The thesis work was done as a part of the company's proposal writing work for the Horizon Europe projects, which is the European Union's key funding program for research and innovation with a budget of €95.5 billion. The budget for this project call was €5 million and aimed towards demonstrating the possibilities of Photovoltaic thermal technologies (PVT), which will produce heat and electricity at the same time on agricultural land to combat climate change. The initial stage of the project, which the thesis work corresponds to, consists of the concept of implementing the objectives of the call and demonstrating how it could be achieved by forming a consortium of different companies, allocating the sites, possible applications of the PVT technology, understanding the plants which can grow in the relevant climate conditions under the shading of the panels. There are different companies who participate in the project call and, if they succeed, are liable to demonstrate the objectives of the call under the allocated budget and share the results with the European Union. The thesis work tried to focus on the company's objective for the call, which was to find out the suitable crops to be planted under the integrated PVT greenhouses, details on the weather conditions and applications of heat and electricity on the demonstration sites, i.e., Greece and Portugal. The emphasis was also given to creating a business canvas model and doing the strengths, weaknesses, opportunities, and threats (SWOT) analysis to make a business plan for this project. In this project, an Absolicon X10 PVT collector has been proposed with thermal heat up to 75 ºC and electricity at 230V. The outcomes also showed that each PVT collector integrated into the greenhouse could produce 4.73 MWh/year of thermal energy and can supply 2.2 MWh/year of electrical energy, which can save up to 0.48 tons/year of oil equivalent and avoid 37.6 tons of CO2 emissions during its lifetime of 25 years compared to burning oil. Considering the weather conditions in Greece and Portugal and to make sure the plants do not need much shading, tomatoes, barley and cacao seeds were identified as the potential crops to be planted in the PVT-integrated greenhouses.

Call number: LD2668 .T4 1979 L65 / Master of Science

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2006. / Successful housing and breeding of exotic animals or plants often requires an environment that is quite different to the ambient conditions present. The current study approached the problem of sub-optimal water temperatures experienced by Central African Bream (Tilapia) housed within a South African greenhouse during winter months. A theoretical and experimental study of fundamental heat and mass transfer processes relevant to an aquacultural greenhouse was conducted. Experimental results were generally in agreement with those of previous researchers; while evaporation tests were found to concur particularly well with an analytical equation developed. The experimental results were used to develop a simple glass greenhouse model to evaluate the expected thermal behaviour during the coldest time of the year. Manipulation of the model revealed that water has the ability to absorb large quantities of solar radiation and regulate temperature fluctuations within such a system, and that the appropriate use of thermal insulation during both the night and day can maintain acceptable water temperatures for extended periods of time. With the conclusions drawn from the experimentation and modelling done, an optimised conceptual greenhouse design was presented, along with associated guidelines and principles for attaining the required water temperatures, and consequently providing the exotic fish specie with a healthy environment.

Controlled environment agriculture offers a solution to challenges including less available land, water deficits, and consumer demand for pesticide free produce. However, control of soil-borne diseases is a major limiting factor. The goal of this dissertation was to examine predictions of the hypothesis that border cells function to protect plant health by controlling microorganisms associated with plants grown in hydroponic culture. Border cells separate from root tips upon immersion in water, and appear to have important roles in the defense mechanisms of plant roots. The general objectives were (1) to study the delivery of border cells in hydroponics; (2) to evaluate interactions between border cells and microorganisms in hydroponics; and (3) to explore approaches to alter border cell production for improved root disease control. In this study it was confirmed that border cells can be released continuously into the solution of hydroponic culture suggesting that plants grown in this system may use extra energy in the production of new border cells. Free border cells interacted with microorganisms present in the hydroponic solution by secreting an extracellular capsule. Previous studies showed that proteins are a key component of this capsule, including lectins. The interaction of pea lectin and Nectria haematococca spores therefore was explored. Results demonstrated that pea lectin agglutinates fungal spores in a hapten-specific manner, and inhibits their germination. Lectin had no negative effect on root development suggesting that it could be used as a potential control for soil-borne diseases in hydroponics. To control the production of border cells, subsequent studies measured the impact of a transient exposure of root tips to different metabolites secreted by root caps and border cells. Exposure to specific metabolites altered the production of border cells without measurable effects on root growth and development. This is in contrast to results obtained with altered gene expression. For example, gene silencing of a border cell specific gene resulted in altered root growth.

