Theses

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A long essay or dissertation or thesis involving personal research, written by postgraduates of University of Ghana for a university degree.

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    Monitoring Phosphorus Nutrition of Maize on Four Landform Technologies in The Vertisols of the Accra Plains
    (University of Ghana, 1997-04) Abunyewa, A.A.
    A field trial was started in August 1994, during the minor cropping season to investigate the efficiency of tour Landforms in the production of maize with special emphasis in phosphorus (P) management in Vertisols at three localities in the Accra Plains of the Coastal Savanna zone of Ghana. The four Landforms were: Flat, Ridged, Ethiopian and Cambered beds. Generally, the soils were low in available P. Raising available P levels in the soil by the addition of fertilizer led to significant increase in dry weight of maize in all the Landforms. On the Cambered bed, however, raising the fertilizer above 50 % of the recommended rate did not cause significant yield increase. The Landforms had significant influence on P uptake and dry matter production. In all instances, the raised beds, i.e. Ridged (R), Ethiopian (EB) and Cambered (CB) significantly outperformed the Flat (F) bed in terms of P uptake and dry matter production. Among the raised beds, the Cambered bed had significantly higher dry matter yield than the Ridged and Ethiopian beds. The relative agronomic efficiency (RAE) of the four landforms were in the order of CB > EB = R> F (P < 0.05). Unlike the Ridged and the Ethiopian beds, the RAE of the Cambered bed at 50 % fertilizer application was higher than the 100 % fertilizer application. Soil organic P formed about 25 % of the total P and this value did not change significantly throughout the growing season. Calcium bound phosphate (Ca-P) was the dominant inorganic P and constituted about 78 % of the active inorganic P in the soils. Iron bound phosphate (Fe-P) was the least and constituted 2 % of the total active inorganic P. The two inorganic P fractions significantly correlated with P uptake and dry matter production. Though both Ca-P and Aluminium bound phosphate (Al-P) did not change significantly during the maize growing period, the Fe-P on the other hand reduced to about one-half its initial value. Generally, increase in fertilizer application increased P uptake, with the highest P uptake on the CB and least on the F. A significant Landform x fertilizer interaction was observed for dry matter production when 50 % fertilizer application on the CB out yielded 100 % fertilizer on the F. Generally, there was negative soil available P balance in all the Landforms and at all the rates of fertilizer application at the end of the season.
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    Influence of the Metabolites of three Paecilomyces Species on the Germination and Seedling Development of two Ghanaian Maize Varieties (Abeleehi and Obaatanpa)
    (University of Ghana, 199-10) Minamor, A.A.; Odamtten, G.T.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Botany
    The mycoflora of two recently-developed maize (Zea mays L) varieties Abeleehi and Obaatanpa have been studied under varying ambient equilibrium relative humidities ERH’s (55, 60, 65, 70, 75, 80, 85, 90 and 95%) representative of the Ghanaian ambient conditions. The potential pathogenicity of selected contaminating fungal species (A. alutaceus, = A. ochraceus, Fusarium, moniliforme, Penicillium digitatum, Peacilomyces carneus, P. puntoni and P. varioti) was also tested under laboratory, field and greenhouse conditions. Finally, the fungal succession or phenology of the species encountered in the rhizosphere and non-rhizosphere soil containing treated maize grains (Abeleehi and Obaatanpa varieties) treated with conidia/mycelium or culture filtrate of the three Paecilomyces species (P. carneus, P. puntoni and P. varioti) was studied. About thirty (30) and twenty-eight (28) species of fungi belonging to the genera Aspergillus, Penicillium, Curvularia, Chaetomium, Cladosporium, Emericella, Eurotium, Fusarium, Paecilomyces, Mucor, Neurospora and Rhizopus were isolated from Abeleehi and Obaatanpa varieties respectively at ERH’s 55-95%. Aspergillus species {Aspergillus candidus, A. effusus, A. fumigatus, A. giganteus, A. niger, A. ochraceus, (= A. alutaceus), A. sulphureus, A. tamarii, A. ustus, A. versicolor, A. wentii and Aspergillus sp) predominated over the others followed by Penicillium (Penicillium brevi-compactum P. critinum, P. verrucosum, P. digitatum, P. expansum, P. funiculosum, P. glabrum and P. nigricans). Fungi belonging to the other genera encountered were Curvularia, Paecilomyces, Chaetomium, Cladosporium, Emericella, Eurotium, Fusarium, Mucor. The species diversity was influenced by grain variety and the ERH at which the grains were stored. Aspergillus flavus was ubiquitous and was encountered in all grains stored at 55-95% ERH. Fusarium