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The effects of photoperiod, drought stress and cold storage treatments on the susceptibility of strawberry plants (Fragaria ananasa x Duch.) cvs. Tamella, Cambridge Favourite and Red Gauntlet to crown rot caused by Phytophthora cactorum (Leb. and Cohn.) Schroet. were studied. Infection and disease susceptibility were assessed by; a) the time from inoculation to first symptom appearance; b) measurement of crown necrosis; c) measurement of fungal colonisation by a comminution-colony count method developed during the study; d) detached leaf bioassay. The effect of photoperiod was assessed independently from photosynthetically active radiation and long day treatments consistently increased susceptibility; a result contradicting previous findings. Drought treatments applied prior to inoculation generally increased plants' resistance to colonisation and necrosis. Treatments applied after inoculation significantly reduced the level of colonisation capable of causing wilt symptoms. Cold storage treatments increased the susceptibility of plants to infection, colonisation and wilt symptom development. Susceptibility to infection by normally non-pathogenic isolates was also increased by cold treatments although no wilt symptoms resulted from these infections. Plants stored with latent infections developed immediate chronic symptoms when transplanted from cold storage. The mortality of these plants in the cold store also increased with storage time. Cold storage-enhanced susceptibility occurred irrespective of pathogen factors. Large-scale sudden collapse of cold-stored strawberry stands was caused by carriage of oospores through storage, either in soil or in scattered latent infections. P. cactorum produced the cell wall degrading enzymes (CWDEs) exo 1,4--galactanase and endo polygalacturonase in culture. Both enzymes were detected in infected plants. CWDE activities increased with colonisation and symptoms, and levels of PG and galactanase were significantly greater in cold-stored tissues than in controls but their importance in symptom expression and virulence was not conclusively demonstrated.

Strawberry Hill, the Gothic villa and associated landscape, seat of Horace Walpole (1717-97), is without doubt mandatory in any assessment of eighteenth-century British architecture, yet the reasons for its creation have never been adequately explained or fully understood. This thesis asserts, for the first time, that Walpole’s ideas which informed Strawberry Hill are inspired by theories that stimulate ‘The Pleasures of the Imagination’ as articulated in essays by Joseph Addison (1672-1719) published in the Spectator (1712). The thesis argues that Walpole’s reasons for choosing Gothic have been misunderstood and that he valued this ‘true’ style of British architecture for its associative and imaginative connotations and as a means of expressing historical interpretation through material objects. It affirms that Strawberry Hill expressed the idea that it was based on monastic foundations using architectural quotations from Gothic tombs, representing visual links to historical figures and events. The thesis, moreover, develops an argument as to how Walpole’s theories expressed in Anecdotes of Painting (1762-71) and The History of the Modern Taste in Gardening (1780) became manifest at Strawberry Hill. Avoiding the straightforward architectural description of previous texts, the thesis demonstrates Strawberry Hill to be a sequence of theatrical spaces playing with scale, colour and atmosphere, specifically designed to create surprise and wonder in order to stimulate the imagination. A series of sensory effects and moods, based on contemporary landscape theory, create a background to Walpole’s collection of cultural and historical artefacts – each ‘singular,’ ‘unique,’ or ‘rare’ - artfully displayed to produce their own narrative. Unlike previous studies, the villa and landscape are evaluated as an entity, a structured essay in associative, imaginative thought. Finally, the dissertation reconstructs Strawberry Hill as it existed in Horace Walpole’s time, leading the reader on an integrative virtual tour of buildings, gardens, emblematic models and associative inspirations.

High tunnels have been used successfully in many areas of the world to extend the growing season for numerous crops. However, very little research has been conducted to evaluate the season extension benefits offered by high tunnels to small fruit crops in high elevation growing areas such as the Intermountain West region of the United States. The use of high tunnels was investigated in North Logan, Utah (41.766 N latitude, 1405 m elevation, 119 freeze free days) to extend the growing season for both strawberries and raspberries. June-bearing `Chandler' strawberries in a fall-planted annual hill system were evaluated for early season production. High tunnels advanced spring strawberry production by approximately 3 weeks compared to field-grown plants. High tunnels were used for earlier planting and growth in a spring-planted day-neutral strawberry system. Day-neutral cultivars (`Albion', `Seascape', `Evie 2', and `Tribute') produced strawberries throughout the summer and into the fall with significantly higher yields from the high tunnel treatments than the field-grown plants. High tunnels also extended late-season strawberry production until mid-December. The floricane-fruiting red raspberry `Tulameen' was evaluated for early season production, and primocane-fruiting `Caroline' was evaluated for late season extension. High tunnels were unable to provide sufficient winter protection for the cold-tender `Tulameen' at this location. Results from late season extension indicated that high tunnels could extend late season raspberry production by as much as three weeks. However, peak yields for `Caroline' were before the first fall frost, and a later fruiting cultivar would be more suitable. In addition to research results, this thesis contains chapters on practical management considerations for commercial producers, and enterprise budgets to assist in evaluating the economic costs and returns of high tunnel strawberry and raspberry production.

