Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45785
Vv Vordzogbe, D. Attuquayefio, F. Gbogbo
The study presents results of a floristic and mammal survey undertaken in the Sefwi-Wiawso District within moist semi-deciduous vegetation zone of the Western Region of Ghana. The floral survey involved estimating the floral distribution, abundance and diversity using the standard indices, Shannon-Wiener, Simpson’s, evenness, species richness, similarity, and â-diversity, while the mammal survey was conducted using direct opportunistic observation, live-trapping (small mammals), animal spoors/trophies, and interviews. There were 271 plant species recorded, out of which 174 species comprising 172 species and 67 families of angiosperms (Angiospermae) and two species of ferns (Pterydophyta) were scientifically-named. Forty species of mammals representing eight orders were recorded, with the dominant orders being Rodentia and Artiodactyla. The greatest faunal diversity occurred in the forest reserves, where suitable habitat niches still occur. There were 48 individuals of seven species of rodents and one individual of one insectivore species captured during live-trapping, with the commonest species being common mice (Mus spp.) and brush-furred mice (Lophuromys flavopunctatus). The greatest threat to the survival of the fauna is habitat destruction. Generally, the Sefwi-Wiawso District is very rich in forest tree species, the commonest being the Celtis-Triplochiton Associations, but bad agricultural practices, bush burning, intense logging, fuelwood harvesting and pollution have resulted in poor soil quality and land degradation in certain areas. Hunting of animals for meat, and destruction of habitats were the greatest threats to faunal diversity and abundance in the Sefwi-Wiawso District.
{"title":"The Flora and mammals of the moist semi-deciduous Forest Zone in the Sefwi-Wiawso District of the Western Region, Ghana","authors":"Vv Vordzogbe, D. Attuquayefio, F. Gbogbo","doi":"10.4314/WAJAE.V8I1.45785","DOIUrl":"https://doi.org/10.4314/WAJAE.V8I1.45785","url":null,"abstract":"The study presents results of a floristic and mammal survey undertaken in the Sefwi-Wiawso District within moist semi-deciduous vegetation zone of the Western Region of Ghana. The floral survey involved estimating the floral distribution, abundance and diversity using the standard indices, Shannon-Wiener, Simpson’s, evenness, species richness, similarity, and â-diversity, while the mammal survey was conducted using direct opportunistic observation, live-trapping (small mammals), animal spoors/trophies, and interviews. There were 271 plant species recorded, out of which 174 species comprising 172 species and 67 families of angiosperms (Angiospermae) and two species of ferns (Pterydophyta) were scientifically-named. Forty species of mammals representing eight orders were recorded, with the dominant orders being Rodentia and Artiodactyla. The greatest faunal diversity occurred in the forest reserves, where suitable habitat niches still occur. There were 48 individuals of seven species of rodents and one individual of one insectivore species captured during live-trapping, with the commonest species being common mice (Mus spp.) and brush-furred mice (Lophuromys flavopunctatus). The greatest threat to the survival of the fauna is habitat destruction. Generally, the Sefwi-Wiawso District is very rich in forest tree species, the commonest being the Celtis-Triplochiton Associations, but bad agricultural practices, bush burning, intense logging, fuelwood harvesting and pollution have resulted in poor soil quality and land degradation in certain areas. Hunting of animals for meat, and destruction of habitats were the greatest threats to faunal diversity and abundance in the Sefwi-Wiawso District.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V8I1.45785","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70414566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45797
C. Behrensdorff, B. Elberling, L. Krogh
Acidic tropical soils often have high Al3+ concentrations in soil solutions, which can be toxic to plants and, thereby, reduce agricultural yields. This study focuses on the impact of deforestation and cultivation on the short and long-term Al geochemistry of acidic soils in Ghana, West Africa. Site-specific investigations were made at two sites covered with forest and one site cultivated with maize (Zea mays L.). The capacity of soil to resist acidification was investigated in a leaching experiment and the corresponding release of aluminium quantified. Field results revealed a significant aacidification and Al mobility in the root zone of the cultivated site as compared to the forest sites. The leaching experiment showed that further acidification would significantly enhance Al-release and, consequently, the presence of Al3+ in soil solution. It is concluded that deforestation and cultivation in the study area has resulted in increasing levels of Al3+ and a lowering of the soils capacity to resists further acidification. This may be critical in relation to land-use management and long-term agricultural productions.