monilifonne was isolated from some grains incubated at 65-95% ERH. Xerophilic or xerotolerant fungal species like Aspergillus fumigatus, A. alutaceus ( = A. ochraceus), A. gigunteus, Paecilomyces carneus, P. puntoni and P. varioti were isolated at 55-65% ERH in both grain varieties. The best vegetative growth (radial) of selected species was influenced by both the medium and temperature of incubation. Paecilomyces carneus grew best at 30°C, P. puntoni at 30-35°C and P. varioti at 30°C. All the Paecilomyces species, however, could grow well at 40°C. Aspergillus species tested (A. flavus, A. giganteus, A. alutaceus) grew best at 30°C and remained depressed in growth at 40°C; so did Penicillium digitatum and Fusarium moniliforme. The three Paecilomyces species produced their toxic metabolites in 2 days and their undiluted culture filtrates depressed seed germination of ’Abeleehi’ and ’Obaatanpa’ by 10-75% (depending on fungal species and period of incubation). This inhibitory effect was gradually removed with increasing dilution (up to 1:10v/v). There were varietal differences in the response of the germinating grains to the toxic metabolites of P. carneus, P. puntoni, and P. varioti. Undiluted culture filtrate of the listed three Paecilomyces species also severely depressed length of the emerging radicles of ‘Abeleehi’ and ‘Obaatanpa’ by 45-90% but this inhibition was gradually removed by increasing dilution of the culture filtrates (up to 1:10V/V dilution). The inhibition of seed germination and radicle development by culture filtrate of the three Paecilomyces species was not confined to maize only as their adverse effect on seed germination and radicle development was reproduced in vitro using tomato (Lycopersicon esculentum Mill var. Owusu-Bio and Wosowoso) and pepper (Capsicum annuum L). In this instance, the inhibitory principle was still potent even at 1:10V/V dilution level. Culture filtrate of Aspergillus alutaceus ( = A. ochraceus) at the highest concentration depressed seed germination of Abeleehi and Obaatanpa varieties by 50-70% and reduced radicle length by 60-90%. The inhibitory effect was gradually removed by increasing dilution (up to l:10v/v). Similarly, F. moniliforme and P. digitatum had the same deleterious effect on germination and radicle development of ’Abeleehi’ and ’Obaatanpa’ maize varieties. Seed germination was depressed 50-70% and radicle length by 40-90% when the undiluted culture filtrate of F. moniliforme and P. digitatum were applied to the grains. In all instances, the inhibitory effect was gradually removed by increasing dilution o f the culture filtrates. There were varietal differences between the three Paecilomyces species in their effect on vegetative growth and dry matter accumulation of Abeleehi and Obaatanpa maize varieties. Metabolites of P. carneus, P. puntoni and P. varioti variably depressed plant height, leaf width, leaf length, dry matter accumulation, (dry weight of root and shoot systems) as well as chlorophyll a and b contents of Abeleehi and Obaatanpa varieties cultivated in the field and under green house conditions. The maize cobs obtained from the field plants infected with Paecilomyces species were diminutive with fewer and smaller grains in the cob as compared to the control. Culture metabolites of P. carneus, P. puntoni and P. varioti reduced by 2-3 times diameter of roots of the seedlings of Abeleehi and Obaatanpa although the endodermis and pericycle were clearly formed and demarcated in both the control and treated seedlings. The pith parenchyma was thinly lignified and 2-3 times narrower in diameter in the treated plants exposed to the three Paecilomyces species; pro - and metaxylem vessels were about 2 times wider in the control seedlings and the phloem and xylem regions o f the roots o f the treated plants were reduced in number and size. Maize grains (Abeleehi and Obaatanpa varieties) inoculated with three Paecilomyces species influenced the rhizosphere mycoflora and their succession profile. Generally, the species of fungi that were stimulated, depressed or eliminated varied from one grain variety to another growing either in the field or under greenhouse conditions. Aspergillus flavus, A. niger, A. alutaceus, ( = A. ochraceus) and A. versicolor remained viable in the rhizosphere soil inspite of the presence of the inhibitory principles exuding from the Paecilomyces species; Penicillium citrinum could tolerate the same metabolites while P. digitatum, P. brevi - compactum did not grow very well in competition with the three Paecilomijces species. Population o f other fungi encountered belonging to the genera Cladosporium, Fusarium, Mucor, Scopulariopsis, Trichoderma and Yeast declined with time. Cladosporium herbarum, F. moniliforme, Mucor sp, Rhizopus otyzae and T. viride survived in the treated soil in competition with the metabolites of the Paecilomyces species. The practical implication of these findings are discussed and future studies suggested.
