Effects of mowing and spraying of 2,4,5-T on blackberry (Rubus fruticosus agg.) and pasture species

Abstract

In a field trial in southern Victoria, boom spraying with 2,4,5-T gave a higher level of control of blackberry than mowing, and mowing in addition to spraying did not improve (P = 0.05) the level of control. In a second trial, spraying was superior to mowing although the difference was smaller than in the first trial, and less marked, and the combination of mowing and spraying resulted in a greater reduction in the percentage ground cover of blackberry. Sprayed thickets were colonized by grasses and weedy species but not by Trifolium repens, which is a basic component of pastures in areas where blackberry is often a weed. It is concluded that repeated mowing, or boom spraying with 2,4,5-T, and topdressing with fertilizer are only moderately successful in attempting to replace blackberry with a productive pasture. This is attributed to the difficulty in killing the extensive root system of blackberry and the effect of 2,4,5-T on T. repens.