Woody Plant Control in the Post Oak Savannah of Texas With Hexazinone

Abstract

Hexazinone, applied as spheres or pellets (1.27 cm in diameter) in grid patterns (1.5 or 3 m spacings) at 2 or 4 kg/ha effectively controlled post oak and blackjack oak in east central Texas. The herbicide also appeared promising for control of water oak, American elm, and downy hawthorne. Willow baccharis and winged elm appeared to be moderately susceptible to 2 kg/ha of the herbicide and were controlled by 4 kg/ha. Yaupon canopies were initially reduced by the herbicide but had begun to recover by the second or third growing season after application and replaced the oaks as the primary limitation to range improvement following treatment, regardless of hexazione rate applied. Saw greenbrier, mustang grape, southern dewberry, American beautyberry, and woolly-bucket bumelia were not controlled by hexazinone.