Dissertations / Theses on the topic 'Horticulture (General)'

Biodegradable mulch may offer the benefits of polyethylene mulch for crop production with the added benefit of biodegradability. Four studies were carried out in Mount Vernon, WA to evaluate biodegradable mulch for tomato (Solanum lycopersicum L.) and broccoli (Brassica oleracea var. italica) production. The first study compared four biodegradable mulch treatments: BioAgri, BioTelo, WeedGuardPlus (cellulose product), and SB-PLA-10/11/12 (experimental, non-woven fabric), to polyethylene mulch and bare ground in high tunnels and in the open field for tomato yield and fruit quality over three growing seasons. Biodegradable plastic films produced yields and fruit quality comparable to polyethylene. Moreover, high tunnels increased total and marketable fruit weight five and eight times, respectively, compared to the open field.

The second study quantified relationships among visual assessment parameters and mulch mechanical properties. Visual assessments and mechanical property tests of polyethylene, BioAgri, BioTelo, WeedGuardPlus, and SB-PLA-10/11/12, were made over three growing seasons. Regression analyses found the strongest relationship overall (r² = 0.41) to be between the percent of initial breaking force in the machine direction and log ₁₀ of percent visual deterioration. However, evaluating mulch products individually and increasing sample frequency are recommended for future research.

The third study evaluated three biodegradable mulch products, BioAgri, Crown 1, and SB-PLA-11, after soil-incorporation. The average area of recovered mulch fragments decreased for all mulch products over time. The number of mulch fragments initially increased for all mulch products, with the greatest number of Crown 1 and BioAgri fragments recovered 132 and 299 days after incorporation, respectively. At 397 days after soil-incorporation, the total area of recovered fragments of Crown 1 and BioAgri was 0% and 34% of the theoretical maximum area, respectively.

The fourth study used the diffusion of innovations framework to study perceptions about biodegradable mulch and employed the concept of "tactile space" to create sensuously rich learning environments wherein participants could interact with each other and the environment to evaluate biodegradable plastic mulch. Participants' perceptions about biodegradable mulch and attitudes toward adoption improved. Employing tactile space as a diffusion strategy may encourage non-representational learning to supplement and reinforce the knowledge claims being made at outreach/education events.

Tillage is the common practice for seedbed preparation prior to early spring vegetables. To investigate the possibility of eliminating the need for spring tillage through the use of cover crops, spring seedbed characteristics after winterkilled cover crops forage radish (Raphanus sativus L.) and oat (Avena sativa L.) were monitored prior to and during growth of no-till and rototilled plantings of spinach (Spinacia oleracea var. Tyee) over four site years in Maryland's Coastal Plain and Piedmont regions. Results indicate that forage radish can facilitate no-till planting of spring vegetables in the mid-Atlantic without herbicides or fertilizer. Forage radish increases soil nitrate and sulfate in early spring and is best suited as a cover crop before the earliest planted main crops.

Master of Science
Department of Plant Pathology
Megan Kennelly
Dollar spot disease of turfgrass, caused by the fungus Sclerotinia homoeocarpa, is the most economically important disease of intensively managed turfgrass such as creeping bentgrass (Agrostis stolonifera) in golf course fairways and putting greens. While several cultural management practices can lessen the severity of the disease, fungicide applications are necessary to manage the disease to acceptable levels. Host resistance is another avenue of improving the quality of turfgrass in response to dollar spot disease, but more information on cultivar susceptibility levels is necessary. Many fungicides are available to control dollar spot, but S. homoeocarpa has shown resistance to both demethylation inhibitor (DMI) and benzimidazole class fungicides. The objectives of this thesis were: (1) to evaluate 15 cultivars of creeping bentgrass under putting green and fairway management for both overall quality and disease severity of dollar spot in the presence and absence of fungicide applications; (2) to determine the sensitivity of Kansas S. homoeocarpa isolates to the DMI fungicides propiconazole, metconazole, tebuconazole, and triticonazole using in vitro mycelia growth assays; (3 to determine a best discriminatory dose concentration for each DMI fungicide that will provide for rapid testing of relative sensitivity, and (4) to sequence the entire β-tubulin gene of several resistant and sensitive isolates to determine mutations associated with resistance. There were differences in turfgrass quality among the 15 cultivars at putting green height but not fairway height. There were no significant differences in disease. In the fungicide resistance assays, the mean EC50 values were 0.0163, 0.038, 0.0612, and 0.0994 µg/ml for metconazole, propiconazole, tebuconazole, and triticonazole, respectively. Correlations were significant and positive for all pairwise comparisons of log10EC50 values. Regressions using discriminatory concentrations tested were significant. The most predictive concentrations were 0.01, 0.05, 0.05, and 0.10 µg/ml a.i, for metconazole, propiconazole, tebuconazole, and triticonazole, respectively. The entire β-tubulin gene was sequenced for four resistant and four sensitive isolates. The resistant isolates all harbored a substitution of alanine for glutamic acid at codon 198 (E198A).

Master of Science
Department of Horticulture, Forestry, and Recreation Resources
Cary L. Rivard
Grafting with inter-specific hybrid rootstock is effective for tomato (Solanum lycopersicum) growers looking to reduce soilborne disease organically and increase fruit yield in the Southeastern US. However, production with grafted tomatoes has not been tested in the Great Plains region of the US. Small-acreage growers would like to produce grafted plants themselves, but many have difficulty with propagation due to water stress in the scion post-grafting and/or high temperatures within healing chambers. Growers may be able to reduce water stress post-grafting by removing the upper portion of the shoot to reduce leaf surface area, but no data exist on the potential effects of this practice on mature plant yield. Five high tunnel and one open-field study were conducted in 2011 and 2012 to investigate yield effects related to the use of two rootstocks and shoot removal during the grafting procedure. Grafting significantly increased fruit yield in five of the six trials (P<0.05). The average yield increases by Maxifort and ‘Trooper Lite’ rootstocks were 53% and 51%, respectively, across all trials. In some trials shoot removal during the grafting process reduced yield and could depend upon rootstock vigor. Another series of experiments were performed testing the efficacy of shoot removal for graft survival during the healing period prior to field planting. Five healing chambers designs were evaluated, and no significant effects of treatment design were observed upon grafted seedling survival. Plants grafted with no chamber had success rates of 81% to 91%. Additionally, three grafting leaf removal techniques were studied, and a partial leaf removal method had significantly higher success rates as compared to fully foliated and defoliated plants (P<0.05). Partial leaf removal may be recommended as a way to reduce water stress in the plant, and could potentially be a way to simplify the grafting process for small-scale producers.

