Abstract
A survey of district Sheikhupura, Punjab, Pakistan was carried out during September-October 2006 after the rainy season, to study the distribution of an alien weed Parthenium hysterophorus L. in comparison with the native flora. Eleven sites, each of about 1 hectare area, were selected in different regions of the district. Sampling was done with the help of a 1 m2 quadrate. Data regarding prevalence, frequency and density of P. hysterophorus and other weed species were recorded. P. hysterophorus was found to be present at all the 11 studied sites exhibiting 100% prevalence. P. hysterophorus exhibited an absolute frequency (AF) of 76% and relative frequency (RF) of 3.52. Only 8 out of 37 local weed species namely Achyranthes aspera L., Amaranthus viridis L., Calotropis procera Br., Malvestrum tricuspidatum A. Gray, Cypreus rotundus L., Cenchrus biflorus Roxb., Cynodon dactylon Pers. and Dactyloctenium aegyptium Beauv. showed higher AF and RF than this alien weed species. P. hysterophorus was found eighth most densely populated weed in the studied area exhibiting an absolute density of 3.37 and relative density of 4.45. An urgent integrated management strategy is the need of the hour to limit the rapid spread of this noxious alien weed in the area.
