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S’analitzarà la planificació d’una derrota transoceànica des de Cadis fins a Nova York tenint en compte els aspectes nàutics, d’equipament, burocràtics i les funcions que realitzen els diferents oficials de pont.

[SPA] Esta tesis doctoral se presenta bajo la modalidad de compendio de publicaciones. El tema principal de la presente tesis doctoral es el estudio de la viabilidad de la utilización de los indicadores de estado hídrico del cultivo como herramienta para la programación de riego deficitario controlado de nectarinos tempranos. En esta línea se realizaron cinco ensayos: Utilidad del uso de las líneas de referencia de la fluctuaciones de diámetro de tronco y el potencia hídrico de tallo para la programación del riego de nectarino temprano Se realizó un estudio durante tres años en nectarino temprano (cv Flanoba). El objetivo fue estudiar líneas de referencia con las que estimar valores del potencial hídrico de tallo al mediodía (ΨT), tasa de crecimiento diaria de tronco (TCD) y máxima contracción diaria de tronco (MCD), en condiciones no limitantes de agua en el suelo a partir de diferentes variables meteorológicas. MCD presentó el mejor ajuste con el déficit de presión de vapor en el periodo comprendido entre las 11:00 y las 15:00 hora solar, periodo en el que la contracción del tronco era más rápida. Se discute el hecho de la baja correlación de MCD con ET0. Las ecuaciones eran diferentes para cada periodo fenológico pero estables en los tres años de estudio. Un nuevo enfoque para evaluar la sensibilidad de los indicadores de estado hídrico de la planta en nectarino temprano Se evaluó la sensibilidad de diferentes indicadores de estado hídrico de la planta (MCD, TCD, ΨT, conductancia estomática –Gs- y fotosíntesis neta –Pn-) durante la poscosecha de nectarinos tempranos (cv Viowhite). Se propuso un tratamiento control (TCTL), regado a 120% de la evapotranspiración del cultivo a fin de evitar condiciones limitantes de agua en el suelo, y un tratamiento deficitario (TD), regado al 50% de TCTL. Las mayores intensidades de señales (IS, relación de los valores de TD y TCTL) fueron alcanzadas por TCD, Gs y Pn (2.6, 3 y 2.9, respectivamente): Sin embargo, la sensibilidad (S) – calculada a partir de la relación entre IS y el coeficiente de variación (CV) de las medidas – fue mayor en ΨT y MCD (14 y 11.4 respectivamente) debido a que los CV fueron menores (11 y 14%, respectivamente). Un nuevo enfoque (S*) se propone para calcular la sensibilidad de los indicadores de estado hídrico de la planta, ya que el método estándar puede presentar valores altos de sensibilidad sin que dicho indicador presente diferencias entre tratamientos de riego. Establecimiento de un protocolo de programación del riego deficitario a partir de indicadores de estado hídrico de la planta en nectarino temprano El experimento realizado en nectarino temprano (cv Flanoba) se prolongó durante tres años (2009-2012). Se evaluaron diferentes metodologías de programación del riego llevadas a cabo en 3 tratamientos: un control (TCTL, regado sin condiciones limitantes de agua en el suelo); un tratamiento basado en la práctica habitual del agricultor (TFINC); y un tratamiento de riego deficitario controlado (TRDC), con el mismo riego que TCTL durante los periodos críticos del primer año y al 60% de TCTL durante la poscosecha de este mismo año. En los dos años posteriores, este tratamiento fue programado para mantener una IS de MCD con diferentes niveles de estrés (IS=1 durante los periodos críticos y IS =1.4 y 1.5 durante la poscosecha de 2010 y 2011, respectivamente). Los valores de IS obtenidos se ajustaron a los valores umbral durante gran parte del periodo de estudio. Los parámetros productivos no presentaron diferencias significativas entre tratamientos de riego. La disminución de agua aplicada en TRDC fue del 17, 15 y 37% respecto al riego aplicado en TCTL en los tres periodos de estudio. En contra, TFINC aplicó más agua (20 y 5% más que TCTL) durante los dos primeros años y un 10% menos que TCTL durante el tercer año. Las contracciones tempranas de diámetro de tronco son altamente sensibles al estrés hídrico de nectarinos La sensibilidad de diferentes indicadores de estado hídrico del cultivo fue evaluada durante dos años consecutivos. Los indicadores de estado hídrico estudiados fueron: ΨT, indicadores tradicionales derivados de las fluctuaciones de diámetro de tronco (MCD y TCD) y dos nuevos indicadores propuestos por primera vez en este trabajo (contracción temprana del tronco –EDS- y contracción tardía del tronco -LDS-). Las medidas se realizaron durante la poscosecha en un tratamiento control (TCTL, regado sin condiciones limitantes de agua en el suelo) y en un tratamiento de riego deficitario (TD, con déficit hídrico variable que promedió una reducción de riego de 37% respecto a TCTL). Los indicadores más sensibles fueron ΨT y EDS. IS fue mayor en EDS que en ΨT pero este último tenía CV menores. A diferencia de MCD, EDS presentó relaciones lineales con ΨT y mantuvo la sensibilidad al final del periodo de poscosecha. Efecto combinado del déficit hídrico y la carga productiva en nectarino temprano Durante tres años se evaluó el efecto del déficit hídrico y diferentes cargas productivas en el crecimiento vegetativo, el estado hídrico del cultivo, la producción y la calidad de la cosecha. Los parámetros productivos y de calidad no presentaron diferencias claras entre tratamientos de riego en ninguna de las cargas frutales estudiadas. Solamente la firmeza se vio reducida en TCTL cuando los niveles de carga frutal fueron bajos. Como era de esperar, TRDC presentó mayor eficiencia en el uso del agua (EUA) y menor crecimiento vegetativo. La relación entre la producción y el incremento anual de sección transversal de tronco se incrementó en TRDC respecto a los otros tratamientos conforme avanzaba el experimento, alcanzando diferencia del 53%. [ENG] This doctoral dissertation has been presented in the form of thesis by publication. The main topic of the present doctoral thesis is the study of the viability of the use of indicators of water status of the crop as a tool for the scheduling of regulated deficit irrigation of early nectarines. In this way, five trials were carried out: Feasibility of using trunk diameter fluctuation and stem water potential reference lines for irrigation scheduling of early nectarine trees A three-year experiment on early nectarine trees (cv. Flanoba) was carried out with the aim of studying the impact of environmental variables on the trunk diameter fluctuation parameters and the usefulness of the reference-lines derived from the relationship between different meteorological variables and plant water status indicators for sustainable irrigation scheduling. Plants were drip-irrigated and submitted to non-limiting soil water conditions. Measurements of stem water potential at midday (Ψstem), trunk daily growth rate (TGR) and maximum daily trunk shrinkage (MDS) were related with meteorological variables. MDS presented the best fitting line-regressions with both the average air temperature and vapour pressure deficit during the period 11.00–15.00 h solar time, since the most important fraction of trunk shrinkage occurred during that period of time, reaching 74% of MDS (on average over the three years studied), and sometimes 90%. Despite the continuous trunk growth of the trees during the experimental period and slight difference in crop load, inter-annual differences were not observed for the three reference lines obtained in any given year (fruit growth, early and late postharvest period). A new approach to ascertain the sensitivity to water stress of different plant water indicators in extra-early nectarine trees The sensitivity to water stress of different plant water indicators was evaluated during the late postharvest period of extra-early nectarine trees growing in a commercial orchard and submitted to two irrigation treatments: (i) a control (TC), irrigated at 120% of crop evapotranspiration, and (ii) a water deficit treatment (TD), irrigated at 50% of TC. The plant indicators studied were: MDS, TGR, Ψstem, leaf conductance (Gs); and net photosynthesis (Pn). Although the highest signal intensity (SI) values -the ratio of deficit irrigation treatment values to control values- were reached by TGR, Gs and Pn (2.6, 3 and 2.9, respectively), the sensitivity (S) values calculated as the ratio of SI to coefficient of variation (SI CV−1) were higher in Ψstem and MDS (14 and 11.4, respectively), since their CV values were the lowest (11 and 14%, respectively). A new approach (S*) is proposed to calculate the sensitivity of the plant water indicators, since the standard method can result in high sensitivity values without identifying differences between irrigation treatments. While S is more influenced by the CV values, S* would be influenced by both the SI and CV values. Implementing deficit irrigation scheduling through plant water stress indicators in early nectarine trees A three-year experiment on early nectarine (cv. Flanoba) trees was carried out with the aim of increasing water use efficiency through applying a sustained irrigation treatment. Experiments compared irrigation scheduling using conventional micrometeorology (110% of crop evapotranspiration, ETc) as a control treatment (TCTL), a treatment based on the normal practice of the farmer (TFINC) and a regulated deficit irrigation treatment (TRDI), which involved irrigating the crop at the same level as the control (TCTL) during the critical periods of the first year (second rapid fruit growth period and 2 months after harvest) and at 60% TCTL during postharvest. In the last two years (2010 and 2011), the irrigation was scheduled 20 to maintain SI of the maximum daily shrinkage of the trunk at different water stress levels depending on the phenological stage SI = 1.0 (non-water stress) and SI = 1.4 (moderate water stress). Most of the time that irrigation scheduling was based on MDS SI, this parameter varied only slightly around the pre-established threshold values. The information given by the stem diameter sensors and stem water potential (Ψstem) gave -1.5 MPa and MDS SI 1.5 as threshold values not to be exceeded during postharvest, since MDS and Ψstem SI values were only linear down to 1.5. The water saved amounted to 17, 15 and 37%of the amount used in the control in the three seasons, respectively. In contrast, the TFINC treatment applied more water (about 20 and 5% more than TCTL) during the first 2 years, and 10% less than TCTL during the third season. Early morning fluctuations in trunk diameter are highly sensitive to water stress in nectarine trees The sensitivity to water stress of different plant water status indicators was evaluated during two consecutive years in early nectarine trees. Measurements were made post-harvest and two irrigation treatments were applied: a control treatment (CTL), irrigated at 120 % of crop evapotranspiration, and a deficit irrigation treatment, that applied around 37 % less water than CTL during late postharvest. The plant water status indicators evaluated were Ψstem) and indices derived from trunk diameter fluctuations (MDS and TGR) and early daily shrinkage measured between 0900 and 1200 hours solar time (EDS), and late daily shrinkage (LDS) that occurred between 1200 hours solar time and the moment that minimum trunk diameter was reached (typically 1600 hours solar time). The most sensitive [highest ratio of signal intensity (SI) to noise] indices to water stress were Ψstem and EDS. The SI of EDS was greater than that of Ψstem, although with greater variability. EDS was a better index than MDS, with higher SI and similar variability. Although MDS was linearly related to Ψstem down to -1.5 MPa, it decreased thereafter with increasing water stress. In contrast, EDS was linearly related to Ψstem, although the slope of the regression decreased as the season progressed, as in the case of MDS. Further studies are needed to determine whether EDS is a sensitive index of water stress in a range of species. Combined effects of deficit irrigation and crop level on early nectarine trees A three-year long experiment was implemented in an early nectarine (cv. Flanoba) commercial orchard to evaluate the effects of deficit irrigation and different crop levels on vegetative growth, plant water status, and fruit yield and quality. Three irrigation treatments were assessed: (i) control, (TCTL); (ii) normal practice of the farmer (TFRM); and (iii) regulated deficit irrigation (TRDI). Besides, during the last two seasons, the interactions between TCTL and TRDI were studied at five different crop levels, which were obtained by controlling the distance between fruits left on the branches: from very low (16 cm between fruits) to very high (8 cm between fruits). Crop water use efficiency (WUE) of TRDI was higher than in TCTL and TFRM, increasing by around 25% in 2010 and 2011, and around 74% the final year. Interestingly, TFRM increased the WUE from the first year by more than 30%. The yield/annual increase in trunk-cross-sectional area (TCSA) ratio increased in TRDI with respect to the other treatments as the experiment progressed, reaching differences of 53%. Vegetative growth was clearly sensitive to deficit irrigation with a strong correlation between the increase in the water stress integral obtained by midday stem water potential (Ψstem) and the reduction in TSCA. In contrast, fruit production and quality were not affected by water deficit. As regards the interaction between crop level and water deficit, fruit firmness was the only fruit quality parameter studied that presented significant differences, the highest values corresponding to the fruits from TRDI trees and the lowest crop level. Frutas Esther S.A. Las referencias de las publicaciones son las siguientes: Artículo 1.