Chemical control of broad-leaved pepper tree (Schinus terebinthifolius Raddi)
F.D. Panetta and T.M.D. Anderson, Alan Fletcher Research Station, Department of Natural Resources, PO Box 36, Sherwood, Queensland 4075, Australia
Summary
Field experiments were carried out in south-eastern Queensland between 1995 and 1998 in order to assess the efficacy of various products and methods of application in controlling broad-leaved pepper tree (Schinus terebinthifolius Raddi), a serious invader of semi-natural and natural habitats. A screening experiment demonstrated that Starane 200®, Grazon DS®, Tordon 75-D®, Banvel 200®, Glyphosate 360®, Hyvar X® and Arsenal® were promising as foliar applications. Tordon TCH®, Glyphosate 360, Brushoff® and Arsenal demonstrated good activity as cut stump treatments, and Tordon 75-D was effective when stem injected. Further detailed investigations were made with some of these products.
Starane 200 at 1:300 and Grazon DS at 1:300 both gave ≥95% control when applied as foliar sprays in winter. However, the activity of both products was markedly reduced when applied during summer. While Glyphosate 360 at 1:1, Arsenal at 1:20 and Tordon TCH at 1:20 all seemed to give total or near-total kills at 12 months after application as cut stump treatments (in winter or summer), by 26 months suckering had occurred in all treatments. Cut stump treatments with these herbicides thus appear to give suppression only. Injection of 10 mL of Tordon-75 D (1:30) with a Sidewinder stem injector resulted in 86% mortality at nine months after treatment. This last method of application shows considerable promise, given the small amounts of chemical required and the minimal risk of off-target damage in environmentally sensitive areas.
Plant Protection Quarterly (2001) 16 (1) 26-31.