Absolute Configuration of Falcarinol (9Z-heptadeca-1,9-diene-4,6- diyn-3-ol) from Pastinaca sativa

Falcarinol (9Z-heptadeca-1,9-diene-4,6-diyn-3-ol; 1) is a polyacetylene commonly found in several plant families. The absolute configuration of naturally occurring 1 is not clear and contradictory results have been reported in the literature. Determination of the absolute configuration of 1 from Pastinaca sativa L. was carried out. Isolation of 95% pure 1 was performed via successive fractionation and preparative-HPLC. A racemic mixture comprised of 3R-1 and 3S-1 was synthesized in order to confirm the absolute configuration of the isolated natural product using chiral HPLC. Based on a combination of chiral HPLC and specific rotation, 1 present in P. sativa was found to have a 3R absolute configuration (i.e. (3R, 9Z)-heptadeca-1,9-diene-4,6-diyn-3-ol)

Extrapolating base-line trunk shrinkage reference equations across olive orchards

preprintMaximum daily trunk shrinkage is a common measurement in irrigation scheduling of fruit trees. But the strong relationship between these measurements and the environment severely limit field applications. Reference baselines are the solution for understanding the influence of environmental conditions. Nevertheless, the extrapolation out of the original conditions is not clear. The aim of this study was to compare several approaches to estimate a reference baseline in an olive orchard where there were no previous data from other seasons. Two orchards, separated 60. m, with different tree density were used. Orchard 1 had greater tree density than orchard 2, though the age and the cultivar were the same. Trunk diameters of both orchards were similar but the crown volume of orchard 2 was slightly lower than orchard 1. The current reference baselines of maximum daily trunk diameter in both orchards were not significantly different between them (p<0.05). In orchard 1, the previous reference baseline was calculated in a 5-year study (the so called multi-seasons approach). The multi-seasons approach was not significantly different in slope but it was in the y-interception to the current reference baselines in both orchards (p<0.05). This approach over-estimated the values in both orchards. Two additional approaches were tested. These latter approaches used data before massive pit hardening to estimate the current reference baseline. One of them used the early data to estimate a complete reference baseline (the so-called early approach). The other (the so-called y-early approach) used the same data only to estimate the y-interception and assumed that the slope was the same as in the multi-seasons approach. The early approach under-estimated the value of maximum daily trunk shrinkage. The early-y approach provided a satisfactory estimation of the reference baseline and improved those obtained with the multi-seasons approach. The limitations and uses in irrigation scheduling are also discussed.MINECO AGL2010-19201-CO4-03AECID D/030431/1

Limitations and usefulness of maximum daily shrinkage (MDS) and trunk growth rate (TGR) indicators in the irrigation scheduling of table olive trees

Maximum daily trunk shrinkage (MDS) is the most popular indicator derived from trunk diameter fluctuations in most fruit trees and has been reported to be one of the earliest signs in the detection of water stress. However, in some species such as olive trees (Olea europaea L.), MDS does not usually change in water stress conditions and trunk growth rate (TGR) has been suggested as better indicator. Most of this lack of sensitivity to drought conditions has been related to the relationship between the MDS and the water potential. This curvilinear relationship produces an uncertain zone were great variations of water potential do not imply any changes of MDS. The MDS signal, the ratio between measured MDS and estimated MDS with full irrigation, has been thought to be a better indicator than MDS, as it reduces the effect of the environment.. On the other hand, though literature results suggest an effect of environment in TGR values, there are not clear relationship between this indicator and meteorological data. The aims of this work are, on one hand, to study the improvements of the baseline approach in the MDS signal and, on the other, study the influence of several meteorological variables in TGR. Three years’ data from an irrigation experiment were used in to carry out the MDS analysis and six years’ data for full irrigated trees during pit hardening period were used for TGR study. The comparison between MDS vs. water potential and MDS signal vs. water potential presented a great scattering in both relationships. Values of MDS signal between 1.1 and 1.4 were always identified with moderate water stress conditions (−1.4 to −2 MPa of water potential). However, since this MDS signal values are around the maximum in the curvilineal relationship with water potential, greater values of MDS signal (in the range of 1.1–1.4) were not necessary lower values of water potential. In addition, during low fruit load seasons MDS signal was not an accurate indicator. On the other hand, absolute values of several climatological measurements were not significantly related with TGR. Only daily increments explain part of the variations of TGR in full irrigated trees. In all the data analysed, the daily increment of average vapour pressure deficit was the best indicator related with TGR. The increase of this indicator decreased TGR values. In addition, the agreement between this indicator and TGR was affected for fruit load. Great yield seasons decrease the influence of VPD increment in TGR.Spanish Ministerio de Ciencia e Innovación, (AGL2010-19201-CO4-03 and AGL2013-45922-C2-1-R