Master of Science
Department of Horticulture, Forestry, and Recreation Resources
Candice Shoemaker
Agriculture is a driving industry for most areas of the United States, and the Great Plains region is no exception. In the state of Kansas, agriculture is the primary industry capturing a spot in the USDA 2012 Census of Agriculture’s Top 10 states for total agricultural sales, total crop sales, and total livestock sales (USDA, 2012). Despite the thriving agricultural industry, little research has been completed on the food systems supporting Kansas communities. What are the characteristics of a local food system within the fabric of an agriculturally rich state? The goal of this study was to evaluate the characteristics and perceptions of the local food system supporting Manhattan, Kansas – a metropolitan area located in North Central Kansas. Specifically, we wanted to understand producer barriers to expanding beyond direct markets into institutional markets such as school dining services, grocery stores, and hospital food services. The objectives were to 1) understand producer concerns for selling to institutions, 2) identify resources producers need to access institutional markets, 3) understand institutional preferences for local purchasing, and 4) understand producer and institution definitions of “local” food. In February 2013, a survey was mailed to 162 Kansas producers identified within a 150 mile distance of Manhattan, Kansas. The response rate was 63% and descriptive statistics were completed. Interviews were completed with eleven local institutions in March/April 2013. Common themes were qualitatively assessed. In general, farms were small-scale, producing a diversity of products, and utilizing direct-to-consumer markets while selling to institutions on a limited basis. Producer concerns for selling to institutions included low prices, small production quantities, and delivery costs. Institution concerns included product quantities, quality, and seasonality, quality of communication, and food safety. There was no consensus on a definition for “local” food systems. Opportunities for developing the local food system of Manhattan, Kansas include increasing seasonal production, increasing producer access to resources, and fostering relationships between local producers and institutions.

Master of Science
Department of Horticulture, Forestry, and Recreation Resources
Steven Keeley
Common dandelion (Taraxacum officinale Weber) is an important perennial weed in turfgrass. Fall is considered the optimal time for postemergence herbicidal control of dandelions; however, applications in spring, when volatility damage to surrounding plants is an additional concern, are often needed. Therefore, we conducted research to determine the volatility of common broadleaf herbicides, and their efficacy when applied at spring and fall application timings. Volatility was determined by applying herbicides to turfgrass and using potted tomatoes as indicator plants. Tomatoes exposed to turfgrass treated with Trimec Classic, Confront, Surge, Escalade 2, and Imprelis exhibited little or no volatility damage, while exposure to Speedzone, 4 Speed XT, and Cool Power caused significant damage. In general, herbicides causing little or no damage were amine formulations. Two field studies determined the effect of spring and fall application timing on dandelion control with several herbicides. Herbicide applications in the spring coincided with dandelion anthesis stages: pre-bloom, peak bloom, and post-bloom. Results were dependent on dandelion pressure in the studies. In 2010, with lower pressure, there were no differences among herbicides at any spring timing when dandelion control was evaluated after one year; all herbicides gave ≥ 80% control. In 2011, with higher dandelion pressure, Imprelis SL and 4 Speed XT provided ≥ 96% dandelion control at the spring pre- and post-bloom timings, which was better than Surge, Escalade 2, Cool Power, and Confront. The best choices for spring efficacy combined with minimal to no volatility were Escalade 2 and Trimec Classic. Finally, because interest in organic dandelion control is increasing, we compared several organic weed control tactics with a conventional herbicide. In a two-year field study, the conventional herbicide gave much better control (> 96%) than any organic method. Horticultural vinegar corn gluten meal, and fertilizer-only gave < 25% control, while hand-weeding gave 58 to 71% control. While hand-weeding was the best of the organic tactics, the time required was considered prohibitive for turfgrass managers, unless initial weed levels were very low.

Precision horticulture and spatial analysis applied to orchards are a growing and evolving part of precision agriculture technology. The aim of this discipline is to reduce production costs by monitoring and analysing orchard-derived information to improve crop performance in an environmentally sound manner. Georeferencing and geostatistical analysis coupled to point-specific data mining allow to devise and implement management decisions tailored within the single orchard. Potential applications range from the opportunity to verify in real time along the season the effectiveness of cultural practices to achieve the production targets in terms of fruit size, number, yield and, in a near future, fruit quality traits. These data will impact not only the pre-harvest but their effect will extend to the post-harvest sector of the fruit chain. Chapter 1 provides an updated overview on precision horticulture , while in Chapter 2 a preliminary spatial statistic analysis of the variability in apple orchards is provided before and after manual thinning; an interpretation of this variability and how it can be managed to maximize orchard performance is offered. Then in Chapter 3 a stratification of spatial data into management classes to interpret and manage spatial variation on the orchard is undertaken. An inverse model approach is also applied to verify whether the crop production explains environmental variation. In Chapter 4 an integration of the techniques adopted before is presented. A new key for reading the information gathered within the field is offered. The overall goal of this Dissertation was to probe into the feasibility, the desirability and the effectiveness of a precision approach to fruit growing, following the lines of other areas of agriculture that already adopt this management tool. As existing applications of precision horticulture already had shown, crop specificity is an important factor to be accounted for. This work focused on apple because of its importance in the area where the work was carried out, and worldwide.

