Which statement best describes contact and systemic herbicides?

• A. Contact herbicides are absorbed and translocated; systemic do not move
• B. Systemic herbicides do not move within the plant
• C. Contact herbicides do not move within the plant and only kill touched parts
• D. Systemic herbicides are absorbed and translocated

Answer: (D)

Movement within the plant is what separates contact from systemic herbicides. Systemic herbicides are absorbed by plant tissues and then moved through the plant’s vascular system, reaching new growth, roots, and meristems so the entire plant can be affected. This translocation is what lets a single treated leaf or root area kill the whole plant.

In contrast, contact herbicides stay where they’re applied and do not move to other parts of the plant. They kill only the tissue they touch, so good coverage is essential to control the plant.

Therefore, the statement that systemic herbicides are absorbed and translocated best captures the primary difference between the two types. The other options describe some aspects correctly but don’t consistently describe how systemic herbicides behave or they misstate movement within the plant.