Risk Analysis On Ragweed(Ambrosia L.)

Abided by the pest risk analysis (PRA) criterion formulated by Food and Agriculture Organization (FAO) and International Plant Protection Convention (IPPC) and combined the characters of ragweed, the studies in this paper were made on qualitative and quantitative evaluations of the dangerous ragweed possibly entering China and establishment of an integrated evaluating system for their risks. The main results were as follows.1. The preliminary risk evaluations were made on the 40 species of ragweed (Ambrosia. L.) in respect of geography and management standards, entering possibilities, establishing and spreading possibilities, economic influences and risk manage measures, and 11 species of ragweed were screened out for their potential risks in possession of evaluation value.2. Using the PRA multi-index integrated evaluation system and the qualitative and quantitative methods, an integrated quantitative evaluation system of PRA was established for ragweed.3. Based on the PRA multi-index integrated quantitative evaluation system of ragweed, the further sdudies were made on the PRA for those 11 species of ragweed. The results were as follows.(1) Among the forty species of ragweed, only three species (A. artemisiifolia, A. trifida, A. psilostachya) had a higher rate of PRA (R>2.0) . It is necessary for these species to be classified as prohibited dangerous pests.(2) There were five species (A. acanthicarpa, A. maritima, A. bidentata, A. tenuifolia, A. confertiflora) not meeting the requirements of quarantine (1.73≥R≥ 1.43) , but owing to their poisonous pollens and broad distribution, some potential dangerousness existed. Systematic examination on these species and establishing an...