Classification of weeds Ecology of weeds 3 Dispersal of weeds 2 Adjuvants 1 Aquatic weeds 1 Beneficial effects of weeds 1 Crop weeds competition 1 Crop-weed association 1 Formulation of herbicides 1 Harmful effects of weeds 1 Herbicide interactions 1 Non selective control of vegetation 1 Weed control 1