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 7d, REI 4h, Group 9.
- paraquat (Gramoxone SL 3.0*): 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 3:
- pendimethalin (Prowl H2O): 1.5 to 3 pt/A; REI 24h. 1 application per year. Preplant surface apply, or apply within 60 days of planting and incorporate.
- trifluralin (Treflan HFP): 1 to 2 pt/A; REI 12h. 1 application per year. Apply and incorporate before planting; a second incorporation pass in the opposite direction may be required.
HRAC Group 5:
- linuron (Lorox DF): Up to 2 lb/A; REI 24h. Dry peas only. 1 application per year. Apply after planting but before crop emergence.
HRAC Group 13:
- clomazone (Command 3ME): 21.3 fl oz/A; REI 12h. Succulent peas only. 1 application per year. Apply to the soil surface after seeding but before crop emergence. Temporary partial whitening of leaf or stem tissue may occur but should not affect yield.
HRAC Group 14:
- sulfentrazone (Aquesta 4F): 2.25 to 8 fl oz/A; REI 12h. 1 application per year. For dry shelled peas: Apply from 60 days prior to planting up to 3 days after planting but before soil cracking; can be incorporated. For succulent peas: Apply preemergence; do not incorporate. Wait a minimum of 7 days after application to plant in coarse-textured soils with less than 1.5% organic matter.
HRAC Group 15:
- s-metolachlor (Dual Magnum): 1 to 2 pt/A; REI 24h. Do not exceed 2 pt/A per year. Apply within 14 days of planting and incorporate, after planting but before crop emerges, or after crop has reached the first trifoliate growth stage.
Pre- and Postemergent Herbicides
HRAC Group 5:
- metribuzin (Metribuzin): PHI 50d, REI 12h. Apply 0.25–0.5 lb/A per application. Do not exceed 0.6 lb/A per year. Can be applied in a single preemergent application 0.25–0.5 lb/A in at least 10 gal/A of spray. Apply before or after planting. Incorporate 1"–2” into the soil with cultivation or water through rainfall irrigation. One post-emergent broadcast application may be made per season when weeds are less than 2’’ tall or wide and before crop is 6’’ tall. For spring peas, apply 0.16–0.3 lb/A and for winter peas, apply 0.25–0.3 lb/A. Apply in a minimum of 20 gal/A of spray.
HRAC Group 14:
- saflufenacil (Sharpen): 1 to 2 fl oz/A; PHI 3d, REI 12h. Edible podded and succulent peas only. Do not exceed 2 fl oz/A per year. Apply and incorporate up to 1 week before planting, or up to 3 days after planting but before soil cracking. Can be applied as a harvest aid to dry field peas. May result in delayed crop emergence and stunting if cool wet conditions occur after application.
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, or as a directed and shielded spray during crop growth.
HRAC Group 1:
- clethodim (Select Max): 9 to 15 fl oz/A; PHI 21d for edible podded, 30d for dried shelled and succulent shelled peas, REI 24h. 1 application per year. Apply before bloom, to actively growing grasses.
- quizalofop (Assure II): 4 to 12 fl oz/A; PHI 60d dry, 30d succulent, REI 12h. Do not exceed 14 fl oz/A per year. Apply to actively growing grasses.
- sethoxydim (Poast): 0.5 to 2.5 pt/A; PHI 30d for dry, 15d for succulent, REI 12h. Do not exceed 4 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:
- imazamox (Raptor): 3 or 4 fl oz/A; REI 4h. English peas and dry peas only. 1 application per year. Apply when English peas are at least 3” tall but before 5 nodes or flowering, or to dry peas before flowering. Apply at least 1 hour before rainfall or overhead irrigation. Some English pea varieties are sensitive. Must be used with Basagran for dry peas.
HRAC Group 6:
- bentazon (Basagran 5L): 0.8 to 1.6 pt/A; PHI 10d for succulent peas, 30d for dry peas, REI 48h. Do not exceed 3.2 pt/A per year. Apply when crop as 3 pairs of leaves or 4 nodes. Leaf yellowing, bronzing, speckling, or burning may occur but should not affect yield.
HRAC Group 9:
- glyphosate (Roundup PowerMax): 10 fl oz to 3.1 qt/A; PHI 7d, 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. For dry peas can also spot treat or use preharvest, but do not use both on the same field in the same year. 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 up to 1 day after direct-seeding, or to row middles of emerged crops with hooded sprayer. Contact with crop will cause damage.
HRAC Group 22:
- paraquat (Gramoxone SL 3.0*): 0.8 to 2.7 pt/A; REI 48h. Do not exceed 8 pt/A per year. Apply before, during, or after planting, but before emergence as a banded or broadcast application, or as a harvest aid for dry peas. 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.