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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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Item The Influence of the Brukung Cult in the Social Organization of Shiare(University of Ghana, 1979-06) Pollock, R.Item Cultural Ecology of Asante: 1702 - 1945(University of Ghana, 1974-06) Boakye-Boateng, A.The present can be considered as the product of the past" The truth of the statement is demonstrated in a study like this one which uses the genetic approach. Such an approach makes it possible for the present to be illuminated by the past: thus making it possible to explain many of the elements in the environment. This study on Asante reveals that the region had passed through two major socio-economic phases since the formation of the Asante Confederacy in about 1702. The date 1702, therefore, marks me beginning of the first phase which ends In 1901. During this phase the dominant force (theme) which controlled the cultural ecology was the Asante political power. The Asante Court controlled the main economic activities, namely, trade and gold mining; as well as me various crafts, such as goldsmithing, cire purdue metal casting, cloth making wood carving. The Court also controlled the population growth and distribution. Unfornmately, agriculture was not considered an important economic venture, therefore, it did not form part of the Court's delliberations. The Asante political power did not flourish forever. In 1902 this power oollapsed completely and Asante annexed to the British Crown. This saw the beginning of the second phase. This phase was characterized by the establishment of Pax Britanica. Within this peaceful atmosphere the cultivation of cocoa was encouraged. This was the era of commercial agriculture. It was this innovation which made all the difference in the cultural ecology of Asante. The processes In this phase ushered Asante into the contemporary by 1945. Indeed, by this date, it was clear that the basic characteristics of the contemporary cultural ecology were sketched. The various elements that make each phase distinctive have been treated with the view of showing both developments and changes that occurred.Item Studies on Effect of Decomposing Products of Leaf Of Cocoyam (Xanthosoma Mafaffa Schott.) On Phytophthora Palmlvora (Butl.) Butl.(University of Ghana., 1978-04) Takyi, N.K.Germination of P.palmivora sporangia and zoospores, growth of the hypha and formation of the sporangia in the presence of decomposing leaves of cocoyam were investigated. Cocoyam leaves buried in soil, from an experimental cocoa plot at the Cocoa Research Institute at Tafo, were rapidly decomposed and they completely rotted in 12 days. Fungal species belonging to the genera Alternaria, Aspergillus, Cladosporium, Curvularia, Fusarium, Penicillium, Rhizopus and Trichoderma were isolated from the decomposing cocoyam leaves. Two of the fast growing species, Rhizopua oryzae and Rhizopus stolonifer, were selected and used as agents for decomposition of the cocoyam leaves under sterile conditions. Decomposition of the cocoyam leaves in the laboratory was carried out at 25°C and 30°C, the respective optimum temperatures for growth of R.oryzae and R.stolonifer. Growth by both species in Cassava-dextrose broth at the optimum temperature caused a shift in the pH of the medium from pH 5.30 to around pH 2.30. Culture filtrates of these fungi were therefore adjusted to neutral pH in experiments in which they were used. Direct germination of P.palmivora sporangia was greatly stimulated, by about 400 per cent, by both Rhizopus culture filtrates. Large number of germ tubes emerged from sporangia growing in the culture filtrates of the Rhizopus species. Zoospore germination was also improved by at least 30 per cent by culture filtrates of both R.oryzae and R.stolonifer. R.stolonifer greatly stimulated vegetative growth of P.palmivora, whilst R.oryzae slightly suppressed it. Direct germination of P.palmivora sporangia was stimulated by exudate of undecomposed dry cocoyam leaves; germination in the exudate and in distilled water was 54.9 and 15.3 per cent, respectively. Indirect germination and zoospore germination were, however, inhibited by about 80 and 50 per cent, respectively, by the leaf exudate. Vegetative growth on Cassava-dextrose agar containing different concentrations was slightly improved whilst sporangial formation was depressed. . Direct germination of P.palmivora sporangia at 30°C Was inhibited by extracts of Rhizopus-decomposed cocoyam leaves. Amendment of the R.oryzae-decomposed leaf extract with Fructose Glucose, Maltoso or Sucrose negated the inhibitive influence. ' sodium nitrite, Asparag1ne