Dissertations / Theses on the topic 'Peach Trees'

In the last years, sustainable horticulture has been increasing; however, to be successful this practice needs an efficient soil fertility management to maintain a high productivity and fruit quality standards. For this purpose composted organic materials from agri-food industry and municipal solid waste has been used as a source to replace chemical fertilizers and increase soil organic matter. To better understand the influence of compost application on soil fertility and plant growth, we carried out a study comparing organic and mineral nitrogen (N) fertilization in micro propagated plants, potted trees and commercial peach orchard with these aims: 1. evaluation of tree development, CO2 fixation and carbon partition to the different organs of two-years-old potted peach trees. 2. Determination of soil N concentration and nitrate-N effect on plant growth and root oxidative stress of micro propagated plant after increasing rates of N applications. 3. Assessment of soil chemical and biological fertility, tree growth and yield and fruit quality in a commercial orchard. The addition of compost at high rate was effective in increasing CO2 fixation, promoting root growth, shoot and fruit biomass. Furthermore, organic fertilizers influenced C partitioning, favoring C accumulation in roots, wood and fruits. The higher CO2 fixation was the result of a larger tree leaf area, rather than an increase in leaf photosynthetic efficiency, showing a stimulation of plant growth by application of compost. High concentrations of compost increased total soil N concentration, but were not effective in increasing nitrate-N soil concentration; in contrast mineral-N applications increased linearly soil nitrate-N, even at the lowest rate tested. Soil nitrate-N concentration influenced positively plant growth at low rate (60- 80 mg kg-1), whereas at high concentrations showed negative effects. In this trial, the decrease of root growth, as a response to excessive nitrate-N soil concentration, was not anticipated by root oxidative stress. Continuous annual applications of compost for 10 years enhanced soil organic matter content and total soil N concentration. Additionally, high rate of compost application (10 t ha-1 year-1) enhanced microbial biomass. On the other hand, different fertilizers management did not modify tree yield, but influenced fruit size and precocity index. The present data support the idea that organic fertilizers can be used successfully as a substitute of mineral fertilizers in fruit tree nutrient management, since they promote an increase of soil chemical and biological fertility, prevent excessive nitrate-N soil concentration, promote plant growth and potentially C sequestration into the soil.

6 pp.
Training and pruning newly-planted deciduous fruit trees is one of the most important steps in developing trees with a strong framework (scaffold branches). Trees with a good framework of branches can support heavy crops without limb breakage and will help to bring the young tree into production at an early age. Selection and arrangement of these branches determines the type of development and growth in later years. The goal of pruning and training is to balance vegetative and fruiting wood growth.

Batticaloa district on the Eastern coast of Sri Lanka has been one of the most disrupted and devastated areas of the island since civil war began in the early 1980s. Ethnically and culturally diverse, the Eastern province has been under the control of different military actors, the Sri Lankan army, the Indian Peace-Keeping Forces, and the LTTE (Liberation Tigers of Tamil Eelam), however, none maintained full control of the Eastern areas until May 2009 when the Sri Lankan Army successfully defeated the LTTE. Exploring the lives of Tamil communities in Batticaloa, this thesis examines the ways in which people make sense of an ‘everyday life’ shaped by conflict. Following the idiosyncratic journey of the researcher through the uncertain environment of escalating conflict and the aftermath of the tsunami, it builds up a larger picture of life, moving between accounts of everyday violence and suffering and more sustained dwelling on the particular people who are actively making it possible to endure by investing in a more humane future. In areas such as Batticaloa, where violence frames the past, present and foreseeable future, resistance in some shape or form has become a way of life. As Foucault (1976, 2003) maintains, violence which is embedded in social and material structures can create an environment where power and control saturate the routines of the ordinary, making its existence appear ‘normal’. However, from this way of life, what may emerge beyond the more obvious signs of violence, is the fact that people do keep pushing forward. Integral to this is the importance of risk, hope, and trust, which, woven through the interactions of daily activity, mark out what is possible and what is not. The chapters in this thesis, explore individuals who, in the spaces between accepted understandings of ordinary and extraordinary, work around the various controls and constraints to forge habitable spaces in which relations of trust and support can be strengthened and the future can be imagined. Starting with a focus on the relationship between personal narrative and history, I trace the experiences of a woman living through poverty, displacement, and loss. From this I suggest that it is the paradoxical existence of violence, risk, fear, friendship, and trust as worked through the endurance of daily interactions that is integral to understanding the texture of everyday life. Therefore, I argue that what can on the one hand look like a hopeless and negative picture of militancy and violence, can also, contain within it, fragments of hope and survival, captured for example, in the work of local people to reclaim space. I also deal with the complexities of the research experience in a violent environment and look at the strategies that people employ to negotiate and minimize risk in contested and militarized spaces. The second part of the thesis examines the meaning of the everyday and the ordinary through the experiences of a widow and group of fishermen, and thus challenges conventional academic writing which relates ‘normalcy’ in violence prone-areas to peace and productivity. Overall, these chapters argue that a capacity for hope, for building trust, safety, and peace, however fragile and tentative, is as much an integral part of a conflict situation as the more obvious capacity for fear and silence.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is a polyphagous, invasive, and highly significant pest of mid-Atlantic fruit orchards. Its capacity to invade orchards season-long is believed to be facilitated by the availability of wild host plants near orchards and the high dispersal capacity of adults and nymphs. Interactions between H. halys and its hosts were investigated via laboratory and field experiments. Rearing H. halys nymphs in the laboratory on several of its known wild and tree fruit hosts used alone and in combination showed that peach was much more suitable for nymphal development and survival than was apple, tree of heaven, or catalpa and that nymphal performance was enhanced on mixed host diets. Nymphs reared on different host plant diets yielded adults that differed in protein, sugar or lipid content, offering new insights into plant diet effects on H. halys nutrition. The majority of tree species identified from unmanaged woodlands next to apple orchards in Virginia and West Virginia were known hosts of H. halys. Passive trunk traps were developed to capture H. halys nymphs walking up and down tree trunks and used to measure their temporal patterns of movement onto and off of wild and tree fruit hosts at the orchard-woodland interface via weekly assessments during two consecutive seasons. More upward- than downward-walking nymphs were captured, which may be partially explained by the positively phototactic and negatively geotactic behavior of H. halys nymphs demonstrated in laboratory studies. Most nymphs captured while walking up and down trunks were second instars, although the data also reflected temporal changes in the distribution of instars and temporal variation in the numbers of nymphs captured. A field study to characterize injuries to apple and peach fruit at harvest from feeding by young or older nymphs early or late in the season revealed that feeding by young nymphs early in the season resulted in least injury to both crops. In combination, these studies greatly improve our understanding of the biology and ecology of H. halys in eastern fruit orchards and provide relevant data that will inform the development of ecologically-based management programs for it.
Ph. D.

