Harmful effects and chemical control study of Mikania micrantha H.B.K in Yunnan, Southwest China

Invasive alien species Mikania micrantha, which originated from Central and South America, has spread quickly and become one of the most seriously invasive weedy species in Yunnan Province, Southwest of China. The harmful effects of this plant on major cash crops and local plant communities have been surveyed in 50 townships of 6 counties of Yunnan Province since 2006. Moreover, bioactivity and selectivity of 20 types of herbicides on M. micrantha and farming crops have been tested and analyzed since 2007. The results showed that M. micrantha is mostly distributed in subtropical and tropical areas of Yunnan, such as Lincang District, Baoshan District and Dehong Prefecture. The species has resulted in a series of negative impacts on farming cash crops and local plant communities. Compared with the control effects of 20 soil and foliar-applied herbicides, soil-applied herbicides Atrazine, Bensulfuron methyl and Prometryne have higher bioactivity and selectivity to M. micrantha germination and seedling. Foliar-applied herbicides Sulfometuron methyl, Starane and Glyphosate have better control efficiency on M. micrantha growth, but the security is low. As a result, it recommends that Atrazine should be used for sugarcane, orchard and rubber land, Glyphosate for non farming land and rubber land, Sulfometuron methyl for forest land, and 2, 4-D for maize land, respectively.