Oluwatoyin A Fabiyi - Academia.edu (original) (raw)
Papers by Oluwatoyin A Fabiyi
CRC Press eBooks, May 18, 2023
CRC Press eBooks, May 18, 2023
Pakistan Journal of Nematology, 2014
The Journal of solid waste technology and management, Aug 1, 2022
Meloidogyne incognita is known to be a foremost pest of carrot in Nigeria. It is a component to a... more Meloidogyne incognita is known to be a foremost pest of carrot in Nigeria. It is a component to appraise in carrot production. Application of synthetic nematicides as control measures is unsafe to humans and detrimental to the environment. Development of safe control process is worthwhile. Effect of three peels (potato, pineapple, orange) and composited soil from municipal refuse dump site was assessed and compared with carbofuran a standard synthetic nematicide at four different doses (0, 1500, 2000, 2500g and 2.0kg/a. i/ha, 1.5kg/a. i/ha, 1.0kg/a. i/ha and 0kg/a. i/ha for carbofuran) on carrot plants. The concentrations of heavy metals like Cd, Pb, Ni, Cu, Cr, Mn, Zn and Fe in the composited soil was determined with Atomic Absorption Spectrophotometer (AAS). Experimental pots were inoculated with approximately 2000 M. incognita juveniles, in a randomized complete block design experiment. The composited municipal refuse soil was analysed for the presence of fungi and bacteria using molecular methods based on 16S rRNA gene sequencing. Reproduction and multiplication of M. incognita was significantly (p<0.05) low with all the treatment materials. Best inhibitory effect was observed in the soil of carrot plants treated with composited soil which had 49 nematode populations at harvest rather than 4606 recorded in untreated plants. Equally, heavier carrots were harvested in plants administered with composited soil (1309.6 gram), while the control plants had poor weight (312.7 gram). Performance of each waste material was quantity dependent. Gene sequencing revealed the presence of Pseudomonas alcaligenes strain ATCC 14909, P. putida strain ATCC 12633, P. aeruginosa strain ATCC 10145, Pseudomonas stutzeri NBRC 14165, Acinetobacter venetianus ATCC 31012, Enterobacter cloacae ATCC 130047, Streptomyces spp B7-3TC02, Bacillus subtilis NBRC 13719, Aspergillus niger strain MPVCT 158, Penicillium georgiense strain EV 24 and Rhizopus oryzae strain ATCC 20344, which are beneficial soil microorganisms. The metal concentration analysis of the composited municipal refuse dump soil exhibited low concentrations of heavy metals which ranges from 0.002-1.03 mg/kg with Zinc (Zn) having the highest concentration. The waste materials are cheap and ecofriendly option that can be adopted as soil amendment in M. incognita infested fields to significantly boost yield in carrot production and reduce reliance on mineral fertilizer. The peels, as well as composited municipal refuse dump soil can be used to improve soil properties and substitute lost nutrients to enhance crop production, and at the same time mitigate the environmental consequences of inappropriate waste disposal problems in Nigeria.
International Journal of Nematology, 2016
European Journal of Plant Pathology, Dec 4, 2023
Pakistan Journal of Nematology, 2022
Pesticide residues and metabolites are often found in fruits, vegetables, soil and underground wa... more Pesticide residues and metabolites are often found in fruits, vegetables, soil and underground water as contaminants. This necessitated the search for bio-nematicides, accordingly the nematicidal prospect of chromatographic fractions from Mangifera indica as a substitute to synthetic nematicides in the control of Meloidogyne incognita pests of tomato was evaluated. Crude extracts of M. indica bark was fractionated on silica-gel (120-150 mesh) using glass column. The resulting fractions were investigated in screenhouse and field trials. The fractions were equated with carbofuran a synthetic nematicide. Each experimental pot containing 40 kg of pasteurized soil was inoculated with 1000 eggs of M. incognita in the screenhouse, while 2500 eggs was introduced to the base of each tomato plant on the field. Significant (p<0.05) increase was noted in the vegetative growth of treated tomato plants. Fruit weight per plant and number of fruits per plant increased notably as opposed to the untreated tomato plants. Nematode population in root and soil of treated tomato plants also reduced significantly. Terpenes, esters, aldehydes, phenols and ketones were identified as the major constituents of the fractions with partial characterization. The reduction in nematode population in the screenhouse and field signifies that fractions from M. indica could be employed in place of the environmentally undependable synthetic nematicides, while encouraging a sustainable and safe environment in tomato cultivation.