La transformació de terres marginals, juntament amb un augment dels processos de degradació del sòl (p. e. salinització) estan traslladant l'agricultura a sòls més desfavorables, fet que obliga al desenvolupament de noves estratègies de maneig dels cultius. Durant els últims anys s'han introduït noves estratègies de reg, com el reg localitzat enterrat (subsurface drip irrigation, SDI) o el reg deficitari controlat, tot i que resulta necessari avaluar la seva viabilitat i sostenibilitat quan són aplicades en sòls amb propietats físiques limitants. Alhora, l'ús d'esmenes orgàniques i les tècniques d’aeració forçada estan sorgint com a mètodes de recuperació de sòls a baix cost, que podrien millorar potencialment el rendiment dels cultius en situacions desfavorables. És important estudiar els efectes d'aquestes estratègies i tècniques sobre les propietats del sòl, així com en la fisiologia dels cultius i la seva productivitat, tot i que també sobre paràmetres de qualitat d'importància creixent en el sector fructícola, com el potencial de conservació de la fruita. L'objectiu general d'aquesta tesi ha estat el d'avaluar diferents estratègies de maneig del sòl i de reg, i estudiar els seus efectes en plantacions de presseguer i nectarina en sòls amb condicions físiques limitants.
La transformación de tierras marginales, junto con un aumento de los procesos de degradación del suelo (p. ej. salinización) están trasladando la agricultura a suelos más desfavorables, lo que obliga al desarrollo de nuevas estrategias de manejo de los cultivos. Durante los últimos años se han introducido nuevas estrategias de riego, como el riego localizado enterrado (subsurface drip irrigation, SDI) o el riego deficitario controlado, a pesar de que resulta necesario evaluar su viabilidad y sostenibilidad cuando son aplicadas en suelos con propiedades físicas limitantes. Al mismo tiempo, el uso de enmiendas orgánicas y las técnicas de aireación forzada están surgiendo como métodos de recuperación de suelos a bajo coste, que podrían mejorar potencialmente el rendimiento de los cultivos en situaciones desfavorables. Es de suma importancia el estudiar los efectos de estas estrategias y técnicas sobre las propiedades del suelo, así como en la fisiología de los cultivos y su productividad, aunque también sobre parámetros de calidad de importancia creciente en el sector frutícola, como el potencial de conservación de la fruta. El objetivo general de esta tesis fue el de evaluar diferentes estrategias de manejo de suelo y riego, y estudiar sus efectos en plantaciones de melocotón y nectarina en suelos con condiciones físicas limitantes.
Transformation of marginal land along with an increase of soil degradation processes (e.g. salinization) is moving the agriculture into more unfavorable soils, forcing the development of new management strategies. Subsurface drip irrigation (SDI) and deficit irrigation strategies have been widely studied although it is necessary to evaluate their feasibility and sustainability when applied in soils with limiting physical properties. At the same time, organic soil amendments and oxygation techniques are arising as low-cost soil reclamation methods that could potentially improve the crop performance under such situations. It is of paramount importance to study the effects of these strategies and techniques on soil properties as well as on crop physiology and productivity, but also on some quality parameters of growing importance in the fruit sector, such as fruit storability. The general aim of this thesis was to assess various soil management and irrigation strategies and study their effects on peach and nectarine orchards under limiting soil conditions.

