Huisache Control by Power Grubbing

Abstract

Low-energy mechanical grubbing of huisache densities of 181 to 689 trees/ha, 1.8 to 2.6 m tall, reduced the canopy by 90 to 96% and killed 65 to 81% of the treated plants on the Coastal Prairie. Grubbing time was a linear function of huisache density and varied from 0.5 hr/ha for removal of 181 plants to 1.6 hr/ha for removal of 689 plants. Resprouting rapidly occurred from residual stem tissues if huisache stems were not grubbed to the first lateral root. Grubbing depth had to be increased as basal trunk diameter increased to ensure huisache mortality. Plants 1 to 4 cm in diameter were killed by grubbing 5 to 10 cm deep; plants with diameters of 6 to 15 cm required grubbing as deep as 20 cm for elimination. Soil disturbed by grubbing revegetated naturally within 15 months after treatment. Standing grass crop was unaffected 20 months after grubbing; but the relative proportions of cool-season grasses, Texas wintergrass and Canada wildrye, were increased, especially in the pits.