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This paper provides a compendium of the utilisation potential of aquatic invasive plants found in the Owabi Dam in the Ashanti Region of Ghana. In total, seven aquatic invasive plants were identified in the Owabi Dam, which included Ceratophyllum demersum, Nymphaea odorata, Polygonum lanigerum, Arthropteris orientalis, Typha domingensis, Pistia stratiotes, and Cyprus papyrus. Some of the identified invasive plants were found to be highly nutritious and suitable for human consumption or use as feed for livestock, fish, and poultry. Other plants had high medicinal potential and aesthetic value. Several of the invasive plants were suitable for bio-industrial usages as feedstock to produce biofuels, insecticides, and biofertilizer, among other products. Therefore, if an effective utilization method of these currently unutilized aquatic invasive plants is established, it can provide a source of livelihood and income generation for individuals and households and contribute to controlling the impact of invasive plants on the Owabi Dam.

Cabbage from 3 major markets (Abinchi, Bantama and Sofoline) in Kumasi were screened for organochlorine, organophosphate and pyrethroid insecticide residues. Ninety cabbage heads-30 from each market-were randomly sampled and analysed at the Pesticide Residues Laboratories of the Ghana Standards Authority, Accra. The analysis was carried out using Multiple Reaction Monitoring by Gas Chromatography-Pulsed Flame Photometric Detector (GC-PFPD), Gas Chromatography-Electron Capture Detector (GC-ECD) and Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method to detect residues. The limit of detection (LOD) of organochlorine was set at 0.005 mg/kg and that of organophosphate and pyrethroid was set at 0.01 mg/kg. We observed that no organochlorine was present in any of the samples. Only Diazinon was present in the samples from Abinchi and Bantama but at a level (0.003 ± 0.006 mg/kg) below the maximum residue limit (MRL) of 0.01 mg/kg for cabbage. However, there was a multi-residue contamination in samples from the Sofoline market with Diazinon (0.057 ± 0.098 mg/kg), Cypermethrin (0.007 ± 0.012 mg/ kg), Fenvalerate (0.010 ± 0.017 mg/kg) and Lambda-cyhalothrin (0.003 ± 0.006 mg/kg). With these, only the Diazinon was found to exceed its established MRL (0.01 mg/ kg) and so is more likely to pose danger to consumers health.

This study evaluates the quality and performance of compost produced from household biowaste (CBIO), aquatic invasive plants (CAIP) and a mixture of the invasive plants and biowaste (CBAIP) in comparison with mineral fertilizer (NPK) application. The composts were produced using Aerobin 400 Composter with aquatic invasive plant collected from the Owabi dam and solid biowaste from households within the Owabi catchment in the Ashanti Region of Ghana as feedstock. A field experiment in a 35 m x 19 m plot of maize was conducted with 9 treatments of the different compost produced and mineral fertilizers in a randomized complete block design (RCBD) with 4 replications. The results show that the compost types produced have acceptable quality with regards to nutrients (NPK), organic matter (OM), organic carbon (OC), bulk density, porosity, and heavy metal contents (Cu, Zn, Cd, Pb, As, Ni) among other properties. Grain yields following treatment with CAIP (2.06 ± 0.692 tons/ha), CBAIP (2.15± 0.668 tons/ha) and CBIO (2.052 ± 0.915 tons/ha) were similar to grain yields from NPK application (2.55 ± 0.611 tons/ha) but significantly higher than the control (1.34 ± 0.500 tons/ha) at 5%. The results show that the different compost types produced have beneficial impacts on grain yields comparable to NPK application. It is, therefore, concluded that aquatic invasive plants and biowaste are suitable feedstock for the production of high-quality compost that significantly improves grain yields.