Master of Science / Department of Entomology / Kun Yan Zhu / Raymond A. Cloyd / Protected environments, such as greenhouses and interior plantscapes provide optimal conditions for arthropod (insect and/or mite) pests to survive, develop, and reproduce. Two commonly encountered insect pests in protected environments include the citrus mealybug (CMB), Planococcus citri, and the western flower thrips (WFT), Frankliniella occidentalis. It is difficult to mitigate CMB and WFT populations due to the behavioral characteristics of the insects and few pesticides that are registered for use in protected environments. This research involved two distinctly different studies. The objectives of the first study were to determine the efficacy and residual activity of systemic insecticides registered for use against CMB and to quantify CMB feeding locations. The objectives of the second study were to determine the compatibility and efficacy of commonly used binary pesticide mixtures against the WFT under both laboratory and greenhouse conditions. To determine the efficacy of systemic insecticides against CMB, greenhouse experiments were conducted in which coleus, Solenstemon scutellarioides, plants were artificially infested with CMB. Drench applications of each designated treatment were applied to each plant. Results associated with drench applications of the systemic insecticides against CMB indicated minimal CMB mortality (<30%) for both preventative and curative drench applications of azadirachtin and spirotetramat. Thiamethoxam, a neonicotinoid-based insecticide, at the labeled and twice the labeled rate provided the highest CMB mortality; however, not until 21 days after treatment was this observed, and CMB mortality was <80%. In all cases, significantly more CMB were located on the stem of green coleus plants compared to the leaf top and bottom. Pesticide mixture compatibility was determined using jar tests. In addition, phytotoxicity and efficacy of pesticide mixtures against WFT was determined through a series of laboratory and greenhouse experiments for each individual pesticide, and the mixtures to determine synergism, antagonism, or no effect. Results associated with the jar tests indicated that all the mixtures were compatible. Furthermore, the mixtures were not phytotoxic to the horticultural plant species evaluated. Laboratory results indicated that mixtures containing spinosad + bifenazate were antagonistic against WFT. Greenhouse experiments demonstrated significantly reduced efficacy associated with the abamectin + azadirachtin mixtures; however, each binary mixture provided approximately 80% mortality of WFT.

