does anyone know how much root-pruning quinclorac does, if any? Could this economically be used as a pre-m, in split, high-volume spray applications in spring? After this heat and drought, I've been wondering if root-inhibiting pre-ms are having an unacceptable amount of adverse affects on my turf during undesirable weather. All the pre-emerged lawns around here are totally dead, while the natural ones look decent (but full of crabgrass and weeds). What do you think?