Local grasses for the control of the invasive vine Mikania micrantha

Aims Mikania micrantha (Asteraceae) is an invasive vine found in tropical and southern subtropical Asian and the Pacific Islands. The current methods used to control this vine are inadequate, which warrants the development of ecologically sustainable methods. Therefore, we investigated the ability of four grass species to prevent the invasion of M. micrantha, with an ultimate goal of developing ecologically sustainable control methods for widespread application. Methods The clumps of native grass species from China (Panicum incomtum, Pennisetum purpureum, Saccharum arundinaceum and Microstegium vagans) were established. We sowed M. micrantha seeds and transplanted the seedlings into the grass clumps to examine whether the clumps could eliminate the new M. micrantha plants. In addition, we transplanted M. micrantha into existing grass clumps to examine whether the grass clumps could prevent the re-invasion of M. micrantha. Furthermore, we grew M. micrantha with P. incomtum and P. purpureum in the field to examine whether the grasses could outcompete M. micrantha. Important Findings M. micrantha seeds had difficulty germinating in the grass clumps, and all seedlings died within 3 months. It was difficult for the vine to survive in the existing grass clumps. Our field experiment showed that the coverage of M. micrantha was significantly lower than that of the grass species in the first year, and the vine was outcompeted after 2 years. To our knowledge, this study is the first to reveal that tall grasses, particularly P. incomtum and P. purpureum, have potential to serve as bio-control agents for M. micrantha.