Studies of the effects of stem poise and bending in young and older fruit trees showed clear responses to gravity in the outgrowth of lateral buds, terminal shoot growth, and cambial activity. A distinctive seasonal pattern in the outgrowth of shoots was found in upright maiden apple trees. This pattern was also evident in trees grown in the inclined, horizontal, and inverted positions, but was modified by the effects of gravity. These effects included changes in the symmetry of bud growth about the axis, changes in the relationship between growth in different portions of the trunk, and tropistic reactions. Using a stem-splitting technique, shoots were induced to grow out from buds on the under sides of horizontal branches, and in an experiment with bent stems rotated about a horizontal axis the outgrowth of "gourmand" shoots was shown to be an effect of bending, rather than a response to gravity. Bending also affected bark anatomy. Effects of gravity on flowering in apple trees were far less clear. In some young non-fruiting trees, inclination and bending of the trunk resulted in increased flowering, but in other young trees, and in older orchard trees, no effects of gravity on flower bud formation were observed. It was concluded that a horizontal or pendulous branch poise in bearing apple trees is mainly a result of fruiting rather than a cause of fruitfulness. It was suggested that the stimulative effects of gravity on the flowering of inclined apple shoots may be obscured by countervailing factors such as the inhibitive eff~cts of the presence of fruits on flower bud formation, effects of vegetative growth, and effects of variety. From the practical aspect, branch bending techniques are likely to have their greatest effects in inducing precocious flowering in vigorously growing trees of shy-bearing varieties.

No description available.

No description available.

African Walnut (Tetracarpidium conophorum- Mull. Arg) is a perennial climbing shrub which grows mainly in the Western region of Africa. It is found mainly in Nigeria, Gambia, Sierra Leone, Gabon, Equatorial Guinea and Cameroon as well. The nuts are encased in pods which may contain between 2 to 5 nuts. The seed is enclosed in a hard shell-like case. The nuts are commonly processed by boiling or roasting and consumed as a snack or used as soup thickener. In ethnobotanical medicine, the nut extract is extensively used in decoctions for treatment and/or management of common and chronic ailments such as malaria, dysentery, high blood pressure, diabetes and cancer. The nuts are generally exposed to high temperatures (25 – 37 °C) and relative humidity (RH) which increases susceptibility to fungal contamination and nutrient degradation, hence, raising concerns over product quality and safety. Experiment simulating the common retail postharvest storage and processing practices was conducted to: (i) determine the effects on the fatty acid profile; (ii) assess the impact on the fungal population contaminating the nut shells at different maturity stages, and potential mycotoxigenic implications; (iii) evaluate the cytotoxicity of four extract of the nut on lung cancer (A549) cells; and finally (iv) assay the total phenolic content and profile potential individual phenolic components of the nut. Results indicated the presence of essential and non-essential fatty acids namely; palmitate, oleate, stearate, linoleate, arachidate and α-linolineate with α-linolineate being the most abundant (1.1 – 8.2 mg/g freeze-dry weight). Boiling and roasting generally improved the concentration of the fatty acids best when nuts are cold stored at 5 °C for maximum of 10 days. Potential mycotoxigenic species - Aspergillus section Nigri, Aspergillus flavus/Parasiticus, Fusarium spp. and Penicillium spp. - were frequently isolated from cultured shell pieces of stored nuts. When compared with unprocessed nuts, roasting completely prevented fungal contamination in shell pieces from nuts in the non-stored (NSN) group at early maturity stage, while boiling significantly reduced the level of contamination to about 58 % (P < 0.05). Simulating open market conditions caused 100% fungal contamination in all boiled samples and roasted samples at early maturity. Mycotoxin analysis using Yeast Extract agar (YES) and High Performance Liquid Chromatography (HPLC) - Fluorescence detector (FLD) showed that