Faba Bean: Chemistry, Properties and Functionality
Agriculture and Biology Journal of North America, 2013
Chemical compositions of a plant determine its resistance and vulnerability to pathogens. The var... more Chemical compositions of a plant determine its resistance and vulnerability to pathogens. The varietal susceptibility of sunflower (a good producer of edible and nutritious oil) to Meloidogyne spp and other field pathogens was investigated. Five cultivars of Helianthus annus L, namely France lever, Isanka, Peredovicks, Pwk E 5 and Sigco 445 were investigated for their susceptibility to Meloidogyne spp, Alternaria leaf spot and virus mosaic. They exhibited different degrees of susceptibility to Alternaria leaf spot, Meloidogyne spp and virus mosaic. Most parameters of growth and yield that is; mean plant height, mean number of leaves, weights of head and seeds at harvest also differ significantly (p<0.05) among the cultivars. France lever appeared to be the least affected by the diseases and consequently exhibited superiority over others in most growth and yield parameters.
Natural Product Research, Nov 23, 2015
Three antifungal compounds have been isolated for the first time from the peels of Ipomoea batata... more Three antifungal compounds have been isolated for the first time from the peels of Ipomoea batatas Lam. Their structures were established on the basis of 1D and 2D NMR spectra data as well as ESI-MS and IR analysis. Urs-13(18)-ene-3β-yl acetate was found to possess a weak activity against Sporothrix schenckii and Trichophyton metagrophytes fungi with an MIC value of 50 μg/mL each. Stigmasterol and 3-Friedelanol were equally active against Trichophyton metagrophytes.
Tropical Agriculture, Nov 1, 2021
Constituents of watermelon (Citrullus lanatus) rind were extracted in ethanol and derivatized to ... more Constituents of watermelon (Citrullus lanatus) rind were extracted in ethanol and derivatized to produce white water soluble crystals designated as derivatized citrulline. The derivatized citrulline, chromatographic fractions and ethanolic crude extracts from Citrullus lanatus (Thunb.) were assessed in the laboratory and screenhouse on possible toxicity to Meloidogyne incognita (Kofoid & Chitwood). The structure elucidation of the citrulline derivative (CTRL/DRVT) and chromatographic fractions (CMTG/FRCT) were established with spectral data from infrared (FTIR), 1 H/ 13 C-NMR spectroscopy as well as gas chromatography mass spectrometry (GCMS). The infrared spectral data of the derivatized citrulline revealed a prominent absorption bands at 3431 cm-1 which is characteristic of N-H stretching vibration of primary amides. The bands at 1506 and 1456 cm-1 further support the presence of an amide group. The major compounds identified from GC-MS analysis of fractions include hydroxycinnamic acid (17.16%) p-anisic acid (16.10%) and chlorogenic acid (16.22%). 1 H-NMR data showed chemical shifts at δ 0.
Selcuk journal of agriculture and food sciences, Dec 13, 2016
This study aims to investigate the phytochemical composition of the leaves of Alstonia boonei and... more This study aims to investigate the phytochemical composition of the leaves of Alstonia boonei and Bridelia ferruginea. The leaves of the two plants were extracted successively with n-hexane and ethyl acetate, concentrated and fractionated over gravity silica gel column chromatography. Some fractions obtained were analyzed using gas chromatography mass spectroscopy (GC-MS). GC-MS results indicated that the main constituents of the fractions from Alstonia boonei were fatty acid methyl esters, while the main constituents of the fractions from Bridelia ferruginea were fatty acid esters (47.46%) and triterpenoids (43.39%). Each of the fractions has at least one exclusive tetracyclic or pentacyclic triterpenoid present. Friedelan-3-one and clionasterol were present in the Alstonia boonei fractions, while beta-amyrin, lup-20(29)-en-3-one, lupeol, alpha-amyrin acetate and 4,
Tropical Agriculture, Oct 5, 2016
Synthetic pesticides are usually environmentally hazardous. In an attempt to obtain an eco-friend... more Synthetic pesticides are usually environmentally hazardous. In an attempt to obtain an eco-friendly alternative to synthetic nematicidal agents, isovitexin, a flavonoid glycoside isolated from butanol fraction of the leaf extract of Kigelia pinnata was examined for its in vitro nematicidal potential. The chemical structure of the isovitexin was confirmed by comparing its UV, IR, MS and NMR spectroscopic data with that reported in literature. The compound induced a hundred percent mortality at 24 h of exposure and inhibited egg hatch of Meloidogyne incognita at a concentration of 0.16 mg/mL. There was no significant difference (p<0.05) in the action of isovitexin and the synthetic nematicide, oxamyl, when tested at the same concentration. The bioactivity and toxicity evaluation on ‘molinspiration’ and ‘toxpredict’ evaluators indicated that isovitexin is a potentially bioactive compound with low genotoxic carcinogenicity and high enzyme inhibition activity. The biodegradability evaluation indicated that it belongs to a class 2 persistent chemical. The results of this study could be harnessed to make isovitexin commercially available as a natural nematicide. This is the first account of isovitexin being isolated from Kigelia pinnata and evaluated for nematicidal potential.