El siglo XXI plantea un nuevo reto para la agricultura: las predicciones de aumento de la población mundial exigen aumentar la productividad de los cultivos. La incidencia del cambio climático sobre regiones históricamente agrícolas es causa ya del descenso en el rendimiento agrícola, al estar afectados por el impacto creciente de estreses abióticos como la sequía y la salinidad. Una de las estrategias para abordar este desafío es la generación y análisis de colecciones de mutantes de especies vegetales de gran importancia agro-alimentaria como tomate para la identificación de genes y la disección de mecanismos implicados en el desarrollo y la producción así como en la tolerancia a estreses abióticos. Dentro del programa de mutagénesis insercional con T-DNA en tomate que se lleva a cabo entre los grupos de investigación del IBMCP, UAL y CEBAS, en este trabajo nos hemos centrado en la identificación de mutantes afectados en el desarrollo reproductivo, que en último extremo afecta a la producción de fruto, y en la respuesta a la salinidad y la sequía, por ser estreses abióticos tan importantes por su incidencia en el rendimiento final. En el primer caso se aborda la identificación y caracterización de un mutante de gran interés agronómico por su fenotipo afectado en el desarrollo reproductivo, denominado afs1 (abnormal fruit set-1). El mutante afs1 se caracteriza por presentar una mayor tasa de cuajado de fruto, reflejada en un marcado aumento del número de frutos que, aunque de menor tamaño, promueven una mejora significativa de la producción. Entre las características de afs1 cabe destacar que sus frutos son partenocárpicos y destacan por su mayor calidad debido a una mayor concentración de glucosa y fructosa, así como de ácido cítrico, que dan lugar a un incremento del índice de sabor. La mutación responsable de dicho fenotipo no se debe a una inserción de T-DNA si no a una mutación somaclonal generada durante la transformación y cultivo in vitro, algo ya observado en otras colecciones de mutantes insercionales, y se está procediendo a su localización genómica. En el segundo caso se aborda la caracterización de un mutante alterado en la respuesta al estrés salino e hídrico. El mutante se ha denominado wak1 (Wall-associated kinase 1), ya que la mutación responsable ha sido etiquetada por un inserto T-DNA que se sitúa en la región promotora del gen SlWAK1, que forma parte de un clúster génico de cuatro isoformas que están localizadas en el cromosoma 9, que codifican para unas proteínas quinasas asociadas a pared celular (cell wall-associated kinases). Aunque la expresión del gen SlWAK1 está anulada en el mutante, no lo están sin embargo los genes flanqueantes SlWAK2 y SlWAK3. El mutante wak1 presenta un fenotipo similar a la planta no transformada cuando se cultiva sin estrés, muestra un fenotipo sutil en condiciones de estrés hídrico y salino a medio plazo, y finalmente reduce significativamente el rendimiento en términos de producción de fruto en estrés a largo plazo. A nivel fisiológico, el mutante wak1 presenta mayor tolerancia al estrés iónico inducido por salinidad, con menor acumulación de Na+ en hoja. Sin embargo, el mutante es sensible al estrés osmótico inducido tanto por estrés salino como hídrico. Además, la anulación del gen SlWAK1 provoca una acumulación de sacarosa en raíz, relacionada con una alteración en la expresión de genes implicados en el metabolismo de sacarosa. Considerados en conjunto, los resultados de la caracterización de estos mutantes fenotípicamente tan diferentes demuestran el gran interés que tiene el análisis de mutantes para avanzar en el conocimiento de los procesos y los genes clave en el desarrollo y en la tolerancia a estreses abióticos.
The XXI century poses new challenges to agriculture: the predictions of global population growth invite us to focus all our efforts on increasing crop yields. In turn, the impact of climate change on historically farming regions promotes the decrease of the performance of these vegetable species with high agronomic interest, such as the tomato, which is one of the most important global vegetable species. Among the strategies proposed to address the problems exposed, generating mutant collections is one of the most widespread strategies and it has provided much information about processes, pathways and relevant mechanisms. To this end, a collection of insertional mutants using an enhancer trapping has been created in the commercial cultivar of the tomato "Moneymaker" and we have directed our interest in selecting mutants affected in the reproductive development and in the response to abiotic stresses (salinity and drought) to be key processes that directly affect the final crop yield. Within the collection, we have identified a mutant with high agronomic interest related to reproductive development, which we have named afs1 (abnormal furit set-1), characterized by an increased vegetative growth rate and higher rate of fruit set. Their flowers show an opening in the base of the stamen caused by the early fruit set, initiated before the anthesis. The higher fruit set rate is reflected in the increase in fruits number, despite the smaller size, leading to a significant improvement in the production and final yield in greenhouse conditions. Among the characteristics of production, it is noteworthy that this afs1 produces parthenocarpic fruits with improved organoleptic characteristics, brought about by an increase in glucose and fructose, and citric acid therefore, leads to an increased rate of flavor. It has also been selected and characterized by a mutant response to salt and water stresses, named wak1 (Wall-associated Kinase 1) which carries a T-DNA inserted in the promoter region for canceling the SlWAK1 gene expression in the mutant. This gene is part of a gene cluster consisting of four total WAK isoforms genes in chromosome 9. qPCR expression analysis has indicated that the SlWAK1 expression is root specific and reduces its expression levels in response to salt stress . The two flanking SlWAK1 isoforms genes (referred to SlWAK3 and SlWAK2 in this paper) are not affected by the T-DNA insertion and have a similar pattern to the described for SlWAK1 response. At a phenotypic level, this mutant has a WT phenotype in standard culture conditions and displays a subtle phenotype under water and salt stresses, characterized by a significant reduction in the height rate of the aerial part, and the reduction of shoot water content. Paradoxically, despite the reduction in development, salt stress experiences have shown that the wak1 mutant has an increased tolerance to the accumulation of toxic concentrations of Na+ in the shoot. Furthermore, it has been shown that this mutant is sensitive to osmotic effect, which occurred in both the water stress and in the first phase of the salt stress. The results indicate that the basis of this sensitivity is an alteration in osmotic adjustment ability and in the sugar metabolism promotes an increased sucrose transport to the root at the expense of the growth rate and the transport of water toward the apex.

