The influence of the application of grass herbicides on the production of dryland medic and lucerne pastures in the Rûens area of the southern Cape

Abstract

A trial was conducted over a period of three seasons in which the advantages of the removal of grass weeds from dryland lucerne and medic pastures were determined. The pastures were grazed at four stocking rates, i.e. 6, 8, 10 and 12 non‐lactating Merino ewes and wethers/ha. Two herbicide treatments, an unsprayed control and a grass herbicide treatment were compared for three seasons. The herbicide treatment consisted of two applications, one each of fluazifop‐butyl and propyzamide, respectively, during the first two seasons. On the lucerne pastures the removal of the grass weeds resulted in an increased wool production and, to a lesser extent, ADG, which also resulted in an economic advantage. On the medic pastures, however, the removal of the grass weeds did not result in any animal production or economic advantage. Herbicide treatment, however, did result in a higher medic pod yield, which should increase the productive lifespan of these pastures.