Orientador: Magali Ribeiro da Silva / Coorientador: Iraê Amaral Guerrini / Banca: Hélio Grassi Filho / Banca: Gisela Ferreira / Resumo: A produção de mudas da espécie Eucalyptus grandis x Eucalyptus urophylla tem crescido muito nos últimos anos no Brasil, devido a sua boa adaptação nos diferentes solos e regiões, possuindo comportamentos diferentes quanto à exigência nutricional em diferentes tipos de substrato que o mercado oferece. O conhecimento desses comportamentos trará benefícios econômicos e diminuição dos impactos ambientais causados pelo uso excessivo de fertilizantes. Neste trabalho buscou-se avaliar o efeito de doses de fósforo em três tipos de substratos na produção de mudas de Eucalyptus grandis x Eucalyptus urophylla. O experimento foi inteiramente casualizado em fatorial 3x4, utilizando 3 substratos e 4 doses de fósforo na base, totalizando 12 tratamentos distribuídos em 4 parcelas com 25 plantas. O adubo usado na fertilização de base foi o superfosfato simples e as doses foram de 0, 160, 320 e 480 g por m3 de substrato. Os substratos utilizados foram: Carolina Soil® a base de turfa, vermiculita e casca de arroz carbonizada; substrato Mecplant® a base de casca de pinus e vermiculita e substrato a base de fibra de coco e vermiculita. As avaliações do experimento constituíram-se de análise química do substrato e características morfológicas das mudas: altura da parte aérea, diâmetro do coleto, massas secas da parte aérea e radicular e qualidade de raiz. Em função dos resultados obtidos pode-se inferir que para o substrato Carolina Soil® a dose que apresentou mudas com maior desenvolvimento foi a de 320 g m-3. Para o substrato fibra de coco + vermiculita foi a de 160 g m-3 e para o substrato a Mecplant® tanto na dose zero quanto na de 480 g m-3 apresentaram resultados semelhantes, indicando a não necessidade de aplicação de P na adubação de base neste substrato. Os três substratos produziram mudas semelhantes e dentro do padrão de qualidade adequado / Abstract: The production of cuttings of the species Eucalyptus grandis x Eucalyptus urophylla has grown significantly in recent years in Brazil due to its good adaptation to different types of soil and region, having different behaviors a far as its nutritional demands on the different kinds of substrate offered by the market. Knowledge of these behaviors will bring economic benefit and a diminishing of the environmental impact caused by the excessive use of fertilizers. This investigation sought to validate the effect of doses of phosphorus on three types of substrate in the production of cuttings of Eucalyptus grandis x Eucalyptus urophylla. The experiment was entirely done on 3x4 factorial, using 3 substrates of 4 doses of phosphorous on the base, totaling 12 applications distributed among 4 parcels with 25 plants each. The fertilizer used for the base was a simple superphosphate and the doses were 0, 160, 320 and 480 g per m3 of substrate. The substrates used were: truffle based Carolina Soil®, vermiculite and carbonized rice shells, vermiculite and pinus shell based Mecplant® and coconut fiber and vermiculite substrate. Evaluations in the experiment include chemical analysis of the substrate and morphological characteristics of the cuttings: height of the airborne area, stalk diameter, dry spots on the airborne area and root and overall quality of the root. From the obtained results, it's possible to infer that for the Carolina Soil® substrate, the dosage that showed the best growth was 320 g m3. For the coconut + vermiculite substrate the best results came with 160 g m-3 and for the Mecplant® substrate, both the zero dose and the 480 g m3 showed similar results, indicating that there isn't a need for the application of P on the fertilizing of the base of this substrate. The three substrates will produce similar cuttings and within an adequate pattern of quality / Mestre

Please read the abstract in the section 00front of this document. / Dissertation (MSc (Plant Production))--University of Pretoria, 2004. / Plant Production and Soil Science / unrestricted

The influence of nitrification on the “soil” solution of container media has not been documented. The investigation of this influence is justified since the ionic form of N in a soil solution has a significant influence on plant tissue nutrient content and growth. Three genera of woody plants were grown in one-liter containers filled with pine bark, treated with and without a nitrification inhibitor and fertilized with 210 ml of a 100 ppm NH₄-N solution. Without the inhibitor and over time, “soil” solution NH₄-N concentrations and pH decreased and NO₃-N concentrations increased. “Soil” solution and tissue cation concentrations were generally greater without the inhibitor. In a second experiment, pine bark in one-liter containers was treated with either 0, 3 or 6 kg lime m⁻³. “Soil” solution data and NO₃-N accumulation rate (NAR) data showed an earlier nitrification of NH₄-N at the 6 kg lime compared to the 3 kg lime treatment whereas NO₃-N was not found at the 0 kg lime treatment. In a 3rd experiment, pine bark in one-liter containers was treated with 210 ml of either 25, 100 or 200 ppm NH₄-N. Over time “soil” solution NO₃-N concentrations were greatest and pH values were lowest at the 200 ppm N treatment. The NAR of the 25 ppm N treatment was less than the 100 and 200 ppm N treatment which were not different. The lack of correspondence between the “soil” solution NO₃-N data and the NAR data for the 100 and 200 ppm N treatments was explained on the basis of NH₄-N supply. In a 4th experiment, pine bark in one-liter containers were subjected to either 10°, 20°, 30° or 40° C for 24 days. “Soil” solution NH₄-N concentrations decreased over time at 10°, 20° and 30°. “Soil” solution NH₄-N and NO₃-N concentrations at 40° were considerably higher and lower, respectively, than at other temperatures. Over time the general order of NAR was: 20° = 30° > 10° > 40°. Results of these experiments indicate that nitrification is an important consideration in the nutrition of container-grown plants. / Ph. D.

