Long-term Effects on Chemical Control of Big Sagebrush

Abstract

In 1960 and 1961, big sagebrush (Artemisia tridentata) on four cattle ranges in the Bighorn Mountains was sprayed with 2,4-D. By 1971, the canopy cover of big sagebrush was 8-42% of the pretreatment levels, seedling density ranged from 5.7-11.3 plants/120 ft2, herbage production was below the pretreatment levels with the proportion of graminoids about equal to that prior to spraying. Effects of grazing deferment for as long as 3 years after spraying could not be detected.