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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

Challenges in the Greenhouse Production of Rosmarinus officinalis L.

Westervelt, Paul Matthew 03 September 2003 (has links)
Rosmarinus officinalis L. (rosemary) is popular as a culinary herb, landscape plant, and potted florist's crop. Little research has been reported on the greenhouse production of this plant. Effects of irrigation rate, fertilizer concentration, and growing media on root and shoot growth were investigated for R. officinalis 'Athens Blue Spires'. In the first experiment, rooted cuttings were potted and received fertilizer treatments of 100, 200, or 300 mg?L-1 nitrogen (N) from 15N-2.2P-12.2K water-soluble fertilizer for twelve weeks. Two irrigation regimes were imposed - plants were irrigated with fertilizer solution when the growing media dried down to less than 30% or 20% volumetric soil moisture content. Root and shoot dry weights showed irrigation rate did not effect roots, but the higher irrigation rate produced larger shoots at all fertilizer concentrations. The largest roots and shoots were a product of the lowest fertilizer concentration. In the second experiment, rooted cuttings of the same cultivar were potted and received fertilizer treatments of 50, 100, 150, or 200 mg?L-1 N from 15N-2.2P-12.2K water-soluble fertilizer for 2, 4, 6, or 8 weeks. Plants were harvested at the end of each treatment. A third irrigation regime was imposed - plants were irrigated with fertilizer solution when the growing media dried down to less than 40%, 30%, or 20% volumetric soil moisture content. Root and shoot dry weights showed neither irrigation nor fertilizer were significant at week two, six, or eight. Dry weights showed irrigation was significant for roots at week four with the lowest irrigation rate producing the largest roots at all fertilizer concentrations except 100 mg?L-1 at the less than 30% irrigation rate. Irrigation was also significant at week four for shoots with the lowest irrigation rate producing the largest shoots at all fertilizer concentrations except 100 mg?L-1 at the less than 30% irrigation rate. In the third experiment 'Athens Blue Spires' rooted cuttings were potted in five different soilless media [Fafard 52 (24% peat, 60% bark, 8% perlite, 8% vermiculite); Fafard 3B (45% peat, 25% bark, 15% perlite, 15% vermiculite); Scott's Sierra Perennial Mix (25% peat, 65% bark, 10% perlite); Scott's Metro Mix 700 with Coir (25% coir, 50% bark, 10% perlite, 15% vermiculite); and a nursery mix (89% pine bark, 11% sand)]. Plants were irrigated for fourteen weeks with 150 mg?L-1N fertilizer solution when the growing media dried down to less than 30% or <20% volumetric soil moisture content. Growing media affected shoot dry weight with the highest-percentage peat media (Fafard 3B) producing the largest plants. All were of marketable quality. Irrigation rate did not affect root dry weight, but the higher rate produced larger shoots in each of the five media. The fourth experiment examined the growth of R. officinalis 'Tuscan Blue' rooted cuttings when planted in five different growing media [Fafard 52, Fafard 3B, Scott's Perennial, Metro Mix 560 with coir (30% coir, 15% peat, 40% bark, and 15% perlite), and 100% pine bark]. A third irrigation regime was imposed - plants were irrigated with 150 mg?L-1N fertilizer solution when the growing media dried down to less than 40%, 30%, or 20% volumetric soil moisture content. Treatments lasted for 2, 4, 6, or 8 weeks and plants were harvested at the end of each treatment. Dry weights showed neither media nor irrigation was significant for roots or shoots at weeks four or eight. However, at week two, media significantly affected root dry weight with the heaviest roots produced by the two perennial mixes (Scott's perennial and Fafard 52). Growing media affected shoot dry weight at week six with the highest-percentage peat media (Fafard 3B) producing the largest plants at the low and high irrigation rate. Irrigation also affected root dry weight at week six with the two lowest irrigation rates producing the heaviest roots in all media. / Master of Science
2

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
3

Growth, yield and quality of hydroponically grown tomatoes as affected by different particle sizes of sawdust

Maatjie, Maboloke Abram 23 March 2016 (has links)
The tomato is one of the most important vegetable crops grown in the South African community. Most hydroponic tomato growers in South Africa are using sawdust as a growing medium due to its availability and affordability. However, there is little or no information on how particle sizes of sawdust influence tomato yield and quality. The aim of the study was to determine the effect of the particle size of sawdust on plant growth, yield and quality of tomato. Six treatments of different particle sizes of sawdust i.e. fine (F), medium (M), coarse (C) and 50:50 ratio of F: M, C: M, and C: F extracted from pine tree were used for the experiment. Treatments were arranged in a randomized complete block design with four replicates. The size of the sawdust particles did not have a significant effect on plant height, stem diameter, leaf length and width, shelf-life, marketable yield, total yield and unmarketable yield. A tendency to increase marketable and total yield was observed when tomato plants were grown at a 50:50 C: F ratio. Fruit and leaf mineral content were not affected by sawdust particle size. After completion of the experiment, air- filled porosity was significantly high on particle size C, M, and C: M while the water holding capacity was significantly high on F followed by M. The study showed that the suitable growth medium for production of tomatoes under the hydroponics system used was the CF particle substrate. Generally, the experimental crop performed better under the CF particle substrate in terms of growth parameters, and fruit quality, thus leading to the conclusion that the CF growth medium is ideal for hydroponically grown tomato under a non-environmentally controlled polytunne / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)
4

