What should an applicator look for on the label when trying to kill noxious perennial weeds by targeting the roots?

When targeting noxious perennial weeds, it's essential for an applicator to choose a herbicide that effectively translocates within the plant. Translocated herbicides are designed to move throughout the plant's system, including down to the roots. This characteristic allows these products to reach and kill the root system, which is vital for controlling perennial weeds that can regrow from remnants if only the foliage is treated.

The other categories don't achieve the same effectiveness in this context. Contact herbicides primarily affect the parts of the plant that they directly touch and do not move through the plant to reach the roots. Residual herbicides remain active in the soil for a time after application; however, they may not effectively kill established roots of perennial weeds. Nonpersistent herbicides break down quickly and may not provide the necessary longevity to ensure root kill. Thus, a translocated product is the most suitable choice for effectively managing noxious perennial weeds through targeting their root systems.