Weeds constitute an integral part of any productive terrestrial ecosystem and are specialized form of vegetation highly successful in agricultural lands. They are characterized by rapid growth, short lifecycle and wide ecological amplitude. The evolution of weeds has been markedly influenced by agriculture and human disturbances. The weeds are commonly known as alien invasive species which spread very fast at the cost of native vegetations. Invasive species means an alien species which becomes established in natural or semi-natural ecosystems or habitats, is an agent of change, and threatens...