Weeds remain one of the most significant agronomic problems associated with organic arable crop production. It is recognised that a low weed population can be beneficial to the crop as it provides food and habitat for a range of beneficial organisms (Millington et al., 1990; Clements et al., 1994; Aebischer, 1997; Fuller, 1997; Patriquin et al., 1998). However, above critical population thresholds, weeds can significantly reduce crop yield and quality in conventional (Cussans, 1968; Hewson et al., 1973; Cousens, 1985; Cudney et al., 1989) and organic (Bulson, 1991) crops alike. The challenge for organic farmers is to manage weeds in such a way as to accommodate their beneficial effects whilst still producing an acceptable crop
