EWRS Working Group:
At the time of establishment of the Working Group "Crop- weed interactions" the main research related to this topic focused on descriptive models to support rational decision-making on the use of herbicides to minimize damaging effects of weeds on crops. Later on, a more ecological approach was pursued (Mortensen 2002). The WG proceeds to track current trends in ecological research and the management of weeds and develops new directions of research relevant to weed management in general and crop-weed interactions in particular.
Currently, the focus of the WG is on the mechanisms of competitive interactions between crops and weeds and how these can be modified by management measures (Workshop 2017) and on factors which play a major role in the outcome of such interactions (Verwijst et al. 2018).
A quantitative reduction in crop yield due to weeds is ascribed to the ability of weeds to compete for light, water and nutrients, at the expense of the crop. The relative competitive ability of weed species is determined by two groups of interacting factors. The first one consists of weed species characteristics, such as propagation and dispersal features and other life cycle characteristics, and potential crop growth rate. The second one is made up by the environment, which to a large extent is determined by the cropping system and its management. This implies that improvements in weed control in agriculture need to be based on both weed (and crop) ecology (Mortenson et al. 2002), and on the influence of the particular crop and management system on the population dynamics of weeds (Barberi 2001).