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Allelopathic effect of pentaclethra macrophylla benth. leaf extracts on germination and seedling growth of maize and okra
(2020) Ogbu, J.U.; Awodoyin, R.O.; Olubode, O.S.
Pentaclethra macrophylla Benth. is an indigenous leguminous tree of southern Nigeria's agroecosystems, whose seeds are used as spices; however, its allelopathy potential is not understood. Therefore, this study was aimed at investigating P. macrophylla allelopathic effects on germination and seedling growth of maize and okra. Materials and Methods: Allelopathic effects of Aqueous Leaf Extracts (ALE) of P. macrophylla at 0 (control), 10, 20, 40 and 80% concentrations on maize (n = 200) and okra (n = 200) seed germination and seedling growth were assessed in laboratory and screen house nursery. Total germination (%) for both crops was determined at one Week After Sowing (WAS); while Number of Leaves (NL), Plant Height(PH) (cm), Root Length (RL) (cm) and Dry Weight (DW) (g) were evaluated at 8 WAS. Experimental design used in the study was completely randomized design. Data were analyzed using descriptive statistics and ANOVA at a0.05. Results: Above 90.0% germination was recorded for maize in all the ALE concentrations, while for okra ALE-10 gave significantly highest germination (90.0±8.7%) and ALE-80 gave least (42.5±26.3%). Maize and okra seedlings given ALE-40 had highest NL, PH and DW;* while ALE-0 (control) had least values in PH and DW, respectively. Control had highest RL in both crops. The ALE-10 gave least RL in maize and ALE-20 gave least RL in okra. Conclusion: Pentaclethra macrophylla aqueous leaf extract at 10% enhanced germination, while 40% concentration encouraged dry matter accumulation and height in maize and okra seedlings.
Allelopathic effects of aqueous extracts of olax subscorpioidea oliv. on seed germination and growth of okra (abelmoschus esculentus (l.) moench) in Ibadan, Nigeria
(2022) Ayoola, D.O.; Olubode, O.S.
Allelochemicals are being explored as environmentally friendly options in weed management and crop yield improvement as opposed to use of synthetic pesticides which have serious environmental damages. Allelopathic effects of aqueous extracts of different parts of Olax subscorpioidea on Okra seed germination in Petri-dish bioassays and okra performance in pot experiment were conducted in the Department of Crop Protection and Environmental Biology, University of Ibadan using a complete randomized design (CRD) and with treatments replicated five times. Ten okra seeds in three replicates were treated in separate petri-dishes with 2 ml water extracts of stem, leaf, fruit, bark and root of Olax subscorpioidea, and 2 ml distilled water (control) in two trials. Pot trials was carried out using okra seedlings with treated with 100 ml extracts at seven days intervals. Data were collected on number of germinated seeds daily and lengths of five randomly selected plumules and radicles at 7 days after sowing (DAS). Number of leaves, plant height, root and shoot dry weight of seedlings were also measured using standard methods. Data were analyzed by analysis of variance. Statistically significant (P<0.05) means were separated using Duncan’s Multiple Range Test. Leaf extract had the highest concentrations of phenolic, flavonoid and saponin compounds compared, while the stem extract had the least metabolite concentrations. Leaf extracts exerted highest inhibition on okra germination at 2 and 7 DAS in the first trial and at 7 DAS in the second trial compared to the bark, stem, root and fruit extracts of Olax subscorpioidea. The seedling growth and yield parameters in treatment extracts were better than control. In conclusion, Olax subscorpioidea has allelopathic potential with effects on germination and seedling growth of okra. It can be used as an alternative bioherbicide. Its production and agricultural potentials should be promoted.
Allelopathic potential of some biocontrol agents for the control of fungal rot of yellow yam (Dioscorea cayenensis Lam)
(2015) Dania, V. O; Fadina, O.O; Ayodele, M..; Kumar, P. L.