and Ammonium tartrate also improved direct germination in the R.oryzae-decomposed leaf extract, but addition of asparagine caused further inhibition. The Rhizopus-decomposed cocoyam leaf extract slightly inhibited indirect germination of P.palmivora sporangia at 20°C. With the exception of Fructose at 1.0 percent with improved germination there was greater depression of germination in R.oryzae-decomposed cocoyam leaf extracts amended with Glucose, Maltose and Sucrose of concentrations of 1.0, 2.0, 3.0 and 4.0 per cent w/v or with Ammonium nitrate, Peptone and Sodium nitrate at 0.5, 1.0 and 1.5 per cent. Asparagine improved indirect germination only at 0.5 per cent concentration, but slightly suppressed it at higher concentrations of 1.0 and 1.5 per cent. Zoospore germination was slightly inhibited by Rhizopus - decomposed cocoyam leaf extract. The inhibition was annulled by Fructose, Glucose, Maltose and Sucrose. Higher concentrations of Peptone and Sodium nitrate, at 1.5 per cent, supported even poorer germination than the unamended extract, but germination at the lower concentrations of 0.5 and 1.0 per cent in Ammonium tartrate and Peptone-amended extract was superior. The zoospores of P.palmivora diSintegrated in extract of R.oryzae-decomposed cocoyam leaf extract of pH 4.0. Germination improved gradually from 40.9 to 79.3 per cent on raising the pH of the extract from pH 5.0 through 9.0. Optimum sporangial germination occurred at pH 7.0 and gradually decreased as the pH moved away from the optimum to both the alkaline and acid ends of the pH range. There was germination at the extremes, pH 4 and pH 9, used. Extracts of leaves decomposed by either Rhizopus species slightly improved vegetative growth of P.paluivora on Cassava dextrose agar but depressed sporulation with increase in concentration, from 5.0 to 20.0 per cent. An aqueous extract of soil from the same plot at the Cocoa Research,Institute Tafo only slightly reduced direct sporangial germination at 30 C and zoospore germination but did not affect indirect germination at 20˚C nor vegetative growth and sporangial formation in P.palmivora. However, extract of the soil containing decomposed cocoyam leaves substantially decreased zoospore germination from 14.6 per cent in the control of distilled water to 2.9 per cent., Direct sporangial gemination was similarly reduced from 40.2 in distilled water to 7.7 per cent in the extract. Vegetative growth remained unaffected but sporulation was reduced slightly at higher concentrations (15.0 and 20.0 per cent v/v) of the extract. The decomposition products of cocoyam leaves contained very little nutrients. Although Glucose, Fructose, Mannitol and Sorbitol were identified, by paper chromatography, in the exudate of dry cocoyam leaves, at concentrations of 5.0 - 7.0, 6.0 - 7.0, 2.0 - 3.0 and less than 1.0 microgram per gram of dry leaf, respectively, only Trehaloso,at 18.0 - 20.0 microgram per gram, was identified in the Rhizopus-decomposed leaf extract. The amino acids, Alanine, Amino-butyric acid and Asparagine were also identified, by paper chromatography, at concentrations of 1.0 - 2.0, less than 1.0 and 2.0 - 3.0 microgram per gram, respectively, in the exudate of dry cocoyam leaves but none was detected in the Rhizopua-decomposed leaf extract.Item Studies on the Release, Survival And Germination Of Conidia Of Phyllactinia Corylea (Pers.) Karst.(University of Ghana., 1968-06) Ankora, J.K.Conidia of P.corylea germinated best at 25 - 28˚c. and germinated well, uniformly and at the same rate at any humidity from zero to 100% R.H., but poorly in liquid water. Germ tubes conidia germinating at lower humidities were short whilst those at high humidities were fairly long. Approximately 30 per cent of both germinated and ungerminated conidia shrivelled when incubated. at 0% R.H. This value decreased with rise in humidity to show shrinkage in only one per cent of conidia held at 100% R.H. The conidia had a brief latent period of germination of 2 - 3 hours. The germinating conidia usually produced a single germ tube and occasionally two. Branching of germ tubes was rare on glass surface but appressoria were freely formed. On the host (Carica papaya) leaf surface the germ tubes grew randomly over the epidermis am equally freely formed appressoria. The appressoria were either terminal, intercalary or lateral. Germ tubes produced at lower humidities collapsed and shrivelled within a few hours after emergence. All germ tubes produced and held at 0% R.H. shrivelled in 11 hours and those at 80.3% R.H. in 30 hours. Those at 92, 96.9 and 100% R.H. showed 94.5, 25.0 and 20.2% of shrivelled germ tubes respectively in 48 hours. The Conidia germinated better in light and