Indian phytopathology, Mar 17, 2022
Pakistan Journal of Nematology, 2022
| Jew's mallow (Corchorus olitorius) is a vegetable of importance in Nigeria which is often times... more | Jew's mallow (Corchorus olitorius) is a vegetable of importance in Nigeria which is often times infested with root-knot nematodes (RKNs), thus reducing yield and expected income. Principally, synthetic nematicides are employed in the management of RKNs on agricultural fields. The synthetics are confronted with a web of regulations on account of their unhealty negative effect on humans and the environment. Plant protection is primarily saddled with replacing the synthetics. A promising technique is the application of bio-pesticides. Organic fatty acid esters (FAE) are reassuring materials with nematicidal activities. Medicinal plants are rich source of acid esters, hence Alstonia boonei (Apocynaceae) leaves were extracted cold in ethyl acetate. This yielded crude extract that was subjected to column chromatography (silica gel 100-120 mesh grade), which afforded fractions that were analysed with GCMS and FTIR for constituent identification. The result shows octanoic acid; hexanoic acid methyl ester; ethyl octanoate; 9, 12-octadecadienoic acid methyl ester; dodecanoic acid; octadecanoic acid methyl ester; decanoic acid; octadecanoic acid ethyl ester and tetradecanoic acid as the major components while the infra red spectral diagnostic signals agree with the expected vibrational frequencies corresponding to C-H and carbonyl C=O functional groups of fatty acid and esters. Jew's mallow plants infected with Meloidogyne incognita on the field were treated with the fatty acid esters (FAE) and compared to deionised water and carbofuran as control in two season trials. There was increase in biomass and vegetative growth with notable reduction in M. incognita reproduction in plants treated with FAE at 0.75 mg/ml in the first and repeat experiments. Juvenile population per gram root and soil were reduced significantly at 0.75 and 0.50 mg/ml of FAE in comparison with control. Late flowering was recorded in the untreated control experiment, while plants treated with FAE flowered notably earlier. Application of FAE is recommended for the sustainable management of M. incognita in Jew's mallow plants.
Pakistan Journal of Nematology, 2012
Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, Sep 1, 2021
Field studies were conducted on the application of Leucaena leucocephala leaf extracts as an alte... more Field studies were conducted on the application of Leucaena leucocephala leaf extracts as an alternative to carbofuran a synthetic nematicide, while possible residues of carbofuran in tomato fruits were also analysed. Acetone, methanol and petroleum ether fractions of the leaves of L. leucocephala were applied at 200 mg/mL in variants of 100 mL, 150 mL and 200 mL to a naturally nematode infested field. Comparison was made with carbofuran a synthetic insecticide and nematicide. Samples of tomato fruits from carbofuran treated and untreated beds were extracted with ethyl acetate for residual pesticide analysis to ascertain the exceedance of the maximum residue limit (MRL). Results revealed that pesticide residue was significantly (p = 0.05) higher in plots treated with carbofuran compared with standard MRL for carbofuran in tomatoes. Crude extracts of L. leucocephala were as effective as carbofuran, while the fraction was however significantly better in producing higher numbers of fruits and reduced nematode population in root and soil of tomato plants.