- Feasibility of using trunk diameter fluctuation and stem water potential reference lines for irrigation scheduling of early nectarine trees. De la Rosa, JM., MR Conesa, R. Domingo, R. Torres, A. Pérez-Pastor. 2013. Agricultural Water Management 127: 31-39. Artículo 2.- A new approach to ascertain the sensitivity to water stress of different plant water indicators in extra-early nectarine trees. De la Rosa, JM., Conesa MR., Domingo, R., Pérez-Pastor A. 2014. Scientia Horticulturae 169, 147-153. Artículo 3.- Implementing deficit irrigation scheduling through plant water stress indicators in early nectarine trees. De la Rosa, JM., Domingo, R., Pérez-Pastor A. 2015. Agricultural Water Management 152: 207-216. Artículo 4.- Early morning fluctuations in trunk diameter are highly sensitive to water stress in nectarine trees. De la Rosa, JM., IC. Dodd., Domingo, R., Pérez-Pastor A. 2016. Irrigation Science 34: 117-128. Artículo 5.- Combined effects of deficit irrigation and crop level on early nectarine trees. De la Rosa, JM., Conesa MR., Domingo, R., Aguayo, E., Falagan, N., Pérez-Pastor A. 2016. Agricultural Water Management 170: 120-132. Escuela Internacional de Doctorado de la Universidad Politécnica de Cartagena Universidad Politécnica de Cartagena Programa de Doctorado en Técnicas Avanzadas en Investigación y Desarrollo Agrario y Alimentario por la Universidad Politécnica de Cartagena

Dado el elevado coste de las versiones comerciales, el objetivo principal de este proyecto es el diseño y desarrollo de una cámara de cultivo de bajo coste para estudiar el crecimiento de las plantas de forma controlada. En concreto, será necesario diseñar tanto el habitáculo de la cámara, así como todos los componentes hardware y software para su correcto funcionamiento. Esto implica que dentro del objetivo principal tendremos una serie de objetivos secundarios para cumplirlo: - Diseño y desarrollo del habitáculo de la cámara de cultivo utilizando componentes de bajo coste. - Diseño, integración y desarrollo de todos los componentes hardware necesarios. - Diseño y desarrollo de los componentes software de control de la cámara, así como la interfaz de la misma. Escuela Técnica Superior de Ingeniería Industrial Universidad Politécnica de Cartagena

Mención Europeo / Mención Internacional: Concedido [SPA] Esta tesis doctoral se presenta bajo la modalidad de compendio de publicaciones. La tesis estudia el funcionamiento hídrico del cerezo a partir del empleo de diferentes estrategias de riego y técnicas de cultivo. Para ello, se evaluaron las respuestas agronómica y fisiológica del cultivo y se estudiaron y compararon diferentes indicadores del estado hídrico del continuo suelo, planta, atmósfera con el fin último de aumentar la productividad del uso de agua. [ENG] This doctoral dissertation has been presented in the form of thesis by publication. The global sweet cherry production has sharply increased in the last decades. As consumer interest in this seasonal fruit keeps growing, growers from areas where cherries have not been traditionally cultivated exhibit interest and consider its cultivation due to a demand exceeding the offer. These new areas are interested in extending sweet cherry season and providing high quality fruit when there is a low supply on the market. To achieve these goals, it has been necessary to adopt new orchard systems, new cultivar/rootstock combinations adapted to different edaphoclimatic conditions, and drip irrigation systems. Los artículos que componen la tesis son los siguientes:: Artículo I. Blanco, V., Domingo, R., Pérez-Pastor, A., Blaya-Ros, P.J., Torres-Sánchez, R., 2018. Soil and plant water indicators for deficit irrigation management of field-grown sweet cherry trees. Agricultural Water Management, 208:83-94. DOI: 10.1016/j.agwat.2018.05.021. Artículo II. Blanco, V., Martínez-Hernández, G.B., Artés-Hernández, F., Blaya-Ros, P.J., Torres-Sánchez, R., Domingo R., 2019. Water relations and quality changes throughout fruit development and shelf life of sweet cherry grown under regulated deficit irrigation. Agricultural Water Management, 217:243-254. DOI: 10.1016/j.agwat.2019.02.028. Artículo III. Blanco, V., Torres-Sánchez, R., Blaya-Ros, P.J., Pérez-Pastor, A., Domingo, R., 2019. Vegetative and reproductive response of ‘Prime Giant’ sweet cherry trees to regulated deficit irrigation. Scientia Horticulturae, 249:478-489. DOI: 10.1016/j.scienta.2019.02.016. Artículo IV. Blanco, V., Zoffoli, J.P., Ayala, M., 2019. High tunnel cultivation of sweet cherry (Prunus avium L.): physiological and production variables. Scientia Horticulturae, 251:108-117. DOI: 10.1016/j.scienta.2019.02.023. Escuela Internacional de Doctorado de la Universidad Politécnica de Cartagena Universidad Politécnica de Cartagena Programa de Doctorado en Técnicas Avanzadas en Investigación y Desarrollo Agrario y Alimentario por la Universidad Politécnica de Cartagena