The adverse effects of synthetic pesticides on human health and natural ecosystem necessitate the need to explore natural mechanisms of disease control in plants. This study evaluated the allelopathic potential of five biocontrol agents: Trichoderma longibrachiatum, Trichoderma asperellum, Bacillus subtilis, Bacillus cereus and Pseudomonas fluorescens in the control of six fungal pathogens associated with tuber rot of Dioscorea cayenensis. Rotten tuber samples were randomly collected across three agro-ecological zones (AEZs): humid rainforest (HF), derived savanna (DS), and southern Guinea savanna (SGS) in Nigeria. Biocontrol agents were isolated from the yam rhizosphere using the serial dilution method; the agar paring method was used for the in vivo trials. The destruction sampling method was used to evaluate rot control by the antagonists in vivo. Aspergillus niger had the highest incidence of 64.71% across the HF, 52.08% across the DS, and 41.98% across the SGS. B. subtilis had the highest inhibitory zone of 16.7+0.05% when paired with A. niger, 15.4+ 0.01% with Lasiodiplodia theobromate, 14.0 + 0.33% with Penicillium oxalicum, 7.1 + 0.14% when paired with Rhizoctonia solani: 17.1 + 0.11% with Sclerotium rolfisii, and 10.3 + 0.94% with Fusarium oxysporum. All biocontrol agents significantly (P=0.05) reduced rot development of the test pathogens relative to the control in the in vivo experiment. The establishment of a distant zone of inhibition, especially by the bacterial antagonist attests to the fact that they produced allelochemical substances. Therefore, further research is recommended to evaluate the biochemical composition of these microbial metabolites, their level of toxicity, and fate in the environment
The Antifungal and nematicidal potentials of vernonia amygdalina on cowpea (vigna unguiculata (l.) walp)
(2013) Onoja, C.U; Fadina, O.O
Vernonia amygdalina is a herbaceous plant that grows in the wild and is widely cultivated as food crop in sub-Saharan Africa. The study evaluated its fungicidal and nematicidal Potentials. Isolates of Macrophomina phaseolina were obtained from germinating cowpea variety IT845-2246-4 growing on natural infested soil at screen house in International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria (70 261 N, 50 541 E) and then subcultured to achieve pure culture, while inculum of the root knot nematode, Meloidogyne sp. was obtained from infested Celosia sp. plants through Standard pathological and hematological procedures. Aqueous and ethanol extracts of V. amygdalina at various concentrations of 2.5%, 5% and 10% were prepared and tested in-vitro against Macrophomina phaseolina and the root knot nematode Meloidogyne sp. At incubation of 27.50C-30C for 7-days, radial growth of the plated M. phaseolina was measured at 24-hour intervals and percentage fungitoxicity calculated, while Meloidogyne sp. egg hatch and Td juvenile stage mortality were observed at 24-hour intervals for a 10- day period. Fungitoxicity tests showed aqueous extracts of 5% and 10% concentration significant/y inhibited mycelia growth (32.08% and 34.77%, respectively) when compared with the control Ethanol extracts exhibited 100% fungicidal activity. Furthermore, egg hatch by Meloidogyne sp. was completely inhibited by both extracts preparation at 2.5% and 5% concentrations while 100% mortality of Meloidogyne sp. juveniles was observed on the fifth day post-treatment. Vernonia amygdalina was identified as a natural, readily available and cheap source of fungicide and nematicide. It is recommended for control of charcoal rot infection and Meloidogyne sp. infestation of cowpea.
Assessment of bitter yam (dioscorea dumentorum [kunth] pax) production in Oyo state, Nigeria
(2023) Olubode, O.S.; Fasola, I.A.; Gbadamosi, I.T.
