Pendimethalin (Prowl)
WSSA Group 3: microtubule assembly inhibitor
Prowl H2O and Prowl 3.3 EC are pre-emergence herbicides that are particularly effective against grasses. Prowl 3.3 EC is only labeled for non-bearing vineyards, while Prowl H2O is labeled for both non-bearing and bearing fruit crops. Apply directly to the ground in dormant grapes before bud-break and before weeds emerge. Overhead moisture is required within 7 days for herbicide activation. Do not apply to newly transplanted vines until the soil has settled and no cracks are present. If applying before transplanting, do not allow treated soil to come into contact with roots. Do not apply during or after bud swell in the spring. Do not apply over the tops of vines with leaves or open buds. Both labels include specific instructions regarding pre-plant or surface incorporated, surface-applied, and pre-emergence applications. The use rate is determined by the weeds requiring control and the length of control needed.
At least one weed species 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 pendimethalin on Grapes
Pre-Emergence (Weeds)
| Target | Rate of application | REI | PHI | MOA | Eff. | Notes |
|---|---|---|---|---|---|---|
| Annual Broadleaf Weeds | 2.4-4.8 qt | 24 | - | 3 | "Prowl 3.3 EC application" Prowl 3.3 EC is labeled only for nonbearing vineyards; Prowl H2O may be used in nonbearing or bearing vineyards. Do not apply to newly transplanted vines until the soil has settled and no cracks are present. | |
| Annual Grasses | 2.4-4.8 qt | 24 | - | 3 | "Prowl 3.3 EC application" - Prowl 3.3 EC is labeled only for nonbearing vineyards; Prowl H2O may be used in nonbearing or bearing vineyards. Do not apply to newly transplanted vines until the soil has settled and no cracks are present. |