Soil-applied herbicides are only translocated in the photosynthetic stream?

• A. True
• B. False

Answer: (B)

Soil-applied herbicides work primarily through root uptake, and they can be translocated throughout the plant via the xylem and phloem. The assertion that they are only translocated in the photosynthetic stream is inaccurate because while photosynthesis happens in the leaves and involves the phloem to transport sugars, soil-applied herbicides also enter the plant through its roots and move systemically.

After absorption by the roots, these herbicides may be carried upward through the xylem, where they can affect various plant tissues, including stems and leaves, independent of the photosynthetic process. Additionally, certain herbicides can also be translocated downwards or laterally to other parts of the plant, depending on their chemistry and the plant's physiological conditions. Therefore, the system of movement in plants is more complex than just the photosynthetic stream, allowing for a wider range of herbicidal activity and effectiveness.