{"title":"Aluminium release from acidic forest soil following deforestation and maize cultivation in Ghana, West Africa","authors":"C. Behrensdorff, B. Elberling, L. Krogh","doi":"10.4314/WAJAE.V8I1.45797","DOIUrl":"https://doi.org/10.4314/WAJAE.V8I1.45797","url":null,"abstract":"Acidic tropical soils often have high Al3+ concentrations in soil solutions, which can be toxic to plants and, thereby, reduce agricultural yields. This study focuses on the impact of deforestation and cultivation on the short and long-term Al geochemistry of acidic soils in Ghana, West Africa. Site-specific investigations were made at two sites covered with forest and one site cultivated with maize (Zea mays L.). The capacity of soil to resist acidification was investigated in a leaching experiment and the corresponding release of aluminium quantified. Field results revealed a significant aacidification and Al mobility in the root zone of the cultivated site as compared to the forest sites. The leaching experiment showed that further acidification would significantly enhance Al-release and, consequently, the presence of Al3+ in soil solution. It is concluded that deforestation and cultivation in the study area has resulted in increasing levels of Al3+ and a lowering of the soils capacity to resists further acidification. This may be critical in relation to land-use management and long-term agricultural productions.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V8I1.45797","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70414996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45801
C. Edokpayi, A. Ayorinde
A comparative study conducted on three swampy water bodies draining through the University of Lagos into the Lagos Lagoon describes the physical, chemical and macrobenthic invertebrate characteristics of these water bodies at the study sites. Three stations, one at each water body were sampled fortnightly from June to December, 2000. Water temperature, total alkalinity and salinity were the only physical and chemical conditions significantly different at the study stations. The physical and chemical conditions at stations A and B were similar and significantly different from station C exposed to domestic effluent, thereby, reflecting the perturbational stress at that site. A total of 43 benthic invertebrate taxa belonging to five classes, 31 families and 2424 individuals were recorded at the study stations. The study stations can be ranked as B > A > C and B > C > A in terms of number of taxa and number of individuals, respectively. The low number of taxa and individuals in stations A and C is suggestive of habitat instability. The pattern of invertebrate distribution and abundance was influenced by the fluctuations in the abundance of Oligochaeta, Hemiptera and Diptera. The taxon richness (D), genera diversity (H) and evenness (E) estimated for the study sites supported the trends observed in the numbers of taxa occurring and their abundance. The low concentrated dominance (C) calculated for station B compared to stations A and C reflects an ecologically heterogenous and relatively stable site. Morisita-Horn index showed that station C was dissimilar to stations A and B. Jaccard’s coefficient indicated that all stations were dissimilar. In general, the faunal comparison showed that the level of exposure to urban discharges, inert pollutants and the presence of aquatic macrophytes influenced the differences in the abundance, occurrence and number of taxa at the three stations.
对通过拉各斯大学流入拉各斯泻湖的三个沼泽水体进行了比较研究，描述了研究地点这些水体的物理、化学和大型底栖无脊椎动物特征。2000年6月至12月，每两周采样三个站点，每个水体一个站点。水温、总碱度和盐度是各研究站唯一存在显著差异的物理和化学条件。A站和B站的物理和化学条件与暴露于生活污水的C站相似，但存在显著差异，从而反映了该站点的扰动应力。共记录到底栖无脊椎动物5纲31科43种，个体2424只。按类群数和个体数分别为B > A > C和B > C > A。A站和C站的类群和个体数量较少，表明生境不稳定。少毛目、半翅目和双翅目动物的丰度变化影响了无脊椎动物的分布格局和丰度。类群丰富度(D)、属多样性(H)和均匀度(E)与类群数量和丰度的变化趋势一致。与A站和C站相比，B站的低集中优势度(C)反映了生态异质性和相对稳定的立地。Morisita-Horn指数表明C站与A站和b站不相似。Jaccard系数表明所有站都不相似。总的来说，区系比较表明，城市污水暴露水平、惰性污染物和水生植物的存在影响了3个站点的类群丰度、发生率和数量的差异。
{"title":"Physical, chemical and macrobenthic invertebrate fauna characteristics of swampy water bodies within University of Lagos, Nigeria","authors":"C. Edokpayi, A. Ayorinde","doi":"10.4314/WAJAE.V8I1.45801","DOIUrl":"https://doi.org/10.4314/WAJAE.V8I1.45801","url":null,"abstract":"A comparative study conducted on three swampy water bodies draining through the University of Lagos into the Lagos Lagoon describes the physical, chemical and macrobenthic invertebrate characteristics of these water bodies at the study sites. Three stations, one at each water body were sampled fortnightly from June to December, 2000. Water temperature, total alkalinity and salinity were the only physical and chemical conditions significantly different at the study stations. The physical and chemical conditions at stations A and B were similar and significantly different from station C exposed to domestic effluent, thereby, reflecting the perturbational stress at that site. A total of 43 benthic invertebrate taxa belonging to five classes, 31 families and 2424 individuals were recorded at the study stations. The study stations can be ranked as B > A > C and B > C > A in terms of number of taxa and number of individuals, respectively. The low number of taxa and individuals in stations A and C is suggestive of habitat instability. The pattern of invertebrate distribution and abundance was influenced by the fluctuations in the abundance of Oligochaeta, Hemiptera and Diptera. The taxon richness (D), genera diversity (H) and evenness (E) estimated for the study sites supported the trends observed in the numbers of taxa occurring and their abundance. The low concentrated dominance (C) calculated for station B compared to stations A and C reflects an ecologically heterogenous and relatively stable site. Morisita-Horn index showed that station C was dissimilar to stations A and B. Jaccard’s coefficient indicated that all stations were dissimilar. In general, the faunal comparison showed that the level of exposure to urban discharges, inert pollutants and the presence of aquatic macrophytes influenced the differences in the abundance, occurrence and number of taxa at the three stations.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V8I1.45801","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70415230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45780
