Pros and cons of olive fertigation: Influence on fruit and oil quality

Agronomic practices can modify olive fruit and oil quality. However, there is little information on the influence of fertigation, a common practice in most intensive orchards. We studied nutrient distribution in the soil profile following fertigation with different doses of N-P-K fertilizer, and its effect on nutrient concentrations, yield and both table olive and oil quality. Measurements were performed in an adult 'Manzanilla de Sevilla' olive orchard in which 100, 200 and 400 g N per tree and irrigation period of a 4N-1P-3K fertilizer were applied by fertigation from 1999 to 2001 (three growing seasons) and 200, 400 and 600 g N of the same fertilizer were applied in the two following growing seasons (2002-2003). A control treatment, irrigation without fertilizer, was also established. Irrigation amounts were similar in all treatments. In 2003, NO3-N, P and K concentrations in the root zone wetted by irrigation were studied: they increased with respect to those in the drying zone, showing a general linear relationship with fertilizer dose, particularly in the top soil layer where most of the olive roots were active. In the 600 g N treatment, leaching losses were observed at 0.8-0.9 m depth, possibly leading to groundwater contamination. We found an increase in fruit yield with increasing fertilizer dose, likely due to the observed greater concentrations of NO3-N, P and K in the soil. In fact, our data show a positive relationship between increased soil NO3-N, P and K availability and higher leaf N, P, K concentrations. This could have accounted for the observed increase in canopy volume, fruit number per tree and fruit weight with the amount of fertilizer. Despite the fact that fruit weight, pulp/stone ratio and volume increased with fertilizer dose, reducing sugars, necessary for olive fermentation, and pulp texture decreased. Differences in texture remained after 'Spanish-style' green olive processing. In addition, no differences were found in oil content but its quality was negatively affected with increasing fertilizer: in particular, polyphenol total content, bitterness, oxidative stability and the relation of monounsaturated/polyunsaturated fatty acids decreased with fertilizer dose

HVDC grids with heterogeneous configuration stations under DC asymmetrical operation

As a response to the future challenges that power systems will have to face, a gradual growth of present High Voltage Direct Current (HVDC) links is expected, leading to an HVDC supergrid integrating different configurations of HVDC stations. Such stations may suffer contingencies affecting just one pole (asymmetrical contingencies). The effects of these contingencies on an HVDC grid are very dependent on the configuration of the HVDC stations and their earthing system. Furthermore, when symmetrical monopolar stations exist in the DC grid, asymmetrical contingencies will also affect its healthy pole. For that reason, this paper focuses on the influence of the earthing system resistance of symmetrical monopolar stations on the performance of a heterogeneous HVDC grid during asymmetrical operation. The impact on the protection system is also investigated. The analysis concludes that an inappropriate earthing resistance magnitude may lead to a poor performance of heterogenous HVDC grids during asymmetrical operation. In addition, the study also indicates that the decisive factors for the selection of the grounding impedance of a symmetrical monopolar station are the asymmetrical operation of the whole grid and its contribution to pole-to-ground fault currents

Suitability of Two Table Olive Cultivars (‘Manzanilla de Sevilla’ and ‘Manzanilla Cacereña’) for Mechanical Harvesting in Superhigh-density Hedgerows

