Spread, menace and management of Parthenium

Parthenium hysterophorus is an aggressive annual herbaceous plant, native to the tropical America. It is now widely distributed in a number of tropical and sub-tropical countries threatening natural ecosystems, agro-ecosystems and biodiversity worldwide. It has been considered a great cause of skin allergy in mankind and animals too in many countries around the globe. Parthenium has achieved major weed status in India and Australia and posing lurking threat to many African and South-Asian countries. Earlier, it was not considered a major threat to agricultural crops in India and other countires, but now, all types of crops are infested with the weed in India. The infestation of this weed causes yield losses up to 40% in several crops and reduces forage production up to 90%. The rapid spread of Parthenium in India would be a bigger risk to the expansion and sustainable production of many crops, orhcards and grassland ecosystems in protected forests. Various management approaches namely cultural, mechanical, chemical and biological have been used to minimize losses caused by this weed, but most of these approaches are ineffective and suffer from one or other limitations. Although management using herbicides and exotic bioagents Zygogramma bicolorata for biological control has been found to contribute effectively to suppress Parthenium in India, nevertheless, the weed remains a significant problem. Integrated Parthenium Management is advoated to fight against this invincible weed.Hence, an attempt has been made to review its current spread, impact on agriculture, human and animal health and management in context to world in general and India in particular.