INVASION OF PARTHENIUM HYSTEROPHORUS L. IN DISTRICT NANKANA SAHIB, PAKISTAN

Abstract

A survey of different areas of district Nankana Sahib, Pakistan was carried out in 2009 to evaluate the invasion of parthenium (Parthenium hysterophorus L.), an invasive alien weed that is rapidly spreading in many parts of Pakistan. Eight different localities in the district Nankana Sahib were surveyed. Parthenium was found growing at 90% localities of the district. A total of 64 weed species belonging to 25 angiospermic families were identified in the surveyed area. Parthenium was found to be the second most frequently occurring weed species in the area after the Coronopus didymus. The density of the parthenium weed was highest among the 64 identified weed species. The present study clearly indicates that the parthenium has become one of the most dominating weed species in this area. High reproductive potential, conducive environmental factors, allelopathic nature, fast growth rate and lack of natural enemies are the major factors responsible for rapid invasion of
parthenium in Pakistan. It is need of the hour to take appropriate measures to contain the further spread of this aggressive weed in the country.