Does 24d kill pines

Yes, 2,4-D (2,4-dichlorophenoxyacetic acid) can harm or kill pines and other conifers if applied improperly or in high concentrations. It is a broadleaf herbicide, but conifers are sensitive to it, especially young trees. Care should be taken to avoid drift or direct application to pines when using 2,4-D in areas where they are present. Always follow label instructions to minimize the risk of damage.