Paraquat (Gramoxone SL 3)
WSSA Group 22: photosystem I electron diverter
Foliage applied, contact herbicide used to control annual broadleaf and grass weeds and to suppress perennial weeds. Apply as a directed, shielded spray to the base of vines when grasses and other weeds are growing actively and new growth is from 1 to 6 inches high. With mustard-type annual weeds, apply before leaves exceed 1 inch in diameter. Avoid contact of spray or mist on new foliage or green shoots as severe vine injury may result. Add a nonionic surfactant or crop oil concentrate according to label; avoid anionic formulations that react in the tank to form insoluble precipitates. Paraquat is corrosive to aluminum. Spray in 50 to 200 gallons of water for thorough coverage of the weeds. Five applications are allowed per year. This is a restricted-use herbicide. Do not ingest or inhale spray mist. Wear protective clothing, face shields and respirators when mixing and during application.
No weed species are resistant to this mode of action documented to occur in ID, OR, or WA; data from Heap, I.
The International Survey of Herbicide Resistant Weeds. Available at www.weedscience.org
Usage for paraquat dichloride on Grapes
Sucker Management
| Target | Rate of application | REI | PHI | MOA | Eff. | Notes |
|---|---|---|---|---|---|---|
| Sucker Management | 1.7-2.7 pt | 48 | - | 22 | Can be used for sucker management. Suckers must be less than 8 inches long. |
Post-Emergence (Weeds)
| Target | Rate of application | REI | PHI | MOA | Eff. | Notes |
|---|---|---|---|---|---|---|
| Annual Broadleaf Weeds | 1.7-2.7 pt | 48 | - | 22 | Use a shield or wrap plant when spraying around young trees or vines. | |
| Annual Grasses | 1.7-2.7 pt | 48 | - | 22 | Use a shield or wrap plant when spraying around young trees or vines. | |
| Perennial Grasses | 1.7-2.7 pt | 48 | - | 22 | Use a shield or wrap plant when spraying around young trees or vines. |