Distribution of Invasive Weed Parthenium hysterophorus in Natural and Agro-Ecosystems in Arusha Tanzania

The invasive weed Parthenium hysterophorus is aggressive and hazardous weed causing harms to biodiversity of natural plant communities, humans and animals in more than 20 countries worldwide. In Tanzania, Parthenium weed was first reported in Arusha region in 2010. Since 2010, areas invaded by parthenium weed in Arusha region has increased. However, detailed information on the distribution, density, frequency and abundance of P. hysterophorus weed in Tanzania are rare. Therefore, the present study was carried out to address two objectives: 1) to identify areas infested with parthenium weed in Arusha region in Tanzania 2) to determine density, frequency and abundance of parthenium weed. Field surveys were carried out at Njiro suburb, Arusha-Kilimanjaro border and Arusha Airport in Arusha region during January to February 2013. Parthenium weed was identified using visual method; and quadrates were used to determine number of parthenium weeds in the fields. The weed was found growing along the roadsides, near residential areas, crop land and grazing lands. The mean number of parthenium weeds were significantly among the three locations (p