produced longer germ tubes but formed fewer appressoria than those incubated in darkness. Conidia stored at 5˚c and at various relative humidities were preserved longest at the higher humidities and died quickest at the lower humidities. Longevity was however brief and did not exceed 20 days at any humidity. Multicellular, non-branching conidiophores, commonly 300 u long, arose perpendicularly from the superficial mycelium. Each was terminated by a generative cell which formed the conidia. Usually only one mature conidium was distinguishable at the tip of the conidiophore. Immediately after maturation of the conidium the generative cell bent approximately at the middle while the two arms of the cell stood at right angles. This movement loosened the attachment of the conidium to the conidiophore and the conidium fell at the slightest disturbance. The bent generative cell then abstricted the next conidia. In still air conidial chains were readily formed. A few conidia germinated whilst still attached to the conidiophore. The conidia matured predominantly in the dark and heaviest crop of spores were obtained in the morning. The rate of bending of the generative cell was the same at 20 and 28˚c., in light and in dark and at 76 and 100% R.H. The ourvature in the generative cell remained unaltered in sucrose solutions and in water. The generative cell was not phototropic Whilst the entire conidiophoreItem Studies on the Physiology of the Different Sized Sporangia of Phytophthora Palmivora (Butl.) Butl.(University of Ghana, 1977-09) Asomaning, C.M.Item Development of the Bottom and Perihytic Invertebrate Fauna into the Volta Man-Made Lake during the First Years(University of Ghana, 1970-07) Tomislav, P.Development of the Bottom and Perihytic Invertebrate Fauna into the Volta Man-Made Lake during the First YearsItem Studies on the Effects of Microclimates on the Distribution of Larval Ticks in the Eastern Cape Province(University of Ghana, 1961-12) Kraft , M.K.Item Studies on the Development of Secondary Sporangia of Phytophthora Palmivora (Butl) Butl.(University of Ghana, 1977-06) Manu, M.A small proportion of sporangia of P. palmivora, less than 1.0 per cent, formed by hyphae growingon coooa pods germinated in humid air at 25°C whilst still attached to the hypha. to produce germ tubes terminated by seoondary sporangia. Sporangia in suspension in distilled water formed the greatest number of secondary sporangia at 30oe. Germination in samples of sporangia of the Sameage and formed under the same conditions varied, and, the percentage of directly germinated sporangia bearing seccndary sporangia at 30 0c ranged from 1.5 to 17.1 in the various samples.Item Laboratory Studies on Forest and Savannah Populations of Bulinus (Physopsis) Globosus in Ghana(University of Ghana, 1972-11) Kuma, E.E.Studies on laboratory colonies of Bulinus globosus from forest, savannah and transition zones have been carried out. The morphology, growth and reproduction of such snails have been oompared. Crosses between single snails from the three zones have been carried out and the effect of overcrowding on growth and reproduction has been investigated. Certain aspects of their behaviour such as mating, pattern of oviposition, feeding and distribution in a culture dish have been described. The effect of temperature on the snails' oviposition has a1so been studied. Finally, the problem of desiccation has been looked at end the esterase fractions of' the snails have been compared.. \Item Nutritional Studies with Specific Reference to Thiamine on Koko a Ghanaian Cereal Product(University of Ghana, 1970-09) Andah, A.'Koko' was prepared in the laboratory from Ghanaian maize. The effect of grinding and sieving on the protein content wa3 determined. Protein losses were highest with the coarsest grinding. Starters were used in the fermentation and were found to increase the rate of acid production. Preservation of 'Koko' was carried out by Roller-drying, Spraydrying, Freeze-drying and Canning. The volatile constituents of the flavours were lost during Roller-drying and Spray-drying. Freese- • drying was very successful but it would be too expensive for commercial processing of 'Koko'. It could, however, be used in the laboratory for research, work. Canning of 'Koko' was also successful, though more work on its microbiological aspect is needed to give conclusive results. Thiamine and Riboflavin contents were determined at various stages in the preparation of 'Koko'. Slight losses of these two vitamins occurred during steeping of maize. Fermentation increased Thiamine considerably although only very slight increases were recorded for Riboflavin. The significance of these results are discussed.