Which of the following herbicides is not effective against velvetleaf?

The identification of which herbicide is not effective against velvetleaf is crucial for managers dealing with this particular weed. Velvetleaf, a plant that can be troublesome in agricultural settings, responds variably to different herbicides.

RoundUp, which contains glyphosate, is a non-selective herbicide that effectively controls a wide range of broadleaf weeds, including velvetleaf. Therefore, it supports efficient management of such troublesome plants.

2,4-D is a selective herbicide primarily targeting broadleaf weeds and is also proven to be effective against velvetleaf, particularly in certain formulations and application contexts.

Dicamba is another herbicide effective at controlling broadleaf weeds, including velvetleaf, and is often used in combination with other chemicals to enhance its efficacy.

Choosing "None of the above" indicates that all mentioned herbicides (RoundUp, 2,4-D, and Dicamba) are effective for controlling velvetleaf, aligning with the recognized effectiveness of each herbicide in managing this weed species. Consequently, all options listed provide valid methods for controlling velvetleaf, confirming that the response indicating no ineffective herbicides is correct.