At a time of increasing demand, the extremely high cost of manual labor required to harvest fruit in table olive groves is limiting the economic survival of the crop in many producing countries. New grove designs and management practices such as superhigh-density (SHD) groves now in use in oil olive production should be explored as an option to facilitate mechanical harvesting in table olives. The feasibility of two table olive cultivars, Manzanilla de Sevilla and Manzanilla Caceren˜a, to be harvested in a 5- year-old SHD grove (1975 trees/ha) was studied in 2012 when trees of both cultivars formed highly productive continuous hedgerows (’10,000 and 18,000 kg·haL1 , respectively). The differences between manual and mechanical harvesting using a grape straddle harvester were evaluated taking into consideration harvesting time, efficiency in fruit removal, and fruit quality both before and after processing as Spanish-style green olives. The average harvest time per hectare with a grape straddle harvester was less than 1.7 hours compared with 576 person/hour or more when done manually. Fruit removal efficiency was high in both cases, 98% for mechanical treatment and 100% for hand treatment. Mechanically harvested fruits had a high proportion of bruising damage (greater than 90%) and the severity of the damage was greater in ‘Manzanilla de Sevilla’ than in ‘Manzanilla Caceren˜a’. After Spanish-style green processing, however, the proportion of bruised fruits was below 3% in each cultivar. The fruit size in both cultivars was suitable for table olive processing and only 7% and 4% of ‘Manzanilla de Sevilla’ and ‘Manzanilla Caceren˜a’ fruits, respectively, were diverted to oil extraction as a result of insufficient size. Small differences were found between processed ‘Manzanilla Caceren˜a’ fruits that were manually or mechanically harvested. In contrast, mechanically harvested ‘Manzanilla de Sevilla’ fruits showed a significantly higher proportion of cutting (18%), a type of damage that may take place during harvesting, and lower firmness and texture than those harvested manually

Genetic Diversity of Stone Fruit Cultivars Preserved On-Farm in Southern Spain

Old traditional cultivars are valuable genetic resources for crop improvement, but a great number of them have disappeared in the past century. This study aimed to characterize traditional cultivars of different Prunus species collected in small family orchards in southwestern Spain and to evaluate their genetic diversity and relationships. One hundred and twelve accessions belonging to 36 traditional cultivar denominations were analyzed using eight SSR loci transferable across the genus Prunus. The most useful loci to analyze different Prunus species were UDP96-005, BPPCT-002, UDP98-410 and ps02a12. A total of 152 alleles were observed, and 112 were unique to certain species. Sixty-eight different genotypes were found, revealing the possible existence of homonyms among traditional cultivar names. The clustering analysis was consistent with the taxonomic classification of the different species studied and with the geographical origins of the accessions within each species. The results showed wide genetic variability of traditional cultivars of stone fruits grown in small family orchards, which highlights the need to preserve them using both in-situ and ex-situ strategies. Twenty-eight of these accessions are currently conserved ex-situ at the University of Sevilla, Spain. The use of highly transferable SSRs has been proven as efficient in multi-species surveys performed on-farm

High-Throughput System for the Early Quantification of Major Architectural Traits in Olive Breeding Trials Using UAV Images and OBIA Techniques

The need for the olive farm modernization have encouraged the research of more efficient crop management strategies through cross-breeding programs to release new olive cultivars more suitable for mechanization and use in intensive orchards, with high quality production and resistance to biotic and abiotic stresses. The advancement of breeding programs are hampered by the lack of efficient phenotyping methods to quickly and accurately acquire crop traits such as morphological attributes (tree vigor and vegetative growth habits), which are key to identify desirable genotypes as early as possible. In this context, an UAV-based high-throughput system for olive breeding program applications was developed to extract tree traits in large-scale phenotyping studies under field conditions. The system consisted of UAV-flight configurations, in terms of flight altitude and image overlaps, and a novel, automatic, and accurate object-based image analysis (OBIA) algorithm based on point clouds, which was evaluated in two experimental trials in the framework of a table olive breeding program, with the aim to determine the earliest date for suitable quantifying of tree architectural traits. Two training systems (intensive and hedgerow) were evaluated at two very early stages of tree growth: 15 and 27 months after planting. Digital Terrain Models (DTMs) were automatically and accurately generated by the algorithm as well as every olive tree identified, independently of the training system and tree age. The architectural traits, specially tree height and crown area, were estimated with high accuracy in the second flight campaign, i.e. 27 months after planting. Differences in the quality of 3D crown reconstruction were found for the growth patterns derived from each training system. These key phenotyping traits could be used in several olive breeding programs, as well as to address some agronomical goals. In addition, this system is cost and time optimized, so that requested architectural traits could be provided in the same day as UAV flights. This high-throughput system may solve the actual bottleneck of plant phenotyping of "linking genotype and phenotype," considered a major challenge for crop research in the 21st century, and bring forward the crucial time of decision making for breeders

