True or False: 2,4-D and dicamba are effective herbicides against common cocklebur and velvetleaf.

The assertion is true; 2,4-D and dicamba are both effective herbicides against common cocklebur and velvetleaf. These herbicides belong to the category of synthetic auxins, which mimic natural plant hormones and can disrupt the normal growth patterns of broadleaf weeds like common cocklebur and velvetleaf.

2,4-D is particularly effective as it targets a wide array of broadleaf weeds and can lead to their effective control when applied at the recommended stages of growth. Similarly, dicamba is known for its strong activity against many problematic broadleaf species, making it a suitable option for managing common cocklebur and velvetleaf in agricultural fields.

Understanding the modes of action of these herbicides is key. Both are categorized as selective, which means they can target certain weed species while sparing many grasses. Additionally, effective application timing, adherence to labeled rates, and environmental conditions play vital roles in their success, but these factors do not negate the inherent efficacy of these products against the stated weeds.

By focusing on the effectiveness of the herbicides, it becomes clear why the assertion of their efficacy is indeed true, contrary to the choice indicating otherwise.