SPREAD OF AGGRESSIVE ALIEN WEED PARTHENIUM HYSTEROPHORUS L. IN DISTRICT OKARA, PAKISTAN

Distribution of aggressive alien weed species Parthenium hysterophorus L. was studied in district Okara, Pakistan during September-October 2006. Eight waste and grazing lands, each of about 1 ha, were selected randomly in different parts of district Okara with 3–8 km distance between the two adjacent localities. P. hysterophorus was found in 7 out of 8 studied sites exhibiting 88% prevalence. The absolute and relative frequencies of P. hysterophorus were 36% and 2.56%, and absolute and relative densities were 0.56 and 2.71%, respectively. The frequency and density of P. hysterophorus were higher than 28 and 30 out of 38 weed species, respectively, identified from the studied areas.