The development of a plant growth chamber capable of sustaining plant growth over multiple generations is a necessary step towards the attainment of a Controlled Ecological Life Support System (CELSS). The studies herein examine the effects of aeration abilities and rates on plants grown in three model nutrient delivery systems during germination and over the life-cycle of the plant. These studies are the first time a porous tube nutrient delivery system was compared to another active nutrient mist delivery system. During germination an indicator of hypoxic stress, alcohol dehydrogenase (ADH) activity, was measured and was more affected by aeration rate than mode of nutrient delivery. Over the life-cycle of the plant, however, plants grown in the porous tube system had the least ADH activity and the highest levels of shoot (leaf + stem), root and leaf biomass. None of the plants in any system, however, produced viable seed. This study highlights the need to optimize aeration capabilities in the root zone of enclosed chambers.

Micropropagation of Aloe polyphylla, an endangered species with a high ornamental and medicinal value, is an important part of its conservation. However, the in vitro culture was hindered by the phenomenon of hyperhydricity. The research reported in this thesis was undertaken for two reasons. Firstly, to understand the role of various culture factors involved in the process of hyperhydricity in A. polyphylla and to identify the in vitro conditions, under which this disorder can be prevented. Secondly, we conducted an investigation into the underlying mechanisms of this phenomenon by probing if it was mediated through internal cytokinins. Ammonium (NH4 +) ions, applied cytokinins (CKs) and CK concentrations were tested in multifactorial combinations and significantly influenced the regeneration rate and occurrence of hyperhydricity. Shoots were grown on media with different NH4 + concentrations (10.3, 20.6 and 61.8 mM) and supplemented with BA, zeatin or TDZ at 0, 5 or 15 ìM. Elevating the levels of NH4 +, in the absence of CKs, could not induce hyperhydricity. Similarly, very low hyperhydricity was observed when CKs were added to media containing low NH4 + (10.3 mM). However, in the presence of higher NH4 + concentrations, CKs increased hyperhydricity in a concentrationdependant manner, suggesting that they were capable of inducing this syndrome only when other factors in the culture system were not optimised. High numbers of healthy looking shoots were produced on media with low NH4 + and low BA or zeatin (5 ìM). The use of TDZ resulted in the formation of buds, which did not develop into shoots. In view of the fact that NH4 + was supplied in the form of NH4NO3, it was difficult to determine if NH4 + or nitrate (NO3 -) ions were associated with the increase in hyperhydricity. We further examined the role of nitrogen (N) supplied as inorganic NH4 + or NO3 -, or organic glutamine. The omission of total N from the culture medium resulted in low multiplication and hindered shoot growth. Ammonium as the sole source of N depressed shoot regeneration and growth and escalated the frequency of hyperhydricity to ca. 50%. When NO3 - was used as the sole N source, shoots of fine quality were produced and hyperhydricity was completely eliminated. Overall, the MS N mix was superior to any single N source for multiplication and growth of shoots, suggesting a synergistic effect between NH4 + and NO3 - on shoot regeneration. Furthermore, not only the absolute amount of N, but also the relative amounts of NH4 + and NO3 - influenced the multiplication rate, frequency of hyperhydricity and shoot quality. The highest regeneration was obtained with NH4 + : NO3 - ratios (mM) of 20 : 40, 30 : 30 and 40 : 20. Decreasing the ratio of NH4 + : NO3 - lowered the occurrence of hyperhydricity. The potential of glutamine as the sole source of N was also demonstrated, since its application resulted in the production of good quality shoots and almost no hyperhydricity. Shoot explants grown in static liquid media became hyperhydric and lost their ability to regenerate. The type of gelling agent used to solidify the medium affected greatly hyperhydricity and shoot multiplication. Gelrite resulted in a significantly lower multiplication rate and four times higher hyperhydricity (64.7%) compared to when agar was used. Gelrite was further selected to test the hypothesis if hyperhydricity can be overcome by decreasing the relative matric