Weed competition can cause significant yield losses in all crops. Weeds are programmed to compete and they do this very effectively. For example in arable crops, whether it is small, annual broad-leaved weeds that grow in large numbers and which complete their life cycle very quickly, or large grass weeds like wild oats, that have a life cycle similar to that of your crop, the result is the same. All weeds compete for water, nutrients and energy with the result that you harvest lower yields of inferior quality grain.
Herbicides are an important management tool for the control of weeds in crops. Herbicides can be broadly split into three categories, pre-emergent, post emergence and non-selective. Pre-emergent herbicides control seedling weeds as they germinate and thus prevent establishment. Post-emergent herbicides selectively control weeds once they are established in the crop. Non-selective herbicides have activity on weeds but also on the crop and their use is restricted to stale seed bed use, prior to crop emergence and in perennial fruit crops.
Bayer has an extensive range of herbicides. In arable crops these include Firebird, Othello and Hussar. Sencor is a pre and post emergence herbicide that can be used in several vegetable crops.