Se realizó la caracterización morfológica, fisiológica y molecular de tres cepas de Beauveria brongniartii: CIPCa18(85), CIPCu1(44) y CIPH1(1), además de evaluar su actividad entomopatógena en Phthorimaea operculella y Symmetrischema tangolias. La cepa CIPCu1(44) presentó conidias redondas, pequeñas y la formación de sinemas, diferenciándose de las cepas CIPCa18(85) y CIPH1(1) que presentaron conidias elipsoidales. El análisis molecular mediante la técnica RAPD permitió determinar que esta cepa estaba genéticamente más relacionada con la cepa de Beauveria bassiana CIPLM1 (50.4% de similaridad). Al evaluar la actividad entomopatógena de las tres cepas en larvas de primer estadío de P. operculella y S. tangolias, se encontró que utilizando 1 x 109 conidias/ml el porcentaje de mortalidad fue hasta del 100%. Se determinó que para P. operculella la CL50 de las cepas CIPCa18(85), CIPCu1(44) y CIPH1(1) fue 2.71 x 105, 5.53 x 105 y 5.19 x 105 conidias/ml y la CL90 fue 6.81 x 106, 1.22 x 107 y 5.97 x 106 conidias/ml, mientras que para S. tangolias la CL50 para las cepas CIPCa18(85), CIPCu1(44) y CIPH1(1) fue 1.16 x 106, 9.37 x 106 y 4.52 x 106 conidias/ml y la CL90 fue 6.01 x 107, 1.46 x 109 y 2.17 x 108 conidias/ml respectivamente. En ensayos posteriores se determinó que la cepas de B. brongniartii necesitaron mayor tiempo (9-10 días) para que las CL50 pudieran causar el 50% de mortalidad a las larvas de primer estadío de S. tangolias mientras que sólo necesitaron 3 a 5 días para causar el 50% de mortalidad en P. operculella. Posteriormente se evaluó cada CL50 y CL90 en huevos, larvas de último estadío y pupas de P. operculella y S. tangolias, encontrándose que todos los estados de desarrollo fueron susceptibles con diferente grado de infección. En todas estas evaluaciones, la cepa CIPCa18(85) presentó la mejor actividad entomopatógena para el control de P. operculella y S. tangolias.
--- The objective of this research was to carry out morphological, phisiological and molecular characterization of three isolates of Beauveria brongniartii: CIPCa18(85), CIPCu1(44) y CIPH1(1). In addition, entomogenous activity was tested in Phthorimaea operculella y Symmetrischema tangolias. Isolate CIPCu1(44) showed shorter and spherical conidia while isolates CIPCa18(85) y CIPH1(1) showed tipical elipsoidal conidia. RAPD technique showed a relation between isolates CIPCu1(44) and CIPLM1 (B. bassiana) with 50.4% of similarity. Patogegenicity test showed that isolates were effective to first instar larves, the use of 1 x 109 conidia/ml caused until 100% mortality for both insects. CL50 for isolates CIPCa18(85), CIPCu1(44) and CIPH1(1) obtained in P. operculella larves were 2.71 x 105, 5.53 x 105 and 5.19 x 105 conidias/ml and CL90 for each isolate were 6.81 x 106, 1.22 x 107 and 5.97 x 106 conidias/ml respectively. CL50 for isolates CIPCa18(85), CIPCu1(44) and CIPH1(1) obtained in S. tangolias were 1.16 x 106, 9.37 x 106 and 4.52 x 106 conidias/ml and CL90 for each isolate were 6.01 x 107, 1.46 x 109 and 2.17 x 108 conidias/ml respectively. In other essays, isolates of B. brongniartii needed more time to kill 50% of S. tangolias larves (9 to 10 days) while isolates of B. brongniartii needed only 3 to 5 days to kill 50% of P. operculella. With CL90, isolates needed about 3 days for both insects. Finally, each CL50 y CL90 of three isolates were tested in eggs, last instar larves and pupae, results showed that all develop stages were susceptible to B. brongniartii. Isolate CIPCa18(85) showed the best entomogenous activity to make control of P. operculella y S. tangolias because it came of the same insect order, we suggest more studies with this isolate in greenhouse.
Tesis

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Althought there are researches that report the influence of rootstock about the scion cultivar, changing their behavior in relation to development, productivity, resistance, nutrition, maturation time and the quality of the fruits, these results are not conclusive. Objective of the study was evaluate the effect of rootstock Aldrighi, Capdeboscq, Flordaguard, Nemaguard, Okinawa and Umezeiro about quality of peaches cultivar Maciel. The fruits of the cultivar Maciel are from two orchards located in the Agricultural Center of Palma UFPel/Capão do Leão and in the experimental Estation of the Federal University of Rio Grande do Sul UFRGS/Eldorado do Sul. After the harvest, the fruits carried the following Physico-chemical analysis: acidity, skin color, total soluble solids, pH, 'Ratio' and firmness. For phytochemical analysis, fruits were separated into peel and flesh, stored in ultra-freezer, and later held the analysis of individual and total phenols, total and individual carotenoids and antioxidant activity. For Palma‟s fruits, the rootstock evaluated influenced considerably the acidity parameters, firmness, color of coating, pH, and ratio. These effects were not observed in the experimental Estation UFRGS with the same cultivar. The values of phenols and carotenoids total and individual were influenced by the rootstocks both the flesh and the peel, for the two localities. The Okinawa‟ had the highest average of total phenols in the peel for both places, Flordaguard‟ the flesh showed the highest average for the CAP‟s fruit and Nemaguard‟ to the fruits EE/UFRGS. The quantification of phenolic compounds, the gallic acid is the highest expression followed by p-hydroxybenzoic, p-coumaric and caffeic. For carotenoids in the flesh Okinawa‟ showed the highest average not differing from Aldrighi‟ while in the largest EE/UFRGS results were found in the Capdeboscq‟, Nemaguard‟ and Umezeiro‟. For carotenoids, β-cryptoxanthin, is the majority pigment, still presenting licopen and β-caroten in minors amounts. Nemaguard, Aldrighi and Umezeiro‟ present a higher value for antioxidant capacity. In the analysis of correlation between phytochemical were watched a weak and positive correlation for the flesh of the fruits and for the peel a correlation weak and negative. It is conclude that the rootstock might affect in an undirected form some phytochemical and physico-chemical, for both localities in which fruits were characterized.
Embora existam pesquisas que relatem a influência do porta-enxerto sobre a cultivar copa, alterando o seu comportamento em relação ao desenvolvimento, produtividade, resistência, nutrição, época de maturação e qualidade dos frutos, os resultados ainda não são conclusivos. Objetivou-se com o trabalho avaliar o efeito dos porta-enxertos Aldrighi, Capdeboscq, Flordaguard, Nemaguard, Okinawa e umezeiro sobre a qualidade de pêssegos da cultivar Maciel. Os frutos foram provenientes da safra de 2008 de dois pomares, sendo um localizado no Centro Agropecuário da Palma UFPel/Capão do Leão (CAP/UFPel) e outro na Estação Experimental da Universidade Federal do Rio Grande do Sul UFRGS/Eldorado do Sul (EE/UFRGS). Após a colheita dos frutos procederam-se as seguintes análises físico-químicas: acidez (AT), coloração da epiderme, sólidos solúveis totais (SST), pH, relação SST/AT e firmeza de polpa. Para as análises fitoquímicas os frutos foram separados em casca e polpa e armazenados em ultra-freezer e posteriormente realizou-se a análise de fenóis totais e individuais, carotenóides totais e individuais e atividade antioxidante. Para os frutos provenientes do CAP/UFPel, os porta-enxertos avaliados influenciaram significativamente a acidez, firmeza, cor de recobrimento, pH e ratio. Estes efeitos não foram observados com os frutos provenientes da EE/ UFRGS com esta mesma cultivar onde somente a firmeza apresentou efeito significante dos porta-enxertos. Os valores de fenóis e carotenóides totais e individuais foram influenciados pelos porta-enxertos tanto na polpa quanto na casca, para as duas localidades.O Okinawa‟ obteve as maiores médias de fenóis totais na casca para as duas localidades, na polpa Flordaguard‟ apresentou as maiores médias para os frutos do CAP/UFPel e Nemaguard‟ para os frutos da EE/UFPel. Na quantificação de compostos fenólicos, o ácido gálico foi o de maior expressão seguido dos ácidos hidroxibenzóico, cumárico e cafeíco. Para carotenóides totais, na polpa, Okinawa‟ e Aldrighi‟ apresentaram as maiores médias não diferindo entre si no CAP/UFPel enquanto que na EE/UFRGS os maiores resultados foram quantificados em Capdeboscq‟, Nemaguard‟ e Umezeiro‟. Na quantificação dos carotenóides individuais, o β-criptoxantina é o pigmento majoritário apresentando ainda licopeno e β-caroteno em quantidades menores. Nemaguard, Aldrighi e Umezeiro‟ apresentaram maiores valores para capacidade antioxidante para a polpa dos frutos do CAP/UFPel sendo que Nemaguard‟ e Aldrighi‟ mantiveram este resultado para polpa da EE/UFRGS. Na análise de correlação entre os fitoquímicos, observou-se uma correlação fraca e positiva para a polpa dos frutos e para casca uma correlação fraca e negativa. Conclui-se que o porta-enxerto pode afetar de forma indireta alguns parâmetros físico-químicos e fitoquímicos, para as duas localidades na qual os frutos foram caracterizados.