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At present, the global population is increasing, while soil and fresh water resources for crop production are declining. It is important to adopt sustainable practices to optimise the use of limited natural resources without compromising the environment, and to enhance continuous production in the long term. The rapid growth of UK strawberry industry has been achieved through the precision use of varieties, nutrients and polythene tunnels. This intensive production has caused significant environmental impacts especially Greenhouse Gas (GHG) emissions from the production. Strawberry powdery mildew (Podosphaera aphanis) is a major fungal disease affecting strawberry production worldwide particularly in polythene tunnels. The disease can result in yield losses of up to 70% of the crop. A ruleQbased system was used in the field trials to predict high risk days of P. aphanis development, taking into account the optimal environmental conditions conducive to conidial germination and disease development. The results (Chapter 3) showed that the use of this prediction system achieved satisfactory control of P. aphanis in commercial strawberry production, with reduced fungicide applications compared with commercial spray programme. The results were consistent in two consecutive years and on different varieties. In addition, it was suggested that the use of the prediction system may also lead to lower GHG emissions associated with fewer fungicide applications, thereby benefit strawberry growers both environmentally and economically. Results from 2014 & 2015 silicon fertigation trials showed that the use of a silicon nutrient via the fertigation system reduced the strawberry susceptibility to P. aphanis and twoQspotted spider mites (Tetranychus urticae Koch) in two consecutive years on different varieties (Chapter 4). In both years, crops received the silicon nutrient only without fungicides had both lower rate of epidemic (r) and lower value of Area Under the Disease Progress Curve (AUDPC) (r = 0.0036, AUDPC = 475 in 2014; r = 0.001, AUDPC = 267 in 2015) compared with the untreated control (r = 0.0042, AUDPC = 662 in 2014; r = 0.0011, AUDPC = 281 in 2015). Silicon also delayed the epidemic buildQup in the silicon nutrient only treatment for approximately two weeks compared with the untreated control. Crops from the silicon nutrient plus fungicides treatment had lower susceptibility (r = 0.0012 in 2014; r = 0.0004 in 2015) than those from the fungicides only treatment (r = 0.0017 in 2014; r = 0.0005 in 2015) suggesting that the silicon nutrient may also enhance fungicides performance in reducing the epidemic buildQup when used together. Moreover, the presence of T. urticae on strawberry leaves was significantly lower (P < 0.001) in plants treated with the silicon nutrient than those without. In addition, initial results suggested that silicon may play a positive role in raising °Brix of strawberry leaf petiole, improving pollen viability, and influencing the length of flower receptacle and stamens. Maltmas Farm has a wide range of semiQnatural habitats that provide food and nesting resources for wild pollinators. Hoverflies, bumblebees and solitary bees were found to be the main wild pollinators that pollinate commercial strawberries at Maltmas Farm (Chapter 5). The number of pollinators in tunnels or open fields significantly correlated with the abundance of strawberry flowers (P < 0.05). Pollinator presence also differed between groups throughout the day and over the seasons. Hoverflies appeared early in the day and were abundant in summer months; bumblebees and solitary bees were present most of the day and throughout the season, whereas honeybees were only active in sunny days. Temperatures, relative humidity and cloud coverage also affected pollinator presence. In addition, pollinator activity was not significantly (P > 0.05) affected by the application of the silicon nutrient via the fertigation system. The integrated use of the prediction system (to reduce fungicide applications and subsequent GHG emissions), the silicon nutrient (to reduce crop susceptibility to P. aphanis and T. urticae), and sustainable farmland management (to encourage the presence of wild pollinators) could help strawberry growers to achieve a more sustainable production.

Two orchard floor management strategies were evaluated beginning in the fall of 1997 in a 'Valencia' orange (Citrus sinensis) grove at the University of Arizona Citrus Agricultural Center (CAC) in Waddell, Arizona. The clean culture or bare ground treatment produced more yield than the ‘Salina’ strawberry clover treatment when harvested on March 10, 1999 and the tree canopy volume of the clean culture treatment was also greater than that of the clover treatment. Yield efficiency (lbs of fruit per cubic meter of canopy) was similar in the two treatments. The clean culture treatment produced more large size fruit (size 88 and larger) and less small size fruit (size 113 and smaller) than the strawberry clover treatment. Although the yield efficiency parameter suggests that it may be possible to produce as much fruit in the clover treatment as the clean culture treatment, the total yield and fruit size distribution of the clover treatment compared to the clean culture treatment were characteristic of the negative effects of competition from vegetation on the orchard floor found in other studies. Based on previous studies, competition for water was the most likely cause of the negative competitive effect. Installation of additional tensiometers to measure soil moisture at greater depths and leaf water potential measurements to assess the degree of water stress in both treatments prior to irrigation will hopefully allow further improvement in irrigation scheduling to eliminate the negative affect of having vegetation on the orchard floor in the clover plots.