Este trabalho teve como objetivo estudar os efeitos de três lâminas de irrigação e de quatro doses de potássio aplicadas via água de irrigação por gotejamento na produtividade e na qualidade dos frutos de melão (Cucumis melo L.), cv. Dom Carlos, com espaçamento de 1,2 m x 0,4 m. Visa também determinar os níveis de irrigação e as doses de potássio mais adequados para o meloeiro, cultivado sob fertirrigação em ambiente protegido no período de outono-inverno. O experimento foi realizado no período de abril/2000 à julho/2000 no Departamento de Engenharia Rural da ESALQ/USP. Foi utilizado delineamento experimental inteiramente casualizado com três repetições, em esquema fatorial 4 x 3. Os tratamentos resultam da combinação de três lâminas de irrigação(L1=50% Etc, L2= 75% ETc e L3=100% da ETc) e de quatro doses de potássio (K1=30; K2=90; K3=150 e K4=210 kg de K2O há -1 ). A fertirrigação foi realizada a cada dois dias, utilizando-se tanques onde os fertilizantes eram dissolvidos na água de irrigação. O monitoramento da umidade do solo foi feito com tensiômetros instalados em torno da planta; pelos valores de potencial mátrico, a lâmina de irrigação L3 manteve o perfil de distribuição de água mais constante do que os de L1 e L2. As produtividades, comercial , não comercial e total, foram influenciadas pelos níveis de irrigação, pelas doses de potássio e pela interação entre eles, sendo as maiores produtividades totais de 29,7 e 27 t ha -1, obtidas com as combinações de 150 kg de K2O ha -1 e 105 L planta -1 ciclo -1 (K3L2) e 150 kg de K2O ha -1 e 140 L por planta por ciclo (K3L3), respectivamente. Já as maiores produtividades comerciais foram 12,6 e 10 t ha -1, obtidas com as combinações 30 kg de K2O ha -1 e 105 L planta -1 ciclo -1 (K1L2) e 210 kg de K2O ha -1 e 140 L planta -1 ciclo -1 (K4L3), respectivamente. / The objective of this work was to study the effects of irrigation water depths and potassium levels applied by drip irrigation on yield and fruit quality of melon (Cucumis melo L.), cv. Dom Carlos, spaced 1,2 m x 0,4 m between rows and plants, respectively, and to determine the irrigation depths and potassium levels most suitable for fertigated melon cultivated in a greenhouse in the autumn-summer season. The trial was accomplished from april/2000 to june/2000 at the Departamento de Engenharia Rural of ESALQ/USP. The treatments were completely randomized with three replications in a factorial scheme 4 x 3, and resulted from a combination of three irrigation water depths (L1=50% ETc, L2=75% ETc and L3=100% ETc) and four potassium levels (K1=1,45; K2=4,35; K3=7,25 and K4=10,15 g of K2O plant -1 season -1 ). Fertigation was taken every two days using tanks where fertilizers were dissolved in the irrigation water. Soil moisture monitoring was made by tensiometers installed around the plant. From the matric potential values, the irrigation depth L3 maintained the water distribution pattern more constant than the L1 and L2. The marketable, non-marketable and total yields were modified by the irrigation depths, potassium levels and their interaction, with the higher total yields (29.7 and 27.0 ton ha -1 ) obtained with the combination of 150 kg K2O ha -1 and 105 L plant -1 season -1 (K3L2) and 150 kg K2O ha -1 and 140 L plant -1 season -1 (K3L3), respectively. The higher marketable yields were 12.6 and 10.0 ton ha -1 , obtained with the combinations of 30 kg K2O ha -1 and 105 L plant -1 season -1 (K1L2) and 210 kg K2O ha -1 and 140 L plant -1 season -1 (K4L3), respectively. Fruits' physical and chemical parameters evaluated are in agreement with that demanded by market.

Hydroponics basically is the method of growing plants using mineral nutrient solutions, in water, without soil. Vertical nutrient film technique (NFT) is one of the most used hydroponic technique that has constant flow of nutrient solution. In this study the effects of different support medium on strawberry quality and yield using vertical NFT in glass greenhouse was investigated. NFT-only system was compared to rockwool, coco fiber, perlite and expanded clay as supporting medium for strawberry production. Parameters such as weight of product, amount of product, rate of marketable product, and including physico-chemical properties such as pH, rigidity, color, dry matter amount, EC, vitamin C, sugar content, resistance to certain pathogens were observed among all supporting medium trials. NFT-only system significantly differed from other supporting medium trails by most of the parameters including fruit number per plant, average fruit weight, toughness of the fruit, vitamin C amount, sugar amount and finally soluble solid material amount in water . Revealing the effects of supporting medium on strawberry production shed light on how should NFT must be applied to fruit growing.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 6 uppsatser.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