This study explores different actors’ perceptions on how the democratization process is being influenced in Kosovo. It is based upon empirical facts gathered during a field study in Kosovo. The material was mainly gathered through interviews with different representatives from international organizations present in Kosovo and with members of the Kosovar political elite.

The theoretical standpoint in the study draws on the theory of polyarchy for defining the concept of democracy, and the two-level game. The interaction between domestic and international actors within the democratization process is highlighted.

The conclusions are that different actors are influencing the ongoing democratization process in Kosovo, mainly international external ones acting in several ways and on different levels. This influence is considered by the international community and the domestic political elite to be necessary both for the continued development of democracy and for the preservation of stability. However as the influence has more or less become institutionalized, problems occur when responsibility is handed over to domestic authorities without accountability being made clear.

Our project, ViEWS+, expands the software functionality of the Violence EarlyWarning System (ViEWS). ViEWS aims to predict the probabilities of armed conflicts in the next 36 months using machine learning. Governments and policy-makers may use conflict predictions to decide where to deliver aid and resources, potentially saving lives. The predictions use conflict data gathered by ViEWS, which includes variables like past conflicts, child mortality and urban density. The large number of variables raises the need for a selection tool to remove those that are irrelevant for conflict prediction. Before our work, the stakeholders used their experience and some guesswork to pick the variables, and the predictive function with its parameters. Our goals were to improve the efficiency, in terms of speed, and correctness of the ViEWS predictions. Three steps were taken. Firstly, we made an automatic variable selection tool. This helps researchers use fewer, more relevant variables, to save time and resources. Secondly, we compared prediction functions, and identified the best for the purpose of predicting conflict. Lastly, we tested how parameter values affect the performance of the chosen functions, so as to produce good predictions but also reduce the execution time. The new tools improved both the execution time and the predictive correctness of the system compared to the results obtained prior to our project. It is now nine times faster than before, and its correctness has improved by a factor of three. We believe our work leads to more accurate conflict predictions, and as ViEWS has strong connections to the European Union, we hope that decision makers can benefit from it when trying to prevent conflicts.
I detta projekt, vilket vi valt att benämna ViEWS+, har vi förbättrat olika aspekter av ViEWS (Violence Early-Warning System), ett system som med maskinlärning försöker förutsäga var i världen väpnade konflikter kommer uppstå. Målet med ViEWS är att kunna förutsäga sannolikheten för konflikter så långt som 36 månader i framtiden. Målet med att förutsäga sannoliketen för konflikter är att politiker och beslutsfattare ska kunna använda dessa kunskaper för att förhindra dem.  Indata till systemet är konfliktdata med ett stort antal egenskaper, så som tidigare konflikter, barnadödlighet och urbanisering. Dessa är av varierande användbarhet, vilket skapar ett behov för att sålla ut de som inte är användbara för att förutsäga framtida konflikter. Innan vårt projekt har forskarna som använder ViEWS valt ut egenskaper för hand, vilket blir allt svårare i och med att fler introduceras. Forskargruppen hade även ingen formell metodik för att välja parametervärden till de maskinlärningsfunktioner de använder. De valde parametrar baserat på erfarenhet och känsla, något som kan leda till onödigt långa exekveringstider och eventuellt sämre resultat beroende på funktionen som används. Våra mål med projektet var att förbättra systemets produktivitet, i termer av exekveringstid och säkerheten i förutsägelserna. För att uppnå detta utvecklade vi analysverktyg för att försöka lösa de existerande problemen. Vi har utvecklat ett verktyg för att välja ut färre, mer användbara, egenskaper från datasamlingen. Detta gör att egenskaper som inte tillför någon viktig information kan sorteras bort vilket sparar exekveringstid. Vi har även jämfört prestandan hos olika maskinlärningsfunktioner, för att identifiera de bäst lämpade för konfliktprediktion. Slutligen har vi implementerat ett verktyg för att analysera hur resultaten från funktionerna varierar efter valet av parametrar. Detta gör att man systematiskt kan bestämma vilka parametervärden som bör väljas för att garantera bra resultat samtidigt som exekveringstid hålls nere. Våra resultat visar att med våra förbättringar sänkes exekveringstiden med en faktor av omkring nio och förutsägelseförmågorna höjdes med en faktor av tre. Vi hoppas att vårt arbete kan leda till säkrare föutsägelser och vilket i sin tur kanske leder till en fredligare värld.

