Techniques for chemical control of invasive palm trees in protected areas in the São Paulo metropolitan region.
Invasive alien species harm native plant communities by directly eliminating native species or inhibiting their regeneration. There is evidence that the exotic palm trees Livistona chinensis and Archontophoenix cunninghamiana, which colonize Atlantic Forest remnants, threaten the successional processes of native vegetation and, therefore, must be controlled. In this study we assessed the efficacy of glyphosate at chemically controlling invasive populations. The herbicide Roundup Transorb R (30%) was injected into the stem of 30 individuals of each species and the dose was adjusted according to the size of the palm. Senescence symptoms were monitored weekly until all individuals had died, which happened after 18 weeks for L. chinensis and 29 weeks for A. cunninghamiana. Glyphosate proved to be an effective herbicide for both species. Priority should be given to using glyphosate to eliminate large adult palm trees first, since they are responsible for producing the most propagules.