potential of the media, and respectively the availability of water, as represented by increasing gelrite concentrations. Satisfactory reduction in hyperhydricity was achieved only at 16 g l-1 gelrite, however the regeneration also decreased. The nature of the gelling agent is therefore essential for the successful control of this phenomenon. It appears that a crucial prerequisite for the reduction of hyperhydricity in tissue cultures of A. polyphylla is the gaseous exchange between the in vitro atmosphere and the outside environment. In ventilated cultures, achieved by using a modified lid with a hole (d = 7 mm) covered with polyester or cotton mesh, hyperhydricity was completely eliminated, irrespectively of the type of gelling agent. Ventilation was further advantageous for the in vitro regenerants by increasing their leaf chlorophyll content as well as epicuticular wax deposition, the last one being indicative of the development of the water loss regulation mechanisms of explants. The increased culture ventilation, however, was negatively correlated with the regeneration rate and shoot growth. Endogenous CKs were measured in in vitro regenerants after an eight-week cycle to examine whether the hyperhydricity-inducing effect of exogenous CKs and gelling agents is associated with changes in the endogenous CK content. The content of endogenous CKs, determined by HPLC-mass spectrometry, in the shoots grown on CK-free media comprised isopentenyladenine-, trans-zeatin- and cis-zeatin-type CKs. The application of exogenous CKs resulted in an increase in the CK content of the shoots. Following application of zeatin, dihydrozeatin-type CKs were also detected in the newly-formed shoots. Application of BA to the media led to a transition from isoprenoid CKs to aromatic CKs in the shoots. Shoots grown on gelrite media contained higher levels of endogenous CKs compared to those on agar media. Total CK content of hyperhydric shoots was higher than that of normal shoots grown on the same medium. We suggest that the ability of exogenous CKs and gelrite to induce hyperhydricity in shoots of Aloe polyphylla is at least partially due to up-regulation of endogenous CK levels. However, hyperhydricity is a multifactor process in which different factors intervene. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Peat extraction for horticultural production poses a threat to wetland ecosystems. The rapid growth rate of the horticulture industry has prompted an ongoing search for sustainable alternative growth media components to replace peat. The alternative components need to provide properties (physical and chemical) similar to or better than peat and provide conditions that will enhance ideal growth and yield of potted plants. Potted Dendranthema x grandiflorum is one of the most important pot plants cultivated worldwide in the floriculture industry. There is a global research effort to replace peat with a sustainable alternative growth media for potted plants; however, so far, no study has been conducted in South Africa that used similar treatments on potted Dendranthema x grandiflorum. The aim of this study was to determine a suitable alternative growth media to replace peat as a growth media for cultivation of potted D. x grandiflorum. A greenhouse experiment was conducted at the University of South Africa’s Horticulture centre in Florida, Johannesburg for 89 days. Eight growth media (100 % peat (T1) (control), 100 % bagasse (T2), 50:50 % v/v bagasse:peat (T3), 75:25 % v/v bagasse:peat (T4), 25:75 % v/v bagasse:peat (T5), composted bagasse (T6), Coir (T7), and pine bark (T8)) as treatments and one hybrid (Mount® Runca) of D. x grandiflorum were arranged in a randomized complete block design with four replicates. In this study, nutrient uptake, chlorophyll content, growth, and yield parameters were measured for potted D. x grandiflorum grown in all eight growth media. The results show that treatments had different chemical and physical properties compared to peat. The pH of 100 % bagasse and coir were within the ideal range recommended for growth media. The EC results indicated that after the experiment, other treatments were within the defined range except for composted bagasse due to high concentration of soluble salts. The BD of control and composted bagasse were similar and may have resulted in the low root response. The concentration of total N was high in the shoots of plants cultivated in 100 % peat with a subsequent increased