Aflatoxins - G1 (AFG1), B1 (AFB1), G2 (AFG2), and B2 (AFB2) were produced by 20 isolates with both AFG1 and AFB1 being predominant at concentration ranges 4 – 32,200 and 4 – 22,700 ng/g plug weight, respectively. No Ochratoxin A (OTA) was detected. Phenolic component analysis indicated unprocessed (20.79 ± 1.0 mg gallic acid equivalent per gram freeze-dry weight – GAE/g FDW) samples showed the highest value for total phenolics while both boiling (9.90 ± 1.8 mg GAE/g FDW), and roasting (9.32 ± 2.7 mg GAE/g FDW) reduced the amount by more than 50 % when compared with unprocessed. Potential individual phenolic compounds were unambiguously separated using high performance liquid chromatography – diode array detector (HPLC-DAD). There were no differences between chromatograms of defatted and non-defatted unprocessed, roasted and boiled samples. Cytotoxicity evaluation showed no decrease in cell densities in plates treated with extracts from unprocessed nuts at all concentrations. Diethyl ether-ethyl acetate (10 µg/mL) and n-butanol (1000 and 500 µg/mL) extracts of roasted nuts as well as dichloromethane and water (1, 10 µg/mL) of boiled nuts caused a non-significant decrease of < 10 % in cell densities when compared with the phosphate buffered saline-media control. However, all extracts showed no cytotoxic effect on the A549 cells African walnut is basically produced at subsistence level in Nigeria, but considering the presence of desirable fatty acid profile and phenolic compounds, need for increased industrial scale production is herein recommended. Although fungal attack and potential mycotoxin risk on the nut may be high, retail processing by roasting has prospects to greatly accentuate the risk. Cold storage of the nut may help to improve the shelf life although it may not be cost effective for local farmers in Nigeria and Africa, however, it provides opportunity for export business. Although the nut extracts showed no cytotoxic effect on A549 lung cancer cell lines, there is need to investigate further to confirm it non-cytotoxicity activity on other cancer lines and normal cell lines.

Tomato landraces are highly appreciated by consumers in the market. The main reasons are the presumed superior organoleptic quality with respect to modern cultivars, as well as the widespread perception that landraces are original varieties with unique agromorphologic characteristics. Nevertheless the amount of intravarietal genetic variability and its effect on important economic characters is unknown. With the aim to understand the attributes that singularize each variety and to design strategies to boost them on quality markets, a complete characterization of catalan landraces Montserrat, Pera de Girona and Penjar has been conducted. A previous survey of more than 200 accessions allowed us to select representatives of the intravarietal genetic variability of each landrace. Selected accessions were studied on an agromorphological, chemical, sensory (a sensory panel has been trained with this purpose) and molecular (AFLP) basis. Results show that while each landrace has unique traits that differentiate them from others, there is a great heterogeneity within landrace for all the traits recorded. Montserrat and Pera de Girona can be separated only using external fruit morphology traits. A great intra-varietal heterogeneity and overlapping among accessions of both landraces exists for the remain agronomic, morphologic and organoleptic traits (each landrace has not a distinctive sensory profile). Furthermore both varieties have the same genetic background, and the wide variation observed is based on narrow genetic diversity. Penjar landrace is characterized solely by its long shelf life and the small sized fruits. For the remaining characters (including molecular data) intra-varietal diversity is very large. Long shelf life is due to the presence of the ripening mutant alcobaça (alc) (replacement of thymine by adenine in position 317 of the coding sequence of the NAC.NOR gene) in combination with the reduced size of the fruit. The great heterogeneity for sensory attributes among accessions of the same landrace restricts its consolidation on quality vegetable markets. For this reason a breeding program has been conducted in order to obtain pure lines that combine good organoleptic and agronomic characteristics with the unique fruit morphology