Case history for weed competition/population ecology: velvetleaf (Abutilon theophrasti) in corn (Zea mays)

According to Grime's model, velvetleaf can be classified as a competitive-ruderal species. Its biological and ecological characteristics make it particularly competitive and persistent in cultivated fields. Herbicide control is difficult and, once established, it is almost impossible to avoid seed production. The economic threshold, on a single year basis, varies between 0.3 and 1.7 plants m-2. When the competitive relationships and their effects are evaluated, it is very difficult to apply a weed management system based on a single-season threshold. When one considers the agronomic implications of the ecological characteristics of velvetleaf over a longer period, it can be concluded that the use of a single-season economic threshold is probably not the best management strategy.