Evaluation of herbicides for the control of the environmental weed bridal creeper (Asparagus asparagoides)
G.H. Pritchard, Keith Turnbull Research Institute, Agriculture Victoria, Department of Natural Resources and Environment, PO Box 48, Frankston, Victoria 3199, Australia.
Five herbicide trials were conducted on the environmental weed bridal creeper (Asparagus asparagoides (L.) W.Wight) growing in native vegetation in southern Victoria. Glyphosate at 180 g and 360 g 100 L-1 and metsulfuron methyl at 1 to 6 g 100 L-1 applied in winter-spring gave 88- 99.5% control of above-ground growth after one year and 87-94% control two years after application.
Re-application one or two years after an initial application increased this control to 91-99%. Control of above-ground growth with either herbicide was little affected by concentration. Glyphosate had more effect on the root system than metsulfuron methyl. A single application of glyphosate at 180 g 100 L-1 reduced the root system by 78%, while one year after a repeat application this concentration reduced the root system by 90-99%. Glyphosate at 360 g 100 L-1 reduced the root system by 95% after a single application and two applications did not improve on this result. A single application of metsulfuron methyl at 1.5 g 100 L-1 reduced the root system by 32% but 3 g 100 L-1 gave no reduction. One year after a repeat application at 1.5 g, 3 g and 6 g 100 L-1 root reductions were 41-92%, 29-53% and 74% respectively.
Control with both herbicides was better with August application (flowering) than with July (flower bud) or October (green berries) application. Chlorsulfuron and a commercial mix of thifensulfuron methyl plus metsulfuron methyl gave effective foliage control but offered no improvement over metsulfuron methyl in root control. Tribenuron methyl gave less foliage control than the other herbicides.
Plant Protection Quarterly (2002) 17 (1) 17-26.