Bk Kortatsi, E. Young, A. Mensah-Bonsu
The potential impact of large-scale groundwater abstraction on the shallow groundwater and crop production within the Keta Strip was examined. The assessment was based on geophysical data, data on groundwater quality, soils, irrigation water requirement and hydrogeology of the Strip. The results indicate that the shallow groundwater can support only medium to high salt tolerant crops. This is consistent with the medium salt tolerant crops especially shallot and onion currently grown in the area. Large-scale irrigation of the Strip will require at least 2 x 107 m3 of water during the dry season. Abstraction of such large volume of water from the shallow aquifer will result in the lowering of water table by approximately 1.0 m per year. The consequence of this will be the up coning of the fresh/saline water interface probably by as much as 4.7 m, resulting in salinisation of the fresh water lenses particularly around the lagoon end where most of the shallot farms are situated. Apart from up conning, salinisation may result from ingress of brackish/saline water from the lagoon and sea into the fresh water lenses. Though post irrigation rainfall will be adequate to nullify the water table depression, once the fresh water is contaminated, it is extremely difficult to decontaminate. Consequently, the shallow groundwater will evolve from medium through high to very high salinity hazard to crops. Specific ions toxicity will also increase due to increment in the concentrations of individual ions. Thus, the previously freshwater will become unsuitable for the production of even high salt tolerance crops. This will effectively halt the lucrative shallot and other vegetable farming in the Keta Strip and thus signify socio-economic disaster for the Keta Strip in particular and Ghana in general.
{"title":"Potential impact of large scale abstraction on the quality of shallow groundwater for irrigation in the Keta Strip, Ghana","authors":"Bk Kortatsi, E. Young, A. Mensah-Bonsu","doi":"10.4314/WAJAE.V8I1.45780","DOIUrl":"https://doi.org/10.4314/WAJAE.V8I1.45780","url":null,"abstract":"The potential impact of large-scale groundwater abstraction on the shallow groundwater and crop production within the Keta Strip was examined. The assessment was based on geophysical data, data on groundwater quality, soils, irrigation water requirement and hydrogeology of the Strip. The results indicate that the shallow groundwater can support only medium to high salt tolerant crops. This is consistent with the medium salt tolerant crops especially shallot and onion currently grown in the area. Large-scale irrigation of the Strip will require at least 2 x 107 m3 of water during the dry season. Abstraction of such large volume of water from the shallow aquifer will result in the lowering of water table by approximately 1.0 m per year. The consequence of this will be the up coning of the fresh/saline water interface probably by as much as 4.7 m, resulting in salinisation of the fresh water lenses particularly around the lagoon end where most of the shallot farms are situated. Apart from up conning, salinisation may result from ingress of brackish/saline water from the lagoon and sea into the fresh water lenses. Though post irrigation rainfall will be adequate to nullify the water table depression, once the fresh water is contaminated, it is extremely difficult to decontaminate. Consequently, the shallow groundwater will evolve from medium through high to very high salinity hazard to crops. Specific ions toxicity will also increase due to increment in the concentrations of individual ions. Thus, the previously freshwater will become unsuitable for the production of even high salt tolerance crops. This will effectively halt the lucrative shallot and other vegetable farming in the Keta Strip and thus signify socio-economic disaster for the Keta Strip in particular and Ghana in general.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V8I1.45780","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70414483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45787
F. Nunoo, G. Ameka
Dense growths of macro-algae contribute to primary productivity in nearshore marine environments and their abundance has been correlated with fish catch. Though the two resources are captured together in beach seine nets, macro-algae are usually regarded as a nuisance by fishermen and discarded (as by-catch). The species composition, abundance and seasonality of macro-algal species in fisheries by-catch of beach seine nets at Sakumono, Ghana were determined between November 1999 and September 2001. Data was analysed using a combination of both univariate and multivariate procedures. The species richness of macro-algae in the catch was high and appeared to vary monthly. Biomass of macro-algae in the catch was found to be low (range 0–6.7%) and formed only 7.7% of the by-catch. The significance of macro-algae in by-catch is discussed.