Sarhad Journal of Agriculture, 2020
CRC Press eBooks, May 18, 2023
CRC Press eBooks, May 18, 2023
Pakistan Journal of Nematology, 2014
The Journal of solid waste technology and management, Aug 1, 2022
Meloidogyne incognita is known to be a foremost pest of carrot in Nigeria. It is a component to a... more Meloidogyne incognita is known to be a foremost pest of carrot in Nigeria. It is a component to appraise in carrot production. Application of synthetic nematicides as control measures is unsafe to humans and detrimental to the environment. Development of safe control process is worthwhile. Effect of three peels (potato, pineapple, orange) and composited soil from municipal refuse dump site was assessed and compared with carbofuran a standard synthetic nematicide at four different doses (0, 1500, 2000, 2500g and 2.0kg/a. i/ha, 1.5kg/a. i/ha, 1.0kg/a. i/ha and 0kg/a. i/ha for carbofuran) on carrot plants. The concentrations of heavy metals like Cd, Pb, Ni, Cu, Cr, Mn, Zn and Fe in the composited soil was determined with Atomic Absorption Spectrophotometer (AAS). Experimental pots were inoculated with approximately 2000 M. incognita juveniles, in a randomized complete block design experiment. The composited municipal refuse soil was analysed for the presence of fungi and bacteria using molecular methods based on 16S rRNA gene sequencing. Reproduction and multiplication of M. incognita was significantly (p<0.05) low with all the treatment materials. Best inhibitory effect was observed in the soil of carrot plants treated with composited soil which had 49 nematode populations at harvest rather than 4606 recorded in untreated plants. Equally, heavier carrots were harvested in plants administered with composited soil (1309.6 gram), while the control plants had poor weight (312.7 gram). Performance of each waste material was quantity dependent. Gene sequencing revealed the presence of Pseudomonas alcaligenes strain ATCC 14909, P. putida strain ATCC 12633, P. aeruginosa strain ATCC 10145, Pseudomonas stutzeri NBRC 14165, Acinetobacter venetianus ATCC 31012, Enterobacter cloacae ATCC 130047, Streptomyces spp B7-3TC02, Bacillus subtilis NBRC 13719, Aspergillus niger strain MPVCT 158, Penicillium georgiense strain EV 24 and Rhizopus oryzae strain ATCC 20344, which are beneficial soil microorganisms. The metal concentration analysis of the composited municipal refuse dump soil exhibited low concentrations of heavy metals which ranges from 0.002-1.03 mg/kg with Zinc (Zn) having the highest concentration. The waste materials are cheap and ecofriendly option that can be adopted as soil amendment in M. incognita infested fields to significantly boost yield in carrot production and reduce reliance on mineral fertilizer. The peels, as well as composited municipal refuse dump soil can be used to improve soil properties and substitute lost nutrients to enhance crop production, and at the same time mitigate the environmental consequences of inappropriate waste disposal problems in Nigeria.
International Journal of Nematology, 2016
European Journal of Plant Pathology, Dec 4, 2023
Pakistan Journal of Nematology, 2022
Pesticide residues and metabolites are often found in fruits, vegetables, soil and underground wa... more Pesticide residues and metabolites are often found in fruits, vegetables, soil and underground water as contaminants. This necessitated the search for bio-nematicides, accordingly the nematicidal prospect of chromatographic fractions from Mangifera indica as a substitute to synthetic nematicides in the control of Meloidogyne incognita pests of tomato was evaluated. Crude extracts of M. indica bark was fractionated on silica-gel (120-150 mesh) using glass column. The resulting fractions were investigated in screenhouse and field trials. The fractions were equated with carbofuran a synthetic nematicide. Each experimental pot containing 40 kg of pasteurized soil was inoculated with 1000 eggs of M. incognita in the screenhouse, while 2500 eggs was introduced to the base of each tomato plant on the field. Significant (p<0.05) increase was noted in the vegetative growth of treated tomato plants. Fruit weight per plant and number of fruits per plant increased notably as opposed to the untreated tomato plants. Nematode population in root and soil of treated tomato plants also reduced significantly. Terpenes, esters, aldehydes, phenols and ketones were identified as the major constituents of the fractions with partial characterization. The reduction in nematode population in the screenhouse and field signifies that fractions from M. indica could be employed in place of the environmentally undependable synthetic nematicides, while encouraging a sustainable and safe environment in tomato cultivation.