Posibilidades de implantación de una plataforma virtual para la mejora de la comercialización de los cítricos en Andalucía. Necesidades de información de los productores y exportadores

Andalucía es la segunda región productora de cítricos de España, teniendo por tanto una extraordinaria importancia económica y social. Sin embargo, la cadena de valor de los cítricos comprende un sector productor bastante atomizado frente a unos compradores muy concentrados y organizados, y un mercado poco transparente. El objetivo de esta investigación fue determinar las necesidades de información de los principales agentes implicados en la cadena de valor de los cítricos y estudiar las posibilidades que tendría la implantación de una plataforma virtual para mejorar las decisiones empresariales en la comercialización de los productos. Para ello, se emplearon fuentes primarias, centradas en la realización de entrevistas a expertos de la producción de cítricos en Andalucía, segmentando el análisis sobre la base de la naturaleza jurídica y la actividad de los entrevistados. Esta acción estratégica puede ser viable puesto que hay una clara demanda de información por parte de la población encuestada, que representa el 65% de la producción citrícola andaluza. Además, se constató que el modelo de gestión debería ser mixto, públicoprivada. La responsabilidad de la misma debería ser privada, ya que en general se percibió cierta reticencia en la Administración. La mayoría de los encuestados estarían dispuestos a pagar por los servicios que suministre la plataforma, si bien señalaron restricciones en cuanto al acceso, calidad del servicio y precioAndalusia is the second largest citrus producer in Spain, and thus, the citrus industry has an extraordinary economic and social importance in the region. However, the citrus value chain comprises a scattered primary sector in contrast to a very concentrated and well organized purchase and distribution sector, as well as a non-transparent market. The aim of this research was to explore the information needs of the different agents in the citrus value chain and to study the possibilities of implementing a opavirtual platform to share information in order to improve their marketing decisions. Primary sources were used for this work: a survey was conducted among citrus production experts in Andalusia. Survey results were analysed according to the legal nature and the activity of the respondents. The strategic action of implementing an information platform may be feasible since a clear demand for information has been detected from the survey population which represents 65% of the Andalusia citrus production. In addition, a public-private management model was preferred by the respondents to control the platform although the responsibility for it should be private. The majority of respondents would be willing to pay for the services provided by the platform, although some aspects regarding access restrictions service quality and price should be consideredFundación Corporación Tecnológica de Andalucía (CTA) 1480/056

Eficiencia de la recolección mecánica y efecto sobre la calidad de la producción en plantaciones superintensivas de variedades de aceituna de mesa

Las plantaciones superintensivas de olivar (Olea europaea L.), con densidades superiores a los 1.000 árboles por hectárea, se han convertido en una interesante alternativa al cultivo de olivar de almazara en la que el coste de recolección disminuye por la drástica reducción de la mano de obra y del tiempo requerido por el empleo de cosechadoras cabalgantes. No hay, sin embargo, experiencia alguna en relación al olivar de mesa. El objetivo de este trabajo ha sido evaluar la aptitud de dos variedades tradicionalmente destinadas al aderezo, como son la ‘Manzanilla de Sevilla’ y ‘Manzanilla Cacereña’, a la recolección con cosechadora cabalgante cuando se cultivan en superintensivo. El trabajo se realizó en septiembre de 2012 y 2014 en una plantación adulta. Antes de la recolección se caracterizaron los setos. Posteriormente se analizó la eficiencia de la recolección mecánica, en términos de porcentaje de frutos derribados y tiempo de recolección, así como las proporciones de frutos con daños. En 2012 también se analizaron los daños en frutos aderezados en verde al estilo sevillano. El tamaño de los setos fue adecuado para la recolección mediante cosechadora cabalgante. La cosechadora derribó prácticamente la totalidad de los frutos en un tiempo no superior a las dos horas por hectárea. La producción media fue mayor en la ‘Manzanilla Cacereña’ que en la ‘Manzanilla de Sevilla’ y la calidad del fruto apta para la comercialización, si bien los frutos de esta última variedad presentaban una mayor susceptibilidad al daño.Junta de Andalucía SGAEX/C

