Is Creeping Indigo Creeping Into Your Pastures?
Creeping Indigo (Indigofera spicata) Creeping indigo is a broadleaf non-native legume that came from Africa 90 years ago. The recent rise of awareness has concerned many Florida horse owners. It is found throughout Central and North Florida, becoming the dominant herb in some pastures. Creeping indigo can be found in high traffic areas, such as pathways, roadsides, or heavily grazed pastures.
Plant Description: Creeping indigo is a prostrate plant (branches lie low to the ground) with a shallow crown. Stems can grow up to six feet long with 5 to 7 alternate leaflets.Flowers form at the base of the leaflets forming numerous pink to red blooms.The perennial root of the plant is difficult to pull up by hand because of its 2 foot taproot.Creeping indigo is spread by the seeds of the plant. The plant produces clusters of 1 inch long downward pointing seed pods containing 4-8 seeds.Numerous fuzzy hairs can be found on the leaves, stem, and seed pods.
Toxins: There are two toxins in creeping indigo that can cause neurologic and non-neurologic symptoms to all livestock, but horses are more susceptible. The progression of symptoms will present itself days to weeks later. Equine deaths have been reported in recent years and can potentially be life threatening to all livestock that consume the plant.
3- Nitropropionate acid (3-NPA) causes the irreversible neurologic symptoms, including depression, head pressing in a corner of the stall, compulsive walking, and crossing of the limbs with a “crablike gait”. The effects of 3-NPA are non-reversible and the toxin metabolizes quickly making it hard to detect in the blood serum.
Indospicine is the toxic agent of the plant that causes non-neurologic symptoms include hyper salivation, dehydration, light sensitivity, weight loss, pale mucous membranes, labored breathing, corneal ulcerations, ulcers in the mouth and tongue, and digital pulses without laminitis.
There is no effective treatment for creeping indigo poisoning. Quickly remove the horse from the pasture where creeping indigo is present and consult your veterinarian.
Prevention and Management: Monthly scouting year round is necessary to prevent creeping indigo from becoming a problem in your pastures. If you need help identifying creeping indigo you can contact your County Extension Agent. GrazonNext HL is the effective herbicide for creeping indigo control in pastures. Its active ingredient is aminopyralid. Broadcast rate is 24 ounces per acres and spot-treatment rate is 0.5 to 1.0 ounces per gallon of water. Both of these rates will give excellent control, but once sprayed, the dead plant can retain its toxicity and should be removed. Retreatment will be necessary.Do not spread manure or use for compost because of the residual from the spray and possible seed dispersal.
The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication do not signify our approval to the exclusion of other products of suitable composition. All chemicals should be used in accordance with directions on the manufacturer’s label.