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*): REI 48h, Group 22. Rutabaga only. *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 1.5 pt/A; REI 12h. Turnip greens only. 1 application per year. Apply and incorporate before planting; a second incorporation pass in the opposite direction may be required.
HRAC Group 14:
sulfentrazone (Aquesta 4F): 8 fl oz/A; REI 12h. Turnip only. 1 application per year. Apply after crop has emerged, 40–60 days before harvest.
Postemergent Herbicides (after weeds germinate)
HRAC Group 0:
pelargonic acid (Scythe): 3% to 10% solution; PHI 1d, REI 12h. Apply for vegetative burndown during site preparation, prior to crop emergence from soil, as a directed and shielded spray, as a harvest aid, or post-harvest. Contact with crop will cause damage.
HRAC Group 1:
clethodim (Select Max): 9 to 16 fl oz/A; PHI 30d, REI 24h. Do not exceed 64 fl oz/A per year. Apply to actively growing grasses.
sethoxydim (Poast): 0.5 to 2.5 pt/A; PHI 14d, REI 12h. 1 application per year. Apply to actively growing grasses. BASF has stopped production and will discontinue the registration at the end of 2027.
HRAC Group 4:
clopyralid (Stinger): 0.33 to 0.5 pt/A; PHI 15d for tops, 30d for roots, REI 12h. Turnip only. 1 application per year. Apply broadcast after the crop has emerged. Spray additives are not recommended.
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, prior to planting, at planting, before crop has emerged, or to row middles with a hooded or shielded sprayer or wiper applicator. For rutabaga, can also be applied over-the-top of the crop with a wiper applicator.
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 season. Apply to row middles of emerged crops with hooded sprayers, including crops grown on mulch or plastic. Contact with crop will cause damage.
HRAC Group 22:
paraquat (Gramoxone SL 3.0*): 1.3 to 2.7 pt/A; REI 48h. Turnip only. Do not exceed 8 pt/A per year. Apply before, during, or after planting but before crop emergence. 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.