ABSTRACT The physiological and morphological characteristics of five strains of Sclerotium rolfsii, namely, XLL, XAl, XA2, ELI and EL2, which were identified as strains by the aversion test, were studied. The susceptibility of five varieties of cocoyam, 'Amankani fitaa', 'Arnankani fufuo', 'Arnankani kyirepe' and 'Amankani pa' of Xanthosoma sagittifolium and a single variety of Colocasia antiquo rum to these strains, was also investigated. The appearance of the strains on Potato Dextrose Aga...
ABSTRACT Seasonal changes in the phytoplankton at four depths at station
ABSTRACT Research was carried out to develop an effective inoculum carrier of the nodule bacterium, Rhizobium sp., for the inoculation of seeds of bambara groundnut [Vigna subterranea (L.) Verde , comb . nov. = Voandzeia subterranea (L. ) T h o u a r s ] f r o m a local material. Five out of 16 strains of Rhizobium sp. isolated from soils of legume farms at eight localities within a radius of 180km from L e g o n were used in experiments to test the efficiency of the carrier that was develope...
ABSTRACT The research was carried out to study diversity (phenotypic and genetic) and population structure of cowpea germplasm assembled from the DPEB and SARI. A total of 78 cowpea accessions from these two sources were used for the study. Data was collected on twelve vegetative and reproductive traits, four polyphenols, crude protein, seven mineral elements, nineteen amino acids and three SSR markers. Methanolic extracts of pulverized cowpea seeds were used to determine concentrations of p...
ABSTRACT Echinoids are recognized as important components of temperate kelp forests because of the impact that they have by grazing. The provision of shelter by some echinoid species for both juvenile conspecifics and for other species of echinoids has been widely documented. The behaviour is thought to be important in the survival of these species. The role of echinoids as protective "nurseries" for several types of marine animals has also been suggested. Adult echinoids are supported 1 - 2 ...
ABSTRACT Five years hav~ passed since the Two Oceans Aquarium, Cape Town, opened it doors for the first time in November, 1995. Since then, a seaweed community has established itself in the Kelp tank. The seaweeds were brought in as either epiphytes on mature macro algae or as epiphytes on boulders that were placed on the floor of the tank. Thus, the community in the tank can be assumed to have established itself naturally. This study looked at the extent of the species diversity, zonation pa...
Abstract: Ten mushrooms species collected within the premises of University of Ibadan were examined for infestation of various insect and fungal pests .Insects belonging to the orders; Coleoptera, Hymenoptera, Diptera, and Collembolla were encountered both at the larval and adult stages of life on the collected mushroom samples. Infestation by the order Coleoptera (adult beetle) on Pleurotus squar-rosulus was found to be higher in incidence, with a total number of 17species which were found a...
ABSTRACT It is envisaged that population numbers of the species Hoodia gordonii will decline rapidly because of its commercial potential. To ensure that genetic materials are not lost due to lack of information, the research was conducted in order to examine the translocation potential of Hoodia gordonii, by assessing various factors affecting its initial establishment and survival. The study was carried out in the !Khob !Naub conservancy, located in the southern arid region of Namibia. Loca...
ABSTRACT Citrus plants are regarded as the world’s second fruit crop consumed by volume next to banana, providing food nutrients, foreign currency, raw materials for agro-industries and source of employment. The production and productivity of citrus in tropical Africa including Ghana is threatened by a number of diseases. Pseudocercospora leaf and fruit spot PFLS of citrus caused by a fungus P. angolensis is the most destructive disease of citrus in most citrus growing areas. The disease wa...
Abstract Within the Cape Floristic Region many lineages are characterised by large floral diversity. The genus Erica is one of these lineages, making up -7% of the CFR. Surprisingly, even though pollinators have been suggested to be a driving force of floral morphology, the role of pollinators in the floral diversification and speciation of this genus is not yet well understood. Therefore the aim of this paper was to establish if Erica species can and do self-pollinate. Two Erica ...
Abstract The disturbance ecology and regeneration patterns of the emergent conifer, Widdringtonia whytei, and five broadleaved species, Aphloia theiformis, Rapanea melanophloeos, Maesa lanceolata, Maytenus accuminata and Psychotria mahonii, were inferred from population size structures in the mixed conifer-broadleaved forests of Mt. Mulanje, Malawi. The size-class structures of the emergent cedar populations were characterised by even-sized, disjunct frequency distributions. Seedling recruitm...
ABSTRACT The occurrence and diversity of bacteria in selected fish culture ponds from three regions in Ghana, Aduabenba Farms, Agyeman Farms, Aheto Farms, Akuse Kpong Farms, ARDEC Station, Asare Farms, Boadi Farm, Boahen Farms, Boateng Farms, Frimpong Farms, K.K. Farms, Pacific Farms and Sagoe Farms and three open systems, Kpong Head Pond, Volta River and Weija Dam were studied over a period of three years, 1996 - 1999. Bacterial populations from the different fish culture systems studied con...
ABSTRACT Significant effort has been put into the development of cost-effective abalone (Haliotis midae; Gastropoda) cultivation systems in South Africa, but the limited availability of suitable seaweed for abalone food is an obstacle to future development. The aim of this study was to investigate whether a land-based recirculating seaweed-abalone integrated aquaculture system using Ulva lactuca was feasible as well as to test the differences between a commercial gravel bed recirculation syst...
Abstract Fires are often used as a management tool in both game reserves and rangelands to manipulate food availability for grazing animals. After fires, large areas of the landscape are quickly covered with nutritious new regrowth, which grazers move into and utilise as a food resource. The effect of this change in animal grazing patterns on the grass communities is not yet well understood. Certain grass communities depend on heavy, continuous grazing for their persistence: they are out-comp...
ABSTRA.CT The studies in this thesis recognise the key role of fire as a factor which has shaped the life-histories of plants in fire-prone mediterranean shrublands. Fire regimes are not simply products of the abiotic elements of climate and ignition sources. The biotic component makes a significant contribution because community structure and processes like litter fall determine fuel loads, and fuel distribution, and will determine properties such as fire recurrence intervals and shapes and ...