{"title":"Occurrence of macro-algae in the by-catch of Beach Seine Fisheries at Sakumono, Ghana","authors":"F. Nunoo, G. Ameka","doi":"10.4314/WAJAE.V8I1.45787","DOIUrl":"https://doi.org/10.4314/WAJAE.V8I1.45787","url":null,"abstract":"Dense growths of macro-algae contribute to primary productivity in nearshore marine environments and their abundance has been correlated with fish catch. Though the two resources are captured together in beach seine nets, macro-algae are usually regarded as a nuisance by fishermen and discarded (as by-catch). The species composition, abundance and seasonality of macro-algal species in fisheries by-catch of beach seine nets at Sakumono, Ghana were determined between November 1999 and September 2001. Data was analysed using a combination of both univariate and multivariate procedures. The species richness of macro-algae in the catch was high and appeared to vary monthly. Biomass of macro-algae in the catch was found to be low (range 0–6.7%) and formed only 7.7% of the by-catch. The significance of macro-algae in by-catch is discussed.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V8I1.45787","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70414627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45784
O. Ansa-Asare, K. Asante
The studies of the changes in Weija lake waters after 20 years of impoundment, were aimed at examining the status in the chemical characteristics of the Weija lake, by analysing available data collected over a 5-year period (1993–1997), and comparing them with the first 5 years of impoundment between 1977 and 1982. The study showed supersaturated dissolved oxygen concentrations, indicating the lake waters had recovered from the initial low oxygen saturation during the first few years of impoundment. The lake waters had high oxygen demand from the high phytoplankton levels and organic matter in the dry season. Chlorophyll ‘a’, which is an indication of algal biomass content, correlated with total inorganic carbon (alkalinity), giving a correlation coefficient of 0.61 at 95% confidence limit, reflecting the fact that both parameters decreased in the rainy season, and were higher in the dry season. The initial high concentration of nutrients also decreased after 20 years with the exception of nitrate, which concentration increased at the rate of 1.07 mg l-1 year –1 over the last 5 years, a condition that could mainly be attributed to nitrogen input from domestic and agricultural origin. The high seasonal trend of nitrate in the months of March and May was due to the fact that the period is the main farming season in the Weija catchment area when most fertilizers are applied. With respect to the major ions, slight increases in their concentrations occurred. Ionic concentration patterns were found to be Na > Ca > Mg > K and HCO3 > Cl > SO4. The cationic pattern was in contrast to the previously reported pattern of Na > Mg > Ca > K, showing complete mixing of the lake waters with moderate rock weathering rate but a strong influence of maritime-derived salts.
