diuron (Diuron 4L (and others))

Diuron (Karmex DF, Diuron 4L)
WSSA Group 7: photosystem II inhibitor

Diuron has pre-emergence and some post-emergence activity. Weeds should not be >2 inches in height or diameter or else post-emergence control may be compromised.

Diuron should be applied during the rainy period (from about November 1 to February 15 in eastern Washington), but not to frozen ground. Spring applications may not be as effective unless rains fall soon after application to incorporate the herbicides; however, heavy rains following a spring application may result in plant injury. Application to vineyards under sprinkler irrigation can be hazardous.

Apply as a banded application to vineyards that have been established for at least 3 years and that have vines more than 1.5 inches in diameter. Do not apply to vineyards with shallow, coarse, sandy, or gravelly soils or to soils with less than 1% organic matter. Serious herbicide injury to grape roots has occurred when this herbicide is applied under improper conditions. Do not apply more than 5 lbs of Karmex DF per acre in a single use; do not apply more than 10 lbs per acre per year. Do not apply more than 4 qts of Diuron 4L per acre in a single use; do not apply more than 8 qts per acre per year.

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 diuron on Grapes

Pre-Emergence (Weeds)

Post-Emergence (Weeds)