Production of bitter yam (Discoreae dumentorum [Kunth.] Pax) is low in Oyo State, Nigeria. Two varieties are mainly cultivated, but there is limited information on factors responsible for low production and varietal preferences among farmers. This study investigated the demography, farming practices and differential proximate compositions as probable causes of low production of bitter yam in Oyo State. One hundred and twenty (120) copies of structured questionnaire were administered to selected respondents. Multistage sampling was used in selecting respondents in Oyo state from local government areas constituting four agricultural zones and 12 villages to collect demographic, production-related information, and constraints to production. Data were analyzed using descriptive statistics as well as analysis of variance (ANOVA). The result revealed that although bitter yam cultivation in Oyo state was male dominated (70%), majority of the farmers were old (57%), married (72%) and poorly educated (55%). Its production was for subsistence, and it was mainly grown in intercrop with other yam species. Ranked production constraints indicated poor marketability as the most extremely severe constraint, followed by labour unavailability and storage inadequacies. White bitter yam variety with superior basic proximate composition than Yellow Yam was preferred for cultivation. Subsistence production of bitter yam in Oyo state could be up-scaled through government intervention via farmer-centered education and public awareness and provision of infrastructure to facilitate cultivation, transportation, and storage.
Assessment of soil seed banks in relation to aboveground vegetation in three ecosystems within university of ibadan, Ibadan, South Western Nigeria
(2020) Afolabi, A.S.; Egberongbe, R.K.; Awodoyin, R.O.; Olubode, O.S.
Succession after disturbance. In the assessment of natural re-vegetation capacity of some ecosystems within the University of Ibadan, Nigeria, SSB contents were assessed and compared with the above-ground vegetation (AGV). Three ecosystems (Arable, Fallow and Plantation) were selected, with 25 x 25 m area marked out in each for random sampling, using XY-ordinate technique. Ten points were located for placement of wooden quadrat (50 x 50 cm). All plant species that rooted within each quadrat were enumerated. Soil samples were collected at 0-15 cm depth at the centre of each quadrat and bulked by site. One kilogram soil, replicated 12 times in each site, was monitored for seedling emergence for five months. Species richness (R), Shannon-Wiener index (H') and Jaccard Similarity Index (J) were determined for AGV and SSB. Plant family Poaceae dominated AGV while Amaranthaceae dominated SSB in all ecosystems. The R in AGV and SSB ranged from 14-24 and 6-15 respectively. The H' in AGV were close (2.27-2.69) but ranged from 0.84 (plantation) to 2.27 (arable) in SSB. The J for SSB/AGV were 33.3%, 14.3% and 5.9% in arable, fallow and plantation ecosystem respectively, indicating the highest species resemblance in the most disturbed arable ecosystem.
Assessment of soil seedbank composition, woody species composition and structure in olokemeji forest reserve, ogun state, nigeria.
(2017) Taiwo, D.M.; Olubode, O.S.; Oyelowo, O. J.
Olokemeji forest reserve has undergone tremendous changes through anthropogenic impact on the forest ecosystem, such human impacts include farming activities, logging of wood and burning. The soil seed bank composition, woody species composition and structure were studied with a view to determine the restoration potential of the forest reserve. Six sample plots (Frequently burnt plot 1, Frequently burnt plot 2, Harvested plot, Unharvested Unburnt plot, Arable plot 1 and Arable plot 2) designated as FT1, FT2, HP, UP, AP1 and AP2 were randomly selected. Floral species identification, relative importance value (RIV), species diversity and multivariate analysis all followed standard procedures. Three replicate soil samples were collected at two different depths (0-15 cm and 15-30 cm) from each plot and they were subjected to seedling emergence for five months to determine the species composition, density and diversity of the seed banks of the six study plots. The results of seedling emergence showed that soil collected at 0-15 cm depth had a higher RIV, species diversity, individual, abundance and dominance index than soil collected at 15-30 cm depth. However, the evenness index for seedlings in the soil seed bank was considerably high across the two soil depths which depicted equal measure of spread within each study plots at both soil depths. Tectona grandis was highest in RIV. The dominance index for the woody flora was 1 in frequently burnt Plot 1 and 2 as well as Arable Plot 1 and 2 except for the Harvested Plot that had the lowest (0.29) while the . Unharvested unburnt Plot had 0.75. The diversity in Harvested Plot was low (1.54), while it was extremely low in Unharvested unburnt Plot (0.43). Trees in Unharvested unburnt Plot had the highest mean diameters at breast height, basal areas and mean heights, while the Arable Plots had lowest mean diameters at breast height, mean basal areas and mean heights.
