What is a key distinction between contact and translocated herbicides?

The choice that emphasizes the key distinction between contact and translocated herbicides is accurate in stating that contact herbicides do not reach underground plant parts. Contact herbicides function by affecting the plant tissues that they directly touch, which means they primarily work on the foliage or other above-ground parts of the plant. As a result, they do not penetrate the plant systemically or affect underground parts like roots or rhizomes.

In contrast, translocated herbicides are designed to move throughout the plant after being absorbed through the foliage and are effective in targeting all parts of the plant, including roots and other underground structures. This systemic action allows them to eliminate entire plants, making them particularly effective against perennial weeds.

Understanding this distinction is crucial for effective weed management strategies, where the choice between using contact or translocated herbicides can significantly influence the results based on the type of plants being targeted.