https://hdl.handle.net/13049/11 2026-04-15T15:16:52Z https://hdl.handle.net/13049/771 Comparative effects of Bioslurry and chemical fertilizer on soil properties and performance of Spider plant (Cleome gynandra L). Motladi, Mosamarea Nurse Spider plant (Cleome gynandra L.) is a promising indigenous leafy vegetable in the diet of many African rural populations. However, soil fertility for production of spider plant remains an unexploited area leading to low crop yields. Bioslurry (BS) is a by-product of biogas production rich in organic matter, plant nutrients and a potential substitute for chemical fertilizer (CF). It can also be utilized as a soil amendment to restore soil health. Pot and field experiments were conducted to compare the effects of BS and CF on soil properties and performance of spider plant. A factorial combination of two landraces of spider plant were laid out in CRD and RCBD with three replications in the greenhouse and field, respectively. Treatments were landraces (Tot 89-26 and Rothwe), and N applied as Urea at 0, 60, 120, and 180kg N/ha and bioslurry at 0, 10, 20 and 30 ton/ha using a sandy loam soil. Results revealed that fertilization with BS and CF significantly (p<0.05) improved plant growth parameters and the effect between the two fertilizers was not statistically different. The highest plant height (27.04cm), leaf number (23.39) and leaf petiole length (9.43cm) were recorded from BS20, CF60 and BS20 respectively compared to the control. Accession alone influenced leaf petiole length and leaf number. All fertilizer treatments significantly increased yield parameters. Furthermore, application rate of 120kg N /ha and 20 ton/ha BS recorded the highest chlorophyll content while high stomatal conductance was recorded from 30 ton/ha BS and the results were at par with BS20, CF60, CF120 and CF180. Spider plant efficiently used N when low rates of bioslurry and urea at 10 ton/ha and 60kg N/ha respectively were applied. Results showed a highly significant (p≤ 0.001) effect of fertilizer application on CO2 emissions and carbon sequestration. High CO2 emissions and low carbon sequestration were recorded from 180kg N/ha of Urea while low emissions and high carbon sequestration were recorded from 30 ton/ha of bioslurry. Various application rates of bioslurry and urea significantly influenced soil xii chemical properties while no significant effect was observed on soil physical properties. Overall, the findings of this study revealed that the impact of bioslurry and urea on growth and yield of spider plant were not significantly different. Thus, bioslurry can be used as an alternate nitrogen supply for spider plant cultivation. Bioslurry significantly improved soil properties, reduced CO2 emissions through carbon sequestration, hence promoting sustainable crop production. 2024-09-01T00:00:00Z https://hdl.handle.net/13049/762 Safflower Growth, Development, Yield and Oil Content as Influenced By Genotype and Environment Interaction Under Onfarm Conditions Mosupiemang, Marang Safflower (Carthamus tinctorius L.) is amongst the neglected and underutilized oilseed crop that is adaptable to environmental conditions present in arid and semi-arid lands (ASALs). It has many uses like foods, textile, pharmaceutical, cosmetic, and industrial (paint, biodiesel). Safflower seed produce healthy and high-quality vegetable oil which is rich in vital linoleic and oleic fatty acids. The economic potential of this crop is very high and has been noticed in Botswana. Recently, the Botswana government has developed a new policy known as Temo-Letlotlo Programme in which the government subsidises inputs for farmers in growing 13 food crops of which safflower is one of them. The goal of this programme is to promote food security, commercialization, inclusivity in agricultural production, and social capital. Therefore, to increase the productivity of safflower in ASALs such as Botswana, genotypes that show greater adaptability and stability for growth, yield, and oil content need to be assessed and recommended to farmers, hence, the aim of this study. In the first study, an on-farm trial was conducted to assess the influence of season, location, and genotype and their interactions on the growth, phenological development, oil content, yield, and yield components of safflower. This study was conducted in summer and winter at three sites (Sebele, Ramonaka, and Molepolole) in the southern part of Botswana using five safflower genotypes (Turkey, Sina, PI537636, Kenya9819, and Gila). The findings demonstrated that winter planting delayed the phenological development (days to emergence (2.56 days), stem elongation (33.3 days), branching (47.8 days), flowering (50 days), and maturity (79.4 days)), and promoted the vegetative growth, yield, yield components, and oil content of safflower (plant height (38.7%), shoot biomass (218%), root biomass (239%), capitula number/plant (18.6%), capitula diameter (4.7%), capitula weight (30%), 1000-seed weight (17.8%), seed yield/ha (84.4%), oil content xviii (20.7%) and oil yield (114.2%)). Safflower planted in winter at Ramonaka had better vegetative growth (plant height (90.6 cm), root biomass (13.2 g/plant), and shoot biomass (132 g/plant)) than that of other locations planted either in winter or summer. The results further revealed variability amongst the studied genotypes for almost all the phenological development (days to emergence, stem elongation, branching, flowering, and maturity), growth (plant height and shoot biomass), oil content seed yield, and yield components traits studied (capitula number/plant, capitula diameter, capitula weight, and 1000-seed weight). In addition, location, season, and their interactions significantly affected these parameters (number of primary branches/plant, capitula/plant, capitula weight, 1000-seed weight, seed yield, oil content, and oil yield/ha). Genotype by environment interactions (GGE) biplots for seed yield demonstrated that Sebele showed greater representativeness and discriminative ability therefore, it was considered a perfect site for choosing genotypes that are adapted to the entire region. Genotype Kenya9819 was identified as the highest seed-yielding and stable genotype based on the GGE biplots. When evaluating genotypes based on overall superiority, the genotype by yield*trait combination (GYT) biplot showed that genotypes Turkey and Kenya9819 had an above-average seed yield-trait combination, hence superior, while genotypes Gila and PI537636 performed poorly (they were below-average for all studied traits except for yield*oil content). Therefore, genotypes Turkey and Kenya9819 were recommended to be grown in the southern part of Botswana based on their overall superiority. On