of each landrace. Breeding lines Punxa (Penjar variety), Sant Jeroni (Montserrat) and Montgrí (Pera de Girona) have been obtained with this approach. Moreover we have studied the effect of postharvest on Penjar tomato aroma, which is a determinant attribute for consumer acceptance. Through sensory analysis we have identified that the dominant aroma of this variety, described as sharp-floral, increases in the early stages of postharvest, reaching its maximum at 2 months. Absence of cis-3-hexanal and the rearrangement of the relative concentrations among volatiles with high impact on tomato aroma would be responsible for this particular behavior. In conclusion, the studies presented in this thesis show that intra-varietal genetic diversity existing in catalan tomato landraces affects almost all traits, both sensory and agromorphological. This high variability within landrace for sensory attributes threatens the success that those varieties have among consumers, so different strategies have been developed in order to improve the genetic and environmental components affecting organoleptic quality of Montserrat, Pera de Girona and Penjar landraces. / Les varietats tradicionals de tomàquet són ben valorades pels consumidors en el mercat. Això es deu a la seva suposada superior qualitat organolèptica respecte les varietats modernes, així com a la percepció generalitzada de que es tracta de materials originals i que presenten unes característiques agromorfològiques úniques. No obstant es desconeix la variabilitat genètica existent en les poblacions cultivades i el seu efecte sobre els caràcters d’interès econòmic. Amb l’objectiu de conèixer els caràcters que singularitzen aquestes varietats i dissenyar estratègies que les impulsin en els mercats de qualitat, s’ha desenvolupat un estudi de tres varietats tradicionals catalanes: Montserrat, Pera de Girona i Penjar. Partint de les dades d’una caracterització prèvia de més de 200 entrades, s’han seleccionat representants de la variabilitat genètica intra-varietal de cada varietat. Aquestes entrades s’han avaluat per caràcters agromorfològics, químics, sensorials (s’ha entrenat un panel de tast amb aquest objectiu) i pel fons genètic (AFLP). Els resultats mostren que tot i que cada varietat tradicional presenta uns trets singulars que la diferencien de les altres, existeix una gran heterogeneïtat intra-varietal pel conjunt de caràcters estudiats. Les varietats Montserrat i Pera de Girona es distingeixen únicament per la morfologia externa del fruit, existint una gran variabilitat intra-varietal i un solapament entre ambdues per la resta de caràcters agronòmics, morfològics i sensorials (cada varietat no té un perfil sensorial distintiu). A més ambdues varietats no es separen per fons genètic, sostenint-se la gran variabilitat agromorfològica i sensorial observada en una diversitat genètica reduïda. La varietat Penjar es caracteritza únicament per la llarga conservació i la mida reduïda del fruit, doncs pels altres caràcters (incloent dades moleculars) la variabilitat intra-varietal és molt elevada. La llarga conservació d’aquesta varietat es deu a la presència de la mutació alcobaça (alc) (una substitució de Timina per Adenina a la posició 317 del cds del segon exó del gen NAC.NOR) i a la mida reduïda del fruit. La gran heterogeneïtat existent per qualitat organolèptica entre els genotips de cada varietat tradicional limita la seva consolidació en els mercats de qualitat. Per aquest motiu s’ha desenvolupat un programa de millora genètica per seleccionar línies que aglutinin bones característiques organolèptiques i agronòmiques, conservant la morfologia del fruit única de cada varietat. Les línies Punxa (varietat Penjar), Sant Jeroni (Montserrat) i Montgrí (Pera de Girona) han estat obtingudes mitjançant aquests programes de millora. Paral•lelament s’ha estudiat l’efecte de la postcollita sobre l’aroma del tomàquet de Penjar, un caràcter determinant en l’acceptació per part dels consumidors. Mitjançant anàlisi sensorial s’ha identificat que l’aroma dominant d’aquesta varietat, descrita com a floral, incrementa en les primeres fases de la postcollita, assolint el seu màxim aromàtic als 2 mesos. L’absència de cis-3-hexanal i las variacions en el ràtio de la concentració entre els diferents volàtils amb impacte sobre l’aroma del tomàquet serien els responsables d’aquest comportament