Els calçots, tiges florals immadures de la ceba (Allium cepa L.), són un cultiu típic de Catalunya i juguen un paper important en l’agricultura catalana. Es calcula que la producció de la campanya 2012-2013 va ser d’uns 48 milions d’unitats, amb un creixement constant els últims anys. Aproximadament el 15% d’aquesta producció es comercialitza sota el segell de qualitat europeu “Indicació Geogràfica Protegida Calçot de Valls”. La varietat més comunament usada per a la producció de calçots és la ceba Blanca Tardana de Lleida (CBTL), que va començar, segons la opinió dels productors, una progressiva disminució del nombre de calçots per planta, ara fa uns 8 anys. L’objectiu principal d’aquesta tesi és, doncs, obtenir nous cultivars més productius, però l’escassa informació sobre la base genètica dels caràcters comercialment importants i les tècniques de maneig més eficients ha obligat a desenvolupar eines metodològiques per avançar en la millora del calçot. Així doncs, la tesi s’articula en cinc articles publicats en revistes indexades i on és recullen com a principals resultats: a) Un mètode estandarditzat de preparació de calçots per anàlisis sensorials i químiques consistent en la cocció al forn durant 18 minuts a 270oC, i la transformació en puré; b) La formulació de l’idiotip sensorial dels calçots basat en una dolçor elevada, baixa fibrositat i absència de sabors atípics; c) El valors elevats de variabilitat sensorial i agromorfològica inter-varietal estimada en calçots produïts per diverses varietats espanyoles de prestigi, algunes de les quals podrien incorporar-se a programes de millora; d) La modelització de poblacions de calçots mitjançant la funció de Gompertz pel que fa a l’evolució del nombre de calçots per planta al llarg del cultiu, la qual cosa permet fer comparacions i facilita la presa de decisions sobre el moment de collita; e) Les similituds en el fons genètic de les varietats tradicionals espanyoles de ceba estimada mitjançant AFLPs i microsatèl•lits, abonant un considerable flux genètic entre varietats i la diferenciació morfològica per pocs loci; f) El desenvolupament d’equacions de regressió eficients que permeten estimar el nombre de calçots de la planta a partir del nombre d’ulls que es detecten en l’estadi de ceba, i determinació de la influència de les dimensions mínimes que ha de tenir la ceba perquè s’expressi el potencial genètic de producció de calçots; g) Finalment, com a resultat del programa de millora, s’han desenvolupat els cultivars Roquerola, amb un desenvolupament primerenc i un nombre mitjà de calçots (4.6 calçots comercials per planta al Gener), i el cultivar Montferri amb un desenvolupament més tardà i que assoleix una mitjana de 8 calçots comercials per planta al Març.
‘Calçots’, the floral stems of second-year onion (Allium cepa L.) resprouts, are a typical crop from Catalonia and they play and important role in Catalan agriculture. In the last season (2012-2013), 48 millions of units were produced and this number is constantly increasing. Around 15% of this production is commercialized under the European quality label ‘Protected Geographical Indication Calçot de Valls’. The landrace ‘Ceba Blanca Tardana de Lleida’ (CBTL), the most commonly used variety in the production of ‘calçots’, has undergone a gradual decreasing of the ‘calçots’ number per plant in the last 8 years. Therefore, the main aim of this thesis is to obtain more productive cultivars for ‘calçots’ production. However, the lack of information about the genetic basis of the main commercial traits and the most efficient handling techniques, made it necessary to develop methodological tools to move forward in ‘calçots’ breeding. As a result, the thesis is articulated in five indexed peer-reviewed papers, with the following main results: a) A standardized protocol for the preparation of samples for sensory and chemical analysis where 50 commercial-size ‘calçots’ per entry are roasted at 270oC for 18 minutes, and then pureed; b) The design of a sensory ideotype for ‘calçots’ based on high sweetness, low fiber perception, and low off flavors perception; c) The finding of high sensory and agromorphological intervariety variability for 'calçots’ produced by different prestigious Spanish onion landraces, which could be incorporated in breeding programs; d) The modeling of ‘calçots’ populations through the determination of the ‘calçots’ number per plant at different stages of the crop, using a Gompertz function, which allows establishing comparisons and clarifying the optimum harvest time; e) The report of a high similarity in the Spanish onion landraces genetic background, estimated using SSR and AFLP, suggesting an important genetic flow among varieties and the implication of few loci in morphological differentiation; f) The development of efficient regression equations enabling good estimations of the number of ‘calçots’ per plant from the number of gemmae measured in the bulb phase, and the determination of the minimum size of the onion bulb that enables a non-limited expression of the genetic potential for ‘calçots’ production; g) Finally, as a result of a breeding program, we have developed the new cultivars ‘Roquerola’, with an early development and an medium number of ‘calçots’ (4.6 commercial ‘calçots’ per plant in January), and ‘Montferri’, with a late development and 8 commercial ‘calçots’ in March on average.

The application of Non-Tariff Measures (NTMs) and specifically non-automatic import licensing schemes has been a source of intense debate to date, despite prohibitive provisions enshrined in multilateral trade agreements. The main aim of this case study research was to assess the consistency of the implementation of the Namibian Horticultural Market Share Promotion Scheme (MSPS) under the General Agreement on Tariffs and Trade (GATT) 1994 and the World Trade Organisation (WTO). The second segment of this study looked at identifying problems associated with the implementation of the scheme, and proposed policy recommendations that are responsive to competitive challenges facing industries in the 21st century. The study used a triangulation research methodology and a rating scale was used to conduct the assessment with respect to all the applicable provisions covered in the WTO Agreement on Import Licensing Procedures. A reliability test was conducted using the SPSS statistical software in order to measure the credibility of the data (scores). In this regard, the Cronbach's alpha coefficient was very instrumental in measuring the degree of data consistency. Moreover, the relative frequency distribution was used to analyse the quantitative data, while an Interrelationship Diagram was used to analyse qualitative data.