Attributes and ecological potentials of dumpsite flora in the peri-urban area of Ibadan, Nigeria
(2023) Olubode, O.S.; Ibrahim, B.A.
Dumpsites are spaces used disposal of urban and peri-urban wastes. Their public health concern has not made them to be adequately explored for positive potentials in Nigeria. This study investigated the the floristic structure and comparative potential of a dumpsite with arable farms for conservation and phytoremediation. The study was conducted at a 10-hectare peri-urban Lapite dumpsite (N 07o34.121ʹ, E 003o54.857ʹ) in Ibadan, Oyo State, Nigeria; and three arable farmlands (Control) located 200 m-300 m away from Dumpsite. Stratified sampling was conducted using 414 quadrats (each 1m2) in five strata of dumpsite, and a systematic sampling of flora of farms with 263 quaddrats in 21 transects laid 5 m apart. Data were collected on species composition, abundance,density and frequency of occurence. They were subjected to analysis of Relative importance value (RIV), density, and multivariate analysis. Species with phytoremediation potentials were identified. Ninety one species of herbaceous flora in 33 families and 99 species in 38 families were enumerated on the dumpsite and farmlands respectively. Solanum nigrum L., Tridax procumbens Linn., Amaranthus spinosus Linn., Laportea aestuans (Linn.) chew., Acalypha fimbriata Schum. & Thonn., and Lufa cylindrica Mill were the most dominant species on the dumpsite with RIVs of 8.40, 8.17, 7.54, 7.21, 6.38 and 5.79 respectively. Talinum fruticosum (L.) Juss., Tridax procumbens L., Euphorbia heterophylla Linn., Spermacoce ocymoides Burm f., and Tithonia diversifolia (Hemsl.) A. Gray were most dominant on farmlands with RIVs of 13.74, 7.05, 6.60, 6.07, and 5.57 respectively. Dumpsite flora had higher diversity (H`=3.501) than control plots (H`=3.294). The dominance value (0.0486) was low compared to the control farms (0.07131). The lora of the two sites were grouped by habitatt preference.Higher species diversity and pervasive presence of invasive Tridax procumbens linn., Laportea aestuans (Linn.) chew., and Lufa cylindrica Mill. On dumpsite indicated potentials for phytoremediation, and candidacy as functional groups and bio-indicators of ecosystem health.
Bacterial Degradation of Contaminated Soil using Organic Manure
(2018) Fadina, O. O.; Solaja, O; Abiodun, A; Adetoyi, H.
Soil contamination is the presence in soil of unwanted impure materials from human activities. Many techniques of remediation of contaminated soils have been developed such as physical, chemical, photo degradation etc. Biological treatments offer the best environmental friendly method for remediating hydrocarbons and other contaminated soils because it utilized the capability of the indigenious micro-organisms in the environment to break down the hydrocarbons and heavy metals into innocuous substances. This study investigated the abilities of bacterial isolated, identified from organic manure and determine the total petroleum hydrocarbon degradative potentials. 2kg of soil was thoroughly mixed with 200ml and 400ml of spent oil to give 5% and 10% (w/w) each of organic manure ,poultry litter(PL),cow dung(CD) and mixed poultry litter and cow dung(MPLCD) was individually introduced into each spent oil contaminated soil and the rate of biodegradation was observed for a period of 12weeks.The percentage of total petroleum hydrocarbon (TPH) loss was significantly higher in the soil contaminated with 5% spent oil amended with MPLCD(40.46%) followed by PL (35.53%) and CD(27.70%) while 32.42% loss only was recorded in the soil contaminated with 10% spent oil and amended with MPLCD while PL was 30.04% and 25.60% for CD. The hydrocarbon-utilizing bacteria isolated band identified includes Bacillus, Pseudomonas, Microccus and Staphyloccus. The amendment spent oil contaminated soil with organic manure enhances the rate of degradation of petroleum hydrocarbon. These additives can best be suited to remove or neutralize the contaminants in the soil
Biological Control of Root Knot Nematodes (Meloidogyne spp.) On Tissue Cultural Banana (Dwarf Carvendish Var. Basarai)
(2004) Fadina, O. O; Nadgauda, S. R
