Cut stem applications are made by cutting the Japanese knotweed stem between the first and second internode, and delivering the herbicide into the “well” created by cutting the internode in half. Approximately 10 mls are delivered into the well using this method. Spillage is a risk and non-target species can be harmed by run-off. Depending upon the site, several herbicide options (listed below) exist for this application method.
| Herbicide | Application | Rate |
|---|---|---|
| Roundup Pro® | Upland & Riparian Sites | 50% + 50% water |
| Aquamaster | Upland & Riparian Areas | 50% + 50% water |
| Roundup Pro + Arsenal® (Growing Season only) |
Upland Sites Only | 50% + 25% + 25% water |
| Roundup Pro + Garlon 3A™ (Growing Season only) |
Upland Sites | 50% + 25% + 25% water |
Note:
Cut stem applications have proven to be about 80% effective on mature plants. Applications made during early season growth often results in partial control.
For re-growth applications, allow plants to reach at least four (4′) feet in height, before making the second cut stem or stem injection application. Waiting for this height, insures the second treatment will be effective.
Although effective, this method requires cutting down the plant, which increases the effort and potential for spreading by fragmentation.