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    Farmer’s participation in the transfer of improved maize production technology in Ghana: A case study of maize farmers in some areas of Fanteakwa and east Akim districts.
    (University of Ghana, 1994-09) Ackah-Nyamike, E.E.; Geker, E.; University of Ghana, College of Basic and Applied Sciences, School of Agriculture, Department of Agricultural Extension
    The task of agricultural extension in Africa will for some time be mainly concerned with the transfer of agricultural technologies to farmers, This is because of the pressure on farmers to increase food production rapidly to match population increases and Agricultural Extension Services' belief that improved food production technologies do exist which, if adopted by the farmers, would significantly increase their food production from the present levels. Farmers' participation with agricultural extension agents was necessary to make them aware of improved maize production practices, and also to enhance their adoption of those practices. However, it did not really matter which extension participatory approach was used. This is because, although the two extension programmes studied (PPP and DAES) used different participatory approaches to deliver similar extension messages (improved maize production practices), the proportion of farmers in each group that used the various improved maize production practices was not significantly different.
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    Effect of Mucuna Pruriens Mulch on the Growth and Yield of Maize (Zea Mays L.)
    (University of Ghana, 1998-06) Mintah, P.; Dzietror, A.; Doku, E. V.; University of Ghana, College of Basic and Applied Sciences, School of Agriculture, Department of Crop Science
    A study to assess the effect of Mucuna pruriens mulch on the growth and yield of maize was conducted at the Crop Science Department, University of Ghana, Legon from October 1994 to June 1998. Treatments comprised maize plants in Mucuna pruriens mulch plots and no-mulch plots superimposed with nitrogen rates of 0, 50, 100 and 200kg/ha arranged in a split plot design, with three replications. Maize plants in the mulch plots grew faster and yielded more than maize plants in plots without the mulch. However, the addition of 50kg/ha of inorganic nitrogen fertilizer to mulch plots gave the highest grain yield. The decomposition rate of the Mucuna forage was moderate compared to values stated for other legumes elsewhere. Mulching with the Mucuna led to higher soil moisture content, lower soil temperature, lower weed growth, lower bulk density, lower acidity and higher levels of soil organic matter and nitrogen. Second season maize grown on the residual mulch plots yielded significantly higher compared to those grown on the no-mulch plots. However, the yield was lower than that obtained from the first season mulched plot. The result clearly indicates that Mucuna pruriens is a good source of mulch material for planting maize in the first season followed by another one in the second season.
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    Description of Sesamia calamisiis [Lepidoptera: Noctuidae] A Pest of Maize and its Parasitoids in Selected Maize farms in the Accra Plains of Ghana
    (University of Ghana, 1997-09) Wardy, A.; Botchey, M.; Cobblah, M.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)
    A study to determine the species range of parasitoids of Sesamia calamistis on maize in some selected maize farms in Accra was conducted on small holder farms at the University of Ghana. Legon, and its environs. Collections of stembororers were made in pre-selected fields and farms. These were then reared on freshly cut pieces of maize stem in 500-ml storage bottles in the laboratory, and observed for the emergence of parasitoids or stemborers. Emerging parasitoids were identified and counted. The parasitoids identified belong to the orders Diptera and Hymenoptera. The dipterans were DRampsina sesamiae Mesnil, , Tachinidae, Anatrichus erinaceus Loew and Zaprionus sp. Drosophilidae. Also collected were undetermined species of muscidae and a Lochaeidae. The only Hymenoptera identified was Syzeuctus sp (Ichneumonidae). The total larval and pupal parasitism rates were 17% and 5% respectively.