Biocontrol powder Phule Trichoderma has been successfully used on a number of horticultural crops. The present investigation was carried out to explore the nematicidal properties of Phule Trichoderma against the root-knot nematode (Meloidogyne spp.) infesting the tissue culture banana (Dwarf Cavendish - var. Basarai). In vitro tests slowed that the various concentrations of Phule Trichoderma prevented nematode egg hatching and also resulted in 100% mortality of nematode juveniles. Tissue culture banana plants were also dipped into various concentrations of Phule Trichoderma before planting out into plastic bags. Plant were inoculated with 250 nematode juveniles and alter ten days, the roots were stained with cotton blue lactophenol and nematodes were counted under a dissecting microscope. The results indicated that the higher the concentration of Phule Trichoderma in banana plants, the lower the ability of the nematode to penetrate the roots. Furthermore, the nematode juveniles that penetrated the treated roots were found dead. This could have resulted from the toxic metabolites produced front Phule Trichoderma. Also, root zone treatment of plants treated with Phule Trichoderma prevented the development of giant cells and roots knots in treated plants while the development of giant cells and root knots were observed in untreated plants exposed to nematode infestation.
Biology and Ecology of the Leafroller (Sylepta derogata Fabricius) on Okra (Abelmoschus esculentus (L.) Moench)
(2012-07) IYAMU, J. I.
Sylepta derogata, Fabricius a major insect pest, defoliates and causes enormous yield loss in Abelmoschus esculentus (L) Moench. Control of the pest with chemicals and other methods have not been successful due to scanty information on the biology and ecology of the pest. This study was conducted to assess the biology and ecology of Sylepta derogata on Abelmoschus esculentus. Abelmoschus esculentus was planted in early (March-June, 2009), mid (July-September, 2009) and late (November 2009-January,2010) seasons at the Crop Garden of the Department of Crop Protection and Environmental Biology, University of Ibadan, Nigeria. The experiment was laid out in Randomized Complete Block Design in four replicates. Larval population of S. derogata was estimated on 23 randomly selected plants/replicate. Data were collected on temperature, rainfall, relative humidity and percentage field infestation. Leaves of weeds around the experimental plot were observed for habitation and damage by S. derogata. Observations were made on the presence of natural enemies on S. derogata in the field and identified in the laboratory. The life cycle of S. derogata was investigated in the field under natural weather conditions of 22oC-31oC, 39-90% relative humidity and mean rainfall of 2.8 mm. In the laboratory, assessment was done under room temperature of 24oC-28oC and 79-92% relative humidity, on the reproductive biology, development and morphometrics of immature stages of S. derogata. Data were analysed using descriptive statistics, correlation and ANOVA at P=0.05. The field population of S. derogata larvae was highest in November and December with 96.2% larval infestation while it was lowest in July and August with 16.1% and 11.3% infestation respectively coinciding with the highest fruit yield. A significant (P=0.05) inverse relationship was observed between S. derogata abundance; and each of rainfall (r = -0.80) and temperature only (r = -0.85) in early season, rainfall (r = -0.28) and temperature (r = -0.17) in mid-season and temperature (r = -0.73) in late season when rainfall receded. However, a significant (P=0.05) direct relationship was observed between S. derogata abundance and relative humidity at the late season planting (r = 0.18). The mean developmental period from egg to adult was 28 days. The life cycle consisted of egg, five larval stages, pre-pupa, pupa and adult stages. The mean oviposition period was 2 days. The head capsule width ranged from 0.2mm in the first instar to 2.1mm in the fifth instar. The growth index of 1.8 recorded did not conform to Dyar’s rule of 1.4. The females were significantly larger in size than the males. The sex ratio was 1.5:1 (male: female). Apanteles sp was the natural enemy identified on S. derogata which could be used as biological control agent of the larval stages of S. derogata, while the alternative host plant was Solanum nigrum. Late season planting of Okra requires control measures. Apanteles sp can be used in the control of S. derogata on okra. The short developmental period of S. derogata indicates the possibility of this pest completing two generations on okra during the growing season thereby increasing the larval population and leaf damage.
