DISTRIBUTION OF PARTHENIUM WEED IN PESHAWAR VALLEY, KHYBER PAKHTUNKHWA- PAKISTAN

摘要

Parthenium hysterophorus L. is a weed of national significance in Pakistan. Although infesting many districts of KhyberPakhtunkhwa province, but more affected districts are Swabi, Mardan, Charsadda and Peshawar where it is highly invasive andinvaded most of the open spaces roadsides, etc and threatening the local biodiversity. Field survey of four districts of thePeshawar valley, Khyber Pakhtunkhwa viz. Swabi, Mardan, Charsadda and Peshawar were carried out during May-June, 2009-2010 to study the distribution and invasion of parthenium weed. Twenty five locations were sampled from each district. Dataregarding absolute and relative density, frequency, relative frequency, importance valve %, average importance value,constancy classes and importance value constancy index of parthenium weed and other weeds of the area were recorded byusing (1x1 m2) quadrate. The mean data across the surveyed districts reveals that the flora is predominated by parthenium weedwith the highest relative density of 42.68% among all species. It was followed by Cannabis sativa, Cynodon dactylon andCyperus rotundus, with relative densities of 15.17, 13.49 and 5.96, respectively. At different locations, it was observed thatparthenium weed is competing with Cannabis sativa which is not so aggressive and problematic weed. While in some areasparthenium weed has already replaced Cannabis sativa. Mean distribution data showed that parthenium weed infestation wasabundant and almost not uniform in all districts, however highest relative frequency of 26.14% was recorded for partheniumweed followed by Cannabis sativa, Cynodon dactylon and Cyperus rotundus having relative frequency of 15.17, 13.49 and9.14, respectively. Rumex crispus and Xanthium strumarium infatuated the smallest relative frequency at most of the locationsstudied thereby indicating them as insignificant among the weed flora of the study area. Importance value data revealed that P.hysterophorus, Cannabis sativa, Cynodon dactylon and Coronopus didymus having IV % of 34.41, 16.30 13.42 and 7.14,respectively. Looking at the overall distribution of flora in Peshawar valley, parthenium weed is spreading rapidly along theroadsides, into agricultural fields and on wastelands. The dominance of parthenium weed is attributable to its invasive abilitydue to its allelopathic properties, higher growth rate, rapid flowering and higher fecundity.