Thesis (M.A. Agricultural Management (Plant Production)) -- University of Limpopo, 2022 / Artemisia afra Jacq. ex Willd is a common medicinal plant in Africa belonging to the
Asteraceae plant family. It has been used for decades as a treatment for cold related
illnesses and a variety of other ailments such as asthma, malaria and kidney disorders.
As such this has led to its high demand and it is faced with threats of overharvesting. As
the plant is naturally occurring and not widely cultivated, it’s seed biology and germination
properties are not documented. The optimum requirements (temperature and
photoperiod) for seed germination as well as the effects of Moringa based biostimulant
and different scarification methods were investigated on A. afra seeds in this study. The
seeds were exposed to different scarification methods including physical scarification
(rubbing using sandpaper), hot water soaking, cold water soaking, acid treatment (H2SO4)
and fermentation (using effective microorganisms) while the untreated seeds served as
the control under all conditions.
Moringa based biostimulant was also used as a seed priming agent at 0, 0.5, 1 and 3%
levels. The seeds were then placed under a variety of photoperiods including constant
light, alternating light (16/8 hours) and continuous darkness at different temperatures
(15°C, 25°C and 35°C). Germination percentages and mean germination time (MGT)
were calculated from the results and Statistix 10.0 software was used at the probability
level of 5%, to compare the mean values. It was observed that under the different
temperatures without any other treatments, the highest germination rate (70%) was
achieved at a 25°C. No germination (0%) was obtained at both 15°C and 35°C in all the
experiments including scarification methods and photoperiods.
Under the scarification treatments, soaking in hot and cold water scarification improved
germination with final germination of 70%, compared to the other scarification methods
(Physical at 20%, acid treatment at 20% and control at 10%). There was no germination
observed (0%) for the fermented seeds in all the experiments. On the photoperiod
treatments, the highest germination percentage of 70% was observed under alternating
light condition. However, when mean germination time was calculated, continuous
xiv
darkness resulted in shortest MGT of 11 days compared to 13 days for both alternating
light and for continuous light in this set of experiment. Seed priming with Moringa based
biostimulant under alternating light conditions and at 25°C resulted in improved MGT.
Under the investigated treatments, the use of 3% biostimulant exerted the highest
improvement on germination with germination percentage of 62% and the shortest MGT
of 7 days compared to the other treatments.
Generally the final germination (%) and time of A. afra seeds were affected by
scarification, temperature, light and priming using Moringa based biostimulant. The
information generated from this study is important because it will contribute in bridging
the scientific gap on the information that has never been documented on optimum
requirements for effective propagation of A. afra through seeds. As such this information
will be useful for small scale farmers and medicinal plant growers who are willing to
recover the lost populations of A. afra through seed propagation thus improving their supply and income / National Research Foundation (NRF)
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ul/oai:ulspace.ul.ac.za:10386/4170 |
| Date | January 2022 |
| Creators | Letsoalo, Mmakoma Mendy |
| Contributors | Ndhala, A.R., Mashela, P.W. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | xiv, 69 leaves |
| Relation |
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