NOTES: For the herbicides listed below, one product trade name and formulation is provided for each active ingredient along with preharvest interval (PHI), restricted entry interval (REI), resistance management group number, and example of rates and special instructions. In many cases, there are other products available with the same active ingredient. However, not all products with the same active ingredient are registered for use in a crop. Always check the product label to be sure that the crop is listed before using.
Preemergent Herbicides (before weeds germinate)
- flumioxazin (Chateau SW): REI 12h, Group 14. For perennial artichokes, apply 6 oz/A per application, only 1 application allowed per year. Must be applied within 2 days of planting crowns or cutback of mature plants, before crop emergence. For annual or newly established artichokes, apply 4 oz/A per application, only 1 application allowed per year. Must be applied no later than 2 days before transplanting. Activate with water through irrigation or rainfall after transplanting, but not before.
- pendimethalin (Prowl H2O): PHI 60d or 200d, REI 24h, Group 3. Apply up to 3 pt/A (60 day PHI) or 3.1-8.2 pt/A (200 day PHI) per application. Do not exceed 8.2 pts/A per year. Apply to the soil surface at least 1-2 days before transplanting artichokes.
Pre- and Postemergent Herbicides
- oxyfluorfen (Goal 2 XL): PHI 5d, REI 24h, Group 14. Apply 4-6 pt/A per application, multiple applications are allowed, 8-10 weeks apart. Do not exceed 6 pts/A per year. Apply as a directed spray to the soil surface between the rows and at the base of artichoke plants in a minimum of 40 gal/A of spray. Can be applied after ditching operations until weeds reach the 8-leaf stage. Contact with spray or drift will cause injury to artichoke fronds or severe injury to buds or flowers.
Postemergent Herbicides (after weeds germinate)
- carfentrazone-ethyl (Aim EC): PHI 0d, REI 12h, Group 14. Apply 0.5-2 oz/A per application, multiple applications allowed per year. Do not exceed 6.1 oz/A per year. Apply as a hooded application, as a preplant burndown no later than 1 day before transplanting.
- diquat (Reglone): PHI 1yr, REI 24h, Group 22. Apply 1.5-2 pt/A per application. Only use during site preparation prior to planting. Spray weeds 1-6” tall, retreatment may be necessary to control established weeds. Apply in a minimum of 15 gal/A of spray. Do not allow spray to contact crop stems, foliage, or fruit.
- glyphosate (Roundup Power Max): PHI 14d, REI 4h, Group 9. Apply 10 oz to 3.1 qts/A per application. Do not exceed 5 qts/A per year. Rate depends on target weeds, see label for rate selection. Avoid contact with any part of the artichoke or crop death could occur. May apply fallow intervals, prior to planting or transplanting, at planting, or before crop has emerged. Could cause injury when applied prior to transplanting or direct-seeding into plastic mulch. Remove residual product from plastic mulch with a 0.5” of water through irrigation or rainfall prior to planting.
- halosulfuron (Sandea): PHI 5d, REI 12h, Group 2. Apply 1-2 oz/A per application, up to 2 applications allowed per year. Do not exceed 2 oz/A per year. Apply uniformly with a minimum of 15 gal/A of spray. Apply to the ground on either side of the row while avoiding crop foliage. May cause significant temporary stunting and delay maturity of artichokes. Use only if you believe the utility outweighs the potential injury. Can also be applied in row middle, avoiding contact with plastic if planted in plastic. If targeting nutsedge, apply with the plants are in the 3- to 5-leaf stage. Weed control may be reduced without the use of a surfactant.
- paraquat (Gramoxone SL 2.0*): REI 12h-24h, Group 22. Apply 1.7-2.7 pts/A per application, up to 3 applications allowed per year, a minimum of 7 days apart. Do not exceed 5.3 pts/A per year. Apply between rows as a directed shielded spray after crop establishment, when weeds are less than 6” tall in 20-100 gal/A of spray. May be fatal if swallowed or inhaled. Applicators must complete an EPA-approved paraquat training listed on the following website https://www.epa.gov/pesticide-worker-safety/paraquat-dichloride-training.... The training must be completed a minimum of every three years.
- pelargonic acid (Scythe): PHI 1d, REI 12h, Group 0. Apply a 3-10% solution (3-10 gallons per 100 gallons of spray). Apply in 75-200 gal/A of spray. Can use before planting, or as a directed and shielded spray during crop growth. Avoid contact with foliage or crop damage may occur. Spray to wet, but do not allow runoff of spray solution.
- sethoxydim (Poast): PHI 7d, REI 12h, Group 1. Apply up to 2.5 pt/A per application, multiple applications are allowed, a minimum of 14 days between applications. Do not exceed 5 pts/A per year. Apply to actively growing grasses. Use with crop oil concentrate (2 pt/A) or methylated seed oil (1.5 pt/A). Note that crop oil can cause injury under hot and humid conditions. Can also be used as a spot-spray by mixing 1-1.5% (1.3-1.9 oz/gal) Poast and 1% v:v crop oil concentrate (1.3 oz/gal). Spray to wet, but do not allow runoff of spray solution.