Growing on Plastic Mulch
Plasticulture is a common practice for okra since it is a warm season crop. Some hand weeding may be needed in the planting holes as okra grows slowly at first after transplanting. Apply the plastic at least 2–3 weeks prior to planting. Kill the weeds between the mulch prior to setting the okra plants on the plastic.
Stale Seedbed
The following herbicides are nonselective and are used to control weeds that are present in a field prior to planting or before the crop emerges, which is especially useful for the Stale Seedbed Technique (see the Weed Management section for more information).
- glyphosate (Roundup Power Max): PHI 14d, REI 4h, Group 9.
- paraquat (Gramoxone SL 3.0*): PHI 21d, REI 48h, Group 22. *Restricted use: Applicators must complete an EPA-approved paraquat training every 3 years: https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training-certified-applicators.
- pelargonic acid (Scythe): PHI 1d, REI 12h, Group 0.
Preemergent Herbicides (before weeds germinate)
HRAC Group 3:
trifluralin (Treflan HFP): 1 to 2 pt/A; REI 12h. 1 application per year. Apply and incorporate before or within 24 hours of planting; a second incorporation pass in the opposite direction may be required.
HRAC Group 14:
sulfentrazone (Aquesta 4F): 2.25 to 12 fl oz/A; REI 12h. 1 application per year. Apply banded or broadcast before transplanting.
Pre- and Postemergent Herbicides
HRAC Group 5:
- prometryn (Caparol 4L): 1.5 to 3 pt/A; PHI 14d, REI 12h. Do not exceed 3 pt/A per year. Apply after planting but before crop emerges or as a directed spray when crop is in the 7- to 9-leaf stage.
HRAC Group 27:
- mesotrione (Callisto): 3 to 6 fl oz/A; PHI 28d, REI 12h. 1 application per year. Apply as a banded row middle treatment OR a hooded post-direct treatment when crop is at least 3” tall (but not both). If banding, leave 6” to each side of the planted row unsprayed. Okra must be at least 3” tall. Contact with crop will cause damage.
Postemergent Herbicides (after weeds germinate)
HRAC Group 0:
pelargonic acid (Scythe): 3% to 10% solution; PHI 1d, REI 12h. Apply as a vegetative burndown during site preparation, prior to crop emergence from soil, as a directed and shielded spray during crop growth.
HRAC Group 1:
clethodim (Select Max): 9 to 16 fl oz/A; PHI 3d, REI 24h. Do not exceed 64 fl oz/A per year. Apply to actively growing grasses.
sethoxydim (Poast): 0.5 to 1.5 pt/A; PHI 14d, REI 12h. Do not exceed 5.5 pt/A per year. Apply to actively growing grasses. BASF has stopped production and will discontinue the registration at the end of 2027.
HRAC Group 2:
halosulfuron (Sandea): 0.5 to 1.5 oz/A; PHI 30d, REI 12h. Do not exceed 2 oz/A per year. Apply between rows for control of broadleaf weeds. Contact with crop will cause damage.
HRAC Group 9:
glyphosate (Roundup Power Max): 10 fl oz to 3.1 qt/A; PHI 14d, REI 4h. Do not exceed 5 qt/A per year. Apply during fallow intervals and up until 3 days prior to planting, or to row middles with a hooded or shielded sprayer or with wiper applicator. Apply a minimum of 3 days before planting. Spray contact can cause crop death. Spray additive recommendation varies with formulation—see label.
HRAC Group 14:
carfentrazone (Aim EC): 0.5 to 2 fl oz/A; PHI 0d, REI 12h. Do not exceed 6.1 fl oz/A per year. Apply as preplant burndown no later than 1 day before transplanting, or to row middles of emerged crops with hooded sprayers. Contact with crop will cause damage.
HRAC Group 22:
paraquat (Gramoxone SL 3.0*): 1.3 to 2.7 pt/A; PHI 21d, REI 48h. Do not exceed 5.3 pt/A per year. 1 application may be made before crop emergence, and 2 may be made after crop emergence. Spray contact can cause plant death. May be fatal if swallowed or inhaled. *Restricted use: Applicators must complete an EPA-approved paraquat training every 3 years: https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training-certified-applicators.