Growth, yield and quality of hydroponically grown tomatoes as affected by different particle sizes of sawdust

Maatjie, Maboloke Abram 23 March 2016 (has links)
The tomato is one of the most important vegetable crops grown in the South African community. Most hydroponic tomato growers in South Africa are using sawdust as a growing medium due to its availability and affordability. However, there is little or no information on how particle sizes of sawdust influence tomato yield and quality. The aim of the study was to determine the effect of the particle size of sawdust on plant growth, yield and quality of tomato. Six treatments of different particle sizes of sawdust i.e. fine (F), medium (M), coarse (C) and 50:50 ratio of F: M, C: M, and C: F extracted from pine tree were used for the experiment. Treatments were arranged in a randomized complete block design with four replicates. The size of the sawdust particles did not have a significant effect on plant height, stem diameter, leaf length and width, shelf-life, marketable yield, total yield and unmarketable yield. A tendency to increase marketable and total yield was observed when tomato plants were grown at a 50:50 C: F ratio. Fruit and leaf mineral content were not affected by sawdust particle size. After completion of the experiment, air- filled porosity was significantly high on particle size C, M, and C: M while the water holding capacity was significantly high on F followed by M. The study showed that the suitable growth medium for production of tomatoes under the hydroponics system used was the CF particle substrate. Generally, the experimental crop performed better under the CF particle substrate in terms of growth parameters, and fruit quality, thus leading to the conclusion that the CF growth medium is ideal for hydroponically grown tomato under a non-environmentally controlled polytunne / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)
5

Implementering av hydroponisk odling i en livsmedelsbutik : En fallstudie av en aktör inom Stockholmsområdet / Implementation of hydroponic cultivation in a grocery store : A case study of an actor in the Stockholm area

Korssell, Caroline, Rudert, Emelie January 2021 (has links)
Denna rapport behandlar en fallstudie i ett kandidatexamensarbete som utförts tillsammans med en livsmedelsbutik i Stockholmsområdet och som grundar sig i intervjuer, platsbesök och vetenskapliga artiklar. Där livsmedelsbutiken har ett intresse av att implementera en odling i form av ett hydroponiskt system direkt i sin butik.  I fallstudien har det undersökts hur implementering av odling i butik genom ett samarbete med ett odlingsföretag skulle fungera och se ut för butiken. Studien har begränsats till två olika odlingsföretag i Sverige, som har varsitt koncept på hur odlingen kan implementeras, gemensamt för dem är att de använder vertikal odling i form av hydroponiska system. Där det ena företaget erbjuder vertikal odling i en odlingscontainer och det andra vertikal odling inne i ett växthus. Båda företagens olika odlingskoncept har redan implementerats i två andra livsmedelsbutiker inom samma koncern som livsmedelsbutiken i Stockholm befinner sig i.  Fallstudien har genomförts genom att först skapa en bred bakgrund genom litteratursökningar i olika databaser kring relevanta nyckelord för att sedan genomföra intervjuer med båda odlingsföretagen och livsmedelsbutikerna. Därefter har kunskap och svar från respondenterna i intervjuerna sammanställts och ett förslag har tagits fram om vilket odlingsföretag som lämpar sig bäst för livsmedelsbutikens ändamål.  Resultatet visar att möjligheterna och fördelarna vid en implementering av hydroponisk odling för livsmedelsbutiken i Stockholmsområdet att implementera hydroponisk odling är flera och överväger till största del de möjliga utmaningarna. Dessutom gynnas flera av hållbarhetsmålen till livsmedelsbutikens koncern genom implementering av en hydroponisk odling i butiken. Vidare gynnas även några av de Förenta Nationernas Globala mål och även livsmedelsbutikens egna hållbarhetsmål. / This report is the result and outcome of a bachelor's thesis project conducted during the spring of 2021. The report presents the performed case study of a grocery store, in the area of Stockholm, where the company is aiming to implement a hydroponic self-cultivation inside their grocery store. The work is based on conducting interviews and reviewing established scientific articles in the field.  In the case study, it has been investigated how a potential collaboration between the grocery store and a cultivation company can be established. The study was limited to investigating two cultivation companies active on the Swedish market. These two cultivation companies have different solutions of how the cultivation can be implemented on the store area, but both offer vertical hydroponic solutions. Further, both systems of the individual cultivation companies’ have been implemented in other grocery stores that can be used as reference for validation of data.  The literature review of existing publications were conducted by searching in different databases by using the keywords of this work, for the researcher to increase knowledge to create guides for the interviews and for creating the theoretical frame of reference. Thereafter, literature findings and answers from the interviewees were compiled, analyzed and discussed to make a proposition of which cultivation company is best suited for a potential collaboration, with regard to the grocery stores’ wishes of implementing a hydroponic solution.  The results show that several of the grocery stores’ sustainability goals would benefit from a potential implementation of a self-cultivation. Also, implementing a hydroponic farm on the store area would increase the grocery store’s contribution towards achieving the Sustainable Development Goals.

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