Le dernier rapport du GIEC confirme clairement des projections climatiques prévoyant une augmentation des températures et de leur variabilité à la fin du XXIème siècle. Les effets de ces changements sur la production et la qualité des fruits ont été étudiés dans le cadre du projet CAQ40(INRA). Les expérimentations menées sur des pêchers en pot placés sous différents climats (témoin,+2°C et +5°C), ont permis d’identifier les processus (phénologie, développement, croissance,photosynthèse, métabolisme) les plus sensibles à l’élévation des températures et leurs conséquences sur le développement et la composition des fruits et la pérennité de la production.L’élévation de température a augmenté la demande climatique entraînant une diminution du potentiel hydrique des arbres, ce qui a pu entrainer une concentration des composés d’intérêt dans le fruit. La réduction du taux de photosynthèse des feuilles dans des conditions de forte température est liée à une inhibition de la photosynthèse par les températures élevées et à un contrôle stomatique lié au statut hydrique.Après floraison, l’élévation de température accélère la croissance végétative, induisant une mise en place de la surface foliaire anticipée. Cette croissance végétative précoce a eu pour conséquence (i) une dynamique très rapide d’élongation des axes en pousse longue (ii) une dominance apicale plus marquée, (iii) une diminution de la ramification des axes axillaires,contrairement aux traitements thermiques plus tardifs qui ont eu un effet défavorable sur l’initiation et la différenciation des bourgeons floraux réduisant le potentiel de production l’année suivante.En outre, l’augmentation de température après floraison a entraîné un raccourcissement très marqué de la durée de croissance du fruit, avec une date de récolte anticipée de près de 3semaines. Ce raccourcissement de la durée de croissance du fruit a entraîné une diminution du flux entrant de carbone dans le fruit, pénalisant sa croissance et sa qualité. Le climat très différent entre les deux années expérimentales a entrainé une forte variabilité de la composition des fruits entre les deux années d’expérimentation. En 2014, une élévation de température précoce ou continue a conduit à récolter des fruits de petites tailles ayant des concentrations et des teneurs en saccharose plus importantes. En 2015, la durée de développement entre floraison et maturité était encore plus courte qu’en 2014 ce qui pouvait être lié au climat plus chaud de 2015 et les fruits ont été moins sucrés et plus acides que ceux de 2014. Toutefois, l’élévation des températures en fin de développement en 2015 a augmenté les teneurs et les concentrations en hexoses et en sorbitol liées à un effet concentration mais également à un effet sur le métabolisme. L’élévation des températures en milieu et en fin de cycle a également favorisé l’accumulation d’acide malique et citrique. Les fortes températures n’ont pas eu beaucoup d’effet sur la vitamine C et ont soit augmenté ou diminué les teneurs en composés phénoliques. Les effets d’une élévation de la température sur le métabolisme sont donc très dépendants du stade de développement du fruit.L’utilisation de modèle à l’échelle du fruit (Virtual Fruit) et à l’échelle de l’arbre (QualiTree)pourrait permettre de simuler à la fois l’effet de l’environnement et des pratiques culturales sur la croissance et la qualité du fruit, et donner une vision plus intégrée du fonctionnement de la plante sous contraintes environnementales
The latest IPCC report clearly confirms the climate projections for increasing temperaturesand their variability at the end of the 21st century. The effects of climate changes in fruit yield andquality have been studied in a project funded by INRA (project CAQ40, Metaprogramme ACCAF).Experiments carried out on potted peaches placed in different climates (control, +2 ° C and + 5 ° C),allowed the identification of the processes (phenology, development, growth, photosynthesis,metabolism) most sensitive to rising temperatures and their consequences on the development andcomposition of fruits and the sustainability of production.Higher temperature has increased the demand for water, leading to a decrease in the waterpotential of the trees, which may have led to a concentration of the compounds of interest in thefruit. The reduction of leaf photosynthesis under high temperature conditions was related to theinhibition of photosynthesis by high temperatures and stomatal control related to water status.After flowering, the rise in temperature accelerates the vegetative growth, triggering a more rapidestablishment of leaf area. This early vegetative growth resulted in: (i) very rapid dynamics ofelongation of the axes in long shoot (ii) a more pronounced apical dominance, (iii) a decrease in theaxillary axial branching. In contrast the later heat treatment had an adverse effect on the initiationand differentiation of floral buds reducing the production potential in the following year.In addition, the increase in temperature after flowering resulted in a marked shortening ofthe fruit growth period, with an expected harvest date almost 3 weeks earlier. This shortening offruit growth duration has led to a decrease in the flow of carbon entering the fruit, penalizing itsgrowth and quality. The very different climates between the two experimental years resulted in ahigh variability in fruit composition between the two years of experimentation. In 2014, increasedtemperature during the early stage of fruit development or continuously led to the harvest ofsmaller fruit with higher concentrations and higher sucrose content. In 2015, the time durationbetween flowering and maturity was even shorter than in 2014, which could be linked to thewarmer climate of 2015. In 2015 fruits were less sweet and acidic than those of 2014. However, therise of temperatures at the end of fruit development in 2015 increased the levels andconcentrations of hexoses and sorbitol; this increase was partially due to a concentration effect butalso to an effect on fruit metabolism. Increased temperatures in the middle and at the end of fruitdevelopment also favoured the accumulation of malic and citric acid. The high temperatures did nothave much effect on vitamin C and either increased or decreased the levels of phenolic compounds.The effects of an increase in temperature on the metabolism are therefore very dependent on thestage of fruit development.The use of a Fruit‐scale model and a tree‐level (QualiTree) model could simulate both the effect ofthe environment and cultural practices on the growth and quality of the fruit, and give a moreintegrated view of the plant's functioning under environmental constraints