Ein zentrales Thema von Modellversuchen in Verbindung mit der Berufsausbildung ist die Entwicklung und Erprobung neuer Konzepte. Grundlage dafür sollte der konkrete Zustand in der reellen Praxis sein. Die Autorin erstellt in Recherche zahlreicher Quellen einen Überblick zum Kompetenzbegriff (Fach-, Methoden-, Sozial-, Personal-, Handlungskompetenz). Sie meint, dass zur Analyse, Evaluierung sowie zur gezielte Selektion relevanter Informationen eine Strategie zur Kompe-tenzentwicklung erforderlich ist, bei der Lernende einen grundlegenden Fundus an Medienkompetenz besitzen müssen und der Lehrende einen Rollenwandlung vom Wissensvermittler zum Anleiter erfährt. Mit Hilfe spezieller Handlungsanleitungen beantwortet der Lernende Fragen und gewinnt selbstständig Fachinformationen. Der Anleitende beaufsichtigt, kontrolliert und bewertet den Prozess der Informationsgewinnung. Die Ergebnisse werden zusammengefasst und dienen der Beantwortung offener Fragen. Die Autorin geht davon aus, dass methodische Orientierungshilfen sowohl bei deduktiv, als auch bei induktiv angelegter Erkenntnisgewinnung im Unterricht der Berufsausbildung angewandt werden können. Die neuen Informationssysteme zeigen uns dabei neue Wege der Informationsverarbeitung auf. Die Autorin kategorisiert aktuelle digitale Medien. In einer empirischen Erhebung mit Auszubildenden im Bildungsgang zum Gärtner/zur Gärtnerin wird geprüft, in welchem Ausbildungs-jahr welche digitalen Medien zur Fachinformationsgewinnung im handlungsorientierten Unterricht geeignet sind. Die speziellen Handlungsanleitungen der Untersuchung befinden sich im Anhang (Band II) der Publikation. Zusätzlich gibt die Autorin Lehrenden eine Anleitung zur selbstständigen Erstellung von Handlungsanleitungen. Das lebenslangen Lernen beginnt mit der ersten Unterweisung und erfordert eine stetige Qualifikation. Das Erfordernis einer modernen Berufsausbildung ist eine Voraussetzung für die Integration der Lernenden in das spätere Arbeitsleben. Handlungsanleitungen können als methodisch-didaktisches Instrumentarium handlungsorientierten Unterricht bereichern und Kreativität, das Vermögen zur Selbstorganisation und Problemlösung sowie die stetige aufgeschlossenen Auseinandersetzung mit disziplinären und interdisziplinären Novitäten fördern.
In the centre of model-trials in connection with the professional education is the development and test of new conceptions. The basis of these conceptions must be the concrete situation in the real practice. In Investigation of numerous sources the author gives a survey on competence (special -, method -, social -, participating -, action competence). The opinion of the author is, that to the analysis and valuation of the information and the specific selection of relevant information a strategy for the development of competence is necessary. The teacher will obtain the role of an instructor. The learner must have basic knowledge in computer science. With help of special action guides the learner answer the questions and realised the independent procurement of specialized information. The guide supervises, controls and assesses the process of information procurement. The results will be compared and answer to the open questions must be found. In the opinion of the author the deductive and the induction way are possible. The new information systems show us new ways in information processing. The author shows in a temporary categorization different digital media. In an empirical survey with trainees in the course of education to a gardener was assayed, in witch year of education they can work with witch digital media. The target of the survey was the independent procurement of specialized information in a lesson with orientation on praxis. The special action guides of the tests are in the appendix (Volume II) of the publication. Additionally, the author give a instruction for teacher, to develop action guides independently. The livelong learning begins with the first instruction and demands a comprehensive qualification. The demand of a modern professional education is a precondition for the integration into the working live. Action guides, as one of the methodical-didactical instruments, are conductive for development of creativity, for the capability to organised by itself, for the capabil-ity to solve problems and for the continuous analysis with innovations.

The recent growth of low-density urban developments in the Mediterranean coast has led to an increase in the number of private domestic gardens. This thesis examines the flora, features and management practices of 258 private gardens in the Alt Empordà region in Catalonia. We also calculated water requirements of gardens based on species composition and land cover, and determined whether they can be predicted from the socioeconomic, demographic and cultural characteristics of households. Of the 635 taxa identified, 68% were exotic. Moreover, 39 species have been considered potentially invasive in Spain, although only 25 were present within the limits of the adjacent Aiguamolls de l’Empordà Natural Park. The distribution of garden floras was significantly related to different socioeconomic and demographic gradients, such as the occupancy rate of the house, the origin of the residents, their income level and the percentage of unemployed members.
L’augment recent dels espais urbans de baixa densitat a la costa mediterrània ha comportat un increment del nombre de jardins privats. La present tesis estudia la flora, les característiques i les pràctiques de gestió de 258 jardins privats a la comarca de l’Alt Empordà. També es van calcular les necessitats hídriques dels jardins d’acord amb la seva composició i estructura vegetal, i es va determinar si es podien predir a partir de les característiques socioeconòmiques, demogràfiques i culturals de les llars. Dels 635 tàxons identificats, el 68% eren exòtics. A més, 39 espècies han estat considerades com a potencialment invasores a Espanya, encara que només 25 són presents dins dels límits del Parc Natural dels Aiguamolls de l’Empordà. La distribució de la flora del jardins es va relacionar significativament amb diferents gradients socioeconòmics i demogràfics, com ara la taxa d’ocupació, l’origen dels residents, el nivell d’ingressos o el percentatge de membres en atur.

Doctor of Philosophy
Department of Horticulture, Forestry, and Recreation Resources
Richard H. Mattson
Subjects of this research were 64 adolescents receiving treatment at two behavioral health service institutions located in an urban mid-western city. Both institutions provided horticultural therapy and non-horticultural therapy programs. Research subjects were adolescents with diverse treatment needs and their responses on research questions were inconsistent compared to other related studies with general population. Current research assessed the adolescents with horticultural therapy treatment and without horticultural therapy treatment in three aspects. First, the levels of psychological aspects of adolescents were assessed with the Rosenberg Self-Esteem Scale and Nowicki-Strickland Locus of Control Scale for Children. The levels of self-esteem and locus of control of adolescents with horticultural therapy treatment were not significantly different from those of adolescents without horticultural therapy treatment at both institutions. Based on the different level of worthiness and competence factors, it is recommended to design horticultural therapy programs focused on improving the worthiness factor of self-esteem. Second, the pastoralism disposition of the Children's Environmental Response Inventory was used to assess the level of environmental attitude of the adolescents with and without horticultural therapy treatment. Horticultural experience and environmental attitude had a positive relationship with most subjects. At one institution, the level of environmental attitude of the adolescents with horticultural therapy treatment was significantly higher than the adolescents without horticultural therapy treatment. The adolescents at the horticultural therapy program which was scheduled more frequently showed higher environmental attitude scores. To improve environmental attitude of adolescents, horticultural therapy program should provide diversity and abundant opportunities of horticultural experiences. Third, basic horticultural knowledge was tested with the Basic Horticultural Knowledge Questionnaire. Vegetable/fruit consumption and preference were described with the Vegetable and Fruit Preference and Consumption Survey. Basic horticultural knowledge scores of the horticultural therapy group were significantly higher than that of the non-horticultural therapy group at one institution, but the scores were similar between the two groups at the other institution. Basic horticultural knowledge of subjects was significantly correlated to their vegetable and fruit consumption. To increase vegetable/fruit consumption, horticultural therapy programs should set goals to incorporate nutrition education.

