Which herbicide is noted for being highly toxic to many plants and long-lived in soil?

Tordon is recognized for its high toxicity to a wide range of plant species and its persistence in the soil. The active ingredient in Tordon, picloram, is a systemic herbicide that can be taken up by the roots and transported throughout the plant. This means it can effectively control many broadleaf weeds and some woody plants. Its long half-life in soil, which can extend for several years, adds to its effectiveness in preventing the regrowth of target species. This makes Tordon particularly useful in areas where long-term weed control is required, but it also necessitates caution in its application to avoid damage to desirable plants due to its residual effects.

In contrast, glyphosate is a non-selective herbicide effective against a variety of plants but is not known for its long-term persistence. Paraquat is a highly toxic herbicide with a short soil life, while 2,4-D primarily affects certain broadleaf plants and does not possess the same level of persistence or toxicity to a wide spectrum of species that Tordon does.