If plant tissue is killed when using a systemic herbicide, what happens to translocation within the plant?

If plant tissue is killed when using a systemic herbicide, what happens to translocation within the plant?

• A. It will be translocated throughout the plant.
• B. It will not be translocated throughout the plant.
• C. It will be rapidly degraded in the killed tissue.
• D. It will move only to the roots.

Answer: (B)

Systemic herbicides rely on the plant’s vascular system (xylem and phloem) to move to growing points and sinks, and this transport requires living, functional tissue. If the herbicide kills tissue, those transport pathways are disrupted or blocked in that area, so the chemical can no longer be moved throughout the rest of the plant. In other words, translocation ceases beyond the dead tissue. The idea that it would still move everywhere or only to the roots isn't consistent with the need for intact, living pathways, and rapid degradation in the killed tissue speaks to the chemical’s fate rather than the movement through the plant.

Systemic herbicides rely on the plant’s vascular system (xylem and phloem) to move to growing points and sinks, and this transport requires living, functional tissue. If the herbicide kills tissue, those transport pathways are disrupted or blocked in that area, so the chemical can no longer be moved throughout the rest of the plant. In other words, translocation ceases beyond the dead tissue. The idea that it would still move everywhere or only to the roots isn't consistent with the need for intact, living pathways, and rapid degradation in the killed tissue speaks to the chemical’s fate rather than the movement through the plant.