Mención Europeo / Mención Internacional: Concedido [SPA] La investigación de la tesis doctoral en curso se ocupa de la evaluación de la respuestas agronómicas y fisiológicas de madura la uva de mesa madura cv. 'Carmesí Seedless 'a secado parcial de la zona raíz (PRD) y el riego deficitario controlado (RDC) con respecto a otros tratamientos de riego que recibieron diferentes cantidades de agua aplicada. Con este fin, se establecieron cuatro tratamientos de riego: (i) Control, que recibe el 110% de la evapotranspiración del cultivo estándar, ETC, a lo largo toda la estación de crecimiento, siguiendo los criterios de la granja comercial; (ii) RDI tratamiento, regadío similar a los niveles de control durante la pre-envero y en el 50% de la misma durante post pinta (considerado el período no crítico); (iii) PRD tratamiento, regado de una manera similar a la IDI pero alternando (cada 10-14 días) las partes secas y húmedas de la zona radicular, dependiendo de déficit de agua con respecto a capacidad de campo; y (iv) un tratamiento de riego null (NI), que sólo recibió la precipitación natural y riego suplementario ocasional cuando el mediodía el potencial hídrico del tallo (ψs) superó -1.2 MPa. Para establecer ecuaciones de referencia Se utilizó otro tratamiento de riego completo (110-115% ETc). Además, el resultados se extrapolaron a un experimento en macetas con el fin de determinar la el comportamiento fisiológico de este cultivar, bajo condiciones controladas en una invernadero. [ENG] The research of the current PhD Thesis deals with the evaluation of the agronomic and physiological responses of mature table grapes cv. ‘Crimson Seedless’ to partial root-zone drying (PRD) and regulated deficit irrigation (RDI) with respect to other irrigation treatments that received different amounts of water applied. To this end, four irrigation treatments were established: (i) Control, receiving 110 % of crop standard evapotranspiration, ETC, throughout the whole growing season following the criteria by the commercial farm; (ii) RDI treatment, irrigated similar to Control levels during pre-veraison and at 50% of the same during post-veraison (considered the non-critical period); (iii) PRD treatment, irrigated in a similar way to RDI but alternating (every 10-14 days) the dry and wet sides of the root-zone, depending on water deficit with respect to field capacity; and (iv) a null irrigation treatment (NI) which only received natural precipitation and occasional supplementary irrigation when the midday stem water potential (ψs) exceeded -1.2 MPa. To establish reference equations another full irrigation treatment (110-115% ETc) was used. Furthermore, the results were extrapolated to a pot experiment in order to determine the physiological behavior of this cultivar, under controlled conditions in a greenhouse. Chapter I analysed the yield response and chemical quality to long-term deficit irrigation (DI) strategies. No significant differences were found between PRD and RDI with respect to well-watered vines irrigated according to ETc, thus the application of a greater amount of water was not essential for plant behavior and berry development in ‘Crimson Seedless’ table grapes. Both PRD and RDI treatments supposed a water saving of 35% without compromising total yield and its components. Only NI (which received 72% less water than Control) led to a reduction in yield and the weight of clusters/berries compared with the other irrigated counterparts. Water use efficiency was also increased in all DI treatments as many water restrictions were assessed. Regarding chemical berry quality, all deficit irrigation treatments increased berry coloration (evaluated subjectively and objectively) which is considered the main issue of this variety for its marketability. Despite the fact that RDI and PRD received the same amount of annual water applied, PRD induced a greater accumulation of skin anthocyanins, resveratrol and antioxidant capacity. Although PRD did not show significant changes in yield response with respect to RDI, the fact that PRD increased the main bioactive compounds analysed that are beneficial to health, underlined the feasibility of the implementation of this strategy by growers. Chapter II focused on the long-term impact of DI strategies on physical berry quality, with particular attention to the berry firmness, since it is one of the most important characteristics in order to be marketed and for consumer acceptance. Moreover, the storage performance to ascertain the potential shelf-life of this cultivar was reported. RDI and PRD did not noticeably affect physical berry quality after cold storage while the subsequent shelf-life period tended to minimise the difference found at harvest or at the end of cold storage. Furthermore, NI treatment showed the worst sensory scores post-harvest and the most dehydrated clusters and lower berry size. In fact, sensory results were similar in RDI and PRD, which provided grapes that were more acceptable to consumers than well-irrigated vines, mainly due to lower stem browning and higher berry coloration. Remarkably, PRD registered the highest berry shattering, which was correlated with the lower concentration of ABAxylem induced by the grower’s strategy. Thus, the results obtained in Chapters I and II indicate that it is possible to decrease irrigation by applying RDI and PRD to ‘Crimson Seedless’ table grapes without adversely affecting yield and the physicochemical berry quality. The physiological response and vegetative growth to DI strategies were described in Chapter III. The analysis of the physiological fluxes (net CO2 assimilation, ACO2 and transpiration rate, E) and their characteristic attributes (stomatal conductance, gs) determined at leaf scale, under saturating-light conditions, showed a water stress response in accordance to the water stress severity imposed, regardless of irrigation strategy. Comparing post-veraison strategies, PRD induced higher plant and soil water deficit levels than RDI. Nevertheless, PRD neither significantly reduced gs nor increased ABAxylem against expectations. These results suggest a greater root development and root density from PRD with respect to RDI for water uptake. As expected, vegetative parameters were adversely affected by the severe deficit reached in NI, while the leaf area index was also modified by PRD. Principal components analysis (PCA) results showed that inter-annual differences detected between irrigation treatments were higher than those observed between phenological periods, especially when RDI and PRD were compared. Furthermore, maximum daily shrinkage (MDS) was the best plant-water status indicator to ascertain irrigation differences before veraison, whereas other conventional plant water status indicators (such as water potential and transpiration rate, E) might be considered for irrigation scheduling during post-veraison. Different reference lines appeared in Chapter IV from plant water status indicators such as MDS and ψs indicators were obtained during pre and post-veraison periods, respectively, for irrigation scheduling