Umbrales sostenibles de estrés hídrico durante el endurecimiento del hueso en la producción de aceituna de mesa

La programación del riego deficitario controlado (RDC) es una necesidad derivada de la escasez de agua disponible para el riego. La resistencia al estrés hídrico de los diferentes estados fenológicos en olivar está bastante bien documentada pero no así los niveles de estrés hídrico. El objetivo de este trabajo es sugerir en base a experimentos realizados en los últimos 7 años los niveles de estrés hídrico para el manejo del RDC en olivar.Los experimentos descritos en la presente comunicación se han desarrollado en la finca “La Hampa” propiedad del IRNAS (CSIC) en Coria del Río (Sevilla), en un olivar de 37 años cv “Manzanillo” y a un marco de 7*5m. Los experimentos se establecieron con diferentes tratamientos de riego, aplicando condiciones de estrés hídrico durante endurecimiento de hueso y unas semanas antes de cosecha. Se discute los diferentes umbrales detectados y su efecto en cosecha, cantidad y calidad, y en la fisiología de la planta en el años en curso en el ciclo bianual del olivo.Ministerio de Economía y Competitividad AGL2007-66279-C03-00Ministerio de Economía y Competitividad AGL2010-19201-CO4-03Ministerio de Economía y Competitividad AGL2013-45922-C2-1-

Identification of water stress conditions in olive trees through frequencies of trunk growth rate

Continuous monitoring of the tree water status will enhance irrigation performance, particularly when applying deficit schedules. The olive tree is a highly drought-resistant species and management of the water stress could increase water savings. Trunk diameter fluctuations can be displayed as daily curves representing the shrinkage and swelling, and can provide information about tree water status. In olive trees, trunk growth rate (TGR) is the most useful indicator, but the daily variability reduced the commercial applications. Recently, weekly frequencies of TGR values were associated to the water status in one seasonal experiment. The aim of this work is to study the seasonal pattern and the interannual variations of these parameters in order to integrate them in an irrigation scheduling tool. The experiment was performed during two consecutive seasons (2018 and 2019) in a superhigh density mature olive orchard at Carmona (Seville, Spain). Three different irrigation scheduling treatments were considered in a randomized complete block design. The control treatment was fully irrigated with 150–175% crop evapotranspiration (ETc) in order to ensure an optimum water status. Regulated deficit irrigation-1 (RDI-1) was scheduled using only TGR data provided through the continuous measurements from a dendrometer. In this treatment, water stress conditions were controlled during the pit hardening period. RDI-2 was similar to RDI-1, but with a more severe water stress conditions during pit hardening and a maximum seasonal amount of water that limited rehydration. Water stress was greater during the 2019 season than the 2018 season, according to the midday stem water potential (SWP). Weekly frequencies of TGR values lower than − 0.3 mm day− 1 (Severe FR) and values between − 0.1 and 0.3 mm day− 1 (Good FR) described the water status pattern in the three treatments for both seasons. Only under severe water stress conditions (SWP more negative than − 4 MPa) the values of these frequencies did not identify accurately the water status. However, the use of weekly frequencies of values greater than 0.3 mm day− 1 (Alert FR) and the pattern of these Severe FR and Good FR themselves identified such conditions. The use of these three weekly frequencies (Severe, Good and Alert (SGA) approach) are suggested for continuous deficit irrigation scheduling in olive trees

Identification of the water stress level in olive trees during pit hardening using the trunk growth rate indicator.

Water scarcity is generating an increasing interest in deficit irrigation scheduling. The trunk diameter fluctuations are daily cycles that have been suggested as tools for irrigation scheduling. The trunk growth rate (TGR) was suggested as the best indicator for olive trees during pit hardening. The aim of this work is to clarify how the TGR could be used to identify water stress levels. The experiment was performed during the 2017 season, in a commercial, super-high-density orchard in Carmona (Seville, Spain). Four different irrigation treatments were performed according to midday stem water potential values and TGR. The data obtained were very variable and both indicators presented a wide range of water status throughout the season. The maximum trunk diameter data clearly showed the pattern of the trees water status but the comparison between treatments and the identification of the water stress level was not possible. The average TGR was linked to the midday stem water potential, but with a minimum amount of data. Irrigation scheduling based on the average TGR was difficult because of the great increases in some daily TGR values. For clarity, the pool of data was grouped by midday stem water potential. These water stress levels were characterized using the weekly frequency of TGR values. The increase of water stress reduced the frequency of values between -0.1 and 0.3mm day-1 from 60% to less than 25%. Moderate water stress levels increased the percentage of values lower than -0.3mm day-1 from 7% to 37%. The most severe water stress conditions increased the TGR values between -0.3 and -0.1mm day-1 from 16% up to 22%.IRNASINSTITUTO DE LA GRASACSI

