A comparison of the effects of foliar applications of glyphosate and fluroxypyr on Madeira vine, Anredera cordifolia (Ten.) van Steenis
S.L. Prior and T.R. Armstrong, Alan Fletcher Research Station, Department of Natural Resources, PO Box 36, Sherwood, Queensland 4075, Australia.
A study was conducted at Beechmont in Queensland from March to November 1998 to compare the efficacy of one, two and three foliar applications of various concentrations of glyphosate and fluroxypyr ester on Madeira vine (Anredera cordifolia). Repeat applications were made at 3-monthly intervals. Counts of Madeira vine density within experimental quadrats were made following treatment applications in autumn, winter and spring 1998. Fluroxypyr applied at 1 and 2 g L-1 water and Glyphosate 360® applied at 3.6 and 7.2 g L-1 water were equally effective in controlling all vine stems present at application.
Fluroxypyr at 1 and 2 g L-1 water were the only treatments which significantly reduced the number of new stems of the plant in the months between applications. Quadrats treated with fluroxypyr at its lowest effective concentration (1 g L-1 water) had less Madeira vine and other broad-leaved weeds, but contained competitive grass species such as kikuyu, which, from a management perspective, may be beneficial by providing competition. Canopy establishment can eventually shade such species out. Removal of competition through the use of the non-selective herbicide glyphosate may favour re-invasion from Madeira vine subterranean tubers, especially if applied at a time of year where translocation activity is not high.
Though the pooled population density was significantly lower from April to July 1998, there were no significant changes within the population trajectories in quadrats treated with fluroxypyr at 1 g L-1 water, indicating no preferential time for spraying.
Model predictions indicated that monthly applications of fluroxypyr at 1 g L-1 water at this particular site would be required to stabilize the population (in the absence of recruitment of new individuals), and subsequently reduce it at a rate dependent upon the mortality of the subterranean tuber 'bank'. The length of time over which herbicide applications would be required would have to be determined empirically.
Plant Protection Quarterly (2001) 16 (1) 33-36.