Rapid screening of unground cocoa beans based on their content of bioactive compounds by NIR spectroscopy

Near Infrared (NIR) spectroscopy was evaluated as a fast and easy method for identifying the most interesting cocoa genotypes according to chemical composition, including bioactive compound contents, in more than 80 samples of cocoa beans from the Mexican Germplasm Bank, which were harvested over three years. Clear dif ferences in chemical composition were detected in fermented and dried samples among genotypes. The contents in fat, protein, total sugars, total phenols, phenolic compounds and theobromine were determined for both whole cocoa beans and ground cotyledon samples; and calibration models were developed from the spectra of intact beans, nibs and ground cotyledons. In general, the calibration models obtained for cotyledon composition from the spectra of cocoa nibs and ground beans were better than those obtained from the spectra of intact beans. Fat content showed better calibration statistic values from the spectra of nibs and ground cotyledon (r2 = 0.70). Bioactive compounds, such as theobromine (r2 = 0.77), total sugars (r2 = 0.74), total phenols (r2 = 0.66) and derivatives of epicatechin (r2 = 0.88), together with fat (r2 = 0.70), protein (r2 = 0.64) and husk content (r2 = 0.82), were well-predicted using NIR spectroscopy in intact beans, cocoa nibs and/or ground cotyledon. The potential of NIRS technology was confirmed to support germplasm banks and breeding programs for the rapid identification of interesting genotypes based on their contents in bioactive compounds

From the juvenile to the adult vegetative phase in olive seedlings: the transition along the stem axis

Sexual reproduction in olive is carried out for purposes such as breeding. The seedlings evolve from the juvenile to the adult stage, and until now, only the discrete developmental phases have been investigated in detail. However, the transition process has been poorly studied in fruit trees, especially in olive. In this paper, juvenile to adult transition has been explored in 30 olive seedlings coming from the Table Olive Breeding Program of the University of Sevilla, Spain. Despite of the great variability found in the olive leaf morphological parameters, mean values increased linearly from the bottom (juvenile) to the top (adult tissue) of the seedling. An upward lineal decrease in the rooting ability was also observed for the set of seedlings evaluated. No significant differences were found for the maximum net photosynthesis (PNmax) or maximum stomatal conductance (gsmax), although the lowest values were measured at <0.5 m. For all of the analysed parameters, the transitional tissue showed intermediate values. These results show for the first time in olive that the transition along the seedling stem axis follows a clear lineal tendency with a stepwise loss of juvenile characters being the shift from juvenile to adult phase in olive not an abrupt change but a gradual process. The usefulness of a fibre optic probe with a reduced sampling surface coupled to near-infrared spectroscopy (NIRS) was evaluated. NIR analysis has been confirmed to be a useful tool to discriminate the juvenile and adult leaves, but not the transition one

Histological characterization of table olive fruit bruising cv. Manzanilla de Sevilla