Faba Bean: Chemistry, Properties and Functionality
Agriculture and Biology Journal of North America, 2013
Chemical compositions of a plant determine its resistance and vulnerability to pathogens. The var... more Chemical compositions of a plant determine its resistance and vulnerability to pathogens. The varietal susceptibility of sunflower (a good producer of edible and nutritious oil) to Meloidogyne spp and other field pathogens was investigated. Five cultivars of Helianthus annus L, namely France lever, Isanka, Peredovicks, Pwk E 5 and Sigco 445 were investigated for their susceptibility to Meloidogyne spp, Alternaria leaf spot and virus mosaic. They exhibited different degrees of susceptibility to Alternaria leaf spot, Meloidogyne spp and virus mosaic. Most parameters of growth and yield that is; mean plant height, mean number of leaves, weights of head and seeds at harvest also differ significantly (p<0.05) among the cultivars. France lever appeared to be the least affected by the diseases and consequently exhibited superiority over others in most growth and yield parameters.
Natural Product Research, Nov 23, 2015
Three antifungal compounds have been isolated for the first time from the peels of Ipomoea batata... more Three antifungal compounds have been isolated for the first time from the peels of Ipomoea batatas Lam. Their structures were established on the basis of 1D and 2D NMR spectra data as well as ESI-MS and IR analysis. Urs-13(18)-ene-3β-yl acetate was found to possess a weak activity against Sporothrix schenckii and Trichophyton metagrophytes fungi with an MIC value of 50 μg/mL each. Stigmasterol and 3-Friedelanol were equally active against Trichophyton metagrophytes.
Tropical Agriculture, Nov 1, 2021
Constituents of watermelon (Citrullus lanatus) rind were extracted in ethanol and derivatized to ... more Constituents of watermelon (Citrullus lanatus) rind were extracted in ethanol and derivatized to produce white water soluble crystals designated as derivatized citrulline. The derivatized citrulline, chromatographic fractions and ethanolic crude extracts from Citrullus lanatus (Thunb.) were assessed in the laboratory and screenhouse on possible toxicity to Meloidogyne incognita (Kofoid & Chitwood). The structure elucidation of the citrulline derivative (CTRL/DRVT) and chromatographic fractions (CMTG/FRCT) were established with spectral data from infrared (FTIR), 1 H/ 13 C-NMR spectroscopy as well as gas chromatography mass spectrometry (GCMS). The infrared spectral data of the derivatized citrulline revealed a prominent absorption bands at 3431 cm-1 which is characteristic of N-H stretching vibration of primary amides. The bands at 1506 and 1456 cm-1 further support the presence of an amide group. The major compounds identified from GC-MS analysis of fractions include hydroxycinnamic acid (17.16%) p-anisic acid (16.10%) and chlorogenic acid (16.22%). 1 H-NMR data showed chemical shifts at δ 0.
Selcuk journal of agriculture and food sciences, Dec 13, 2016
This study aims to investigate the phytochemical composition of the leaves of Alstonia boonei and... more This study aims to investigate the phytochemical composition of the leaves of Alstonia boonei and Bridelia ferruginea. The leaves of the two plants were extracted successively with n-hexane and ethyl acetate, concentrated and fractionated over gravity silica gel column chromatography. Some fractions obtained were analyzed using gas chromatography mass spectroscopy (GC-MS). GC-MS results indicated that the main constituents of the fractions from Alstonia boonei were fatty acid methyl esters, while the main constituents of the fractions from Bridelia ferruginea were fatty acid esters (47.46%) and triterpenoids (43.39%). Each of the fractions has at least one exclusive tetracyclic or pentacyclic triterpenoid present. Friedelan-3-one and clionasterol were present in the Alstonia boonei fractions, while beta-amyrin, lup-20(29)-en-3-one, lupeol, alpha-amyrin acetate and 4,
Tropical Agriculture, Oct 5, 2016
Synthetic pesticides are usually environmentally hazardous. In an attempt to obtain an eco-friend... more Synthetic pesticides are usually environmentally hazardous. In an attempt to obtain an eco-friendly alternative to synthetic nematicidal agents, isovitexin, a flavonoid glycoside isolated from butanol fraction of the leaf extract of Kigelia pinnata was examined for its in vitro nematicidal potential. The chemical structure of the isovitexin was confirmed by comparing its UV, IR, MS and NMR spectroscopic data with that reported in literature. The compound induced a hundred percent mortality at 24 h of exposure and inhibited egg hatch of Meloidogyne incognita at a concentration of 0.16 mg/mL. There was no significant difference (p<0.05) in the action of isovitexin and the synthetic nematicide, oxamyl, when tested at the same concentration. The bioactivity and toxicity evaluation on ‘molinspiration’ and ‘toxpredict’ evaluators indicated that isovitexin is a potentially bioactive compound with low genotoxic carcinogenicity and high enzyme inhibition activity. The biodegradability evaluation indicated that it belongs to a class 2 persistent chemical. The results of this study could be harnessed to make isovitexin commercially available as a natural nematicide. This is the first account of isovitexin being isolated from Kigelia pinnata and evaluated for nematicidal potential.
