http://hdl.handle.net/10386/7 2013-05-13T03:54:07Z http://hdl.handle.net/10386/834 Title: Determination of yield and yield components of selected tomato varities in soil with different levels of cattle manure application Authors: Maleka, Koena Gideon Abstract: Organic tomatoes are increasingly popular with larger market acceptance since organic farming uses limited or no artificial chemicals. Application of organic fertilisers such as cattle manure has potential to boost organic tomato productivity particularly under low input farming systems. However, information is required on the optimum level of manure application on different tomato cultivars to help emerging tomato farmers in South Africa. The objective of this study was to determine the relative response of yield and yield components among selected determinate and indeterminate tomato cultivars using different levels of cattle manure. Two separate field experiments were conducted at the University of Limpopo during 2007 and 2008 using a split plot design with three replications. Two sets of tomato cultivars were included in which one set consisted indeterminate types (Money Maker, Ox Heart and Sweetie) and the other determinates (Roma and Floradade). Cultivars were assigned as the main plot treatments with six rates of manure (0, 10, 20, 30, 40 and 50 in gram per plant) applied as the subplot treatments to each set. Results indicated significant interactions (P ≤ 0.01) between indeterminate tomato cultivars and levels of manure applied for fruit yield and fruit size in both experiments. Plant height showed variation from 78 to168 cm in Experiment I and 87 to 176 cm in Experiment II. During Experiment I fruit number varied from 23 to 91 per plant and 23 to 97 in Experiment II. Significant differences were detected among determinate cultivars on fruit yield varying from 7928 to 3 4705 kg per hectare during Experiment I and 3 169 to 2 9840 kg per hectare during Experiment II. Overall, the best level of manure for maximum fruit yield and greater fruit size was achieved at 40 g per plant in the indeterminate cultivar Sweetie. Conversely, the best level of manure for maximum fruit yield was achieved at 30 g per plant in determinate cultivar Roma. Thus, to achieve maximum yield, tomato growers could apply 600 and 800 kg per hectare manure on the determinate and indeterminate tomato cultivars, respectively. Description: Thesis (M.Sc. (Crop Science)) --University of Limpopo, 2012 2012-01-01T00:00:00Z http://hdl.handle.net/10386/830 Title: Heterosis and combining ability for body weight in a diallel cross of three chicken genotypes Authors: Siwendu, Ndyebo Anathi Abstract: Crossbreeding is one of the tools for exploiting genetic variation. The main purpose of crossing chickens is to produce superior crosses (i.e. make use of hybrid vigor), improve fitness and fertility traits.This study was carried out at the University of Limpopo Experimental Farm located in Limpopo, South Africa. The objective of the study was to evaluate the growth performance of differentpurebred and crossbred chicken genotypes. A 3 x 3 complete diallel mating system involving two indigenous breeds namely Venda (V) and Naked Neck (N) and one commercial broiler breed, Ross 308 (R), were used to produce three purebred (V x V, N x N, R x R), three crossbreds (R x V, R x N, V x N) and three reciprocals (V x R, N x R, N x V).The nine genetic groups were rearedfrom hatch to 13 weeks of age in a deep litter open house. Body weights of 180 chicks (20 chicks per genetic group), recorded at 0, 3, 5, 7, 9, 11, and 13 weeks of age, were used to estimate heterosis, general (GCA) and specific (SCA) combining abilities, maternal ability and reciprocal or sex-linked effects on body weights. Results showed that the Ross 308 had the heaviest body weight at all weeks of measurement except for hatch. With respect to crosses, the reciprocal V x R and the cross R x V had the heaviest body weights at 13 weeks (2448.40 and 2131.50 grams, respectively), although N x R had heavier body weight than R x V at all weeks of measurement except for hatch and 13th week. Results of heterosis estimates indicated that crossing between Venda male and Ross 308 female as well as between the Venda male and Naked Neck femalegave the highest heterotic effects for body weight(11.01% and 10.33%, respectively).General Combining Ability was significant (P≤0.01) for body weight from hatch to 13 weeks of age while SCA and Reciprocal effects (RE) were both significant (P≤0.05) for body weight at all ages of measurement except for hatch weight. The Ross 308 chicken gave the highest positive effect of GCA for body weight except for hatch weight. Venda sire crossed with Naked Neck dams gave the highest and positive effects of SCA for body weight. Naked Neck sire crossed with Venda dams had the highest positive estimate of RE for body weight except