Sin paginarActualmente el sector del olivar en España incluye dos subsectores claramente diferenciados por su aprovechamiento: el olivar de almazara y el de mesa o verdeo, cada uno con unas particularidades específicas que los diferencian, tales como variedades empleada s y técnicas de cultivo como la poda o la recolección. En los últimos años, la necesidad de optimizar los costes de producción ha generalizado la recolección mecanizada mediante brazos vibradores o máquinas cabalgadoras en explotaciones de olivar de aceite. Sin embargo, no se ha extendido de igual manera en plantaciones de aceituna de mesa, debido a los altos porcentajes de frutos dañados por los golpes que se producen durante la recolección mecanizada. El molestado, manchas oscuras en la parte externa del exocarpo de los frutos, hace referencia a los daños provocados en los frutos por los golpes durante la recolección, más notables en la recolección mecánica. Estas manchas deprecian el fruto a nivel comercial con el consecuente rechazo del consumidor. No todos los cultivares presentan la misma susceptibilidad al molestado. ‘Manzanilla de Sevilla’, variedad por excelencia de aceituna de mesa, es considerada sensible al molestado lo que dificulta su recolección por medios mecánicos. El Departamento de Ciencias Agroforestales de la Un iversidad de Sevilla empezó a trabajar en el año 2003 en un programa de mejora genética de olivo para mesa. Una de las líneas de trabajo dentro de este proyecto ha consistido en estudiar diferentes parámetros de calidad, entre los que se encuentra el molestado. En colaboración con el Instituto de Agricultura Sostenible-CSIC, se ha desarrollado una metodología para evaluar el mismo en aceituna de mesa. En este trabajo se describe anatómicamente el molestado en frutos frescos de ‘Manzanilla de Sevilla’, después de un golpe inducido, a los 30 minutos y 24 horas del impacto y fijados posteriormente con FAE (formalina, ácido acético, etanol del 95% y agua destilada (10:5:50:3 5 v/v/v/v)). Se han evaluado histológicamente los cambios (rupturas celulares y pérdida de grosor en paredes celulares) que se producen en el mesocarpo de las zonas dañadas. Las observaciones histológicas han revelad o diferencias en los daños para los dos momentos evaluados. La presencia de rupturas celulares y la pérdida de grosor de las paredes celulares, en las zonas dañadas, han sido más evidentes a las 24 horas tras el golpe.Currently olive growing in Spain includes two main industries: olive oil and table olives, each of which has its own peculiarities, such as different varieties and specific performance of cultivation techniques like pruning or harvesting. In recent years, due to the need of reducing production costs, mechanical harvesting using trunk shakers or straddle harvesters has become widespread in olive oil orchards. However, that is not the case in table olive plantations, due to the high percentage of fruit damaged by the impacts that take place during mechanical harvesting. The term fruit bruising, dark spots on the outside of the fruit exocarp, refers to the fruit damage caused by impacts during collection, most notably in mechanical harvesting. These spots decreases commercial fruit value, being rejected by the consumer. Not all cultivars have the same fruit bruise susceptibility. Manzanilla de Sevilla, Spanish leading table olive cultivar, is considered to be sensitive to bruising being therefore difficult to harvest by mechanical devices Researchers from the Departamento de Ciencias Agroforestales at the University of Seville, Spain, are working since 2003 on a table olive breeding program. One of the research lines within the program has been to study. different table olive quality parameters, including fruit bruising. An evaluation methodology is being developed to asses this phenomenon in collaboration with the Instituto de Agricultura Sostenible-CSIC. This paper describes anatomical changes related to fruit bruising in 'Manzanilla de Sevilla' fresh fruits after an induced impact. Bruised fruits were chemically fixed in FAE (formalin, acetic acid, 95% ethanol and distilled water (10:5:50:35 v/v/v/v)) 30 minutes and 24 hours after the impact. Histological changes (cell breakage, loss of cell wall thickness and higher colour intensity) produced in the mesocarp of the damaged areas have been evaluated. Histological observations revealed differences between the evaluated times. The presence of cell ruptures and the loss of thickness in the cell walls, in the damaged areas, has been most evident at 24 hours after the impact.Ministerio de Ciencia e Innovación y fondos FEDER, proyectos AGL2007-65184-C02-02 y AGL2009-0724