Spraying Tarweed Infestations on Ranges Newly Seeded to Grass

Abstract

A high elevation, tarweed-infested range which had been newly seeded to grass was sprayed with 3 rates of 2,4-D at 2 growth stages of the seeded grass. 2,4-D at 0.5 lb./acre killed over 97% of the tarweed and 1 and 2 pounds killed 99 and almost 100, respectively. Rate of spraying when grasses had 1 to 2 leaves did not affect numbers of grass plants but killed more tarweed than did spraying when grasses had 2 to 4 leaves.