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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Response of fever tea (Lippia Javanica)to fertigation frequency, growth medium and propagation method

Mpati, Kwena Winnie 20 February 2007 (has links)
Fever tea is one of the important medicinal plants belonging to the family Verbenaceae. The leaves of the plant are used as a remedy to treat malaria, stomach pains, colds and fever. There are different clones of Lippia species available with different medicinal value. Therefore, the purpose of this study was to determine protocols for propagation of fever tea so as to multiply an ideal clone. Vegetative propagation of this plant species by stem cuttings, requirements for seed germination and response of fertigation frequencies and growing medium to growth, yield and quality has not been studied. In this study, factors influencing effective propagation of fever tea were studied. Those factors were: cutting position (apical vs. basal), media (pine bark vs. sand), hormone (seradix No. 2 vs. no hormone) light and temperature requirement for fever tea seed germination and effect of fertigation frequencies (0.4 L/day, 1L/day, 2L/day, 2L/2nd day and 2L/week) and growing media (pine bark vs. sand) on growth, oil yield and oil quality. In vegetative propagation by stem cuttings, measurements made were number of roots per rooted cutting, fresh mass, stem circumference and number of leaves and the rate of rooting during four consecutive sampling dates (5, 10, 15 and 20 days after planting). Apical cuttings rooted earlier by 5 days than basal cuttings at 10 days but at 15-20 days after establishment, both cuttings had good rooting. Fresh mass was not affected by cutting position and rooting media, but cuttings performed slightly better when propagated in pine bark medium than sand medium. Basal cuttings resulted in thicker stems and more leaves as compared to apical cuttings. Seradix No.2 (0.3% IBA) hormone increased the fresh mass, stem circumferences, root number and leaf numbers on both apical and basal cuttings. For the establishment of fever tea stem cuttings, both apical and basal cuttings can be used but pine bark is the ideal medium. The cuttings can be ready for transplanting in 15-20 days after establishment and Seradix No. 2 (0.3% IBA) promotes rooting of fever tea cuttings. The ideal combination of light and temperature for seed germination of fever tea was investigated. Germination was tested at constant temperature regimes (15, 20, 25 and 30¨¬C with continuous light or dark period and alternating temperatures of 20:30 and 16L: 8D (light: dark) combinations respectively. Seeds started to germinate after 8 days from incubation and the last germination was observed at 30 days from incubation. Germination percentages increased at 20-30 constant temperatures and 20/30 alternating temperatures but the difference amongst them was not significant. Higher germination of 86% were achieved when seeds were exposed to continuous light than alternating light and dark. Seeds failed to germinate in continuous darkness. Fever tea seeds were positively photoblastic. The effect of fertigation frequency and growing medium on the growth, yield and quality of fever tea were investigated in a tunnel. Treatments used were five fertigation frequencies (0.5L/day, 1L/day, 2L/day, 2L/2nd day, and 2L/week) and two growing media (pine bark and sand). Measurements made were plant height, stem circumference and number of branches at 8, 16 and 32 weeks after planting. At 8 weeks after planting all fertigation frequencies improved fever tea growth except fertigation frequency of 2L/week. All the fertigation frequencies were ideal to sustain the growth and development of fever tea plants except 2L/week. At 16 weeks after planting there were interactive effects between fertigation frequencies and the growing medium for the plant height of fever tea. Plants fertigated with 2L/day grown in sand media grew taller than all the other fertigation frequencies. At 32 weeks after planting there was a significant effect on the plant height from the main effects of fertigation frequency and growing medium. Plants fertigated with 2L/day were significantly the tallest followed by plants fertigated with 0.5L/day, 1L/day, 2L/2nd day and 2L/week. When plants were younger better plant growth was obtained in pine bark media. Stem circumference and number of branches of fever tea were significantly affected by fertigation frequency and growth medium. At 16 and 32 weeks after planting, plants grown in sand media had thicker stems and more branches as compared to plants grown in pine bark media. The essential oil of fever tea was extracted using hydro-distillation. Fertigation frequency did not affect oil yield. Plants grown in pine bark media yielded more oil than plants grown in sand medium. Microscopical studies using scanning electron microscope were investigated to determine the development of oil glands and trichomes on the abaxial (upper) and adaxial (lower) surfaces of the leaves as affected by fertigation frequency and the growing medium. There were no significant effects on the number of oil glands and trichomes developed on both surfaces of the leaves. Pine bark medium resulted in larger oil glands than sand medium regardless of the treatments, and pine bark also yielded more oil percentages than sand medium. Based on this investigations for commercial production of fever tea essential oil pine bark media is recommended. Chemical compounds of fever tea oil were also not affected by fertigation frequency or growth medium. In this study the chemical compounds detected from essential oils of fever tea were monoterpenes (i.e. ¥á-pinene, sebinen, 1.8 cinede, myrcene, ipsenone and ipsedienone) and the sesquiterpenes (i.e. ¥â-caryophyllene and germacrene-D). Compounds that gave the smallest chemical percentages and the shortest time to be detected were ¥á-pinene, sebinen, 1.8 cinede, myrcene, ipsenone and ipsedienone. Compounds found with the highest chemical percentages with highest peaks were ¥â-caryophyllene and germacrene-D. / Dissertation (MSc (Horticulture))--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted
2

