Utility arborists were the first among those caring
for trees to peer over the fence at agricultural and
horticultural fields and ponder the potential of
growth regulators used in those cropping systems as
a tool for tree maintenance. Mechanical trimming,
which was the sole means to combat the unrelenting
growth of trees into overhead electrical wires, was a
costly operation and a chemical alternative was very
attractive. Hence, the electric utility industry provided
funding in the late 1950s for research on chemical
control of tree growth following trimming for electric
line clearance. Results of that early research led to the
use of napthaleneacetic acid (NAA), a synthetic auxin,
painted onto the surface of pruning wounds