O tema da pesquisa é a política pública de crédito rural para a agricultura familiar. O estudo consistiu em uma análise do processo de empresarização, descrito por Abraham (2006) e Solé (2000; 2008), estendido às pequenas unidades produtivas agrícolas desde a instituição do Programa Nacional de Fortalecimento da Agricultura Familiar (PRONAF). A Teoria da Empresarização foi a referência adotada para que se pudesse colocar em evidência a empresa, destacando traços e relações sociais que lhe são peculiares: autonomização da esfera econômica, mito fundador da escassez, racionalidade moderna, propriedade privada, mito do progresso e as relações de assalariamento, dominação, concorrenciais, funcionais e impessoais. O estudo foi realizado em dois municípios gaúchos, Maquiné e Nova Santa Rita, reconhecidos pela produção de gêneros de olericultura, popularmente conhecidos como legumes e verduras. O principal procedimento de coleta do material empírico ocorreu por meio da realização de entrevistas semiestruturadas, mas também foram empregados outros procedimentos, como a observação, a confecção de um caderno de campo, a consulta a documentos e o levantamento de dados secundários sobre os municípios. Os resultados da pesquisa apontam que a política é permeada pelos traços da modernidade relacionados ao fenômeno de empresarização, influenciando as relações estabelecidas pelos agricultores com as pessoas, com o tempo, o espaço, o trabalho, etc. Nesse sentido, as relações de exploração – que no campo não se manifestaram sob um caráter explícito e formal de assalariamento – o individualismo, o produtivismo, a eficiência puderam ser associados e estas relações que se estabelecem e se intensificam a partir da utilização do crédito. Verificou-se que a política de financiamentos favorece indiretamente as empresas do varejo alimentar e que as condições de acesso dos agricultores aos mercados são determinadas pela estruturação e pelo poder de mercado exercido pelo varejo. Por fim, observou-se que os agricultores com experiência de ação política conseguiram, em algumas situações, através de sua organização fazer frente a alguns aspectos da empresarização difundidos pela política pública.
The research theme is the rural credit public policy for family farming. The study cosisted in an analysis of the enterprisation processs as described by Abraham (2006) and Solé (2000; 2008), which has been extended to small agricultural production units since the establishment of the Programa Nacional de Fortalecimento da Agricultura Familiar (PRONAF) [National Program to Strengthen Family Agriculture]. Entreprisation theory was the reference adopted to put the evidence on the entreprise, highlighting its peculiar traits and social relations: the autonomy of the economic sphere, the founding myth of scarcity, modern rationality, private property, the myth of progress and the remuneration, domination, competitive, functional and impersonal relations. The study was conducted in Maquiné and Nova Santa Rita, two cities in the gaucho state that are recognized for producing horticulture genera, popularly known as vegetables. The main procedure to collect empirical material was by conducting semi-structured interviews, but other procedures were also employed such as observation, making a field notebook, documents consultation and the collection of secondary data on the municipalities. The research results indicate that the policy is permeated by traces of modernity related to the enterprisation phenomenon, that is influencing the relationships established by farmers with people, with time, space, work, etc. In this sense, the relations of exploitation – that were not expressed in the field as an explicit and formal character of remuneration – individualism, high productivity, efficiency could be associated and these relations are developed and intensified from the use of credit. It was found that the funding policy indirectly favors the retail food business and that the conditions of farmers' access to markets are determined by the structure and the market power exercised by retailers. Finally, it was observed that farmers with experience of political action in some situations and through their organization succeeded in dealing with some aspects of enterprisation disseminated by public policy.