Water Relations in the Irrigation Scheduling of Olive Orchards

Olive trees (Olea europea L) are traditional Mediterranean specie. The agricultural management of olive orchards has been changed from 90’s of the last century. The most important change is the great increase of the irrigation surface. This new water demand has been produced in water scarcity areas. Such conditions and the traditional rainfed management of the orchards have produced very restrictive water used. The traditional irrigation scheduling based on water budget is a useful tool in conditions of full irrigation, but most of the olive orchards are deficit irrigated. In the last decades, plant water status measurements have been suggested in different fruits trees in order to improve the management of deficit irrigation. In this work, results of several experiments in different olive orchards using midday stem water potential and trunk daily diameter are presented. The water stress sensitivity and the real commercial utility are discusse

Influence of rootstocks on pistachio (Pistacia vera L.) water relations

Pistachio potted plants budded on three different rootstocks were submitted to water stress during 28 days with the aim of studying their water relations and physiological responses. Water stress resulted in an accented drop of stem water potential and leaf conductance. Nonetheless, pistachio plants showed a great capacity to contrast drought effects by the recourse to osmotic adjustment mechanisms. Regarding rootstocks, UCB-I results being the less adapted rootstock to conditions of water stress

Antioxidants (carotenoids and phenolics) profile of cherry tomatoes as influenced by deficit irrigation, ripening and cluster

The purpose of this study was to assess the relationship between the effect of regulated deficit irrigation, cluster, developmental stages and two seasons (autumn 2015 and spring 2016) on the commercial and functional quality (carotenoids and plenolics levels) in ‘Lazarino’ and 'summerbrix’ tomatoes. Autumn had a positive effect on the commercial quality, with larger fruits (22% in 'summerbrix’; 26% in ‘Lazarino’) and higher soluble solids (16% in 'summerbrix’; 12% in ‘Lazarino’). Total carotenoids did not change significantly with irrigation and variety while total phenolics did with the cluster and season. In most cases, the main amounts of carotenoids and phenolic were found in the higher cluster and carotenoids in ripe fruit. Thus, irrigation of such varieties could be reduced drastically (ca. 80%) without affecting considerably the overall quality of their fruits (changes not greater than 30%).Ministerio de Economía y Competitividad AGL2012-37610, BIO2015-71703-RED

Seasonal changes of maximum daily shrinkage reference equations for irrigation scheduling in olive trees: influence of fruit load

Maximum daily shrinkage (MDS) is the parameter of daily cycle of trunk diameter most widely suggested in irrigation scheduling for several fruit trees. However, as in other plant-measured approaches, the irrigation decision may be difficult due to the influence of the environment on the values obtained. Reference equations of MDS have been established in order to avoid the effects of environmental conditions. Such equations are usually related to simple meteorological data, in order to easily estimate MDS values in full-irrigated conditions. This paper studies the influence of fruit load and the inter-annual variations on the reference equation of MDS in olive trees. These reference equations were calculated during 4 seasons in a full-irrigated orchard and the equations were validated with the data from a different season. The MDS values were related to vapour pressure deficit (VPD) and temperature taken near the experimental orchard. In addition, meteorological data were considered as mean daily or as midday values: only for temperature was the maximum daily value also used. The validation of the equations was made using the fits with all the meteorological data considered (midday and mean daily of VPD and temperature). In addition, two different fits were used in each meteorological data one according to fruit load and other with the complete pool of data. The equations fit were significantly different each season in all the meteorological data considered. However, seasons with similar fruit load were more similar to each other. In both meteorological data considered (VPD and temperature) the midday values improved the fit in respect to mean daily values. The equations obtained with maximum daily temperature were similar in accuracy to the one of midday. The reference equations in which temperature was used obtained a better fit that the ones calculated with VPD. No significant differences were found in the validation when equations according to fruit load or the complete pool data were compared. The limitations and usefulness of these reference equations are also discussed.Ministerio de Ciencia e Innovación, Unión Europea AGL2004-0794-C03-02 and AGL2007-66279-C03-02/AG