Occurrence and control of paper mulberry (broussonetia papyrifera) in southern Ghana
Broussonetia papyrifera (L.) Vent. (Paper mulberry) is a fast-growing woody perennial [Moraceae] native to south-east Asia and deliberately introduced to Ghana in the Afram Headwaters and Pra-Anum Forest reserves in the late 1960s. The plant has emerged as a major invasive species, and has invaded a vast area of land in the forest zone. The objectives of the study were to assess the distribution of B. papyrifera in southern parts of Ghana and evaluate the effectiveness of possible control strategies for the plant. A survey revealed that the species has spread from the original sites of introduction to other parts of the forest zone. Three treatments including manual uprooting, direct herbicide application and cut-and-spray with herbicide were applied to saplings in experimental plots. Manual uprooting and cut-and-spray treatments effectively suppressed regeneration/ re-sprouting of B. papyrifera for up to 24 weeks. Pole-sized trees of different stump heights and diameter classes treated with systemic herbicide failed to coppice after 24 weeks. The study showed that manually uprooting seedlings and saplings, and cutting followed by squirting the stumps of pole-sized trees with the appropriate chemicals would be effective measure to suppress the growth of B. papyrifera and prevent it from spreading.