This thesis attempts to determine if food-producing plant growth can be incorporated within a building envelope to create an ideal plant growth environment while simultaneously enhancing the thermal properties of the building envelope. A window system was designed as a means of bringing food production into the built environment in an easily accessible fashion from the interior of a high-rise apartment complex. The Ya-Po-Ah Terrace in Eugene, Oregon, was chosen as a case study site for research on how a window could promote health, provide nutrition, and enhance the thermal comfort of the inhabitants. The design of the window unit is founded in precedent research on methods of plant growth in urban environments and systems for growing food in small and efficient ways. The design found that it is possible to create an ideal plant growth environment within a building assembly for use as a food production method for building inhabitants.

Orientador: Aloisio Costa Sampaio / Banca: Terezinha de Fátima Fumis / Banca: Jaime Duarte Filho / Resumo: O presente trabalho teve por objetivo, obter maiores informações sobre o desenvolvimento de quatro cultivares de morangueiro (Dover, Oso Grande, Camarosa e Sweet Charlie), na região de Bauru - SP, submetidos a sistemas fitossanitários alternativos, como ferramenta na Produção Integrada do Morangueiro (PIMO). Avaliou-se aspectos de produtividade (peso e número de frutos); qualidade (teor de sólidos solúveis totais, acidez titulável, pH, vitamina C e textura) e monitoramento de pragas e doenças. O plantio foi realizado em abril de 2005 sobre plástico preto, no espaçamento de 25 x 25 cm, totalizando-se 20 plantas por parcela. O delineamento estatístico foi em blocos casualizados utilizando-se um esquema fatorial em parcelas subdivididas, no qual o fator principal conteve dois modelos de tratamentos fitossanitários e para o fator secundário, as quatro cultivares de morangueiro. Nos dois modelos de tratamentos foram utilizados agroquímicos convencionais da grade PIF para Morango na fase vegetativa (abamectina e tebuconazol), diferenciando-se para a fase reprodutiva; Modelo PIF 1: tratamento com calda viçosa, super magro, Microgeo (2%) e enxofre e Modelo PIF 2: tratamento com calda bordalesa, super magro, éster de ácido graxo (GOC 109) (5%) e enxofre. Os dados obtidos foram submetidos à análise de variância e as médias comparadas através do Teste de Tukey a 5% de probabilidade. A cultivar Dover apresentou maior produtividade média e número médio de frutos independente do sistema de produção; textura mais firme e menor ratio (sabor) indicando maior aptidão para a indústria. A XI cultivar Oso Grande destacou-se positivamente na produção de frutos graúdos, firmeza e sabor, aspectos importantes para o consumidor e comercialização. Sweet Charlie apresentou excelente características de sabor e vitamina C... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present work had for objective, to obtain more information about the development of four strawberry cultivars ( Dover, Oso Grande, Camarosa and Sweet Charlie), in Bauru - SP, submitted to alternative phytosanitary systems, as tool for the Integrated Strawberry Production. Aspects of productivity (weigh and number of fruits); quality (total soluble solids, titrable acidity, pH, vitamin C and firmness) and pest and disease monitoring were evaluated. The planting was accomplished in April of 2005 over mulching, the spacing of 25 x 25 cm was adopted being totaled 20 plants by plot. Experimental design used was of randomized blocks in factorial scheme of split plots with the main factor contained two models of phytosanitary treatment and for the secondary factor, the four strawberry cultivars. Conventional agrochemicals (abamectin and tebuconazol) registered for this culture in Brazil, were used for both models of treatment, in the vegetative phase. For the reproductive phase; Model PIF 1: treatment with Viçosa mixture, biofertilizer Supermagro, Microgeo (2%) and sulfur; and Model PIF 2: treatment with Bourdeaux mixture, biofertilizer Supermagro, fatty acid ester (GOC 109) (5%) and sulfur. The data were submitted to a variance analysis and the average compared to Tukey's Test at 5% of probability. 'Dover' presented larger medium productivity and medium number of fruits independent of the production system; firmer texture and smaller ratio (flavor) indicating larger aptitude for the industry. 'Oso Grande' stood out positively in the production of great fruits, firmness and flavor, important aspects for the consumer and commercialization. ‘Sweet XIII Charlie' presented excellent flavor characteristics and vitamin C, demonstrating an aptitude for in natura consumption. There were not significant differences among the employed production... (Complete abstract click electronic access below) / Mestre