La disponibilidad de agua es una de las mayores limitaciones en la productividad vegetal (Boyer, 1982) y es uno de los principales factores en la distribución de las especies vegetales. La tolerancia de un cultivo al estrés hídrico esta esencialmente vinculada a su capacidad de acceder al agua del suelo y utilizarla de manera más eficiente. El cultivo del tomate destaca tanto por su importancia económica como por representar un elevado consumo de recursos hídricos, de manera que cualquier mejora en el uso eficiente del agua (WUE) tendría un gran impacto socioeconómico y medioambiental. Se estima que un incremento de un 10% en el WUE en este cultivo podría suponer, en la Región de Murcia, un ahorro de más de 1.1 hm3 de agua de riego, cantidad equivalente a los requerimientos anuales de una población de 20.000 habitantes La sección experimental del manuscrito se ha dividido en dos partes diferenciadas. En primer lugar, con el objetivo de estudiar el papel de las invertasas en la respuesta al estrés hídrico en tomate (Solanum lycopersicon L.), se generaron plantas transgénicas que sobreexpresaban un gen de una invertasa extracelular de Chenopodium rubrum (CIN1) bajo el control de un promotor de invertasa vacuolar de Solanum pimpinellifolium (InvLp6g). En segundo lugar, se realizó una aproximación genética con objeto de identificar y explotar caracteres hídricos y hormonales implicados en la mejora del WUE en tomate mediante el uso de líneas recombinantes (RILs) de tomate procedentes de un cruce entre S. lycopersicum cv Moneymaker y S. pimpinellifollium acc. TO-937. La sobreexpresión del gen CIN1 dio lugar a una disminución de la transpiración acumulada y a un incremento de la tasa fotosintética, resultando, por tanto, en un incremento del WUE en relación a las plantas no transformadas, al final del periodo de estrés hídrico (9 días). Esto parece estar relacionado con una mejor regulación de las relaciones fuente-sumidero a través del mantenimiento del flujo metabólico. Además, se observó una mejora en los mecanismos antioxidativos de las plantas CIN1. Los cambios observados en el metabolismo primario se asociaron con cambios en el balance hormonal: incremento de las concentraciones de la CK más activa en tomate, trans-zeatina (t-Z), y disminución en los niveles del precursor del etileno ACC. De este modo, la invertasa extracelular actúa como punto integrador entre el metabolismo primario y las fitohormonas en respuesta al estrés hídrico, postulándose como una nueva estrategia para superar los efectos adversos del estrés hídricos sobre la fisiología y la productividad final del cultivo. Por otra parte, mediante una aproximación genética se pudieron identificar aquellas señales hídricas y hormonales implicadas en la regulación del WUE a través del control de la biomasa foliar y de la capacidad fotosintética. La explotación de dichos caracteres mediante la tecnología del injerto ha demostrado tener una utilidad directa sobre la mejora de la productividad final de la planta a través de la comunicación raíz-parte aérea. El precursor del etileno ACC y el ABA parecen ser señales hormonales implicadas en el crecimiento foliar principalmente al final del periodo de cultivo, cuando la tasa de transpiración era más elevada. El ACC se asoció positivamente con el WUEaY (en base a producción de fruto) y negativamente con el WUEav (en base a biomasa vegetativa) a través de una regulación negativa del área foliar. Otros factores hormonales, como las CKs, SA, ACC y JA también parecen ser señales (positivas) en la regulación del crecimiento foliar y por tanto del WUEa. Por tanto, mediante una aproximación funcional, se ha puesto de manifiesto el papel de las invertasas en la tolerancia al estrés hídrico a través de una modificación del balance hormonal. Por otro lado, mediante una aproximación genética usando líneas RIL se han identificado caracteres hormonales (principalmente ACC y CKs), implicados en la regulación del WUE en tomate, y que han sido explotados para mejorar la productividad mediante la tecnología del injerto.
Water availability is one of the major constraints on plant productivity (Boyer, 1982) as well as one of the main factors for the distribution of plant species. The tolerance of a crop to drought stress is essentially related to its ability to access to soil water and its efficiency use. In Spain, tomato is an important and high water consuming crop. Any improvement in water use efficiency (WUE) would imply a significant socioeconomic and environmental impact (e.g. an improvement of 10% in WUE of the greenhouse tomato crop in the Region of Murcia would save is equivalent to the water consumption of a population of 20.000 inhabitants). The experimental section of this thesis has been divided into two parts. Firstly, with the aim of studying the role of invertase in response to drought stress in tomato (Solanum lycopersicon L.), we generated transgenic plants overexpressing the cell wall invertase (cwInv) gene CIN1 from Chenopodium rubrum under the control of a promoter of vacuolar invertase from Solanum pimpinellifolium (InvLp6g). Secondly, we applied a genetic approach to identify and exploit water and/or hormonal-related traits associated with WUE through the use of a population of recombinant inbred lines (RIL) derived from a cross between Solanum lycopersicum and Solanum pimpinellifolium. CIN1 overexpression resulted in a decrease in accumulated transpiration and higher carbon assimilation, thereby increasing WUE compared to wild-type (WT) plants at the end of the drought period (9 days). This seems to be related to a better regulation of source-sink relations by maintaining metabolic fluxes. In addition, anti-oxidative mechanisms were improved in the CIN1 plants. Changes observed in primary metabolism were associated with changes in the hormonal balance. The concentration of the most active cytokinin (CK) in tomato trans-zeatin (t-Z) increased while the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) decreased in the CIN1 plants respect to WT. Thus, cwInv critically functions at the integration point of metabolic, hormonal and stress signals, providing a novel strategy to overcome drought -induced limitations to crop yield, without negatively affecting plant fitness under optimal growth conditions. Moreover, by using a genetic approach we could identify water- and hormonal-related traits directly involved in WUE regulation. These physiological traits can be directly transferred from the root to the scion through the use of selected RILs as rootstocks, improving crop productivity through root-to-shoot communication. Both the ethylene precursor ACC and ABA concentrations seem to be hormonal signals involved in leaf growth at the end of the experiment with higher transpiration rate. ACC was positively associated with WUEaY (base on fruit yield) and negatively with WUEav (based on vegetative biomass) through down-regulation of leaf area. Additionally, CKs, salicylic acid, ACC and jasmonic acid seem to be positive hormonal parameters regulating leaf growth and WUEa. Therefore, by using a functional approach it has been demonstrated that invertases play an important role in abiotic stress adaptation through a regulation in the hormonal balance. On the other hand, by using a genetic approach employing RIL lines we identified hormonal characters (mostly ACC and CKs), involved in the regulation of WUE in tomato and, thereafter, we exploited those characters to improve productivity crop thought the use of grafting.

