Time filter

Source Type

Utrera, Spain

Cuevas M.V.,Institute Recursos Naturales y Agrobiologia IRNAS CSIC | Martin-Palomo M.J.,ETSIA | Diaz-Espejo A.,Institute Recursos Naturales y Agrobiologia IRNAS CSIC | Torres-Ruiz J.M.,Institute Recursos Naturales y Agrobiologia IRNAS CSIC | And 4 more authors.
Irrigation Science | Year: 2013

We used sap flow and trunk diameter measurements for assessing water stress in a high-density 'Arbequina' olive orchard with control trees irrigated to replace 100 % of the crop water needs, and 60RDI and 30RDI trees, in which irrigation replaced ca. 60 and 30 % of the control, respectively. We calculated the daily difference for both tree water consumption (DEp) and maximum trunk diameter (DMXTD) between RDI trees and control trees. The seasonal dynamics of DEp agreed reasonably well with that of the stem water potential. We identified peculiarities on the response DEp to changes in water stressing conditions, which must be taken into account when using the index. An analysis of the water stress variability in the orchard is required for choosing the instrumented trees. The reliability of the D MXTD index was poorer than that of DEp. The maximum daily shrinkage (MDS) was not a reliable water stress indicator. © 2012 Springer-Verlag. Source

Landete-Castillejos T.,IREC Sec Albacete | Landete-Castillejos T.,University of Castilla - La Mancha | Molina-Quilez I.,Hospital de Hellin | Estevez J.A.,University of Castilla - La Mancha | And 4 more authors.
Frontiers in Bioscience - Elite | Year: 2012

Antlers represent an ideal experimental model for bone biology studies, because of their easy accessibility, and their rapid growth. Findings from our previous studies revealed that Mn plays an essential role in incorporating the circulating bone Ca to the growing antlers. Based on these findings, we hypothesize that Mn, an essential mineral for Ca fixation (or incorporation) into bones, might be released from bone, during its remodeling, to be available for prioritized function, most likely, brain function; Consequently, Ca incorporation will be dramatically affected, leading to osteoporosis, particularly in elderly people. Therefore, osteoporosis would precede brain malfunctioning diseases such as Alzheimer's or Parkinson's, and clinical data are available to support some of the predictions derived from this hypothesis. Source

The reform of the Common Organization of the Market (CMO) in sugar in the EU is responsible for a 50% loss in production quota for the Spanish sugar sector, with the closure of numerous factories and consequent loss of jobs. The aim of this article is two-fold: 1) to describe the process and basic features of the CMO reform in the EU and Spain, and 2) to present a method for the analysis of the impact of measures implemented in the Spanish sugar beet sector as a consequence of the CMO reform. The method is based on a positive mathematical programming model in which, in addition to sugar beet, other crops which compete with sugar beet for land, such as cereals and oilseeds are taken into account. As well as the agricultural policy measures applicable to sugar beet, the model takes into consideration all the measures of the Common Agricultural Policy (CAP) relative to crops competing with it. The measures derived from the Reform of the Common Organization of the sugar market vary from one autonomous region to another. In this study, the above-mentioned method has been applied to the case of Castilla y León, the autonomous region with the greatest production of sugar beet in Spain. The results, which show that the CMO reform entails a significant loss of profits for the sugar beet sector in Castilla y León, were obtained using data from the 2002 Red Contable Agraria Nacional to define the sugar beet sector, assuming that variations in cost and price are those published by the Ministerio de Medio Ambiente y Medio Rural y Marino between 2002 and 2009. Source

Fernandez J.E.,CSIC - Institute of Natural Resources and Agriculture Biology of Seville | Elsayed-Farag S.,CSIC - Institute of Natural Resources and Agriculture Biology of Seville | Cuevas M.V.,CSIC - Institute of Natural Resources and Agriculture Biology of Seville | Martin-Palomo M.J.,ETSIA
Acta Horticulturae | Year: 2013

Regulated deficit irrigation (RDI), recommended for super-high density (SHD) olive orchards, requires a precise control of irrigation. Water must be supplied on the phenological stages when the plant is most sensitive to water stress, but irrigation promotes plant vigour, and excessive growth hampers management in SHD orchards. A reliable water stress indicator is needed, therefore, for the proper management of RDI. Here we present an evaluation of the performance of DEp, an index previously reported by Cuevas et al. (2012). The index is derived from sap flow measurements in RDI trees and in fully irrigated trees used as a reference. We evaluated the index during the irrigation seasons of 2011 and 2012, in an 'Arbequina' olive orchard with 1667 trees ha-1 close to Seville, southwest Spain. The index showed a potential for scheduling RDI strategies, although its reliability decreased on periods of fluctuating atmospheric demand. The required data analyses and data interpretation make the DEp index suitable for well-trained users only. © ISHS 2013. Source

Fernandez J.E.,Institute Recursos Naturales y Agrobiologia IRNAS CSIC | Rodriguez-Dominguez C.M.,Institute Recursos Naturales y Agrobiologia IRNAS CSIC | Perez-Martin A.,Institute Recursos Naturales y Agrobiologia IRNAS CSIC | Zimmermann U.,ZIM Plant Technology GmbH | And 9 more authors.
Agricultural Water Management | Year: 2011

The need for sophisticated irrigation strategies in fruit tree orchards has led to an increasing interest in reliable and robust sensor technology that allows automatic and continuous recording of the water stress of trees under field conditions. In this work we have evaluated the potential of the leaf patch clamp pressure (LPCP) probe for monitoring water stress in a 4-year-old 'Arbequina' hedgerow olive orchard with 1667treesha-1. The leaf patch output pressure (Pp) measured by the LPCP probe is inversely correlated with the leaf turgor pressure (>50kPa). Measurements of Pp were made over the entire irrigation season of 2010 (April to November) on control trees, irrigated up to 100% of the crop water needs (ETc), and on trees under two regulated deficit irrigation (RDI) strategies. The 60RDI trees received 59.2% of ETc and the 30RDI trees received 29.4% of ETc. In the case of the RDI trees the irrigation amounts were particularly low during July and August, when the trees are less sensitive to water stress. At severe water stress levels (values of stem water potential dropped below ca-1.70MPa; turgor pressure<50kPa) half-inversed or completely inversed diurnal Pp curves were observed. Reason for these phenomena is the accumulation of air in the leaves. These phenomena were reversible. Normal diurnal Pp profiles were recorded within a few days after rewatering, the number depending on the level of water stress previously reached. This indicates re-establishment of turgescence of the leaf cells. Crucial information about severe water stress was derived from the inversed diurnal Pp curves. In addition Pp values measured on representative trees of all treatments were compared with balancing pressure (Pb) values recorded with a pressure chamber on leaves taken from the same trees or neighbored trees exposed to the same irrigation strategies. Concomitant diurnal Pb measurements were performed in June and September, i.e. before and after the period of great water stress subjected to RDI trees. Results showed close relationships between Pp and Pb, suggesting that the pressure chamber measures relative turgor pressure changes as the LPCP probe. Therefore the probe seems to be an advantageous alternative to the pressure chamber for monitoring tree water status in hedgerow olive tree orchards. © 2011 Elsevier B.V. Source

Discover hidden collaborations