Parthenium (Parthenium hysterophorus L.) is a noxious weed due to its potential to decrease the crop productivity,biodiversity depletion and health problems for livestock and human causing hay fever, skin problems and asthma. Some synthetic chemical herbicides such as chlorimuron ethyl, glyphosate, atrazine, ametryn, bromoxynil and metasulfuron are known to be very effective in controlling this weed. However, increasing public concern on environmental issues requires alternative weed management systems, which are less pesticide dependant or based on naturally occurring compounds....