Agron. Sustain. Dev. 25 (2005) 109-121
DOI: 10.1051/agro:2004061

A survey of weeds that are increasingly spreading in Europe

Ewald Weber^{a, b} and Daniel Gut<sup>a

a</sup>  Swiss Federal Research Station of Fruit-Growing, Viticulture and Horticulture, 8820 Wädenswil, Switzerland
^b  Swiss Federal Institute of Technology, Geobotanical Institute, Zürichbergstrasee 38, 8044 Zurich, Switzerland

(Received 19 September 2003; accepted 11 October 2004)

Abstract - A Europe-wide survey was conducted by sending questionnaires to weed scientists in order to evaluate currently troublesome weeds and those which may cause problems in the future. Recipients were asked to list species that are spreading and cause problems in agroecosystems, and to rate these according to three scores (degree of weediness, degree of spread potential, and degree of control success), with three levels for each score (low, medium and high). In total, 281 species were reported from 26 European countries. Most of them were annuals (48%), followed by perennials (34%) and biennials (14%). There were significant differences in weed scores among these life forms. Weed scores were unrelated to each other, implying that they have different meanings with respect to the biology of the species. Weed scores did not correlate with European range size, implying that they indicate the weediness of the species independently of the geographical distribution and can be used to prioritize weed species for management.

Key words: noxious weed lists / risk assessment / surveys / weediness / weed control

Corresponding author: Ewald Weber ewald.weber@env.ethz.ch

© INRA, EDP Sciences 2005