Indigenous knowledge of bush tea (Athrixia Phylicoides) and effect of fertigation frequency and growing medium on plant growth

Rakuambo, Z.J. (Zwonkunda Juliet) 04 August 2008 (has links)
Bush tea (Athrixia phylicoides) is a medicinal herbal tea, which is used for cleansing or purifying the blood, treating boils, bad acne as well as infected wounds and cuts. A. phylicoides also has the potential to be used as an ornamental cut flower due to its beautiful flowers. Because of the many uses of bush tea, it faces problems of being over harvested and exploited. Therefore, there is a need to study more about the plant for possible domestication. A questionnaire survey was conducted in selected villages of Thohoyandou and Nzhelele in Venda, Limpopo Province, by means of personal interviews. The aim of the survey was to gather indigenous knowledge and validate the uses of bush tea from the local people. Interviews were conducted on three types of respondents, viz. traditional healers (31%), street sellers (25%) and bearers of indigenous knowledge (44%). A total of one hundred respondents were interviewed. One important finding of the study was that people from the area of study possess a remarkable knowledge of the plant and its uses to treat a wide range of physical ailments. The bush tea plant is used as medicine, health tea as well as a traditional broom. Some of these ailments that could be treated using bush tea were headaches, stomachache, influenza and leg wounds. It is known to have aphrodisiac properties and it can also be used to cleanse the womb, kidney, and veins and to purify blood. The plant was harvested in different ways depending on the reason for harvesting. Results from the survey indicated that the majority of the respondents had no interest in propagating the bush tea plant, few respondents showed interest in propagating the plant. They also showed enhanced knowledge about the uses of other medicinal plants. A tunnel experiment was also conducted at the Hatfield Experimental Farm of the University of Pretoria in South Africa. The effects of growing media (pine bark and sand) and fertigation frequencies (0.4 ℓ/day, 1 ℓ/day, 2 ℓ/day, 2 ℓ/2nd day and 2 ℓ/ week) on growth and yield of bush tea were studied. Growing media and fertigation frequencies significantly affected the growth performance and yield of bush tea. The growth rate of bush tea between the autumn season and winter season was higher than between winter and spring season. Greater number of stems and shoots were observed in sand grown plants as compared to pine bark grown plants. Sand grown plants had a higher root mass as compared to those of pine bark grown plants over both seasons, with nonsignificant differences in the dry root mass in winter (90 days after planting). Plants grown in sand had significantly longer roots (P≤ 0,05) than plants grown in pine bark at 90 days after planting. However, at 180 days after planting the differences in root lengths were no longer significant. Fertigation frequencies caused significant differences in growth performance and yield of bush tea. Plants fertigated with 1 ℓ/day were significantly the tallest, followed by plants fertigated with 0.4 ℓ/day, 2 ℓ/day, 2 ℓ/2nd day and 2 ℓ/ week. Our results confirmed that bush tea could grow up to 1 metre high (1.08 m). In addition, fertigation frequency of 1 ℓ/day resulted in plants with greater stem and leaf mass (both fresh and dry), thus higher yields. Fertigation frequency of 2 ℓ/day was found to be too high and hence reduced oxygen supply to the roots and consequently retarded above plant growth. Sand grown plants also produced more flowers than pine bark grown plants. Overall, plants grown in sand media had superior stem and shoot mass, leaf mass, root mass and flower mass compared to plants grown in pine bark. Plants that received insufficient amount of water (2 ℓ /week) resulted in stunted growth and produced the least yield. In conclusion, bush tea plants performed better in sand growth media than in pine bark growth media. An optimum application rate of 1 ℓ/day was ideal for growth and performance of bush tea as the plant performed better under this fertigation frequency. / Dissertation (MInstAgrar)--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted

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