- Title
- Germination potential of seeds harvested at the Worcester Veld Reserve
- Creator
- Swart, Rudi
- Subject
- Ecological disturbances -- South Africa -- Karoo
- Subject
- Environmental degradation -- South Africa -- Karoo
- Date Issued
- 2019
- Date
- 2019
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- http://hdl.handle.net/10948/43923
- Identifier
- vital:37084
- Description
- The rangelands of the Succulent Karoo and Nama Karoo biomes are in various states of degradation. The injudicious stocking of overly high numbers of domestic livestock is considered to be the anthropogenic cause of this degradation. The palatable plants of these rangelands have been greatly reduced in number or extirpated from some areas. In order to return palatable plants to degraded rangelands and improve rangeland productivity, many restoration projects have been attempted that involve reseeding. The sowing of seeds into degraded rangelands, or other disturbed areas, has often provided disappointing germination results. This study will attempt to determine what some of the main aspects are that affect Karoo seed germination, both positively and negatively. The specific objectives of the study are to determine the causes of pre-sowing seed mortality, the effect of drying on seed germination, the effect of planting depth on seed germination and the effect of storage time on seed germination. The seeds of four palatable Karoo plant species harvested at the Worcester Veld Reserve were selected to be subjected to germination trails and viability testing. This study uses germination trials under controlled light and temperature conditions, as well as 2, 3, 5-triphenyl tetrazolium chloride tests to determine whether the four species of Karoo seeds harvested at the Worcester Veld Reserve for rangeland reseeding projects are viable and germinable. The practice of drying seeds after harvesting is tested to determine the effect of drying on seed germination. The germination of seed was also tested over 17 intervals of 3 weeks to determine the effect of storage time on seed germinability. Germination trials were also conducted in a nursery to determine whether there was a difference in seedling emergence between seeds planted at 10 mm depth compared to seeds planted on the surface with a partial covering of sand. The seed viability of all four species studied was found to be below 50%. Drying only significantly improved the germination of Osteospermum sinuatum seeds. The seeds of O. sinuatum and Eriocephalus africanus germinated reasonably well throughout the 17 time intervals, while the seeds of Chaetobromus involucratus and Gorteria integrifolia germinated poorly during the first six months after harvesting, after which v germination improved markedly. Seedling emergence of all four species studied was significantly higher when planted at the substrate surface, compared to seeds planted at 10 mm depth. The findings of this study show that while the viability of the seeds harvested for rangeland reseeding projects are quite low, the appropriate pre-treatment, seed age and planting depth will allow a significant increase in germination. This increase in germination should provide a greater chance of establishing palatable plants in rangeland reseeding projects.
- Format
- xi, 63 leaves
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
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NMU School of Natural Resource Management
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Rudi Swart.pdf | 2 MB | Adobe Acrobat PDF | View Details Download |