Indian phytopathology, Mar 17, 2022
Pakistan Journal of Nematology, 2022
| Jew's mallow (Corchorus olitorius) is a vegetable of importance in Nigeria which is often times... more | Jew's mallow (Corchorus olitorius) is a vegetable of importance in Nigeria which is often times infested with root-knot nematodes (RKNs), thus reducing yield and expected income. Principally, synthetic nematicides are employed in the management of RKNs on agricultural fields. The synthetics are confronted with a web of regulations on account of their unhealty negative effect on humans and the environment. Plant protection is primarily saddled with replacing the synthetics. A promising technique is the application of bio-pesticides. Organic fatty acid esters (FAE) are reassuring materials with nematicidal activities. Medicinal plants are rich source of acid esters, hence Alstonia boonei (Apocynaceae) leaves were extracted cold in ethyl acetate. This yielded crude extract that was subjected to column chromatography (silica gel 100-120 mesh grade), which afforded fractions that were analysed with GCMS and FTIR for constituent identification. The result shows octanoic acid; hexanoic acid methyl ester; ethyl octanoate; 9, 12-octadecadienoic acid methyl ester; dodecanoic acid; octadecanoic acid methyl ester; decanoic acid; octadecanoic acid ethyl ester and tetradecanoic acid as the major components while the infra red spectral diagnostic signals agree with the expected vibrational frequencies corresponding to C-H and carbonyl C=O functional groups of fatty acid and esters. Jew's mallow plants infected with Meloidogyne incognita on the field were treated with the fatty acid esters (FAE) and compared to deionised water and carbofuran as control in two season trials. There was increase in biomass and vegetative growth with notable reduction in M. incognita reproduction in plants treated with FAE at 0.75 mg/ml in the first and repeat experiments. Juvenile population per gram root and soil were reduced significantly at 0.75 and 0.50 mg/ml of FAE in comparison with control. Late flowering was recorded in the untreated control experiment, while plants treated with FAE flowered notably earlier. Application of FAE is recommended for the sustainable management of M. incognita in Jew's mallow plants.
Pakistan Journal of Nematology, 2012
Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, Sep 1, 2021
Field studies were conducted on the application of Leucaena leucocephala leaf extracts as an alte... more Field studies were conducted on the application of Leucaena leucocephala leaf extracts as an alternative to carbofuran a synthetic nematicide, while possible residues of carbofuran in tomato fruits were also analysed. Acetone, methanol and petroleum ether fractions of the leaves of L. leucocephala were applied at 200 mg/mL in variants of 100 mL, 150 mL and 200 mL to a naturally nematode infested field. Comparison was made with carbofuran a synthetic insecticide and nematicide. Samples of tomato fruits from carbofuran treated and untreated beds were extracted with ethyl acetate for residual pesticide analysis to ascertain the exceedance of the maximum residue limit (MRL). Results revealed that pesticide residue was significantly (p = 0.05) higher in plots treated with carbofuran compared with standard MRL for carbofuran in tomatoes. Crude extracts of L. leucocephala were as effective as carbofuran, while the fraction was however significantly better in producing higher numbers of fruits and reduced nematode population in root and soil of tomato plants.
Sarhad Journal of Agriculture, 2020