Group 5 and 15 herbicides
Mode of Action
Primextra II Magnum contains two active weed control ingredients - S-Metolachlor and Atrazine.
These ingredients are taken up by the shoots and roots of the plants. In annual grasses and yellow nutsedge, the shoots are the primary site of uptake for S-Metolachlor, while in broadleaf weeds it enters via the roots and shoots. Atrazine is actively absorbed by roots and foliage, and acts by blocking photosynthesis, thereby stopping energy for growth.
Both ingredients effectively inhibit weed growth by translocating to the weed's growth points and restricting shoot and root development. With S-Metolachlor weeds fail to emerge, weed seedlings are deformed, they suffer from trapped leaves, or leaves emerge underground. Atrazine stops the growth of seedling weeds.
Primextra II Magnum Herbicide is both a Group 5 and a Group 15 herbicide. Any weed population may contain or develop plants naturally resistant to Primextra II Magnum Herbicide and other Group 5 and/or Group 15 herbicides. Use tank mixtures or follow up with post-emergent herbicides from a different group when such use is permitted.