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 2.0*): REI 48h, Group 22. 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.
- pelargonic acid (Scythe): PHI 1d, REI 12h, Group 0.
Preemergent Herbicides (before weeds germinate)
HRAC Group 0:
bensulide (Prefar 4E): 5 to 6 qt/A; REI 12h. May be used under plastic. Grass control only.
HRAC Group 3:
ethalfluralin (Curbit EC): 3 to 4.5 pt/A; REI 24h. 1 application per year. Apply up to 2 days after seeding but before the crop emerges, or as a banded spray between rows after crop emergence or transplanting. Do not use during cold, wet weather or crop injury or stunting may occur.
pendimethalin (Prowl H2O): Up to 2.1 pt/A; PHI 35d, REI 24h. Melon only. Do not exceed 4.2 pts/A per year. Apply as a shielded spray between rows before transplanting or before a seeded crop has emerged. Or apply between plastic beds before holes are punched in plastic for transplanting. Maintain 6” unsprayed ground on either side of stem, vines, or seeding location.
trifluralin (Treflan HFP): 1 to 2 pt/A; PHI 60d watermelon, 30d all other cucurbits, REI 12h. 1 application per year. Apply when plants have 3–4 true leaves as a directed spray between the rows.
HRAC Group 5:
- terbacil (Sinbar WDG): 2 to 4 oz/A; PHI 70d, REI 12h. Watermelon only. Do not exceed 4 oz/A per year. Apply after direct-seeding but before crop emerges, or before transplanting. Can be applied under plastic or between rows of plastic. Contact with crop will cause damage.
HRAC Group 13:
clomazone (Command 3ME): 6.4 to 10.7 fl oz/A melons, 6.4 to 16.2 fl oz/A cucumbers; PHI 30d cucumbers, REI 12h. 1 application per year. Apply after seeding but before emergence, or before transplanting. Be sure to place the roots of transplants below the treated soil. Do not apply to soil that will be covered by black plastic. Partial, temporary whitening of leaf or stem tissue may be occur after crop emergence but should not affect yield.
HRAC Group 14:
sulfentrazone (Aquesta 4F): 3 to 8 fl oz/A; REI 12h. Melons only. 1 application per year. Apply from 48 hours before planting up to just before seedling emergence. If seedlings are close to soil surface or have emerged, do not apply solution directly on top of the crop. Do not use on soils that have less than 1% organic matter.
HRAC Group 15:
s-metolachlor (Dual Magnum): PHI 30d, REI 24h. MA, ME, and NH only. Restricted label: Make sure the label for your state is available for download before using this product. Full label instructions are supplied to growers who apply through the website www.syngenta-us.com/labels/indemnified-label-login and agree to a waiver of liability. Main target weeds for this registration are galinsoga and yellow nutsedge.
Pre- and Postemergent Herbicides
HRAC Group 2:
halosulfuron (Sandea): 0.5 to 1 oz/A; PHI 14d cucumber, 57d watermelon, REI 12h. Do not exceed 2 oz/A per year. Can be applied pre- and post-planting to direct-seeded and transplanted crops, on bare ground and plastic mulch, with restrictions. For post-planting applications on plastic mulch, apply between beds only. For control of nutsedge, either apply before and again after the crop emerges, or twice after the crop emerges (cucumbers and muskmelons only). Contact with crop will cause damage. May cause temporary stunting. Heavy rains following application or organophosphate use will increase the potential for crop injury.
Postemergent Herbicides (after weeds germinate)
HRAC Group 0:
- pelargonic acid (Scythe): 3%–10% solution; PHI 1d, REI 12h. Can use preplant or as a directed and shielded spray. Contact with crop will cause damage.
HRAC Group 1:
- clethodim (Select Max): 9 to 16 fl oz/A; PHI 14d, REI 24h. Do not exceed 64 fl oz/A per year. Apply to actively growing grasses.
sethoxydim (Poast): 1.5 pt/A; PHI 3d cucumber and muskmelon, 14d other melons, REI 12h. Do not exceed 3 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 9:
- glyphosate (Roundup Power Max): 10 oz to 3.1 qt/A; PHI 14d, REI 4h. Do not exceed 5 qts/A per year. Apply during fallow intervals and no less than 3 days prior to planting, or to row middles with a hooded or shielded sprayer or wiper applicator. Spray contact can cause plant 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 burndown no later than 1 day before transplanting or 7 days before direct-seeding, or apply to row middles of emerged crops with hooded sprayers. Contact with crop will cause damage.
HRAC Group 22: Electron Diverter
- paraquat (Gramoxone SL 2.0*): 1.3 to 2.7 pt/A; REI 48h. Do not exceed 8 pts/A per year. Apply before or after planting, but before crop emergence or transplanting. 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.