Soil-applied herbicides are only translocated in the photosynthetic stream (phloem).

• A. True
• B. False

Answer: (B)

Soil-applied herbicides can be absorbed by plant roots and are often transported throughout the plant through both the xylem and the phloem. The xylem primarily carries water and dissolved nutrients from the roots to the leaves, while the phloem transports carbohydrates and other organic nutrients produced during photosynthesis.

Herbicides that are absorbed by roots may initially move through the xylem to the above-ground plant parts, especially when the plant is actively transpiring. This allows the herbicides to reach various tissues, including leaves and stems, where they can inhibit growth or disrupt metabolic processes.

Thus, stating that soil-applied herbicides are only translocated in the photosynthetic stream (phloem) is incorrect. The correct understanding is that these herbicides use both vascular systems to distribute their active ingredients throughout the plant, allowing for effective weed control.