El problema de la salinidad y estrés hídrico continúa incrementando su importancia debido a la escasez cada vez mayor de agua para riego junto a la mala calidad de la disponible. La mejora genética de las plantas cultivadas para tolerar este tipo de estrés abiótico puede paliar en parte las consecuencias negativas de este problema. Sin embargo, la tolerancia a los estreses hídrico y salino es un carácter particularmente complejo ya que está compuesto por la interacción de muchos caracteres. Dentro de la sección Lycopersicon del género Solanum está incluido el tomate cultivado (Solanum lycopersicum) y 12 especies afines más, conocidas como tomates silvestres, con accesiones que presentan una alta tolerancia a estos estreses. La cercanía filogenética a la especie cultivada, de gran importancia económica en todo el mundo, hace de estas especies el principal recurso genético para la mejora de tomate cultivado. Este trabajo se enmarca en un proyecto coordinado entre tres grupos de investigación pertenecientes a la Universidad de Almería, la Universidad Politécnica de Valencia y el CEBAS de Murcia, en el que estamos utilizando dos herramientas genómicas (mutagénesis insercional y trapping) en tomate y diversas especies silvestres relacionadas para identificar secuencias codificantes o elementos de regulación de genes implicados en procesos del desarrollo vegetativo (arquitectura de la planta) y reproductivo (flor y fruto), así como en salinidad y estrés hídrico. Objetivos El objetivo fundamental de este trabajo es avanzar en el conocimiento de las bases fisiológicas y genéticas de la tolerancia a la salinidad y estrés hídrico en una especie de interés agronómico, el tomate. Metodología Se han utilizado dos herramientas biotecnológicas, el análisis funcional de dos genes candidatos y la mutagénesis insercional mediante el empleo de una trampa de intensificadores en una especie silvestre relacionada con altos niveles de tolerancia a ambos estreses. En el primer caso, se ha estudiado la respuesta de plantas transgénicas de tomate que sobreexpresan un gen implicado en el estrés iónico inducido por salinidad, el gen HAL5, y plantas que expresan un gen implicado en la última etapa de la síntesis de myo-inositol, el gen IMP1. Por otra parte se ha empleado un vector que porta una trampa de intensificadores, para identificar mutantes insercionales alterados en diferentes caracteres y, especialmente, en la tolerancia a los estreses hídrico y salino. Resultados La sobreexpresión del gen HAL5 incrementa la tolerancia a la salinidad de tomate cuando se mide el peso de frutos por planta, el parámetro más importante desde un punto de vista agronómico. Además, se ha podido comprobar que la sobreexpresión del gen IMP1, incrementa la tolerancia del tomate a la salinidad y al estrés hídrico a largo plazo. Por otro lado, se ha generado la primera colección de líneas T-DNA de la especie silvestre Solanum pennellii. Se han detectado algunas líneas con expresión específica del gen delator en órganos de la planta relacionados con el nivel de tolerancia a ambos estreses abióticos. Por último, se han identificado mutantes insercionales con alteraciones en caracteres del desarrollo vegetativo, desarrollo reproductivo y tolerancia al estrés hídrico y salino. Conclusiones Este trabajo ha permitido conocer la función de dos genes implicados en la tolerancia a estreses abióticos y sus efectos al sobreexpresarse en plantas de tomate. También se ha generado una amplia colección de líneas T-DNA en diversas accesiones de Solanum pennellii, primer paso para poder llevar a cabo un programa de mutagénesis insercional. Además, los diferentes mutantes de S. pennellii seleccionados en este trabajo constituyen un excelente material para la identificación y análisis funcional de genes implicados tanto en estreses abióticos como en procesos de desarrollo vegetativo y reproductivo.
The problem of salinity and water stress in worldwide agriculture is being intensified due to the increasing scarcity of water resources and low quality of the available water for agricultural purposes. Plant breeding of crop plants to promote tolerance to these stresses could alleviate, at least partially, the negative consequences in production and yield caused by these abiotic stresses. Nevertheless, tolerance to water and salt stresses is a particularly complex trait since it is made up by the interaction of numerous individual traits. Within the Lycopersicon section from Solanum genus it is included the cultivated tomato (Solanum lycopersicum) and 12 wild-related species, these lasts with accessions that present a high tolerance to these stresses. The phylogenetic closeness of the wild-related and the cultivated species, the latter of well-known worldwide economic importance, makes the former species the main genetic resource for breeding programmes in cultivated tomato. This research work has been fulfilled within the framework of a coordinated project managed among three groups; one from the University of Almeria, the second from the Polytechnic University of Valencia and the last from CEBAS-CSIC of Murcia. Two genomic tools, insertional mutagenesis and trapping, are being applied on tomato and diverse wild-related species to identify coding sequences or regulatory elements of genes involved in vegetative (plant architecture) and reproductive (flower and fruit) development, as well as in the plant responses to salinity and water stress. Objectives: The essential objective of this research work is to advance in the knowledge of the physiological and genetic basis of the tolerance to salinity and water stress in a species of such agronomic importance as it is tomato. Methodology: For this purpose two biotechnological tools have been used; the functional analysis of two candidate genes and the insertional mutagenesis with enhancer trap applied in a wild-related species exhibiting high levels of tolerance to both stresses. In the first case, it has been studied the response of transgenic tomato plants overexpressing a gene involved in the ionic stress induced by salinity, HAL5, and of another set of transgenic plants overexpressing a gene which product is involved in the last step of myo-inositol biosynthesis, IMP1. On the other side, a genetic construction carrying a enhancer trap, has been used for plant transformation with the aim of identifying insertional mutants altered in different phenotypic traits, but especially in those related to tolerance to salt and water stresses Results: The overexpression of HAL5 augments the tolerance to salinity in the transgenic tomato assessed by fruit weight per plant, the main parameter from an agronomic point of view. Besides, it has been possible to verify that the overexpression of IMP1 increases the tolerance to long-term salinity and drought in the resulting transgenic plants. On the other hand, the first collection of T-DNA lines of the wild-related tomato species Solanum pennellii has been generated. Some mutant lines with specific expression of the reporter gene in plant organs related to the level of tolerance to both abiotic stresses have been detected. Lastly, some insertional mutants with alterations in traits related to vegetative and reproductive development as well as in tolerance to salt and water stresses have been identified. Conclusions: This research work has allowed us to know the function of two genes involved in the tolerance to abiotic stresses and their effects when overexpressed in tomato plants. Also it has been generated a large collection of T-DNA lines in diverse accessions from Solanum pennellii, the first step to accomplish a programme of insertional mutagenesis. Furthermore, the different S. pennellii mutants selected in this research work constitute an outstanding plant material for the identification and functional analysis of genes implicated in abiotic stresses as well as in vegetative and reproductive developmental processes.

Tasmanian lacewing, Micromus tasmaniae Walker, is an important predator of a number of economically important pests such as aphids. This study was conducted to investigate some aspects of general biology and factors affecting the reproductive fitness of this species Emergence of M. tasmaniae peaked 3 h before light off and there was no significant difference in emergence patterns between males and females. Males became sexually mature earlier than females. Mating success significantly increased from the first to the eleventh hour after lights on. Predation, development and oviposition of M. tasmaniae were affected when reared under different photoperiods [i.e. 24:0, 16:8, 12:12, 0:24 h (light:dark)]. Results indicate that no individuals entered diapause at either an immature or adult stage. M. tasmaniae larvae could feed in both the photophase and scotophase and late instar larvae consumed significantly more aphids than early instar larvae. M. tasmaniae reared at 16:8 h developed faster and had lower mortality, heavier adult body weight and higher reproductive output in terms of fecundity and fertility rate. Therefore, mass-rearing programmes are recommended to be carried out at 16:8 h to obtain the higher quality of individuals and faster increase of populations. The larger-the better theory predicts that the reproductive fitness is positively linearly associated with body size or weight. However, the body weight of female M. tasmaniae had no effect on the reproductive fitness in terms of fecundity, fertility, fertility rate, oviposition period and longevity. The male body weight may contribute to the population growth of M. tasmaniae as the average females that mated with average or heavy males had significantly higher fecundity, fertility and fertility rate and longer reproductive period. These results suggest that development of any control method that should selectively mass-produce heavy and average individuals in the laboratory would help increasing M. tasmaniae quality and populations. M. tasmaniae is a polygamous species. Results indicate that female remating either with the same or different males was crucial for maximizing their reproductive success. Males could inseminate up to eight females and father about one thousand offspring during their life span.