particular. En conclusió, els estudis que es presenten en aquesta tesi doctoral mostren que la variabilitat genètica intra-varietal existent en les varietats tradicionals afecta a la major part de caràcters, tant agromorfològics com sensorials. L’heterogeneïtat per qualitat organolèptica posa en risc la gran acceptació que tenen les varietats tradicionals entre els consumidors. Per corregir aquesta situació, s’han desenvolupat diferents estratègies per millorar els components genètic i ambiental que afecten a la qualitat organolèptica de les varietats Montserrat, Pera de Girona y Penjar. / Las variedades tradicionales de tomate son bien valoradas por los consumidores en el mercado. Ello es debido a su supuesta superior calidad organoléptica respecto a las variedades modernas, así como a la percepción generalizada de que se trata de materiales originales y que presentan unas características agromorfológicas únicas. No obstante se desconoce la variabilidad genética existente en las poblaciones cultivadas, así como si tiene un efecto sobre los caracteres económicos de interés. Con el objetivo de conocer los caracteres que singularizan estas variedades y diseñar estrategias que las impulsen en los mercados de calidad, se ha desarrollado un estudio de tres variedades tradicionales catalanas: Montserrat, Pera de Girona y Penjar. Partiendo de los datos de una caracterización previa de más de 200 entradas, se han seleccionado representantes de la variabilidad genética intra-varietal de cada variedad. Estas entradas se han caracterizado a nivel agromorfológico, químico, sensorial (se ha entrenado un panel de cata con este objetivo) y molecular (AFLP). Si bien cada variedad tradicional presenta unos rasgos singulares que la diferencian de otras, se observa una gran heterogeneidad dentro de variedad para el conjunto de caracteres estudiados. Las variedades Montserrat y Pera de Girona se distinguen únicamente por la morfología externa del fruto, existiendo una gran variabilidad intra-varietal y un solapamiento entre ambas para el resto de caracteres agronómicos, morfológicos y sensoriales (cada variedad no tiene un perfil sensorial distintivo). Además ambas variedades no se distinguen por fondo genético, y la gran variabilidad observada se sustenta en una diversidad genética baja. La variedad Penjar se caracteriza únicamente por la larga conservación y el tamaño reducido del fruto, pues para el resto de caracteres (incluyendo datos moleculares) la variabilidad intra-varietal es muy elevada. La larga conservación de esta variedad se debe a la presencia de la mutación alcobaça (alc) (una sustitución de Timina por Adenina en la posición 317 del cds del segundo exón del gen NAC.NOR) y al tamaño reducido del fruto. La gran heterogeneidad existente por calidad organoléptica entre los genotipos de cada variedad tradicional limita su consolidación en los mercados de calidad. Por ello se ha desarrollado un programa de mejora genética con el objetivo de seleccionar líneas que aglutinen buenas características organolépticas y agronómicas, conservando la morfología del fruto única de cada variedad. Las líneas Punxa (variedad Penjar), Sant Jeroni (Montserrat) y Montgrí (Pera de Girona) han sido obtenidas mediante estos programas de mejora. Paralelamente se ha estudiado el efecto de la poscosecha sobre el aroma en el tomate de Penjar, un carácter determinante en la aceptación por parte de los consumidores. Mediante análisis sensorial se ha identificado que el aroma dominante en esta variedad, descrito como floral, incrementa en las primeras fases de la poscosecha, llegando al máximo aromático a los 2 meses. La ausencia de cis-3-hexanal y las variaciones en el ratio entre los distintos volátiles con impacto en el aroma del tomate serían los responsables de este comportamiento particular. En conclusión, los estudios que se presentan en esta tesis doctoral muestran que la diversidad genética intravarietal existente en las variedades tradicionales afecta a casi todos los caracteres, tanto agromorfológicos como sensoriales. La heterogeneidad por calidad organoléptica pone en riesgo la gran aceptación que tienen las variedades tradicionales entre los consumidores, por lo que se han desarrollado distintas estrategias para mejorar las componentes genética y ambiental que afectan a la calidad organoléptica en las variedades Montserrat, Pera de Girona y Penjar.

