Range Site and Grazing System Influence Regrowth after Spraying Honey Mesquite

Abstract

Honey mesquite (Prosopis glandulosa Torr. var. glandulosa) regrowth on the Texas Experimental Ranch in the Rolling Plains of northwest Texas was evaluated 8 years after aerial spraying with 2,4,5-T. Regrowth on rocky hill, rolling hill, and deep upland range sites was measured under two systems of grazing management: heavily stocked (4.86 ha/AU), continuous grazing; and, moderately stocked (6.48 ha/AU), deferred-rotation grazing. Canopy cover, density, and topgrowth production of honey mesquite regrowth were significantly greater under moderate, deferred-rotation grazing than under heavy, continuous grazing of the deep upland site. Honey mesquite density, canopy cover, and topgrowth production did not differ between grazing systems on the rocky hill site. Regrowth on the rolling hill site was usually intermediate between the rocky hill and deep upland sites. Honey mesquite plant density, topgrowth production, canopy cover, and rate of new stem initiation were greater under moderately stocked, deferred-rotation than heavily stocked, continuous grazing. Averaged across grazing systems, regrowth, regardless of variable evaluated, was greatest on the deep upland site.