Cassava micropropagation in a developing economy: efficacy of the use of alternative sources of water, macro and micro-nutrients
(Science Association of Nigeria, 2003) Balogun, M. O.; Ng, S. Y. C.; Fawole, I.
The effect of water, micro- and macro-nutrient source on growth and development of cassava plantlets was investigated. Two varieties of cassava (TME 2 and TMS 4(2) 1425) were used. The double- distilled water currently being used was substituted with well water, IITA tap water and water from air conditioner (a/c); while the Murashige and Skoog (MS) basal medium popularly adopted as the source of macro-nutrients, micro-nutrients and vitamins was also substituted with fertilizers and multimineral tablet. Percentage root formation, plantlet formation and number of roots per plantlet were considerably reduced when tap water was used in TMS 4(2) 1425 but not in TME 2. Well water and a/c water performed equally well as double-distilled water in supporting plantlet growth and development. Almost all the plantlets grown in medium with fertilizer as macro-nutrient source did not survive while those grown in medium with multimineral tablet as micro-nutrient source appeared stunted. Most of those grown in medium with both fertilizer and multimineral tablet as macro- and micro-nutrient sources also did not survive. MS basal medium still proved to be the best in supporting plantlet growth and development, it was however the most expensive.
Clean breeder seed yam tuber production using temporary immersion bioreactors
(International Institute of Tropical Agriculture (IITA), Ibadan, 2017) Balogun, M.; Maroya, N.; Taiwo, J.; Ajayi, A.; Ossai, C.; Lava, K.; Pelemo, O.; Aighewi, B.; Asiedu, R.
Climate change and the potential distribution of the invasive shrub, leucaena leucocephala (lam.) de wit in Africa
(2023) Obiakara, M.C.; Olubode, O.S.; Chukwuka, K.S.
Leucaena leucocephala, previously known as ‘miracle tree’ because of its numerous agroforestry uses has become a seri¬ous invasive species in tropical regions. Despite the risks associated with the spread of L. leucocephala, changes in its distribution with respect to climate are poorly understood, particularly in Africa where it has been widely introduced in more than 30 countries. To provide first-line information for the management of L. leucocephala, we examined its poten-tial distribution in Africa using ecological niche modelling. We identified bioclimatic variables that determine the global distribution of L. leucocephala, and calibrated niche models using MaxEnt and species occurrences recorded between 1973 and 2013. The potential distribution of this species was estimated from model projections in Africa based on cur¬rent and future climatic conditions. We tested the hypothesis of niche conservatism for L. leucocephala by comparing its climatic niche in Africa to that of its native range. Under current conditions, L. leucocephala is constrained between 30° S and 20° N in Africa, with the broadest distribution in East Africa. High rainfall areas in Central Africa with no known records of this species hitherto, were found to be highly suitable for its establishment. We predicted a significant decre¬ment in the extent of areas at risk of invasion by L. Leucocephala under changing climates in Africa. Our results revealed that the study species occupies a similar but non-identical climatic niche in Africa in relation to its native niche. Climate change is likely to impede the spread of L. leucocephala in Africa.
Climate change and the potential distribution of the invasive shrub, leucaena leucocephala (lam.) de wit in Africa
(2023) Obiakara, M.C.; Olubode, O.S.; Chukwuka, K.S.
Leucaena leucocephala, previously known as ‘miracle tree’ because of its numerous agroforestry uses has become a seri¬ous invasive species in tropical regions. Despite the risks associated with the spread of L. leucocephala, changes in its distribution with respect to climate are poorly understood, particularly in Africa where it has been widely introduced in more than 30 countries. To provide first-line information for the management of L. leucocephala, we examined its poten-tial distribution in Africa using ecological niche modelling. We identified bioclimatic variables that determine the global distribution of L. leucocephala, and calibrated niche models using MaxEnt and species occurrences recorded between 1973 and 2013. The potential distribution of this species was estimated from model projections in Africa based on cur¬rent and future climatic conditions. We tested the hypothesis of niche conservatism for L. leucocephala by comparing its climatic niche in Africa to that of its native range. Under current conditions, L. leucocephala is constrained between 30° S and 20° N in Africa, with the broadest distribution in East Africa. High rainfall areas in Central Africa with no known records of this species hitherto, were found to be highly suitable for its establishment. We predicted a significant decre¬ment in the extent of areas at risk of invasion by L. Leucocephala under changing climates in Africa. Our results revealed that the study species occupies a similar but non-identical climatic niche in Africa in relation to its native niche. Climate change is likely to impede the spread of L. leucocephala in Africa.
