Why inject below the third node for Japanese Knotweed?
During recent test trial periods on Japanese knotweed, evaluators noted that when plants were injected above the third internodes, or segments, that only the upper portion of the canes were affected. The day after application, the area above the injection site had wilted and collapsed. On applications made at the same location within the first two segments, above the J. Knotweed root crown, no herbicide symptoms were observed during the first week. After that period, plants showed herbicide symptomology of leaf curling and yellowing. This may suggest that injection applications made above the second internode region are unable to completely translocate herbicide to the roots prior to disruption or collapse of the conductive tissue. This phenomenon occurred in the spring time when most photosynthate is moving up in the plant as opposed to later in the year as photosynthate is being sent to the roots and rhizome structures. In those situations, aggressive re-growth occurs later in the sa