Nurseries growing potted ornamental plants carry an important activity in the overall agricultural production in Catalonia. As a result of the activity developed and agricultural practices adopted by nursery growers (irrigation and fertilization methods) will eventually generate leachates containing nutrients from fertilizers, especially nitrates (NO3-). The final destination of the nursery leachates is frequently it discharges into the surrounding medium. For this reason, certain plant-growing areas causes non-point source NO3- pollution of the groundwater. Many cultural practices have been adopted by nursery growers to limit this type of pollution. The considerations described above highlight the need for studies evaluating the effect of agricultural practices on the leachates composition from outdoor crops and, if appropriate, propose an alternative to reduce NO3- in the same place of origin. Therefore, the objectives of the thesis are: - to identify fertilization methods and other agricultural practices adopted by nurseries growing potted ornamental plants in Barcelona and Girona, - to determine the effect of applying two fertilization methods on the leachates composition from two crops of potted ornamental plants, and - to assess the appropriateness of using horizontal subsurface-flow constructed wetlands (HSsH) for treating nursery leachates and optimize the denitrification process developed in them. Some experiments were carried out to meet these objectives. In the first experiment a survey was designed and conducted to the nursery growers of Barcelona and Girona. As a result of this work common fertilization methods were identified and two successive experiments were raised and conducted to answer the second objective. These experiments consisted on using the two standard fertilization strategies of nurseries (fertigation or controlled released fertilizers-FLC-) for two outdoor potted crops (a woody ornamental plant and other herbaceous ornamental plant) and different doses. Once leachates were characterized in terms of the different forms of N, four experiments were designed to meet the third objective. These consisted on treating nursery leachates by HSsH, an effective alternative to conventional technology in treating water with a high NO3- content. A first-order plug-flow kinetic model based on NO3- removal was used to design a pilot plant with HSsH, in which experiments were conducted. These were different in the type of carbon source (sodium acetate -AcNa- or methanol -Me-) and dose added to promote influent denitrification. The results related to the first goal showed that fertilization methods and other agricultural practices related to irrigation and leachates management are very different depending on the type of common crop in each province. Thus, in Girona, where woody crops are most frequent, growers usually apply FLC and use overhead irrigation. However, in Barcelona, where herbaceous crops in season are performed, growers usually apply nutrient solutions (NS) by continuous fertigation and use drip or micro-sprinkler irrigation systems.The application of FLC to the crop resulted in the acidification of the leachates respect of the application of SN by fertigation.The coincidence of high growing media temperatures and prolonged heavy rain events during one of the two crops, indicated a greater initial loss of N by leaching to the environment when FLC are applied and, consequently, a decrease of FLC longevity.The results related to the third goal showed that the design of the pilot plant with HSsH was suitable for treating nursery leachates. The denitrification rate was greatest applying AcNa to achieve a C:N-NO3- ratio of 3:1. However, the application of this ratio and AcNa involves the addition of carbon and sodium in excess of purified effluent, respectively. The quality of the effluent and the denitrification process were enhanced when Me is applied to reach C:N-NO3- ratio of 1:1.5. / El subsector productor de plantas ornamentales en contenedor al exterior constituye una actividad de remarcable importancia en el conjunto de la producción agrícola de Cataluña. Como resultado de la actividad desarrollada y de las prácticas agrícolas adoptadas (modos de riego y fertilización), eventualmente se generarán lixiviados caracterizados por un alto contenido en nutrientes procedentes de los fertilizantes, principalmente en nitratos (NO3-). Normalmente, el destino de estos lixiviados es su vertido al medio circundante. Por este motivo, las zonas productoras de ornamentales se consideran, entre otras, puntos de contaminación difusa del subsuelo por NO3-. Algunas técnicas para disminuir o evitar este tipo de contaminación, consisten en adoptar ciertas prácticas agrícolas o proceder a su tratamiento. Las consideraciones antes mencionadas ponen de manifiesto la necesidad de realizar estudios que evalúen el efecto de las prácticas agrícolas habituales en la composición de los lixiviados generados y, en el caso que proceda, proponer una alternativa para reducir la carga de NO3- en el mismo lugar de procedencia. Por