the other hand, genotype Gila could be used for breeding purposes to improve the seed oil content of other genotypes due to its high seed oil content. The second study determined the relationship between oleosin genes and oil bodies in regulating the oil content of safflower seeds. This was achieved by isolation and quantifying the oleosin genes and oil bodies from the seeds of five (Gila, Turkey, Sina, PI537636, and Kenya9819) safflower genotypes using qPCR and fluorescence xix microscope, respectively and assessed them against the seed oil content. The results revealed a strong inverse relationship where smaller oil bodies were exhibited by genotypes containing high oil content (Kenya9819 and Gila) and high relative expression of oleosin genes. The findings indicated that oleosin genes and oil bodies are important traits to consider when characterizing oil seed crops for oil content. In the third study, the response of safflower genotypes to drought stress was evaluated under a greenhouse and verified under field conditions. Drought stress was found to reduce the chlorophyll content, leaf relative water content (LRWC), and plant height irrespective of stage of development, genotype, and stress duration. For instance, at days 20 and 30, drought stress reduced chlorophyll content by 37.8% and 63.7%, respectively, during the branching stage under the greenhouse. Furthermore, the levels of ascorbate peroxidase (APX) and proline escalated in response to drought stress irrespective of genotype, developmental stage and stress duration. For example, drought stress increased the APX content by 1.03 and 15.6X higher in stressed plants after 10 and 20 days of drought stress, respectively than control plants during the flowering stage in the greenhouse. This trend was observed in both the greenhouse and field experiments. There was a substantial (P..... Thesis 2024-09-01T00:00:00Z https://hdl.handle.net/13049/755 The Perceptions of Botswana Agricultural Science Teachers towards their In-service Professional Development: An Exploratory Study of the Central Region Mabusa, Kgomotso This study relates to the reforms by the Education Ministry in Botswana of decentralising the coordination of teachers’ In-service Professional Development (IPD) to the Regional Offices with the overall aim of improving students’ academic performance (Republic of Botswana, 2006). In the absence of other research data, the study aims to understand how secondary school teachers of agriculture in Botswana perceive their IPD. The study endeavours to identify gaps in current IPD provision and make recommendations to guide IPD policy reforms at regional level. Based on a review of the literature and the overarching research purpose, a set of research questions was devised. Considering the research questions, a Realist perspective to the research that endorses a flexible pragmatic stance was adopted. The research employed a mixed methods design. A questionnaire was developed and administered to all the Agriculture teachers in the Central Region (n=247). A purposive sample of teachers (n=36) and every Agriculture Education Officer (n=8) were interviewed. The quantitative data was analysed using SPSS software, with descriptive and inferential statistics reported. A coding guide was developed to analyse the interview transcripts which was done with the assistance of NVivo software (Bazeley, 2007). The findings show that the main source of motivation for teachers to attend IPD is to update their knowledge and skills in the subject. The study revealed workshops and meetings to be the most popular IPD opportunities of all IPD opportunities found to be relevant by teachers. The study also identified satisfactory iii and unsatisfactory characteristics of IPD; the contextual factors that adversely influence IPD in the region; and a wide range of IPD needs. The findings have implications for future IPD policy reforms; most important of these include the need to: ▪ adequately resource IPD and create time for it as an integral part of the education programme; ▪ remove restrictions associated with funding teachers’ enrolment in part time courses; ▪ revise teachers’ workload policy to help them find time for IPD; and ▪ have IPD emphasise acquisition of agriculture skills by teachers. Beyond policy, the findings also suggest improvement of the design and organisation of IPD, which include strategies for making IPD interesting, meaningful, sustainable and accessible to all teachers in the region. 2016-05-01T00:00:00Z https://hdl.handle.net/13049/754 Assessment of the species Penaeus latisulcatus and Penaeus japonicus in the shallow-water shrimp trawl fishery at the Sofala Bank, Mozambique. Mosepele, Belda Quetina David Commercial data from 1995 and 1996 of the Pescamar fishing company in Mozambique were used to study the stock dynamics of the two shrimp species Penaeus latisulcatus (marfil) and Penaeus japonicus (tiger). These species are harvested in the Sofala Bank shrimp fishery secondary to the primary species, P. monoceros and P. indicus. The proportion of P. latisulcatus and P. japonicus in the total catches has increased over the last several years, and this has made a need to study their population dynamics by examining mean CPUE, growth parameters, spawning, maturity and morphometric relationships. A new method for estimating mean CPUE, based on a two-stage sampling method over the usual method (total catch divided by total effort) was proposed in this study. The two methods for estimating mean CPUE were compared and it was documented that the new method may give a better reflection of the relative abundance because it smoothes the biases that are inherent in commercial data. Results showed that the mean CPUE was higher for marfil than tiger shrimp during 1995 and 1996. Differences in relative abundance in the catches were attributed to seasonal variations in spatial and temporal distribution. Growth parameters could not be estimated because the commercial data were not representative of all length classes in the population due to gear selectivity. Both marfil and tiger shrimp are multiple spawners and produced several recruitment peaks both in 1995 and 1996. Size-at-maturity for females marfil shrimp was estimated at 42 mm carapace length while females tiger shrimp mature at approximately 43 mm carapace length. While there appeared to be a strong relationship between carapace length and total body weight for both species, no significant differences were observed in these relationships between male and female tiger shrimp while there was a significant difference between male and female marfil shrimp. Generally, females attain a larger carapace length than males in both species. 2000-01-01T00:00:00Z