ | |
| Aminopyralid + Metsulfuron-methyl | ✓* | ✓ | ||
| Aminopyralid + Rinskor (florpyrauxifen-benzyl) | ✓ | ✓ | ✓ | |
| Dicamba | ✓ | ✓ | ✓ | |
| Dicamba + 2,4-D | ✓ | ✓ | ✓ | |
| Glyphosate | ✓ | |||
| Hexazinone | ✓ | ✓ | ||
| Imazapic | ✓* | |||
| Metsulfuron-methyl | ✓* | ✓ | ||
| Metsulfuron-methyl + Dicamba + 2,4-D | ✓* | ✓ | ||
| Metsulfuron-methyl + Chlorsulfuron | ✓* | ✓ | ||
| Metsulfuron-methyl + Nicosulfuron | ✓* | ✓ | ||
| Paraquat | ✓ | |||
| Picloram + 2,4-D | ✓ | ✓ | ✓ | |
| Picloram + Fluroxypyr | ✓ | ✓ | ✓ | |
| Sulfosulfuron | ✓ | ✓ | ||
| Tebuthiuron | ✓ | ✓ | ✓ | |
| Triclopyr | ✓ | ✓ | ✓ | |
| Triclopyr + 2,4-D | ✓ | ✓ | ✓ | |
| Triclopyr + Fluroxypyr | ✓ | ✓ | ✓ | |
| 1 These products are considered nonselective herbicides and should be used for spot treatments only. *Boxes marked with an asterisk indicate that this species may sustain injury from the indicated active ingredient. | ||||
Acknowledgments
The authors would like to acknowledge input from external scientists and specialists for their assistance on updating the efficacy ratings. These contributors include Dr. Sam Ingram (Corteva), Dr. John Willis (Envu), Dr. Jason Belcher (Envu), Mr. Jack Conroy (Envu), and Mr. Jerry McGukin (Envu). Additionally, the authors recognize the contributions of Drs. Dennis Hancock and Patrick McCullough to a previous version of this resource.
