Carolina nightshade (
Solanum carolinense), also known as horsenettle, is a perennial weed that is a member of the nightshade (
Solanaceae) family. It is a common contaminate of horse pastures and poor quality hay bales in the southeastern United States. When in pastures, horsenettle is often difficult to get rid of, due to it's deep roots and prickly stems and leaves.
Horsenettle Toxic Components
Horse nettle is poisonous to horses in fresh or dried form, as it contains highly toxic alkaloids, the most meaningful being solanine. Solanine is a glycoalkaloid that affects the horse's central nervous system and gastrointestinal tract. Horses generally won't eat this plant unless they have nothing else to eat.
What Horsenettle Looks Like
- Height:up to 3 ft
- Stem: Angled at the nodes and covered with prickles and hairs. It often becomes woody with age.
- Leaves: Green, oblong to ovate-shaped, with wavy teeth or lobes. The short petioles, midveins and lateral veins are covered with short yellow prickles. Leaves also emit a potato-like odor when crushed.
- Flowers: Occur in clusters of 5-petaled, pale violet to white, star-shaped flowers which have a yellow center. The flowers bloom throughout the summer, from May through September.
- Fruits: Smooth, globular, tiny berries that are initially green. The berries turn yellow as they mature and become wrinkled after drying. Inside the fruit, a foul-smelling pulp surrounds numerous flat, round, yellow seeds 1/16 to 1/8 inch (1.5 to 3 mm) across. The average number of seeds per fruit is about 85, and one plant may produce as many as 100 fruits.
- Root: Deep, spreading rootstocks
- Drowsiness
- Unthrifty Condition
- Loss Of Appetite
- Dilated Pupils
- Difficulty Breathing
- Loss Of Coordination
- Depression
- Convulsions
- Weakness
- Paralysis
- Unconsciousness
- Abdominal Pain
- Diarrhea
- Death
CHEMICAL CONTROL: Systemic herbicides are effective against horsenettle and should be applied to mature plants in late summer or fall. After herbicide treatment, horsenettle should not be mowed for at least two weeks—the time required to translocate the chemicals into the roots. Similarly, fall herbicides should be applied at least two weeks before expected frost.
MECHANICAL CONTROL
Mowing at thirty-day intervals. The best time for the first mowing is right after horsenettle has come into full bloom, about thirty days after shoot emergence Root reserves are at their lowest right after flowering, and forcing the plant to produce new top growth will further deplete its energy reserves. Continually cutting off the top growth during regular hay harvest will weaken the root system, making it more vulnerable to herbicides. Rotating an infested field into grass or clover hay for one year allows this combination of treatments.
