Control methods against Acer negundo
Acer negundo (Sapindaceae) is a tree native to North America which was introduced in Europe in the 17th century and which has been used as an ornamental tree, particularly in urban environments. A. negundo is widely spread in Europe. The species forms monospecific stands outcompeting riparian native trees.
In Southwestern France, several mechanical control methods were tested. Although the most efficient control methods would consist in the use of herbicides, these were not tested as most substances are not allowed in wetland areas.
The following control methods were tested: stem-base cut, 1 m height cut, girdling (removal of a strip of bark around the tree trunk), and stem cut with an application of juglone (an organic compound used as an herbicide). Tree mortality was assessed during 3 years. Girdling resulted in the highest mortality rate, varying from 32% to 100% according to the site, suggesting that with a longer application time this could be reach full success in the field.
Sources
Merceron N, Lamarque LJ, Brogniez S, Ducournau Y, Buyle S, Degrave L, Roudie J, Felis O, Moreau A, Vernin P, Guengant Y, Delzon S, Porté AJ (2014) Control of Acer negundo L.: insights from experimental and physiological studies. Abstract of the 4th International Symposium on Environmental Weeds and Invasive Plants, Montpellier (FR), 2014-06-19/23.