Modelling weed competition and yield losses to study the effect of omission of herbicides in winter wheat

Abstract

Omission of herbicide application caused a significantly lower Triticum aestivum crop yield only when the densities of certain weed species were extremely high in spring. A dynamic model simulating the competition for light and water between broad-leaved weeds and winter wheat was used to analyse experimental results. In the Netherlands weeds emerging in spring hardly affect crop yield. Weeds emerging in autumn, however, may reduce crop yield considerably if they grow as tall as winter wheat (20% loss at a density of 100 plants per m2). Results are discussed in relation to characteristics of crop rotation systems that include root and tuber crops. -from Authors