The effect of herbicides and burning treatments in killing serrated tussock (Nassella trichotoma (Nees) Hack.)

Abstract

A logarithmic sprayer was used over a ten-month period to apply the herbicides 2,2-DPA and TCA, to serrated tussock (Nassella trichotoma (Nees) Hack.), burnt before spraying, burnt after spraying, and unburnt. Winter application of low rates of herbicides, followed by spring burning, appeared to give better kills than autumn burning followed by winter spraying. Spraying after autumn burning appeared to give better kills than spraying unburnt tussock, but only where the burning took place a short time before spraying. Unburnt tussock appeared to be most successfully killed by applying herbicides in the summer months. 2,2- DPA was approximately five times as efficient in killing serrated tussock as TCA. The minimum rates of herbicides necessary to kill serrated tussock at various times of the year and under different burning treatments were established.