what is meant by weedicides?
Winnowing is the process of separating lighter components of a mixture from the heavier ones by using wind or moving air.
Weedicides refers to a herbicides which is used to kill unwanted plants i.e. weeds fron the field. For example fluchloralin and isoproturon are few examples of weedicides.
Weeds are the unwanted plants that grow (by their own) with the crop plants and compete with them for food, shelter and space.