Sucker Control in NonDormant Grape

carfentrazone-ethyl (Aim EC)

Rate 0.031 lb ai/A (2 fl oz/A Aim EC)

Remarks Suckers must be young and succulent. Control is enhanced with COC (1%) or NIS (0.25%).

Caution Care must be taken not to allow spray mist to contact desirable fruit, foliage or green stem tissue. Do not use on seedlings.

Site of action Group 14: inhibits protoporphyrinogen oxidase

Chemical family Triazinone

oxyfluorfen (Goal 2XL, Galigan)

Oregon and Washington only, wine and processing grapes only

Rate 0.25 to 0.5 lb ai/A (1 to 2 pints/A Goal 2XL)

Time Apply as a directed ground spray to suckers growing from plant base up to 12 inches tall.

Remarks Apply to suckers less than 12 inches long. Immature, expanding leaves at time of contact are most susceptible. Com- plete sucker control requires removing canes by hand. The highest rate, or a second application, may be required for acceptable control or suppression of grape suckers. Not for use on table grapes. Can be tank mixed with glufosinate (Rely) or paraquat (Gra- moxone) to enhance sucker control.

Caution Do not exceed 6 pints/A per season. Preharvest interval is 60 days. Can be applied to nondormant grapes up to 3 weeks after bloom.

Site of action Group 14: protoporphyrinogen oxidase inhibitor

Chemical family Diphenylether

pyraflufen (Venue)

Rate 0.004 to 0.006 lb ai/A (3 to 4 fl oz product/A)

Remarks Apply as a directed application to actively growing suckers. A spray tank adjuvant is recommended. Preharvest inter- val is 0 days.

Caution This product is a contact, nonselective, broadleaf herbicide. Avoid contact with desirable foliage, green bark, or fruit.

Action in plant Inhibits protoporphyrinogen oxidase (PPO) that disrupts cell membranes.

Site of action Group 14: protoporphyrinogen oxidase inhibitor

Chemical family Phenylpyrazole

tiafenacil (Gamma)

Rate 0 .02 to 0.06 lb ai/A (0.5 to 1.5 oz/A Gamma)

Time Best performance observed on weeds less than 6 inches tall.

Remarks Tiafenacil is a broad spectrum non-selective postemergence herbicides. Methylated seed oil, crop oil concentrate, and ammonium sulfate must be added for optimum results. It can be used in tank-mixes with glufosinate, glyphosate and other herbi- cides. Treat small suckers for best results. Wait at least 14 days before reapplying.

Caution Preharvest interval is 7 days. Do not exceed 4.5 oz/A of Gamma (0.2 lb ai/A tiafenacil) per season. Do not apply to grapes established less than 2 years.

Site of action Group 14: protoporphyrinogen oxidase inhibitor

Chemical family N-Phenyl-imides