for the 13th week. Results show that using Venda chickens as a paternal breed in crossing with Naked Neck and Ross 308 females may improve growth performance of indigenous chickens. Description: Thesis (M.Sc. (Animal Production)) --University of Limpopo, 2011 2011-01-01T00:00:00Z http://hdl.handle.net/10386/826 Title: Genetic characterisation of colophospermum mopane (sensu lato) using RAPD analyses Authors: Legodi, Mankone Priscilla Abstract: Colophospermum mopane (sensu lato) is currently recognised on morphological and physiological characteristics. To add to the suite of taxonomic characters, the genetic variability of C. mopane (sensu lato) was investigated using the RAPD technique. DNA was extracted from young seedlings and mature leaves using the CTAB method. Initially, the DNA extraction was problematic due to the presence of polysaccharides, making PCR nearly impossible. An additional phenol precipitation step was introduced to purify the DNA used to perform RAPD analyses. Twenty random primers were tested for their suitability and reproducibility to reveal polymorphism in C. mopane (sensu lato). Nine of the primers tested amplified the genomic DNA. Subsequently, three primers (OPA 03, OPA 08 and OPA 09) were selected based on their reproducibility and demonstration of polymorphism. OPA 03 amplified most of the samples tested whereas OPA 08 and OPA 09 amplified 50% of the samples. RAPD bands ranged from 180 bp to 2000 bp. RAPD profiles of C. mopane (sensu lato) with three random primers showed few polymorphisms. Individual trees of different ecotypes show similar RAPD banding pattern, instances were found where trees of the same ecotype showed different bands. The total character difference based on presence and absence of bands revealed both variability and similarity of C. mopane (sensu lato). Phylogenetic trees from individual primers and combined primers were constructed using Neighbour Joining and Parsimony analysis. The phylogenetic tree from the combined primers of bootstrap parsimony generated three clades with low and high parsimony bootstrap values. The first clade receives weak support (61%) while the second and third clades receive support of 90% and 70%, respectively. The other remaining entities collapsed resulting in basal polytomy. The third clade shows some members of Alba (Alba 11 Phala, Alba 1 Phala and Alba 7 Musina) grouped together. The overall results of C. mopane (sensu lato) show high (84.1%) genetic similarity. No ecotypic marker was obtained. Most of the ecotypes have not diverged genetically far from one another or from the parental material (Mopane – sensu stricto). The genetic results partially support the perceived morphological differences. In this study the RAPD technique has established its value as an additional tool to express the genetic variability in C. mopane (sensu lato). Description: Thesis (M.Sc. (Molecular and Life Sciences)) --University of Limpopo, 2007 2007-01-01T00:00:00Z http://hdl.handle.net/10386/824 Title: Baseline of selected essential nutrient elements of an indigeneous fruit tree (mimusops zeyheri) under natural conditions Authors: Ledwaba, Charlotte Ramasela Abstract: The mineral nutrition of indigenous crop species is not well documented like other known crop species, thus making it difficult for one to know how to plant and maintain the crops. Mmupudu (Mimusops zeyheri), which, happens to be a wild crop, is one of the indigenous trees of interest to the Discipline of Plant Production, University of Limpopo. The current study gives baseline information that will be important in various environmental physiology studies of this plant. Physiological studies will be necessary to assess the importance of “limiting” mineral nutrients in the accumulation of certain mineral nutrients in Mmupudu in relation to its productivity. The experiment was arranged as a 2 x 3 factorial in RCBD, with the first and second factors being time of sampling and location, respectively. The three locations where data were collected were Chuenespoort, Bochum and Sekgosese. In each location, the experiment was replicated 10 times. Data were analyzed using ANOVA and means were separated using the least significant difference test. The two-factor interaction was nonsignificant (P ≥ 0.10) for both pH and electrical conductivity. Soil pH was not affected by time in all three locations suggesting that abscised flowers and fruitlets have no effect on pH. Leaf K experienced an increase of 65% at Chuenespoort and a decrease of soil K after fruiting by 44%. Leaf and soil P decreased after fruiting in all locations as was the case with Cu. Chuenespoort and Sekgosese experienced a decrease in leaf Mn after fruiting while soil Mn decreased in all whereas leaf Mg decreased in all locations. Description: Thesis (M.Sc. Agric. (Horticulture)) --University of Limpopo, 2008 2008-01-01T00:00:00Z