fresh and dry shoots weight. The highest significant chlorophyll content was present in plants cultivated in composted bagasse, which contained high total N and, Fe and Zn concentrations in shoots. Taken together, the results showed that composted bagasse was the best alternative to replace peat for cultivation of potted D. x grandiflorum. / Turfonttrekking vir tuinboukundige produksie hou ʼn bedreiging vir moerasland-ekostelsels in. Die vinnige groeitempo van die tuinboubedryf het gelei tot ʼn voortdurende soektog na volhoubare groeimediakomponente om turf te vervang. Die alternatiewe komponente moet (fisiese en chemiese) eienskappe kan bied wat soortgelyk aan, of beter as dié van turf is, en moet toestande gee wat die ideale groei en opbrengs van potplante verbeter. Potplant- Dendranthema x grandiflorum is een van die belangrikste potplante wêreldwyd wat in die blomboerderybedryf aangeplant word. Daar word wêreldwyd navorsing gedoen om turf met ʼn volhoubare groeimedium vir potplante te vervang; sover is daar egter nog nie in Suid-Afrika ʼn studie gedoen wat soortgelyke behandelings vir potplante- Dendranthema x grandiflorum gebruik nie. Die doel van hierdie studie was om ʼn gepaste alternatiewe groeimedium te bepaal om turf as ʼn groeimedium te vervang vir die aanplanting van D. x grandiflorum-potplante. ʼn Kweekhuis-eksperiment is by die Universiteit van Suid-Afrika se Tuinbousentrum in Florida, Johannesburg uitgevoer vir 89 dae. Agt groeimedia (100% turf (T1) (beheer), 100% bagasse (T2), 50:50% v/v bagasse:turf (T3), 75:25% v/v bagasse:turf (T4), 25:75 % v/v bagasse:turf (T5), bagasse wat tot kompos verwerk is (T6), klapperhaar (T7), en dennebas (T8)) as behandelings en een hibried (Mount® Runca) van D. x grandiflorum is in ʼn verewekansigde, volledige blokontwerp met vier repliserings gerangskik. In hierdie studie is voedingstofopname-, chlorofilinhoud-, groei- en opbrengs-parameters gemeet vir potgroei van D. x grandiflorum in al agt groeimedia. Die resultate toon dat die behandelings verskillende chemiese en fisiese eienskappe in vergelyking met turf het. Die pH van 100% bagasse en klapperhaar val binne die ideale reikwydte wat vir groeimedia aanbeveel word. Volgens die EG (elektriese geleiding)-resultate was ander behandelings binne die gedefinieerde reikwydte – behalwe vir bagasse wat tot kompos verwerk is – vanweë die hoë konsentrasie oplosbare soute. Die BD van beheer en bagasse wat tot kompos verwerk is, was soortgelyk en kon die lae wortelrespons veroorsaak het. Die konsentrasie totale N was hoog in die lote van plante wat in 100% turf aangeplant is, met ʼn gevolglike verhoging in die gewig van vars en droë lote. Die hoogste beduidende chlorofilinhoud was teenwoordig in plante wat gekweek is in bagasse wat tot kompos verwerk is, en wat hoë totale konsentrasies van N, Fe en Zn in die lote bevat het. Alles in ag genome het die resultate getoon dat bagasse wat tot kompos verwerk is, die beste alternatief is om turf te vervang in die kweking van D. x grandiflorum in potte. / Go ntsha borubu mo kumong ya mokgwa wa temo go na le matshosetsi mo matshelong a diphologolo le ditlhare tsa lefatshe le le kolobileng. Kelo ya kgodiso e e bonako ya intaseteri ya matshelo a diphologolo le ditlhare e susumetsa patlo e e tswelelang ya dikarolo tsa mekgwa ya kgodiso ya thefosano e e tswelelang ya go emela go ntsha borubu. Dikarolo tse dingwe di tlhoka go neela dipharologantsho (sebopego le khemikale) tse di tshwanang le kgotsa botoka mo go ntsheng borubu le go neela mabaka a a ka tsholetsang kgodiso e e ikaeletsweng, mme ya ntsha dijalo tse di ka fa dipitseng. Dendranthema x grandiflorum e e ka fa dipitseng ke thefosano nngwe ya dijalo tsa ka fa dipitseng tse di botlhokwa thata tse di jadilweng mo lefatsheng ka bophara mo intasetering ya mokgwa wa temo ya dithunya. Go na le boiteko jwa patlisiso ya bogotlhe ya go emela go ntsha borubu ka mokgwa wa kgodiso wa thefosano o mongwe o o tswelelang wa dijalo tsa ka fa dipitseng; le gale, go le kalo, ga go na thuto e e setseng e dirilwe mo Aforikaborwa e e dirisang ditshwaro tse di tshwanang mo go Dendranthema x grandiflorum e e mo dipitseng. Maikaelelo a thuto eno e ne e le go tlhomamisa mekgwa ya grandiflorum e e mo dipitseng. Maikaelelo a thuto eno e ne e le go tlhomamisa mekgwa ya kgodiso ya thefosano e mengwe e e tshwanelang go emela go ntsha borubu jaaka mekgwa ya kgodiso ya go jala D. x grandiflorum ka mo dipitseng. Tekelelo ya ntlo e tala e ne ya dirwa kwa lefelong la Mokgwa wa