Increased options for controlling mikania vine (Mikania micrantha)with foliar herbicides

摘要

Mikania micrantha Kunth (mikania vine) is a highly invasive tropical weed that was first discovered in Australia in 1997, and has been the target of a nationally cost-shared weed eradication program since 2003. Field crews have been effectively treating the weed with herbicide solutions containing 1 g a.i. L~' of fluroxypyr. During the eradication program there have been limited opportunities to test alternative foliar herbicides or rates. A newly discovered infestation provided sufficient immature vines to compare the effectiveness of eight herbicide treatments.Herbicide solutions containing 0.7 g a.i. LH of fluroxypyr, 1.02 g a.i. L"1 of triclopyr, 1.98 g a.i. LH of triclopyr and 1.05 g a.i. L"' of triclopyr + 0.35 g a.i. L"' of picloram + 0.028 g a.i. L"1 of aminopyralid were equally effective as the currenttreatment containing 1 g a.i. L"1 of fluroxypyr. In these treatments, average mikania presence declined from over 98% of sub-quadrats before treatment to 0-2% presence five months after treatment. Three other treatments were significantly less effective.On average, mikania vine was present in 75% and 31% of sub-quadrats treated with solutions containing 0.06 g and 0.12 g a.i. L-1 of metsulfuron-methyl respectively. It was also present in 88% of sub-quadrats in plots treated with 3.6 g a.i. LH of glyphosate, which was similar to untreated control plots (94%). Several rates of fluroxypyr and triclopyr based herbicides were identified as cost effective alternatives to the current treatment and provide more options for treating this weed.