Seed Bank Distribution of Kongwa Weed (Astripomoea Hyoscyamoides) for Different Land Use Types in Kongwa District, Tanzania

Abstract

Weed invasion poses significant challenges to agriculture and ecosystems, leading to substantial economic losses globally. Astripomoea hyoscyamoides Vatke Verdc. commonly known as Kongwa weed, is a highly invasive species causing a severe infestation in the Kongwa district, Tanzania. This study investigated the seed bank distribution of Kongwa weed across different land use types, specifically arable land, fallow land, and range land in the Kongwa district. Soil samples were collected from chamae, chigwingwili, chimotolo, machenje, msunjulile, ndalibo, nyerere, and sejeli villages, representing range, arable, and fallow land, at different soil depths (0-5 cm, 5-10 cm, 10-15 cm, and 15-20 cm). The results showed significant variations in Kongwa weed seed density among villages, with Msunjulile exhibiting the highest density across all land use types (1.92 seeds/m2 in arable, 6.67 seeds/m2 in fallow, and 9.83 seeds/m2 in range land). In comparison, Chigwingwili displayed the lowest density (0.33 seeds/m2 in arable land) The study revealed a decline in seed density with increased soil depth, with the topsoil (0-5 cm) showing the highest seed density. Also, range land exhibited the highest seed density, while arable and fallow land were comparable. Generally, kongwa weed seeds are observed to be higher in range land with a depth of 0–5 cm, particularly in areas near ranch areas. Implementing control measures, especially before the flowering stage, is crucial to mitigating the kongwa weed invasion. Further research on seed germination patterns is recommended to enhance weed management strategies.