Climate change, impacts and mitigation: Nigerian experience
(2010) Ogunyemi, S.; Awodoyiu, R.O.; Olubode, O.S.
Climate has continued to change for millennia. The various anthropogenic factors have accelerated the change to the extent that what used to be subtle natural changes have become measurable and observable changes. These anthropogenic factors have resulted in the generation of greenhouse gases (GHGs) and their emission to the atmosphere and the depletion of the ozone layer. The GHGs, especially carbon dioxide (COz) generated from various combustion activities; methane (CHf generated from rice paddies and flooded areas as a result of anaerobic fermentation, and from ruminating cattle and nitrous oxide (NfO) generated from decomposition of nitrogen fertilizers and livestock wastes trap some of the heat (infrared) that radiate from the earth. The ozone layer at the upper stratosphere which shields the earth specifically from the ultraviolet (UV) light is constantly being destroyed by the immense quantities of chlorine released by volcanoes and other natural emissions, and by chlorine releasedfrom human-made chlorofluorocarbons (CFC, HCFC, HFC, PFC). The most visible effect of climate change is global warming, which has disrupted the thermodynamic balance of the earth, with some regions unnaturally gaining more heat than the others. This rise in earth temperatures has resulted in continued melting of ice caps, glaciers and sea ice, resulting in a rise in global sea levels of between 20cm and 60cm. The Nigerian Niger Delta is under threat of climate related flooding, habitat destruction and species loss. The coastal erosion in the Niger Delta occasioned by sea-level rise is already a menace, especially, regarding destruction of mangrove vegetation which constitutes an important stabilizing system in the brackish ecosystem. Already, 18,803 square kilometers was reported destroyed and 0.21 million people displaced by up to 2-meter coastal sea-level rise. The receipt of increased UV on earth not only increased the temperature on earth, but has serious implications on human health, causing melanoma skin cancer, cataracts and sunburn and altering human's immune system. Afforestation, reforestation, zero-tillage, replacement offossilized fuels with environment-friendly fitels and energy sources like bio-diesel and sustained public awareness programmes are suggested as ways to mitigate the emission of GHGs.
Combining ability and heterosis for fibre yield traits in Nigeria kenaf (Hibiscus cannabinus L.) Collections
(The Genetics Society of Nigeria, 2014) Akisanya, A. O.; Balogun, M. O.
Kenafas a renewable fibre crop is known to yield lower in Nigeria than in other countries of the world. An experiment was conducted at the University of Ibadan, Oyo State, Nigeria, where sixteen (16) crosses were made among four (4) Nigeria kenaf (Hibicuscannabinus) accessions to investigate the combining ability and heterosis for fibre yield traits in the hybrids. The parents and progenies were planted in three replicates in a randomized complete block design. Data were collected on plant height, stem diameter and girth at flowering and at harvest, as well as stalk weight at harvest and means separated at P=0.05. Results showed no significant differences among genotypes at flowering and for stalk weight at harvest. Higher general combining ability (GCA) over specific combining ability (SCA) was recorded for all characters at harvest. Only accession NHC 10(1) had a positive GCA for height at harvest (21.84) and girth at harvest (1.09). The highest SCA effects were recorded in cross NHC 10(1) X NHC 2(2) for all measured traits. In contrast, the highest positive mid-parentheterosis (28.02%) was obtained in the reciprocal cross NHC 15 X NHC 10(1)followed by NHC 2(2) X NHC 10(1) (25.76%) for HAH. Both crosses had parent NHC 10(1) to be one of their respective parents. Thus, this study identified hybrids NHC 15 X NHC 10(1) and NHC 2(2) XNHC 10(1) as promising for improvement of fibre yield traits. However, performances of these hybrids need to be evaluated in multi-locational and on-farm trials prior to commercial use.