in well-irrigated table grapes cv. ‘Crimson Seedless’. In this sense, MDS and ψs showed better adjustment with mean temperature (Tm) during pre-veraison, while after veraison reference crop evapotranspiration (ET0) and vapour pressure deficit can also be used. The correlation coefficients in MDS decrease during post-veraison due to changes of stem transpiration, the presence of sugar-demanding sinks and the accumulated ABAxylem. Besides this, under commercial conditions, water savings with respect to conventional scheduling based on ETc were achieved when the irrigation scheduling was done using SIMDS around unity (in pre-veraison) and maintaining ψs as a threshold value in well-watered vines (in post-veraison). Moreover, in this Chapter we also observed that some standard cultural practices such as girdling and the collocation of hail mesh to prevent torrential rainfalls might also modify vine water status. From a physiological point of view, the results obtained were extrapolated to a pot experiment in Chapter V. Table grapes showed a substantial loss of photosynthetic capacity as the season progressed both growing in the field (as shown in Chapter III) and in a pot experiment (Chapter V). Crimson Seedless displayed different responses to DI strategies, depending on the diurnal course. At predawn (t1) and early morning (t2), the cultivar showed near-anisohydric behavior, through a less effective stomatal control of drought, whereas at midday (t3), the behavior was near-isohydric. In addition to this, water stress conditions induce avoidance mechanisms to drought, such as stomatal closure, partial defoliation and a reduction in leaf insertion angle. Analysis of the vegetative response does not indicate that PRD vines respond differently, or present a clear distinct adaptive mechanism to water stress with respect to RDI vines. In fact, pruning dry weight was only affected by severe water deficit (NI). Universidad Politécnica de Cartagena Programa Oficial de Doctorado en Técnicas Avanzadas en Investigación y Desarrollo Agrario y Alimentario

Con el objeto de conocer el efecto del déficit hídrico sobre las relaciones hídricas, producción y calidad de la cosecha, así como comparar los diferentes tipos de regímenes de riego utilizados, se realizó un ensayo durante el año 2014, en una parcela comercial de uva de mesa cv. “Crimson Seedless”. Para ello, se aplicaron cinco tratamientos de riego: (i) control (CTL) regado al 110% de la evapotranspiración del cultivo (ETc), (ii) riego deficitario controlado (RDC) regado al 50% del CTL durante el periodo no-crítico de postenvero, (iii) riego deficitario continuado (RDc), regado al 50% del CTL durante toda la estación de crecimiento de la baya, (iv) desecación parcial del sistema radicular (DPR), riego similar a RDC, pero alternando el riego en cada una de las dos mitades en las que se puede dividir el sistema radicular (cada 10-14 días), (v) desecación parcial del sistema radicular continuado (DPRc), similar a RDc pero alternando el riego en cada una de las dos mitades en las que se puede dividir el sistema radicular (cada 10-14 días). Las reducciones de agua aplicada con respecto a CTL fueron de un 24% y de un 28% para los tratamientos de RDC y DPR (riego deficitario moderado), respectivamente. Por su parte, estas reducciones fueron de 65% y del 53% para los tratamientos de RDc y DPRc (riego deficitario severo), respectivamente. La producción total y sus componentes no resultaron afectadas por el efecto del déficit hídrico, sólo se observaron valores significativamente menores en el peso y altura de baya. Sin embargo, los parámetros de color evaluados (e.g. Tono) se incrementaron en todos los tratamientos deficitarios, siendo este incremento mayor en los riegos deficitarios severos (RDc y DPRc), respecto a aquellos que tuvieron en cuenta el periodo crítico de pre-envero (en este caso, RDC y DPR, tratamientos deficitarios controlados). Asimismo, los sólidos solubles totales (SST) fueron significativamente superiores en RDc, respecto al resto de tratamientos de riego. Por todo ello, los tratamientos de riego deficitario severos RDc y DPRc, pueden ser una opción a tratar en este cultivar. De hecho, parece destacar un efecto positivo de RDc frente a DPRc, sin embargo, estos resultados corresponde a un primer año de ensayo, por lo que serán necesarios más años de estudio para poder ratificar esta tendencia. Escuela Técnica superior de Ingeniería Agronómica Universidad Politécnica de Cartagena

[SPA] El Máster de Técnicas Avanzadas en Investigación y Desarrollo Agrario y Alimentario, tiene como principal objetivo la formación de investigadores en el ámbito del desarrollo agrario y alimentario, pues todos los indicadores actuales muestran que es necesario un aumento de la masa crítica de investigadores en éste área en la UE; a pesar de que la agricultura, desde la fase de producción hasta la de procesado y fabricación tiene un campo muy amplio en el que se puede investigar e innovar, existen determinadas herramientas horizontales de trabajo que permiten formar alumnos con unas capacidades técnicas excelentes y de aplicación a ámbitos tan variados como el medio ambiente, genética y mejora animal y vegetal, procesado de alimentos o control de las plagas. Estos antecedentes nos han llevado a formular un programa de Máster que tiene cuatro módulos definidos, uno de cursos metodológicos y tres de cursos fundamentales. [ENG] The Master in Advanced Techniques in Agricultural and Food Research and Development intends to introduce university students into the research in such field. The programme is based on research carried out by the Higher Technical School of Agriculture Engineer on the one hand, and on the other hand on the technological development of the Spanish agricultural and food sector. This Master programme has as its main goal the qualifying of researchers in the area of agricultural and food development, since all the present indicators point at the need for an increase in the critical mass of researchers in this area in the EU; despite the fact that agriculture, from production to processing and manufacturing, is a wide field in which to research and innovate. There exist some horizontal tools that allow us to train students with excellent technical skills, and that can be applied to a wide range of areas such as environment, genetics, animal and vegetal improvement, food processing or pest control. On these grounds we have been led to draw up a Master