PHYSIOCHEMICAL PROPERTIES

This study assessed the physicochemical quality of diesel oil sold in Benin City, Edo State, Nigeria, using aggregate samples collected from four local government areas (Egor, Oredo, Ikpoba-Okha, and Ovia North-East). The scope covered five key parameters—flash point, distillation characteristics, density, basic sediment and water (BSW), and colour selected for their direct impact on safety, efficiency, and compliance with standards. Diesel samples were collected in sealed one-liter containers, combined into four aggregates, and analyzed using ASTM methods (D93 for flash point, D86 for distillation, D1298 for density, D1796 for BSW, and D1500 for color). Results showed distillation ranges within specification, with initial boiling points of 160–165 °C and final boiling points of 355–356 °C, and final recovered volumes of 97–98 mL, indicating uniform volatility. Density corrected to 15 °C ranged from 0.834 g/mL (Oredo) to 0.847 g/mL (Ovia North-East), aligning with the acceptable 0.82–0.85 g/mL range. BSW content was consistently low at 0.05%, while ASTM colour values ranged from 1.0 to 1.5, all within standards. However, flash points were below 52 °C across all LGAs, failing to meet the ASTM D975 minimum, suggesting contamination or blending with lighter fractions. The findings highlight generally consistent diesel quality but raise safety concerns requiring regulatory oversight.

Despite the presence of different variety of chemical fungicides, the search for new antifungal substances against plant pathogens continues because of the negative effect these fungicides has on both the plants and the environment. This study was aimed at assessing the antifungal activities of Moringa oleifera and Olea europaea oil individually and their synergistic combination against selected phytopathogenic fungi. Two fungi were isolated from agricultural soils obtained from different locations. Antifungal activities of Moringa, Olive oil individually and synergistically were performed using the food poisoning method. Penicillium chrysogenum and Mucor circinelloides used in this study were isolated from the agricultural soil. The phytochemical analysis of Moringa oil revealed a cocktail of phytochemicals while Olive oil showed only the presence of terpenoids. From the results, Moringa oil alone demonstrated strong activity against the pathogens with radial growth inhibition ranging from 2.83±0.04mm (Penicillium chrysogenum, 14%) to 5.83±0.10mm (Mucor circinelloides, 6%) this was significantly different from the controls (17.66±0.33mm for Penicillium chrysogenum and 39.16±0.05mm for Mucor circinelloides). For Olive oil alone the radial growth inhibition ranged from 4.90±0.05mm (Penicillium chrysogenum, 14%) to 24±0.30mm (Mucor circinelloides, 2%)
this was significantly different from the controls (17.66±0.33mm for Penicillium chrysogenum and 39.16±0.05mm for Mucor circinelloides). The synergistic combination of Moringa oil and Olive oil gave a result ranging from 0.00±0.00mm (Mucor circinelloides, 14%) to 12.33±0.14mm (Penicillium chrysogenum, 14%) compared to their controls (17.66±0.33mm for Penicillium chrysogenum and 39.16±0.05mm for Mucor circinelloides). The highest percentage mycelial radial growth inhibiton for Moringa oil on day 7 was 89.79% (Mucor circinelloides) and the lowest was 71.70% (Penicillium chrysogenum).