Browsing by Author "Olahan, G. S."

Now showing 1 - 4 of 4
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    Comparative biodiversity assessment of weed species in monocropping plantations of University of Ilorin, Nigeria
    (West African Journal of Applied Ecology, 2020) Olayinka, B. U.; Adeyemi, S. B.; Abdulkareem, K. A.; Olahan, G. S.; Lateef, A. A.; Garuba, T.; AbdulRahaman, A. A.
    The present study investigates the weed species diversity in four plantations of university of Ilorin, Ilorin, Nigeria using quadrat method. The survey revealed two major life cycles (annual and perennial) and recorded a total of 88 weed species belonging to 32 families. Four species (Azadirachta indica, Daniellia oliveri, Desmodium tortuosum, and Tridax procumbens) were common in all the surveyed plantations while the family Fabaceae was the most dominant. The abundant weed species analysis showed a high importance value index and were more adapted to the plantations. Diversity analysis revealed high species richness in the sugarcane plantation. The non-canopy nature of the plantation, soil structure as well as ability to coexist with many other species may underscore the reasons for this pattern of diversity. The evenness and similarity indices between and across the plantations were generally low, thus, indicating varying diversity. As a result of the recorded variation in weed composition between and across the plantations, the study has provided an insight on the pattern of weed diversity in the studied plantations. The study recommended that the most abundant weed species populations be checked for the plantations to thrive. Finally, there is an urgent need to conserve weed species that are not only rare in abundance but also showed great social and economic values.
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    Effect of Aflasafe® Application on the Productivity, Grain Quality, and Aflatoxin Reduction in Maize (Zea mays L.)
    (Bima Journal of Science and Technology, 2026) Olayinka, B. U.; Abdulbaki, S. A.; Ogidigada, B.; Ajadi, I.; Olahan, G. S.; Oyebanji, A.; Ahmed, O.
    Aflatoxin contamination remains a major threat to food safety, crop quality, and public health in sub-Saharan Africa. Aflasafe, a biocontrol product containing atoxigenic Aspergillus flavus strains, has proven effective in reducing aflatoxin levels, yet its broader agronomic impacts are less understood. This study evaluated the effects of Aflasafe applied at vegetative and flowering stages on maize growth, yield, nutritional composition, and postharvest quality. Application at the flowering stage led to marked improvements in vegetative growth, including plant height, leaf area, and stem girth. Yield components such as ear number, grain count, and overall yield were also significantly enhanced. Proximate composition analysis indicated elevated levels of crude fat, protein, and carbohydrate contents. In addition, grains treated with Aflasafe showed higher germination rates and seed vigor, together with reduced populations of toxigenic A. flavus and aflatoxin concentrations that remained within internationally accepted safety limits. These results demonstrate Aflasafe’s dual potential as a biocontrol and growth-promoting agent, advancing sustainable maize production, food security, and public health resilience.
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    Effect of copper-based fungicide on chemical composition of cocoa seeds
    (UNIZIK Journal of Engineering and Applied Sciences, 2025) Lawal, A. R.; Olayinka B. U.; Olahan, G. S.; Omorinoye, O. A.; Abdulsalam, H. A.; Abdulra’uf, L. B.
    Production of cocoa seeds, one of Nigeria’s major non-oil foreign exchange earners as well as a major raw material for the beverage industry, is greatly hindered by diseases caused by various species of the genus Phytophthora. To avert this, copper-based fungicides are sprayed on the leaves of cocoa trees to control or prevent the survival of this organism by the farmers without paying attention to the effects of this chemical on the proximate composition of cocoa seeds. This study therefore investigated the effects of a copper-based fungicide (Ridomil Gold Copper) on the quality of the cocoa seeds by spraying cocoa trees, including the pods, with 50.00 g/L of copper-based fungicide. The results obtained showed that cocoa seeds from the control trees showed significantly higher contents of fiber (4.51%), protein (15.1%), and fat (36.1%) when compared to the respective values of 3.45, 3.95, and 7.59% obtained for the cocoa seeds harvested from the fungicide-treated cocoa trees. All other proximate compositions did not show any statistical difference, except for carbohydrate and calorific values, which were significantly higher in cocoa seeds from fungicide-treated cocoa trees. Seeds from fungicide-treated trees showed significantly higher potassium, phosphorus, and magnesium contents but lower zinc and copper contents. However, phytochemicals such as phenols, alkaloids, flavonoids, and tannins were significantly lower in content in the seeds of fungicide-treated cocoa trees. The contents of glycosides and antioxidants in the cocoa seeds were statistically similar for both the control and treatment, except for ascorbic acid, which showed a significantly lower value (4.8 mg/100 ml) in cocoa seeds from fungicide-treated cocoa trees, compared with the value recorded for the control in this study (13.33%). The foregoing results showed that the use of copper-based fungicides for the control of black pod disease in cocoa adversely affected the quality of cocoa seeds from the treated trees.
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    Molecular characterization of potential crop pathogens associated with weeds as endophytes in Unilorin Plantations, Nigeria
    (Baghdad Science Journals, 2022) Lateef, A. A.; AbdulRahaman, A. A.; Olahan, G. S.; Adeyemi, S. B.; Olayinka, B. U.; Abdulkareem, K. A.; Garuba, T.
    Crop diseases are usually caused by inoculum of pathogens which might exist on alternate hosts or weeds as endophytes. These endophytes, cum pathogens, usually confer some beneficial attributes to these weeds or alternate hosts from protection against herbivores, disease resistance, stress tolerance to secondary metabolites production. This study was therefore carried out to isolate potential crop pathogens which exist as endophytes on weed species in the University of Ilorin plantations. Green asymptomatic leaves were collected from 10 weed species across the plantations, and processed for their endophytic fungi isolation. Isolates were purified into pure cultures and used for molecular identification using the internal transcribed spacer (ITS) region of the ribosomal DNA. Phylogenetic analysis of the fungal sequences using MEGA software revealed 9 fungal genera belonging to 13 species, with species in the genera Curvularia, Epicoccum and Daldinia occurring in more than one weed species, while other genera such as Alternaria, Fusarium, Chaetomium, Macrophomina, Arthrinium and Phomopsis occurred in just one weed species each. Daldinia eschscholtzii was isolated in this study as an endophyte from Loudetia arundinacea for the first time. This plant is very abundant in Nigeria and Africa where it is used majorly for thatching and feeding livestocks. This also represents the first endophytic fungi from the genus Loudetia. Potential relationship between the occurrences of these fungi as endophytes and as pathogens are discussed. These discoveries represent the first large-scale molecular identification and several first reports of endophytes from these weed species. These results also represent the first records of some of these fungi in Nigeria.