tanto, los objetivos de esta Tesis son: - identificar los modos de fertilización y las prácticas agrícolas habituales en el subsector productor de plantas ornamentales en contenedor al exterior en Barcelona y Girona, - determinar el efecto de aplicar los modos de fertilización identificados en la composición de los lixiviados generados por dos cultivos de plantas ornamentales, y - evaluar la idoneidad de realizar un tratamiento de los lixiviados mediante humedales artificiales de flujo subsuperficial horizontal (HSsH) y optimizar el proceso de desnitrificación. Para responder estas cuestiones se realizaron diferentes estudios. En el primero se diseñó y realizó una encuesta a los principales productores de plantas ornamentales de Barcelona y Girona. Una vez identificados los modos de fertilización habituales, se diseñaron dos estudios para responder al segundo objetivo. Estos consistieron en aplicar a dos cultivos (uno de planta leñosa y otro de planta herbácea), fertirrigación o fertilizantes de liberación controlada (FLC) a diferentes dosis. Una vez caracterizadas las diferentes formas de N en los lixiviados de los dos cultivos descritos, se diseñaron cuatro estudios para responder al tercer objetivo. Consistieron en realizar un tratamiento de lixiviados mediante HSsH, un sistema biológico de depuración alternativo a la tecnología convencional para desnitrificar efluentes. Se diseñó y dimensionó una planta piloto según el modelo cinético de primer orden basado en la eliminación de NO3-, en la cual se realizaron cuatro experimentos diferentes en cuanto al tipo (acetato sódico, AcNa, o metanol, Me) y la dosis de la fuente carbonada añadida para promover la desnitrificación del influente. Los resultados mostraron que los modos de fertilización habituales están vinculados al tipo de cultivo realizado. Así, en Girona, donde son más frecuentes los cultivos de plantas leñosas, se aplican fertilizantes de liberación controlada (FLC), y en Barcelona, donde predominan los cultivos de plantas herbáceas de temporada, se aplican soluciones nutritivas mediante fertirrigación continua. La aplicación de diferentes cantidades de N mediante FLC provocó la acidificación de los lixiviados respecto a la aplicación de fertirrigación. El acontecimiento conjunto de precipitaciones elevadas y altas temperaturas en el sustrato durante la realización del cultivo con planta leñosa, provocó una mayor pérdida inicial de N por lixiviación del FLC, por lo que se redujo su longevidad. La tasa de desnitrificación en los HSsH fue máxima al aplicar AcNa en un ratio C:N-NO3- de 3:1. Sin embargo, la aplicación de este ratio y de AcNa supone la adición de carbono y de sodio en exceso al efluente depurado,respectivamente. La calidad del efluente y el proceso de desnitrificación mejoran al aplicar Me en un ratio C:N-NO3- de 1.5:1.

Orchards are biodiversity hotspots, home to a wide range of organisms including epiphytic bryophytes and lichens. However, the area of the UK given over to orchards has become considerably reduced; these habitats are under threat. In response to this, Traditional Orchards are now included as a priority habitat in the UK Biodiversity Action Plan. Local Habitat Action Plans have been produced. It is important that the factors which cause orchards to be such biodiverse habitats are understood in order to facilitate the management of newly planted and restored orchards. Surveys across 7 orchards were carried out, six in Hertfordshire and one in Cambridgeshire. A total of 141 apple trees were surveyed. Epiphytic bryophyte species were recorded, and in 7 of the surveys the cover of individual species was also included. 26 species of epiphytic bryophyte were recorded. There was a high level of similarity in species composition between the orchards, however this was much reduced when relative species cover was taken into account. In order to assess the overall diversity in order to compare orchards, the optimal number of trees to sample was found to be 10. Within the same orchard, significant differences in number of bryophyte species per tree and bryophyte cover were found between two varieties of apple tree, Ashmead's Kernal and Newton Like. This was accompanied by significantly different bark pH and nitrogen concentrations. However, pH was found to be of low importance in explaining the distribution of epiphytic bryophytes on Bramley trees across orchards. In vitro experiments found that low pH inhibited spore germination and growth in the species Brachythecium ve!utinum, Rhynchostegium confertum, Orthotrichum affine and Bryum capillare. High concentrations of nitrogen inhibited spore growth but not germination in the species Orthotrichum affine. The in-depth surveys of Bramley trees showed that across orchards, tree structure, as determined by management, explained about 10% of the observed variation in bryophyte cover. Within that, trunk girth and distance to nearest neighbouring orchard trees were the most important factors. Site was found to be the strongest influence on epiphytic bryophyte distribution in the orchards.