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A produção de pêssego ocupa destaque entre as frutíferas de clima temperado no Brasil, sendo o Estado do Rio Grande do Sul responsável por 65 % da produção. Para obter elevada produtividade com frutos de qualidade, o pessegueiro requer adequado suprimento de água durante a primavera e o verão. Neste período, é frequente a ocorrência de déficit hídrico e a irrigação pode promover aumento de rendimento e qualidade dos frutos. Os objetivos deste trabalho foram: avaliar a resposta do pessegueiro à irrigação, quanto ao estado hídrico das plantas e a produtividade e qualidade dos frutos; determinar o manejo de água no solo mais adequado para a cultura do pessegueiro; e avaliar a influência da textura do solo no manejo da água. O estudo foi realizado em um pomar de pessegueiro comercial, cv Esmeralda, localizado no município de Morro Redondo - RS, durante as safras 2014/15, 2015/16 e 2016/17. Foram demarcadas duas áreas homogêneas em função da classe textural do solo, sendo classificadas como Franco Arenosa e Franco Argilo Arenosa. As plantas foram irrigadas por sistema de irrigação localizada por gotejamento. Os resultados mostraram que: a irrigação na fase de crescimento de fruto não influenciou a produtividade nem o tamanho dos frutos; a irrigação na fase de pós-colheita aumentou o crescimento vegetativo na safra seguinte mas não afetou a produção de frutos; os pessegueiros da área do pomar com solo franco arenoso produziram frutos maiores do que os da área com solo franco argilo arenoso; o manejo da irrigação baseado no potencial de água no ramo gera maior consumo de água, seguido pelo manejo baseado no teor de água no solo e, por último, o manejo baseado no clima
The production of peach stands out among the fruits of temperate climate in Brazil, being the State of Rio Grande do Sul (RS) responsible for 65% of the production. To achieve high productivity with quality fruits, the peach tree requires adequate water supply during spring and summer. During period, water deficit is frequent and irrigation can promote yield increase and fruit quality. The objectives of this study were to evaluate the peach response to irrigation, as the water status of plants and productivity and fruit quality; to determine the soil water management most appropriate for the peach tree; and to evaluate the influence of soil texture on water management. The study was carried out in a commercial peach orchard, cv Esmeralda, located in the municipality of Morro Redondo - RS, during the harvests of 2014/15, 2015/16 and 2016/17. Two homogeneous areas were demarcated according to the textural class of the soil, being classified as Sandy Loam and Sandy Clay Loam. The plants were irrigated by a drip irrigation system. The results showed that: irrigation in the fruit growth phase did not influence fruit productivity nor fruit size; post-harvest irrigation increased vegetative growth in the next crop but did not affect fruit production; the peach orchard area with sandy loam soil produced larger fruit than the area with sandy loam clay soil; the management of irrigation based on the water potential in the branch generates greater water consumption, followed by management based on the water content in the soil and, finally, the management based on the climate.

碩士
國立臺灣大學
園藝學研究所
87
Twenty plants of own-rooted ''Premier'' peach, propagated by semi-hardwood cuttings in the Highland Experimental Farm of National Taiwan University (Mei-Feng, Nantou County, 121''05"E, 24''08"N, 2100 ASL) July, 1996, were selected and planted in National Taiwan University Taipei on Feb.5, 1997. Trees were planted in two troughs of 45 cm deep, 70 cm wide and 9m long with sandy loam soil in it. The distance between two trees was 0.75 m.An arched type rain shelter made of white metal pipes was built, and a piece of 0.08mm thick PE film was covered from Mar. 22 to Aug. 27, 1997, and from Jan. 20 the next year.Leaf buds of newly planted peach trees broke in early Mar and the vegetative growth lasted until Oct. 21 first year. The relative growth rate of spring shoots showed two peaks, one occurred in Apr., the other in Aug. Many secondary shoots immerged just after one month of first order bud breaks. About 2-10% of first order shoots oven showed third order growth. In first year, the average trunk cross sectional area (TCA) of first year growing trees increased in at least 7-11 cm2. Leaves expanded in Mar. and didn''t fall until Jan. the next year under Taipei climatic circumstances. The 50% leaves fall period occurred between late Feb. and early Mar. Some leaves could even survive until Apr. In ordinary condition, buds of new branches without old leaves would break in mild-Mar. a little later than that in the first year due to lack of chilling in Taipei wintertime. Usually, the apical buds of bottom shoots broke earlier than those of lateral one, and new growth began in upward sequence as compared in whole canopy.Newly planted trees started to bloom on Feb. 20 the first year, and full bloom occurred on Mar. 3. Fruitlets completely dropped a month later after full bloom due to young tree''s too vigorous growth. In autumn, after shoot growth ceased, almost 85-90% floral bud formed on lateral buds which emerged from Aug. through Oct. and 35% of them were single type. Under natural Taipei situation, plants began to bloom on Mar. 15 and full bloomed on Mar. 22 the next year, both of which were later than those of first year. The rate of flowering and fruit setting were very still low, less than 10%. In the second year,some fruit could survive to grow and mature around mid Jun., 85 days after full bloom. Under high density condition, the root system of own-rooted ''Premier'' peach trees overlapped each other after one year''s growth. The root density was as high as 0.165 cm-cm3, and 96% of them were absorbing roots with diameter smaller than 3mm, of which mainly distributed in 10-20cm depth of soil.Bending current lateral shoots as early as at the beginning of 10-20cm''s growth increased 23.7% of tree height and formed a shape of slender spindle. The TCA, the number of branches and so as to the number of floral bud also increased in 22.7, 30.6, 53.8% individually. The average width of canopy was 163±10.2cm, of which looked more narrow as compared to trees of without bending.Autumn nutrient foliar spray improved tree growth by increasing 10% of TCA and 3% of floral buds.Spray lime sulphur (60 times diluted and mixed with 2% urea) in late Dec. 1997, defoliated the tree within one week, and significantly advanced bud break and bloom in 30 days as compared to the control. After one week of defoliation, spraying 50x summer oil or 3% Dormex (hydrogen cynamide) improved bud break more evenly, and flower bloomed 37 days earlier as compared to the controls, while the flowering performances were much better by using summer oil than by Dormex.

