Artichokes (Globe)

Ed Peachey
March 2018

clethodim (Select Max)

Rate 0.068 to 0.12 lb ai/A (9 to 16 fl oz/A) depending on growth stage of grass.

Time Usually before weeds are 4 to 8 in tall, but depends on grass species present. Apply to actively growing grasses that are not stressed by drought

Remarks Annual and perennial grass control. The preharvest interval is 5 days. Always add crop oil concentrate at 1% v/v. Apply no more than 16 fl oz/A in a single application and no more than 64 fl oz/A (0.49 lb ai/A) per season. Make repeat applications with at least a 14-day interval.

Caution Do not tank mix with nitrogen fertilizers

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Cyclohexanedione

clomazone (Command 3ME)

Rate 1 lb ai/A (2.6 pints/A product)

Time Apply as a broadcast application to the soil surface before weeds and asparagus spears emerge. If spears have emerged, make an application after a clean harvest (removal of all spears). Cover any exposed spears with soil prior to application. Make application at least 14 days prior to harvest.

Remarks Apply in a minimum of 10 gallons of water per acre prior to spear emergence in the spring. Make only one application per year and do not apply more than 1 lb ai/A per application. Off-site movement of spray drift or vapors of clomazone can whiten or yellow some plants. Before applying, check adjacent properties and avoid spraying within 1,200 ft of desirable plants. Overhead moisture after application is required to move herbicide into soil. All use is at the grower’s risk; growers should review the vegetable disclaimer at the end of the label before using.

Caution Preharvest interval is 14 days. Do not allow particle or vapor drift. Clomazone is a persistent herbicide. Note crop rotation restriction intervals on the label. Clomazone has not been tested on newly planted asparagus in the PNW and growers should proceed with caution and test a small area to ensure crop safety before using on larger plantings.

Site of action Group 13: inhibits DOXP synthase (inhibits isoprenoid pathway)

Chemical family Isoxazolidinone

diuron (Karmex 80DF)

Rate 1.6 to 3.2 lb ai/A (2 to 4 lb/A)

Time Apply to established plants in late fall or early winter, after last cultivation and before weed seedlings emerge.

Remarks Direct spray to cover area between rows and around the base of artichoke plants. Avoid spray contact with plants. Make a single application per year.

Caution Crop injury may result if soil organic matter is <1%.

Site of action Group 7: photosystem II inhibitor

Chemical family Substituted urea

flumioxazin (Chateau SW)

Rate 0.13 to 0.19 lb ai/A (4 to 6 oz/A product) depending on whether annual or perennial artichokes

Time Annual varieties: apply to artichoke beds no later than 2 days prior to transplanting. Irrigation or rainfall after transplanting is necessary to activate after transplanting, but do not irrigate before transplanting. Perennial varieties: applied to artichokes after cut back of mature plants. Make applications within 2 days after cut back and prior to artichoke emergence. Application after the artichokes have begun to crack, or are emerged, will result in crop injury. Application should not be made when artichokes have begun to emerge (cracking).

Remarks Minimize soil movement during transplanting to maximize weed control.

Caution Do not apply more than 6 oz/A during a single growing season. Application to artichoke foliage may result in unacceptable crop injury.

Site of action Group 14: inhibits protoporphyrinogen oxidase (PPO)

Chemical family N-phenylphthalimide

halosulfuron-methyl (Sandea)

Rate 0.047 to 0.094 lb ai/A (1 to 2 oz/A)

Time Apply when nutsedge has 3 to 5 leaves.

Remarks Apply between the rows of perennial artichokes as a directed spray to avoid contact with foliage. If plastic is used on the planted row, adjust equipment to keep the application off the plastic. Due to the risk of crop damage, all such use is at the end user/grower’s risk.

Caution Application of Sandea may cause significant, temporary stunting and delay maturity of artichokes if sprayed directly.

Site of action Group 2: acetolactate synthase (ALS) inhibitor

Chemical family Sulfonylurea

oxyfluorfen (Goal 2XL and Tender)

Rate 1 to 1.5 lb ai/A (4 to 6 pints/A 2XL)

Time Apply as a directed treatment or during midsummer dormant and renovation period, either preemergence or early postemergence, as a single treatment or in split applications 8 to 10 weeks apart. Acts as a contact herbicide, either directly on broadleaf weeds or at soil surface as weeds emerge.

Caution Do not exceed 6 pints/A per year. Preharvest interval is 5 days.

Site of action Group 14: inhibits protoporphyrinogen oxidase (PPO)

Chemical family Diphenylether

paraquat (Gramoxone Inteon, Firestorm)

Rate 0.625 to 1.0 lb ai/A (2.5 to 4 pints/A Inteon; 1.7 to 2.7 pints/A Firestorm)

Time Directed spray to plants large enough to avoid injury.

Remarks Maximum 3 applications and 8 pints/A per season. 7 days between applications. Preharvest interval is 24 hrs.

Site of action Group 22: photosystem I electron diversion

Chemical family Bipyridilium

pendimethalin (Prowl H2O)

Rate Up to 8.2 pints/A (3.9 lb ai/A) as a broadcast spray.

Time Pre-transplant to artichoke, 1 to 2 days before transplanting.

Remarks Preharvest interval is 60 days for 3 pt/A rate and 200 days for rates greater than 3.1 pt/A

Caution Do not apply over the top of, or to foliage of artichokes because crop injury may occur.

Site of action Group 3: microtubule assembly inhibitor

Chemical family Dinitroaniline

sethoxydim (Poast)

Rate 0.47 lb ai/A (2.5 pints/A)

Time Apply to actively growing grasses. Always add crop oil concentrate.

Remarks May be applied by air. Feeding restriction.

Caution Do not exceed 5 pints/A per year. Preharvest interval is 7 days.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Cyclohexanedione