Monilinia laxa is the causal agent of brown rot disease on stone fruits, and also causes blossom wilt and twig canker. The common practice used to manage this disease is through fungicide treatments, especially during the flowering and fruiting period. However the demand to reduce fungicide input has been increasing and there is a growing number of reports of M. laxa strains that are resistant to fungicides. This study is based on the development of biological control agents (BCAs) as an alternative strategy for disease control using either existing BCA products or new indigenous isolates from UK orchards. Efficacy of exotic commercial BCAs against M laxa was investigated using in vivo tests on cherries and plums. Serenade partially inhibited M laxa while the other four BCA products (BioPK, BoniProtect, Prestop and Trianium) had no effect against the pathogen. Indigenous BCAs were isolated from healthy leaves, intact fruits and mummified fruits of cherries and plums collected from orchards in Kent. A total of 217 isolates were screened against two strains of ill! laxa in a series of in vitro tests using a dual culture technique. From these tests, 12 isolates were selected for fUliher screening. The final screening based on in vivo tests on cherries and plums narrowed these down to two isolates with good potential for development. They were further tested under post-harvest conditions by dipping cherries and plums in suspensions of cells of the individual control agents and storing treated fruit under standard storage conditions. The two BCAs did not control brown rot on cherries under these conditions, and the low incidence of natural infection by fvi laxa in plums also meant that significant control could not be demonstrated. The two BCAs were identified as Bacillus amyloliquefacienslsubtilis (isolate B91) and Aureobasidium pulIulans (isolate YI26). Their modes of action were investigated. Bacillus sp. B91 was shown to produce soluble and volatile organic compounds which inhibited M laxaJ while A. pulIulans Y126 apparently competes with the pathogen for nutrients and did not produce inhibitory compounds. The capability of B91 and Y126 to . grow and survive at low temperatures was studied. Bacillus sp. B91 was shown to be a mesophillic bacterium that could grow at 10-2S0C but suffered significant mOltality at 0 and SOC, while A. pulIulans Y126 was both mesophilic and psychrotolerant because it grew between 0-2SoC, although 20°C was the optimum temperature. Once all nutrients were . removed, Y12.6 was able to survive for several weeks in all test temperatures (0-2S°C) but showed significant mortality at 2SOC. The capability of B91 to survive at 20 and 2SoC was h-igher than low temperatures (O-IS°C) . . Molecular studies were used to show that M laxa populations on mummified fruits were likely to be responsible for fruit rot infection in the same orchards the following season. Geographical origin and host also influenced the population structure of A1. laxa. Field trials were conducted in which mummified fruits were either treated with a commercial fungicide (Indar) or BCAs to investigate whether these treatments would significantly reduce sporulation of the pathogen in the field thus reducing the infection load in . the spring. Spraying in Winter alone was not sufficient to significantly suppress sporulation of M laxa but the efficacy was improved when the control agents were applied in Spring either as a single spray or in combination with a Winter spray. Sprays of Indar or A. pulIulans Y126 greatly suppressed sporulation on mummified fruits if the fruits were treated on both occasions. It was concluded that the two novel, indigenous BCAs have potential to control M laxa but more research is necessary to develop these two potential BCAs for field use.