programme that has four clearly defined modules: one with methodology courses and three with basic courses. The students who follow the proposed Master programme should become university experts in research and development in the agricultural and food field. [ENG] The Master in Advanced Techniques in Agricultural and Food Research and Development intends to introduce university students into the research in such field. The programme is based on research carried out by the Higher Technical School of Agriculture Engineer on the one hand, and on the other hand on the technological development of the Spanish agricultural and food sector. This Master programme has as its main goal the qualifying of researchers in the area of agricultural and food development, since all the present indicators point at the need for an increase in the critical mass of researchers in this area in the EU; despite the fact that agriculture, from production to processing and manufacturing, is a wide field in which to research and innovate. There exist some horizontal tools that allow us to train students with excellent technical skills, and that can be applied to a wide range of areas such as environment, genetics, animal and vegetal improvement, food processing or pest control. On these grounds we have been led to draw up a Master programme that has four clearly defined modules: one with methodology courses and three with basic courses. The students who follow the proposed Master programme should become university experts in research and development in the agricultural and food field. Máster TAIDA

[ESP] Con el objetivo de optimizar el manejo del riego en mandarino y almendro, dos cultivos leñosos relevantes en la Región de Murcia, se desarrollaron dos ensayos, uno durante tres años en una explotación comercial de mandarinos cv. Fortune regados con una mezcla de agua procedente del trasvase Tajo-Segura y de pozo, cuya conductividad eléctrica (CE25ºC) varió en función de la disponibilidad de agua del trasvase, alcanzándose valores constantes ligeramente por encima de 4 dS m-1 durante el segundo y tercer año. El otro, durante dos años, en almendros cv. Marta regados con agua del trasvase Tajo-Segura, sin problemas de salinidad. En mandarino, se delimitó de forma precisa con la ayuda de los dendrómetros la aplicación del déficit hídrico durante la fase II del crecimiento del fruto, de modo que la restitución del riego a niveles del control coincidiría con el inicio de la ralentización del crecimiento del tronco, prolongándose el déficit hídrico durante los meses de verano. La salinidad del agua de riego en los dos últimos años no tuvo un efecto negativo en las producciones obtenidas en el tratamiento control (59,5 kg arbol-1), en cambio, sí redujo su crecimiento vegetativo. El tratamiento RDC (regado al 65 y al 50% del control en la primera (2005-06) y las dos últimas campañas (2006-08), respectivamente, y al 80% en la fase III) mantuvo niveles de producción similares a los del control en los dos primeros años, con ahorros de agua del 8 y 36%, sin embargo, el tercer año se redujo un 63%, debido a la disminución del número de frutos por árbol, mostrándose la interacción negativa del riego deficitario controlado y la salinidad. En almendro se observó la posibilidad de programar el riego en base a la intensidad de señal (IS) procedente de la MCD. La programación realizada cada 3 días consiguió ajustar mejor IS al valor deseado, con variaciones en los volúmenes de agua inferiores a los realizados cuando el programa se ajustó semanalmente. Por otro lado, se ha visto la necesidad de prestar especial atención al cambiar el valor umbral de IS, sobre todo durante la fase V, donde una vez restituido el riego, la respuesta adaptativa del cultivo al estrés hídrico propició valores de crecimiento muy superiores al control. La programación del riego deficitario controlado basado en la dendrometría resultó ventajosa sobre la tradicional al conseguir un control más idóneo del estado hídrico de la planta que penalice en menor medida el crecimiento vegetativo, y por consiguiente una repercusión menos negativa en las cosechas siguientes. Entre los indicadores del estado hídrico de la planta estudiados en ambos cultivos (¿t, TCD, MCD), la máxima contracción diaria del diámetro de tronco (MCD) resultó el más idóneo en el establecimiento de líneas de referencia para la programación del riego debido a su respuesta lineal y buena correlación con la temperatura (mandarino, r2>0,7***) y el déficit de presión de vapor (almendro, r2>0,8***). En el mandarino, la comparación de las correlaciones de los dos años de estudio (2005 y 2006) no mostró diferencias entre ellas a pesar del incremento de salinidad y la disminución en la carga productiva que se produjo en el segundo año, además, se observó un mejor valor predictivo de las líneas obtenidas con valores del periodo comprendido entre marzo y octubre (Fases I y II del crecimiento del tronco), que coinciden con el periodo de máximos requerimientos hídricos del cultivo. Del mismo modo, el estudio por fases fenológicas en almendro mostró diferencias significativas entre las líneas de referencia de los dos años de estudio (2006 y 2007) en el periodo correspondiente a las fases II-III, pero no entre este periodo y las siguientes fases. Por lo que la línea de referencia obtenida en este periodo podría ser utilizada para la programación del riego en el resto del ciclo. [ENG]The overall aim of this Doctoral Thesis was to optimize irrigation management in mandarin and almond trees, two relevant fruit trees in the Region of Murcia, according to plant-based water indicators. Two tests were developed for this purpose: i) another one for three years in a commercial orchard of mandarin cv. 'Fortune' and ii) other one, for two years in almond cv. 