{"title":"Changes in the chemistry of the Weija Dam Reservoir in Ghana, twenty years after impoundment","authors":"O. Ansa-Asare, K. Asante","doi":"10.4314/WAJAE.V8I1.45784","DOIUrl":"https://doi.org/10.4314/WAJAE.V8I1.45784","url":null,"abstract":"The studies of the changes in Weija lake waters after 20 years of impoundment, were aimed at examining the status in the chemical characteristics of the Weija lake, by analysing available data collected over a 5-year period (1993–1997), and comparing them with the first 5 years of impoundment between 1977 and 1982. The study showed supersaturated dissolved oxygen concentrations, indicating the lake waters had recovered from the initial low oxygen saturation during the first few years of impoundment. The lake waters had high oxygen demand from the high phytoplankton levels and organic matter in the dry season. Chlorophyll ‘a’, which is an indication of algal biomass content, correlated with total inorganic carbon (alkalinity), giving a correlation coefficient of 0.61 at 95% confidence limit, reflecting the fact that both parameters decreased in the rainy season, and were higher in the dry season. The initial high concentration of nutrients also decreased after 20 years with the exception of nitrate, which concentration increased at the rate of 1.07 mg l-1 year –1 over the last 5 years, a condition that could mainly be attributed to nitrogen input from domestic and agricultural origin. The high seasonal trend of nitrate in the months of March and May was due to the fact that the period is the main farming season in the Weija catchment area when most fertilizers are applied. With respect to the major ions, slight increases in their concentrations occurred. Ionic concentration patterns were found to be Na > Ca > Mg > K and HCO3 > Cl > SO4. The cationic pattern was in contrast to the previously reported pattern of Na > Mg > Ca > K, showing complete mixing of the lake waters with moderate rock weathering rate but a strong influence of maritime-derived salts.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V8I1.45784","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70414557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45800
D. Msuya, S. Reuben, L. Mbilinyi, A. Maerere, T. Msogoya, L. Mulungu, R. Misangu
The storage of bulbs of onion (Allium cepa L.) is very crucial to ensure its availability throughout the year. Experiments were conducted at Sokoine University of Agriculture to evaluate the growth and yield characteristics of some tropical short–day onion cultivars and the storability of their bulbs after harvest. The first experiment in 1994 involved 21 cultivars evaluated for their growth and yield variables. The second experiment, involving six cultivars, was carried out in 1996 and in addition to performance evaluation, the storability of bulbs was investigated. Results showed significant differences among the cultivars in yield, yield components and storability. Granex 429 had the highest yield among cultivars in both trials, but had very poor storability. Serrana and XPH 6074 had long storability and maintained more than 50% of their weight after 5 months of storage. These two cultivars are promising as good sources of genes to incorporate storage traits in other cultivars of onion
{"title":"Evaluation of field performance and storage of some tropical short-day onion ( Allium cepa L.) cultivars","authors":"D. Msuya, S. Reuben, L. Mbilinyi, A. Maerere, T. Msogoya, L. Mulungu, R. Misangu","doi":"10.4314/WAJAE.V8I1.45800","DOIUrl":"https://doi.org/10.4314/WAJAE.V8I1.45800","url":null,"abstract":"The storage of bulbs of onion (Allium cepa L.) is very crucial to ensure its availability throughout the year. Experiments were conducted at Sokoine University of Agriculture to evaluate the growth and yield characteristics of some tropical short–day onion cultivars and the storability of their bulbs after harvest. The first experiment in 1994 involved 21 cultivars evaluated for their growth and yield variables. The second experiment, involving six cultivars, was carried out in 1996 and in addition to performance evaluation, the storability of bulbs was investigated. Results showed significant differences among the cultivars in yield, yield components and storability. Granex 429 had the highest yield among cultivars in both trials, but had very poor storability. Serrana and XPH 6074 had long storability and maintained more than 50% of their weight after 5 months of storage. These two cultivars are promising as good sources of genes to incorporate storage traits in other cultivars of onion","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V8I1.45800","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70415077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45805
J. Senayah, S. Kufogbe, C. Dedzoe
The study was carried out in the Bawku area, which is located within the Sudan savanna zone. The study examined the physical environment, human factor and the interactions between them so as to establish the degree and extent of land degradation in the Bawku area. Six rural settlements around Bawku were studied with data on soils collected along transects. Socio-economic information was collected by interviewing key informants and through the administration of questionnaires. Land degradation in the area is the result of interaction between the physical and human environments. Physical environmental characteristics influencing land degradation include soil texture, topography and rainfall. The soils in the study area are developed over granite and Birrimian phyllite. In the granitic areas soil texture is an important factor, while in the Birrimian area, it is the steep nature of the terrain that induces erosion. The granitic soils are characteristically sandy and, as such, highly susceptible to erosion. Topsoil (10–30 cm) sand contents of three major soils developed over granite are over 80%. Severe erosion has reduced topsoil thickness by over 30% within a period of 24 years. Rainfall, though generally low (< 1000 mm), falls so intensely to break down soil aggregates thus accelerating erosion. Other observed indicators of land degradation include sealed and compacted topsoils, stones, gravel, concretions and iron pan. The major human activities that affect the physical environment are farming and domestic energy production. Associated practices such as land clearing for farming, total crop harvesting, burning of organic material during land preparation and inadequate manure application aggravate the degradation problem. These activities destroy the soil physical and chemical properties, thus, resulting in nutrient–depleted soils. A major effect is a progressive decline in crop yields as confirmed by 94% of 210 respondents.
