Occurrence and Infestation of Invasive Weed in Crop Field in Yunnan

According to investigation of Weed Research Lab.,Institute of Environment and Resource Research of YAAS in crop field from 1996 to 2010,186 invasive weeds belonging to 41 families and 122 genera were identified and recorded in Yunnan province.Among them,Compositae and Gramineae were the main invasive weeds including 37 and 35 species,respectively,then Leguminosae(19), Amaranthaceae(12),Solanaceae(9) and Euphorbiaceae(8).There were 172 species of herb accounting for 92.5 % of the total species,79 annual weed species and 85 perennial weed species which accounted for 42.5 % and 45.7 % of the total species respectively.Most of invasive weeds distributed in South and Central Yunnan,and the major infested crops were vegetable,maize and orchard.It was concluded that the number and infestation severity of invasive weeds of crop field in Yunnan province was No.1 among all the provinces in China,more attention should be paid to this issue,and effective measures should be adopted to tackle the damage of invasive exotic plant.