Dichlobenil (Casoron CS, Casoron 4G)
WSSA Group 29: inhibits cell wall synthesis
A soil-active herbicide for long-term or seasonal control of most weeds, dichlobenil can suppress the growth of some perennials (Canada thistle, quackgrass, field bindweed and bermudagrass), although higher use rates are recommended.
Dichlobenil is most effective when applied in the fall, at the beginning of the rainy season (about November 15 to February 15 in eastern Washington) and when the ground is cool. Application before a rain will reduce volatility and improve weed suppression. Do not apply when the ground is frozen. Applications can be made in the spring up to about May 1 (when the soil surface is still 60°F or below). If an application is not followed closely by rain, either incorporate into the soil surface mechanically or use a light sprinkler irrigation (0.5 to 1 inch of water); do not overwater to the point of runoff. This chemical can be used in sprinkler-irrigated vineyards but injury can occur; use the lower rate of chemical and reduce the amount of water applied in the first irrigation to 0.5 to 1 inch of water. Consult agricultural authorities before applying dichlobenil to sprinkler-irrigated vineyards. Avoid use on coarse, sandy, gravelly, or shallow soils because of potential injury. Do not apply to recently cultivated or loose soil or when the soil surface is wet and warm (above about 70°F); delay application until the soil is settled and dry. Do not apply to young vines until four weeks after transplanting, preferably in the winter after transplanting. Casoron CS can be applied after vines are 12 months old.
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 dichlobenil on Grapes
Pre-Emergence (Weeds)
| Target | Rate of application | REI | PHI | MOA | Eff. | Notes |
|---|---|---|---|---|---|---|
| Annual Broadleaf Weeds | 1.4-2.8 gal | 12 | - | 20 | Casoron CS is a broad spectrum pre-emergent and early post-emergent herbicide. Activity is best when temperatures are below 70*F, and when soil is moist. Ingredient is activated after rainfall or irrigation. Casoron SC should only be used in vineyards after they have been established for at least 12 months. Do not use in nurseries. | |
| Biennial and Perennial Broadleaf Weeds | 1.4-2.8 gal | 12 | - | 20 | "Casoron SC application" - Casoron SC after vines have been transplanted for at least 12 months. |