Comparative assessment of three sources of crude cassava water extract as bio-herbicide
(2013) Fayinminu, O. O.; Fadina, O.O; Olabiyi, T. I
Two experiments were conducted at Owode- Ijako in Ogun State, Nigeria between September 2006 and April 2007 to investigate the efficacy of three sources of Crude Cassava Water Extract (CCWE) as post emergence herbicide on weeds of cowpea. The trials were arranged in randomized complete block design and replicated three times. The treatments were 25% and 50% of Bulk sample, MS6 and TMS extracts respectively, and two controls; unweeded and handweeded in each trial. Herbicidal efficacies of CCWE in controlling cowpea weeds were evaluated using phytotoxicity, weed biomass and density. The results showed that spraying CCWE of Bulk and MS6 at 50% on cowpea weed caused 40 and 50% phytotoxicity respectively. There was no significant difference in weed biomass (65.3% and 74.5%) and weed density (79.92 and 80.33) of CCWE of bulk sample and MS6 respectively. Whereas handweeded achieved 98.68% and 96.65% weed biomass and density respectively. The growth attributes such as plant height, number of leaves and leaf area differed significantly due to different treatments. Grain yield and yield components of cowpea were significantly influenced by the application of CCWE from the three sources. Highest grain yield (540kg/ha) was recorded in handweeded plots but was comparable to plots sprayed with 50% CCWE of bulk samples (450kg/ha) and MS6 (430kg/ha) while least grain yield was recorded in unweeded plots.
Comparative effects of explant sources and genotypes on microtuberization in yams (Dioscorea spp.)
(Wiley InterScience, 2004) Balogun, M. O.; Ng, S. Y. C.; Shiwachi, H.; Ng, N. Q.; Fawole, I.
Single node cuttings of two genotypes each of Dioscorea alata and D. rotundata from both plants grown in screen houses and in vitro plantlets were cultured in a tuberization medium. The screen house explants had significantly higher plantlet tuberization and primary nodal complex formation, and more tubers and primary nodal complexes per plantlet than in vitro explants, whereas in vitro explants performed better only in nodes per plantlet. It appears that in vitro tuberization is explant- , species- and genotype-dependent, the greatest variation being due to explant source. This is a first report of microtuber production from nodal explants of D. rotundata produced in a screen house.
Comparative Effects of Neem (Azadirachta Indica) Extracts and Karate (Lambdacyhalothrin) in the Control of the Root Knot Nematode (Meloidogyne Incognita) on Celosia Argentea
(2013) Okafor, S. A.; Fadina, O.O
In order to compare the effects of lambdacyhalothrin, a synthetic pyrethriods and neem (Azadirachta indica) extracts in the control of the root knot nematode of Celosia argentea, two weeks old plants of C.argentea were inoculated with 7,000 eggs of Meloidogyne incognita. Seven days after inoculation, the plants were treated with two concentrations of lambdacyhalothrin at 6,000ppm and 3,000ppm and neem oil extract at 2.14 ml/kg and 4.28ml/kg of soil. Untreated nematode-inoculated C.argentea plants served as negative control while uninoculated C. argentea plants served as positive control. Three weeks after inoculated and subsequently till the 8th week, data were collected on growth parameters such as stem height, number of leaves and yield parameters such as fresh shoot weight, fresh root weight, and root galling indices. There were significant differences between the untreated-nematode inoculated plants, had the lowest values. There were also no significant differences between Lambdacyhalothrin-treated plants at both 6000ppm and 3000ppm for all the parameters considered. Thus, neem oil at 2.14 ml/kg of soil is recommended as an alternative for Lambdacyhalothrin at 6000ppm and 3000ppm concentrations in the control of root knot nematode of C.argentea since the leaf is the most important part and in view of its environment friendliness