Propagating methods for peach (Prumis persica L. Batsch.) are currently limited to the use of seeds or cuttings. Most of the rootstocks commonly used for establishing peach trees commercially originate from a narrow genetic base. The most commonly used peach rootstock in South Africa is 'Kakamas', which has disadvantages such as slow growth, and a high susceptibility to certain pests and diseases. 'Kakamas' is classified as a mid to late ripening cultivar, hence, its use as a rootstock is restricted in early ripening cultivars. Optimising peach seedling and cutting production may on the other hand increase more selection material that will increase genetic variability and also serve as the basis for future production and selection of rootstocks for peach nursery establishments. Hence, this study was designed to improves success of peach cutting production by increasing the rooting percentage and the survival rate of cuttings. This was firstly achieved by the application of various concentrations of IBA and several rooting-cofactors. Secondly, rooting success of cuttings taken at different seasons was studied. The response of two cutting positions to various IBA and rooting-cofactor was evaluated. Attempts were also made to overcome the requirement of peaches for a seed stratification period by using plant growth regulators. Studies to optimise the establishment and growth of embryos of early to late ripening cultivars ('Klara', 'Oom Sarel' and' Summer Giant') in vitro were undertaken to overcome the problem of small underdeveloped embryos which are often obtained from early ripening peach cultivars. The early ripening peach cultivars 'DeWet', 'Earlibelle' and 'Florida Prince' were propagated by softwood, semi-hardwood and hardwood cuttings prepared from August 1999 to July 2000. It was found that softwood cuttings prepared in October and November responded well to an IBA application of 1000 mg 1(-1), resulting in 100 % rooting in all three cultivars. In 'Florida Prince' and 'DeWet' the rooting-cofactors chlorogenic acid and phloroglucinol at the concentration of 100ug 1(-1) yielded 77 % and 81 % rooting, respectively while quercitin and rutinin gave only 46 and 44 % rooting for all cultivars. The basal portion of the cutting rooted better than the terminal portion (78 % versus 58 %). Rooting percentage differed in all treatments in response to IBA application and rooting-cofactors 74 % for 'Florida Prince', 62 % for 'DeWet' and 54 % for 'Earlibelle'. The use of IBA and Ca-EDTA proved to be beneficial for rooting of 'Florida Prince' cuttings and resulted in a rooting percentage of 86 % in wounded hardwood cuttings of this cultivar. It was also shown that the simple sugars glucose, fructose and sucrose as well as the sugar alcohols sorbitol and mannitol accumulated at the base of the cutting during adventitious base root formation if the cutting bases were treated with 1000 mg 1(-1) IBA. The concentration of these sugars and sugar alcohols were lower in untreated cuttings compared to IBA treated cuttings during the adventitious root formation process. Studies on the origin of adventitious root formation in stem cuttings of peaches were conducted using light microscopy and transmission electron microscopy. These studies revealed that adventitious roots originate (in peaches) in the vicinity of the vascular bundle tissue and in the cells around them. It was found, however, that adventitious root formation in IBA treated cuttings is associated with the formation of root primordia. These may trigger root initiation and ultimately the development of adventitious roots. In embryo culture studies the highest number of roots and greatest length of roots per embryo as well as the highest number of embryos forming roots was achieved when either the medium of Murashige and Skoog (MS) (1962) or of Steward and Hsu (SH) (1978) were employed. The Woody Plant medium (Lloyd and McCowan, 1978) and the medium after Schenk and Hildebrandt (1972) were found to be less effective when compared to MS and SH media. Addition of GA(3) (0.01 mg 1(-1)), BAP (0.2 mg 1(-1)) or GA(3) (0.01 mg 1(-1))+ BAP (0.2 mg 1(-1))+IBA (0.5 mg 1(-1)) to the media gave the best results with respect to embryos forming roots (86 %), number of roots per embryo (8.0) and total length of roots per embryo (7.57 cm). Furthermore, the following conditions for optimal rooting of peach embryos were established: pH 5.2, 1.5 g 1(-1) agar, 60 g 1(-1) sucrose and 16h light/8h darkness photo period. Further studies on the influence of the stratification temperature on germination of embryos revealed the highest germination percentage after exposure to 40 C ±2 constantly for 30 to 60 days. However, this chilling requirement can be successfully substituted by the addition of GA(3) , kinetin, zeatin, BA and thiourea to the culture media.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.