Many wild and underutilised plants contribute to food and nutrition. However, overexploitation due to ever increasing demand for wood products has frequently led to declines in populations of these species. Enhanced knowledge of the status of such species is necessary for livelihood security and conservation of these valuable species. The present study considers an underutilised and threatened species of Bangladesh, namely wild mango (Mangifera sylvatica Roxb.). Although this wild mango is one of the genetically closest species to the common mango (Mangifera indica L.) research is very limited and mostly focused on wood quality and phylogenetic relationships. Therefore, this study investigated the conservation potential of wild mango considering its contribution for food, nutrition and livelihoods. To do so, an assessment was made of the current and future distribution of the species, which is a crucial first step towards mitigation and management of future species losses or habitat shifts. The study characterized fruit quality by profiling morphological, nutritional and medicinal values. Finally, farmers’ preferences, and the agroforestry potential of this unutilized native fruit species were explored. The study conveyed five key messages: 1. Wild mango may become extinct under future climate change scenarios so it is high time to start thinking about conservation initiatives. 2. Wild mango is a small sized mango with a large kernel in relation to other Mangifera species which provides significant nutritional and medicinal advantages that can contribute to nutrition and health of local people. 3. Wild mango fruit kernels producing a butter which has the potential to be used as a Cocoa Butter Alternative (CBA) thus providing new market potential. 4. Wild mango is a considered as a food for wildlife but local people are also appreciative of the taste and colour of the fruits and consume them. The unripe fruit is also sold to the pickle industry and can generate income during the fruiting season. 5. The crown architecture of wild mango is similar to other popular agroforestry species (M. indica, Artocarpus heterophyllus and Acacia auriculiformis). Therefore, urgent conservation initiatives are required to evaluate its potential as a new native agroforestry tree species. It is concluded that these attractive properties of wild mango could be promoted by a coalition of land use planners, climate change policy makers, government or non-government organizations, commercial breeder, potential investors (chocolate, butter, nutraceuticals, flavourings), food industries, food technologists, minister responsible for foreign direct investment in Bangladesh and Bangladesh forestry department to promote more widespread cultivation of this wild fruit species to realise its full potential.

Sown flowering strips can benefit beneficial arthropod groups (pollinators and natural enemies) on farmland and enhance the delivery of arthropod-mediated ecosystem services in crops. However, not all flowering plants may be useful for beneficial arthropod taxa, as differences in floral traits associated with nectar accessibility (e.g. nectar-holder depth) determine resource use. Therefore, increasing the number of distinct floral traits in flower mixes may be an effective way to manage multiple arthropod-mediated ecosystem services in farmland. Here, the response of pollinators and natural enemies in cider-apple orchards to three functionally-distinct flower mixes ('open-nectar plant' mix, 'concealed-nectar plant' mix, and a third 'multi-functional' mix that contained all species in distinct mixes), sown in flowering strips between rows of trees were assessed, and compared to areas under existing management (mown grass), as well as the effects on arthropod-mediated ecosystem services (pollination and pest control) in orchards. Observations of flower visitation revealed a dichotomy in floral resource use by beneficial arthropod groups, with pollinators more abundant in plots sown with the concealed-nectar plant mix, whereas natural enemies were more abundant in plots sown with the open-nectar plant mix. When mixtures were combined, plots sown with the multi-functional mix attracted both suites of beneficial arthropods. Although effects of flower strips on ecosystem service delivery (yield, pest pressure) were less clear, there was some evidence that flower strips influenced service provision (increased predation of sentinel prey), and the abundance of key taxa (Andrena solitary bees). The link between visitation by andrenids during blossom in spring and fruit set was the clearest link found between beneficial arthropods and yield in cider-apple orchards. This thesis provides clear evidence that a trait-based approach to designing flower mixes enables sown flowering strips to support beneficial arthropod taxa and enhance multiple ecosystem services in cider orchards, and quantifies the important role that beneficial arthropods play in supporting crop production.