Made available in DSpace on 2014-06-11T19:24:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-05-07Bitstream added on 2014-06-13T19:31:24Z : No. of bitstreams: 1 dalpai_e_me_botfca.pdf: 1888804 bytes, checksum: 298eb4f0d7cffe8b2da60c97a12927db (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O trabalho descreve o estudo das radiações global(G), ultravioleta (UV), fotossinteticamente ativa (PAR), infravermelha (IV) e da insolação, em uma estufa de polietileno, medidas no período de março de 2008 a fevereiro de 2009 em Botucatu, São Paulo, Brasil. Foram analisados no presente estudo: 1- a evolução anual das radiações e frações solares UV/G, PAR/G e IV/G média mensal; 2- as equações de estimativa para as radiações UV, PAR e IV dentro da estufa em função das radiações global interna e global externa ; 3- evolução anual da insolação média mensal e a equação de estimativa Ångström para as radiações G, UV, PAR e IV dentro da estufa, em função da razão de insolação interna e externa. A evolução anual das radiações G, UV, PAR e IV médias mensais diárias dentro e fora da estufa, mostrou que alem do dia e local, dependem do clima, cobertura do céu, presença de vapor entre outros. As radiações foram maiores no verão-primavera e menores no outono-inverno. Os valores médios total dentro e fora da estufa foram: GIN = 13,1MJ/m2, UVIN= 0,34MJ/m2, PARIN = 6,70 MJ/m2 e IVIN = 6,15MJ/m2, GEX= 17,14MJ/m2, UVEX= 0,72MJ/m2, PAREX = 8.38 MJ/m2 e IVEX= 8.04MJ/m2. Os valores médios total, das frações em percentagem, dentro e fora da estufa foram: UVIN / GIN =2,6% ; PARIN/GIN = 50.6%, IVIN/GIN= 47,1%, UVEX / GEX = 4,18%, PAREX/GEX= 48,9% e IVEX/GEX= 46,9% respectivamente. As equações de estimativa, anual e sazonal, obtidas para as irradiações Huv, Hpar e Hiv em função da radiação HIN e HEX são lineares, tipo Y = aX, onde coeficiente angular quantifica percentualmente a fração espectral: anual HUVIN /HGIN = 2,6%; HPARIN/HGIN = 50,8% e HIVIN/HGIN = 46,7%, enquanto que a sazonal: Primavera HUVIN /HGIN = 2,5%; HPARIN/HGIN = 51,7% e HIVIN/HGIN = 45,7%; Verão: HUVIN /HGIN = 2,7%; HPARIN/HGIN = 51,8% e HIVIN/HGIN = 45,4%,... / This study describes the study of the global radiation(G), ultraviolet (UV), photosynthetically active radiation (PAR), infrared radiation (IV) and insolation, inside a greenhouse of polyethylene, measures in the period of March 2008 to February of 2009 in Botucatu, São Paulo, Brazil. They had been analyzed in the present study: 1 – annual, monthly and average evolution of the radiations UV/G, PAR/G and IV/G; 2 - equations of estimate for radiations UV, PAR and IV inside of the greenhouse in function of the radiations global internal and global external; 3 - annual evolution of the monthly average insolation and Ångström equation of estimate for radiations G, UV, PAR and IV inside of the greenhouse, in function of the reason of internal and external insolation. The annual evolution of radiations G, UV, PAR and IV daily monthly averages inside and outside of the greenhouse, showed that beyond the day and place, they depend on the climate, the radiations had been bigger in the summer-spring and minors in the autumn-winter. The average values total inside and outside of the greenhouse had been: GIN = 13,1MJ/m2, UVIN= 0,34MJ/m2, PARIN =6,70 MJ/m2 and IVIN = 6,15MJ/m2, GEX= 17,14MJ/m2, UVEX= 0,72MJ/m2, PAREX = 8,38 MJ/m2 and IVEX= 8.04MJ/m2. The average values total, of the fractions in percentage, inside and outside of the greenhouse had been: UVIN/GIN =2,6%; PARIN/GIN = 50,6%, IVIN/GIN= 47,1%, UVEX/GEX = 4,18%, PAREX/GEX= 48,9% and IVEX/GEX= 46,9% respectively. The equations of estimate, annual and sazonal, gotten for the irradiations Huv, Hpar and Hiv in function of radiation HIN and HEX are linear, type Y = aX, where angular coefficient it quantifies the spectral fraction percentile: annual HUVIN /HGIN = 2,6%; HPARIN/HGIN = 50,8% and HIVIN/HGIN = 46,7%, whereas the sazonal: Spring HUVIN /HGIN = 2,5%; HPARIN/HGIN = 51,7% and HIVIN/HGIN = 45,7%; Summer: HUVIN /HGIN = 2,7%; ...(Complete abstract click electronic access below)