 Weeds compete with crop plants for water, light, nutrients and space.Some weeds are parasites, either partially or totally, on crop plants.Weeds impair the quality and quantity of plant and animal products e.g. throny weeds.Weeds harbour insects, pests and diseases.Weeds increase cost of labour and equipment.Weeds reduce the efficiency of farm equipment.Some weeds are poisonous and cause hazards to human beings and animals.Weeds reduce the carrying capacity of grazing lands and pastures.Aquatic weedsThey impede water flow in canals, channels, rivers, etc. They impede drainage. They are a menace to fisheries.They spoil the recreational value of water bodies.They pose pollution problems in water and make it un-useable in many cases.They dry water bodiesUsefulness of weedsWeeds add to organic matter content of the soils.Weeds help in controlling erosion.They can be used as fodder for cattle and some as vegetables.Some weeds possess aromatic oils, medicinal value or both.Some weeds are used for fencing purposes.Weeds are used as mulch, to check the evaporation loss.Some weeds are used as green manure and for composting purposes.Some weeds fix atmospheric nitrogen | |