'Marta'. The mandarin trees were watered with a mixture of water from the Tajo-Segura transfer and from well, whose electrical conductivity (EC25°C) varied depending on the availability of water transfer, reaching constant values slightly higher than 4 dS m-1 during the second and third year of testing. Meanwhile the almond trees were irrigated with water from the Tajo-Segura transfer, without salinity problems. In the mandarin experiment four irrigation treatments were compared: i) Control (CTL), irrigated at 100% ETc, applying a leaching requirements of 33% from the second year. ii) Regulated deficit irrigation (RDI), watered as CTL except for phase I and beginning of the phase II of the fruit growth where it was irrigated at 65 and 50% of CTL in the first (2005-06) and the last two seasons (2006-08) respectively, and 80% in phase III. iii) RDI50, watered to 50% of RDI during the deficit period in 2006-07 and 2007-08 seasons and the rest of season like CTL. iv) FARM, scheduled by the farmer, who applied by about 50% of CTL during phases I and II and watered over CTL (170-200% CTL) from the end of phase II until the end of the irrigation season. The length of the less sensitive period to the water deficit in the phase II of the fruit growth was delimited by LVDT sensors in a precise way. So that the restitution of the irrigation at control levels coincided with the start of slowing trunk growth, extending the water deficit during the summer months. The salinity of the irrigation water over the last two years did not have a negative effect on the yields obtained in CTL (59.5 kg tree-1), however, it reduced its vegetative growth. RDI50 and FARM yields decreased in the second and third year of study. RDI maintained similar yield levels than CTL in the two first harvests, with water savings of 8 and 36%. However, in the third year, the obtained yield was 37% of CTL, due to the decreasing in crop load, showing a negative interaction between deficit irrigation and salinity. In the almond experiment four irrigation treatments were compared: i) Control (CTL), irrigated at 110% ETc in order to avoid limiting conditions of soil water; ii) traditional regulated deficit irrigation (RDIt), irrigated at 100% ETc, except during phase IV (≈ June-mid August) when trees received 30% ETc; iii) continuous deficit irrigation based on MDS (RDd), irrigated to maintain the signal intensity (SI = MDSRDd / MDSCTL) around 1.1 throughout the irrigation season and iv) deficit irrigation based on MDS (RDCd), irrigated to maintain SI (MDSRDCd / MDSCTL) between 1 and 1.1, except for phase IV, which was 1.4. The main result in this assay was the ability to schedule irrigation in almond based on SI. When scheduling took place every 3 days it got better adjusted to the desired SI, with minor variations in the water supplied, than the results obtained when the program was adjusted once a week. On the other hand, it has been seen the need to pay special attention when changing the threshold value of SI as observed in RDCd, specially during phase V, where once irrigation was restored, the adaptive response of the crop to water stress led to values of growth much higher than those reached in control. The regulated deficit irrigation scheduling based on LVDT sensors (RDCd) proved advantages over the traditional (RDCt) to get better plant water status which led to increased vegetative growth. So it had a less negative impact in the next year's harvest. Above all indicators of plant water status studied in both crops (Ψstem, TGR, MDS), the maximum daily shrinkage of stem diameter (MDS) was the most suitable in establishing baselines for irrigation scheduling because of its linear response and good correlation with temperature (mandarin, r2 > 0.7***) and vapor pressure deficit (almond, r2 > 0.8***). In mandarin, the comparison of the correlations of the two-years study (2005 and 2006) showed no difference between them, in spite of the fact that, salinity was increased and crop load was decreased during the second year. In addition to this, it was recorded the highest predictive value of baseline values obtained from March to October (phases I and II of trunk growth), period of maximum crop water requirements. In the same way, the study in almond by phenological phases showed significant differences between the baselines of the two-year study (2006 and 2007) in the period corresponding to phases II-III, but not between this period and the following phases. So, the obtained baseline in this period could be used for irrigation scheduling during the rest of the season., Universidad Politécnica de Cartagena

[SPA] El objetivo global de esta memoria fue estudiar la respuesta agronómica y fisiológica de almendros jóvenes y adultos a la aplicación de distintas estrategias de riego deficitario, y evaluar la utilidad y aplicabilidad de distintos indicadores del estado hídrico del árbol en la programación del riego. Para ello se establecieron tres ensayos en dos parcelas experimentales: uno en almendros adultos cv. ‘Colorada’ regados con agua de elevada salinidad y que constó de tres tratamientos de riego: (i) TCTL, regado al 125 % ETC durante todo el ciclo de cultivo; (ii) TRDC, regado al 100 % del TCTL hasta alcanzar el tamaño exterior del fruto, 70 % hasta el inicio de la fase IV, 30 % hasta recolección y 70 % durante el resto de la estación de riego y (iii) TSCO, sin riego durante todo el año, y otros dos en almendros jóvenes cv. ‘Marta’, con agua de buena calidad y con un total de cinco tratamientos: (i) TCTL, regado al 120 % ETC durante todo el ciclo de cultivo; (ii, iii) TRD80 y TRD60, regado al 80 y 60 % de la ETC durante todo el ciclo de cultivo y (iv, v) TRDC40 y TRDC20, regados al 100 % ETC durante todo el ciclo de cultivo excepto en la fase IV, donde recibieron el 40 y 20 % de la ETC respectivamente. Los principales mecanismos desarrollados por los almendros adultos bajo condiciones de estrés hídrico y salino fueron: (i) una disminución del potencial hídrico foliar, al objeto de generar un mayor gradiente de potencial hídrico entre el suelo y la hoja, y de este modo favorecer la absorción de agua, (ii) una temprana regulación estomática, desde las primeras horas del día, permitiéndole una mayor eficiencia en la absorción de CO2 respecto a las pérdidas de agua, (iii) un ajuste osmótico durante la mayor parte de la estación de crecimiento, lo que permitió mantener la turgencia celular y compensar las disminuciones de potencial hídrico foliar y (iv) una disminución del índice de área foliar (LAI), lo que supuso una contribución adicional al mantenimiento de la turgencia, ya que al disminuir el ratio brotes/raíz se redujo la tasa transpirativa para idéntica demanda evaporante. En cuanto a los rendimientos obtenidos, los tratamientos control y de riego deficitario controlado (RDC) mostraron valores superiores a los esperados para la salinidad presente en el agua de riego. Por otro lado, el tratamiento RDC, con un ahorro de agua del 50 % obtuvo una producción similar al control. Estos resultados muestran una buena adaptación de esta variedad autóctona al estrés hídrico y salino, lo que le permite utilizar