matshelo a diphologolo le ditlhare ya Yunibesiti ya Aforikaborwa kwa Florida, Johannesburg mo matsatsing a le 89. Mekgwa ya kgodiso e merobedi (100 % ya go ntsha borubu (T1) (taolo), 100 % bagasse (T2), 50:50 % v/v bagasse: go ntsha borubu (T3), 75:25 % v/v bagasse: go ntsha borubu (T4), 25:75 % v/v bagasse: go ntsha borubu (T5), bagasse e e bodisitsweng (T6), Coir (T7), le kutu ya phaene (T8)) jaaka ditshwaro le lotswakwa lo lo longwe (Mount® Runca) ya D. x grandiflorum di ne di beilwe ka moakanyetso wa boloko e e feletseng ka kakaretso ka ditshwano di le nne. Mo thutong eno, go tsaya kotlo, diteng tsa setalafatsi, kgodiso le diparametara tse di ntshitsweng di ne tsa lekanyediwa mo go D. x grandiflorum e e mo dipitseng e e jadilweng mo mekgweng ya dikgodiso tse di robedi tse tsotlhe. Dipheto di bontsha gore ditshwaro di na le dikarolo tsa dikhemikale le dibopego tse di farologaneng fa di tshwantshanngwa le go ntsha borubu. Bagasse ya pH ya 100 % le coir di ne di le magareng ga paka ya botlhokwa ya kgodiso e e atlenegisitsweng mo mekgweng ya kgodiso. Dipheto tsa EC di bontsha gore morago ga tekelelo, ditshwaro tse dingwe di ne di le magareng ga paka e e tlhalositsweng kwa ntle ga bagasse e e bodisitsweng kwa kokoanong e e kwa godimo ya matswai a a tlhaolositsweng. BD ya taolo le bagasse e e bodisitsweng, mme go ka bo go dirile gore go nne le tsibogelo ya medi e e kwa tlase. Kokoano ya N yotlhe e ne e le kwa godimo mo matlhogeding a dijalo tse di jadilweng ka go ntsha borubu jwa 100 % ka koketso e e latelang ya bokete jwa matlhogedi a mantshwa le a a omileng. Diteng tsa setalafatsi se se botlhokwa se se kwa godimodimo di ne di le teng mo dijalong tse di jadilweng ka bagasse e e bodisitsweng, e e nang le kokoano ya bogotlhe jo bo kwa godimo jwa N, Fe le Zn mo matlhogeding. Di tserwe mmogo, dipheto di bontsha gore bagasse e e bodileng jaaka sengwe se se gaisang go emela go ntsha borubu mo jalong ya D. x grandiflorum ka mo dipitseng. / School of Environmental Sciences / M. Sc. (Ornamental Horticulture)

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)

The main objective of this study is to develop a modeling methodology that facilitates incorporating the plant pathway into environmental contamination models recognizing the fact that plants are dynamic entities that regulate their life cycle according to natural and anthropogenic environmental conditions. A modeling framework that incorporates the plant pathway into an integrated water flow and contaminant transport model in terrestrial systems is developed. The modeling framework is aimed to provide a tool to analyze the plant pathway of exposure to contaminants. The model developed using this framework describes the temporal and spatial variation of the contaminant concentration within the plant as it is interacting with the soil and the atmosphere. The first part of the study focuses on the integration of the dynamics of water and contaminant distribution and plant related processes within the vadose zone. A soil-plant system model is developed by coupling soil-water flow, contaminant transport, plant life-cycle, and plant pathway models. The outcome unifies single media continuous models with multimedia compartmental models in a flexible framework. The coupling of the models was established at multiple interfaces and at different levels of solution steps (i.e. model development phase vs. numerical solution phase). In the second part of the study, the soil-plant system model is extended to cover large spatial areas by describing the environmental system as a collection of soil-plant systems connected through overland flow and transport processes on the ground surface and through lateral interactions in the subsurface. An overland flow model is integrated with the previously coupled model of unsaturated zone soil-water flow and plant life-cycle by solving the flow model equations simultaneously within a single global matrix structure. An overland / subsurface interaction algorithm is developed to handle the ground surface conditions. The simultaneous solution, single-matrix approach is also adopted when integrating the overland transport model with the previously coupled models of vadose zone transport and plant pathway. The model developed is applied to various environmental contamination scenarios where the effect of the presence of plants on the contaminant migration within environmental systems is investigated.

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)