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Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45804
Sts Ateyim, D. Obeng-Ofori
Studies were conducted on the stemborer, Sesamia nonagrioides botanephaga Tams and Bowden (Lepidoptera: Noctuidae), which is a pest of increasing importance on maize in Ghana, to elucidate some aspects of its biology and behaviour in southern Ghana. The pest was more abundant in the minor season than in the major season. The life cycle revealed 10 developmental stages, namely the egg, six larval instars, prepupa and pupa. A female S. n. botanephaga laid eggs within a period of 5 days. The eggs were deposited on the inner side of the leaf sheath fitting tightly onto the maize stem. The mated females laid more eggs per female (330 + 17.7 eggs) than the virgin females (268 + 9.2 eggs). The incubation period of the eggs was 5.23 + 0.03 (5-7) days. The mean larval duration was 29 days and the prepupal period lasted for 1–3 days. The first instar larvae dispersed within 1–3 days after hatching. The third, fourth, fifth, and sixth instar larvae fed actively on maize stalk producing large quantities of frass. The pupal period varied from 6 to 10 days. The life cycle was completed in an average of 35.2 (26-51) days. Adults of S. n. botanephaga lived for between 4–10 days. The adults reared in the laboratory showed a sex ratio of 2:3 (male : female), which was significantly different from the expected ratio (1:1). The implications of these findings are discussed in relation to the effective management of the pest in Ghana.
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Pub Date : 2009-09-08DOI: 10.4314/WAJAE.V8I1.45806
V. Nartey, R. K. Adaboh, J. R. Fianko, A. Donkor
Surface water samples from seven streams on the Akwapim Ridge were analysed over a period of 1 year for various water quality parameters following standard methods prescribed in APHA, AWWA, WEF and AOAC. The study was carried out in order to assess the suitability of the streams for drinking and other domestic purposes. Additionally, the effect of land use activities was assessed. The study revealed that, generally, most of the physico-chemical parameters of the streams were below the World Health Organization (WHO) limits recommended for drinking water, with the exception of the levels of sulphate and conductivity in three of the streams (Opiafo: 224 mg/1, 908.5 iS/cm; Kwati: 221.3 mg/1, 920 iS/cm; and Ademi: 246 mg/1, 1292 iS/cm), respectively, which were above the WHO requirements. Nevertheless, taking these factors into consideration (except the sulphate and conductivity), the waters may be regarded as excellent and good for drinking and other domestic uses.
{"title":"Water quality assessment of streams draining the Akwapim Ridge of Ghana","authors":"V. Nartey, R. K. Adaboh, J. R. Fianko, A. Donkor","doi":"10.4314/WAJAE.V8I1.45806","DOIUrl":"https://doi.org/10.4314/WAJAE.V8I1.45806","url":null,"abstract":"Surface water samples from seven streams on the Akwapim Ridge were analysed over a period of 1 year for various water quality parameters following standard methods prescribed in APHA, AWWA, WEF and AOAC. The study was carried out in order to assess the suitability of the streams for drinking and other domestic purposes. Additionally, the effect of land use activities was assessed. The study revealed that, generally, most of the physico-chemical parameters of the streams were below the World Health Organization (WHO) limits recommended for drinking water, with the exception of the levels of sulphate and conductivity in three of the streams (Opiafo: 224 mg/1, 908.5 iS/cm; Kwati: 221.3 mg/1, 920 iS/cm; and Ademi: 246 mg/1, 1292 iS/cm), respectively, which were above the WHO requirements. Nevertheless, taking these factors into consideration (except the sulphate and conductivity), the waters may be regarded as excellent and good for drinking and other domestic uses.","PeriodicalId":39286,"journal":{"name":"West African Journal of Applied Ecology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4314/WAJAE.V8I1.45806","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70415348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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