碩士
國立臺南藝術大學
民族音樂學研究所
100
The suona piece Peach trees in Blossom originated from a Hakka ditty for male and female duets; in 2003, suona performer Kwok Chin-Chye adapted the ditty for rock version for the Hohak Band; the materials and performing effects got nice feedbacks, and thus Kowk further adapted the rock version for suona solo in 2006; the suona version was the subject of the study. The composer applied Taiwan Hakka music as materials, fusing suona and Chui-Ka art with Hakka materials, and enhanced performing power with traditional elements in an innovative way. As for music content, Peach trees in Blossom transfers vocal into instrumental music; however, vocal and instrumental music have respectively characteristics and effects, via suona, the piece is given a distinct interpretation. The study started from composer Kowk Chin-Chye’s biography and musical background, probing into the composing motive and characteristics of the piece. Next, it discussed Chui-Ka art applied in the piece, trying to figure out the audio effects and traits while imitating human taking and singing, and further made a comparison between vocal and instrumental version of the very piece. Last but not least, after interviewing composer Kowk and getting comprehension of his composing idea, the author brought up his viewpoint toward the two performing versions, and looked forwards to providing future performers with diverse aspects for digging out much more possibilities when re-creating.

碩士
國立臺灣大學
園藝學研究所
90
19 trees slender spindle trained 3-year-old own-rooted peaches (Prunus persica cv. Premier) were grown in Taipei for use in this study. The phenological performance and effects of deficit irrigation, postharvest pruning and dormancy breaking chemicals on the growth of own-rooted ‘Premier’ peach trees were investigated. There was two periods of shoot growth of ‘Premier’ peach trees in Taipei. The peak of spring shoots’ growth occurred from February to May while the peak of autumn shoots’ growth dropped in July to September. In October, the shoots stopped growing and were ready to go into dormancy. After 45 days of winter defoliation full bloom followed without chemical treatment, fruit went into a lag phase about 30 days after bloom and the lag phase sustained about 40 days. The period of fruit rapid growth followed the lag phase was about 25-30 days and was not happened at the same time with the peak of shoot growth. The growth pattern of ‘Premier’ peach fruit in Taipei was similar to that in Mingjian(名間). The lag phase of fruit growth in Meifeng(梅峰) sustained about 10 days only, the period of total fruit growth was about 105 days. In Taipei there were two full blooms: first bloom was happened from Feb.5 to Feb.15 and second bloom was from Mar.5 to May 17. The fruit growth of the second bloom was very slow and the fruit was small, and it grew slightly in the period of rapid growth. Trees received 25% Eps water in the lag phase of fruit growth (Mar.31 to Apr.26) and received sufficient water in other time grew larger and heavier fruits. These fruits gained more 18g than the fruits of the comparing treatment and had better fruit colorness, and the soluble solids reached 14 obrix. Water restriction in the rapid growth phase (Apr.26 to fruit mature) of the fruits caused the fruits small and colorless although the soluble solids reached 17 obrix. Water restriction after harvest greatly inhibited shoot growth. Total shoot length decreased about 50% after the trees received 25%Eps water. Water restriction obviously lowered the amounts of shoot and enhanced the density of flowers and not affected the amounts of flowers, numbers of fruit and yield the following year. The amounts of shoot grew from the trunk can be promoted by severe heading-back in July. Total shoot length, average shoot length and amounts of shoot were not affected by the postharvest severe pruning, but the density flowers was lowered down to 0.35±0.06 flowers per 10 cm while in the ordinary trees it reached 1.51±0.45 flowers per 10cm. Trees received selective thinning-out after harvest had higher flower density, more fruits and better yield. Selective thinning-out after harvest (in June) reduced the leave area index about 5. The canopy received better light penetration (more than 30%) at 100cm above the ground. After defoliation, full bloom of ‘premier’ peach trees began in 23 days after and had only one peak occurred if trees were sprayed with 3% dormex. It was 20 days earlier than that of check treatment. Even with no chemical treatment after defoliation, the period of bloom was very intensive also. However, summer oil spraying advanced the time of bloom about 20 days, but the period of bloom sustained almost one month, within which 2-3 peaks occurred. The fruits of trees treated with dormex matured early, and had heavier weight and more soluble solids. The fruits of the other treatments matured late, showed less fruit weight and bad flavor. The trunk cross-sectional area increased 13.35 cm2 in four years. The effect of root restriction was obvious in container cultural system.

The isotopic labelling of carbon in tree-rings varies as a function of growth season temperature and relative humidity. The isotopic labelling of oxygen in tree-rings varies as a function of source-water isotopic composition and humidity-dependent evaporative enrichment of leaf water during the growth season. The season of carbon-isotope labelling was identified statistically as late-spring to early-fall (April to October) for temperatures and relative humidity with a three-year weighted (50-30-20) carry-over due mainly to stored photosynthates. The season of oxygen-isotope labelling was identified statistically as a combination of a winter (pDecember to March) source-water signal (temperature-dependent precipitation isotope composition) with a late-spring to early-fall (April to October) humidity signal (evaporative enrichment of leaf water). A two-year carry-over was attributed to the residence time of soil water, but no notable photosynthate carry-over was identified. Carbon- and oxygen- (mechanistic) isotope response surface models were then compared and contrasted to regression-based bivariate and univariate models. It was found that in most cases the isotope response surface models were the best means of predicting isotopic labelling when environmental data are known. The carbon-isotope response surface was used to reconstruct 50-years (AD 1900-1954) of relative humidity data by introducing measured carbon isotope values and instrumental growth season temperature. During the analysis of the oxygen-isotope response surface we found an isotope-temperature relation that appears to reflect circulation-dependent damping. To verify this we introduced scaled values of the North Pacific index as a proxy for this suppression. The coupling of the isotope response surfaces generated a humidity reconstruction that is also thought to be driven by atmospheric circulation. Our reconstruction shows that the fluctuations in temperature range have not exceeded the natural variability in the instrumental record of the 20th century; however, the atmospheric moisture (humidity) reconstruction predicts a directional drying trend in the Peace-Athabasca Delta that appears to reflect increasingly zonal circulation in western Canada over this period.