más eficazmente el agua disponible. De los parámetros evaluados en almendros jóvenes fue el crecimiento vegetativo el más sensible al déficit hídrico, y en especial el diámetro del tronco. Los tratamientos más afectados fueron aquéllos en los que el estrés hídrico fue más intenso y aplicado desde el primer año de plantación (TRD60 y TRDC40). Sin embargo, el rendimiento no se vio, prácticamente, afectado, ya que tan sólo TRD60 y en su tercer año de ensayo presentó valores inferiores al control. La disminución del diámetro de tronco y consecuentemente del volumen de copa supone un menor espacio para el asentamiento de frutos y, en definitiva, una menor carga productiva. Cabría, por lo tanto, esperar una acentuación de estas diferencias a más largo plazo. Todo ello, muestra la conveniencia de realizar una programación del riego con criterios de crecimiento y desarrollo en los primeros años de la plantación al objeto de alcanzar el estado adulto lo más rápidamente posible. De los diferentes indicadores evaluados del estado hídrico del árbol fue la máxima contracción diaria del tronco (MCD) la que presentó la mayor correlación con el potencial hídrico foliar al alba (Ψa) y de tallo a mediodía (Ψt), parámetros utilizados tradicionalmente de referencia en este tipo de estudios. Lo mismo sucedió en las correlaciones con la evapotranspiración de referencia (ETo) y el déficit de presión de vapor (DPV). Esto unido al hecho de detectar rápidamente cambios de humedad en el suelo, de su posible automatización y del seguimiento en tiempo real del estado hídrico del árbol le convierte en una herramienta muy útil para el manejo y automatización del riego. Dentro de esta línea, es de destacar la estrecha relación observada a nivel estacional y mensual entre la máxima contracción diaria (MCD) y el déficit de presión de vapor (DPV), lo que ha permitido establecer líneas de referencia de posible aplicación a la programación automática del riego en el cultivo del almendro. [ENG] The main objective of this Doctoral Thesis was to evaluate the agronomic and physiologic responses of both young and adult almond trees to distinct deficit irrigation strategies, as well as to assess the applicability and utility of several plant water status indicators for irrigation scheduling. To this aim, three experiments were planned on two different experimental plots: a) one of them carried out on adult ‘Colorada’ almond trees irrigated with highly saline water, where three irrigation treatments were established: (i) TCTL, irrigated at 125 % ETC throughout all growing season; (ii) TRDC, receiving 100 % TCTL until the fruit reached its definitive external size, then 70 % TCTL until the beginning of stage IV, 30 % during stage IV and 70 % TCTL in postharvest; and (iii) TSCO, rainfed treatment. b) two of them carried out on young ‘Marta’ almond trees, where five irrigation treatments were defined (i, ii, iii) TCTL, TRD80 and TRD60, irrigated at 120, 80 and 60 % ETC all growing season and (iv, v) TRDC40 and TRDC20, irrigated at 100 % ETC during all year except during stage IV, when 40 and 20 % ETc was supplied, respectively. The most significant mechanisms of adult almond trees under both water and salt stresses (Experiment 1) were: (i) a decrease in predawn leaf water potential, which allows the plant to preserve a water potential gradient between soil and leaves in order to maintain root water uptake; (ii) an early stomatal regulation, evidenced since the first hours of the day, that maximizes CO2 assimilation efficiency with respect to water losses; (iii) osmotic adjustment which took place during most of the growing season, and allowed the plant to maintain cell turgor and thus compensating leaf water potential decline; and (iv) leaf area index (LAI) decrease, which supposed an additional contribution to maintain cell turgor, since it reduces shoot/root ratio and therefore the transpiration rate for a similar evaporative demand. With respect to the productive response, both control and regulated deficit irrigation (RDI) treatments showed higher values than expected taking into account the salinity level of irrigation water. On the other hand, RDI treatment, which saved 50 % of the irrigation water volume, presented similar yield to control treatment. These results evidence a good degree of adaptation of this autochthon variety to both water and salt stresses, leading to a more efficient use of soil available water. From the results of Experiments 2 and 3, vegetative growth indicators were the most sensitive to water stress, in particular trunk diameter. Trees growing under the most severe water stress conditions (TRD60 and TRDC40) were the most affected in terms of tree growth, particularly those trees that suffered water restriction since the beginning of the plantation. The analysis of the productive response showed no significant changes between water restricted and control treatments, except for TRD60 which presented lower yield values than control treatment in the third year of study. The general tree growth decrease observed in water-restricted young almond trees when compared to fully irrigated trees lead to smaller tree crowns, and is likely to reduce the number of fruit positions and thus crop load once the trees reach the productive period. Consequently, it results highly convenient to establish irrigation scheduling criteria aimed to allow young trees to reach the productive period as fast as possible. Among all the tree water status indicators considered in this study, maximum daily shrinkage (MDS) presented the best correlation with predawn leaf water potential (Ψa) and midday stem water potential (Ψt), indicators traditionally considered as reference in this kind of studies. A similar result was found when analyzing the correlations with crop reference evapotranspiration (ETo) and vapour pressure deficit (VPD). In addition, we obtained a close relationship between MDS and VPD on both seasonal and monthly basis, which allowed establishing reference baselines that might be used for irrigation scheduling. These results, joined to the reliability of this indicator to detect soil moisture changes as well as the possibility of continuously monitoring tree water status, makes MDS a pertinent and useful plant state variable to be used in almond irrigation scheduling, provided reference baselines are available. Universidad Politécnica de Cartagena Programa de doctorado en Producción Vegetal e Ingeniería Agraria y Alimentaria