Olive Crop Research Articles

Olive Water Use, Crop Coefficient, Yield, and Water Productivity under Two Deficit Irrigation Strategies

Reports on the annual effects of deficit irrigation regimes on olive trees are critical in shedding light on their impacts on water use, yield, and water productivity in distinct olive growing climate regions of the world. From the account of a four-year experiment, the aim of this work is to add insight into such effects on olive growing in southern Portugal. We worked with trees in an intensive ‘Cobrançosa’ orchard (300 trees ha−1) under full irrigation (FI) treatment and two regulated deficit irrigation (DI) treatments designed to replace around 70% and 50% of the FI water supply, respectively. Crop transpiration (T), irrigation water use (IWU), total water use (TWU), irrigation water use efficiency (IWUE), yield (Ya), and water productivity (WP) obtained from all treatments were analyzed, as well as their crop coefficients (Kc), simulated with the SIMDualKc software application for root zone and soil water balance based on the FAO dual crop coefficients. As expected, IWUE of the 50DI treatment was the highest among treatments, with 70DI being slightly lower. Ya showed alternate bearing with an “on-off” year sequence and was consistently higher for the 70DI treatment. WP (the ratio of Ya to IWU) values for the 70DI treatment were also consistently the highest among all treatments and years. The mean simulated Kc act values for 70DI and 50DI for the initial, mid-, and end-season compared well to the FAO56 Kc for olive crops. In general, to rank the irrigation treatments, 70DI presented the highest conversion efficiency among all treatments and years, providing a suitable DI alternative for our ‘Cobrançosa’ orchard. The 50DI treatment may be an attractive DI regime to undertake under scarce farm water resources or the expansion of olive hectares under water constraints.

OliveCan: A Process-Based Model of Development, Growth and Yield of Olive Orchards.

Several simulation models of the olive crop have been formulated so far, but none of them is capable of analyzing the impact of environmental conditions and management practices on water relations, growth and productivity under both well-irrigated and water-limiting irrigation strategies. This paper presents and tests OliveCan, a process-oriented model conceived for those purposes. In short, OliveCan is composed of three main model components simulating the principal elements of the water and carbon balances of olive orchards and the impacts of some management operations. To assess its predictive power, OliveCan was tested against independent data collected in two 3-year field experiments conducted in Córdoba, Spain, each of them applying different irrigation treatments. An acceptable level of agreement was found between measured and simulated values of seasonal evapotranspiration (ET, range 393 to 1016 mm year-1; RMSE of 89 mm year-1), daily transpiration (Ep, range 0.14–3.63 mm d-1; RMSE of 0.32 mm d-1) and oil yield (Yoil, range 13–357 g m-2; RMSE of 63 g m-2). Finally, knowledge gaps identified during the formulation of the model and further testing needs are discussed, highlighting that there is additional room for improving its robustness. It is concluded that OliveCan has a strong potential as a simulation platform for a variety of research applications.

Bayesian networks for evaluating climate change influence in olive crops in Andalusia, Spain

AbstractOlive crops have become a strategic sector in Andalusia, Spain, providing an element of social cohesion and territorial management, but identified as vulnerable under climate change. Their great socioeconomic importance makes the mitigation of climate change effects an important strategy. The main contribution of this paper is to show the application of Bayesian networks into climate change assessment using the evaluation of its impact over olive system in Andalusia. Both classification and regression models were learnt and validated to predict the potential olive grove distribution under an Intergovernmental Panel on Climate Change scenario. A lower error rate was obtained for the regression problem compared to classification. Results predict that climate change will lead to changes into the territorial distribution of olive crops, with a movement from the river valley to the uplands due to the impact of the predicted increase in temperatures.Recommendations for Resource Managers Bayesian networks are a powerful tool that allows dealing with both discrete and continuous data. However, if continuous data are available in order to retrieve all statistical information from them, discretization process should be avoided and original continuous data used for modeling purpose. Olive cropping area follows an altitudinal gradient from the river bed to the mountainous ranges. The minimum temperature limits the establishment of this crop over certain altitude. Under the scenario of climate change, the altitudinal gradient is lost and the main expanse of olive groves becomes fragmented into smaller patches. Besides, mountainous areas would reach optimal conditions for olive growth due to the increase in temperatures.

Evaluation of olive response and adaptation strategies to climate change under semi-arid conditions

AdaptaOlive is a simplified physically-based model that has been developed to assess the behavior of olive under future climate conditions in Andalusia, southern Spain. The integration of different approaches based on experimental data from previous studies, combined with weather data from 11 climate models, is aimed at overcoming the high degree of uncertainty in the simulation of the response of agricultural systems under predicted climate conditions.The AdaptaOlive model was applied in a representative olive orchard in the Baeza area, one of the main producer zone in Spain, with the cultivar ‘Picual’. Simulations for the end of the 21st century showed olive oil yield increases of 7.1 and 28.9% under rainfed and full irrigated conditions, respectively, while irrigation requirements decreased between 0.5 and 6.2% for full irrigation and regulated deficit irrigation, respectively. These effects were caused by the positive impact of the increase in atmospheric CO2 that counterbalanced the negative impacts of the reduction in rainfall. The high degree of uncertainty associated with climate projections translated into a high range of yield and irrigation requirement projections, confirming the need for an ensemble of climate models in climate change impact assessment.The AdaptaOlive model also was applied for evaluating adaptation strategies related to cultivars, irrigation strategies and locations. The best performance was registered for cultivars with early flowering dates and regulated deficit irrigation. Thus, in the Baeza area full irrigation requirements were reduced by 12% and the yield in rainfed conditions increased by 7% compared with late flowering cultivars. Similarly, regulated deficit irrigation requirements and yield were reduced by 46% and 18%, respectively, compared with full irrigation. The results confirm the promise offered by these strategies as adaptation measures for managing an olive crop under semi-arid conditions in a changing climate.

Xylella fastidiosa, a new phytosanitary threat for olive crops

<i>Xylella fastidiosa</i>, a new phytosanitary threat for olive crops

A new decision-support system for the historical analysis of integrated pest management activities on olive crops based on climatic data

Olive tree is one of the most important crop at global scale. Apulia is the first olive-producing region in Italy, with a huge amount of farms that generate Integrated Pest Management (IPM) data. IPM requires the simultaneous use of different crop protection techniques to control pests through an ecological and economic approach. The crop protection strategies are correlated to the climate condition considering the very important relation among climate, crops and pests. Therefore, in this work is presented a new advanced On-Line Analytical Processing (OLAP) model integrating the Growing Season Index (GSI), a phenology model, to compare indirectly the farms by a climatic point of view. The proposed system allows analysing IPM data of different farms having the same phenological conditions over a year to understand some best practices and to highlight and explain different practices adopted by farms working in different climatic conditions.

Methodology for edaphoclimatic assessment of olive cultivation: Application to the area of the quality mark “Olive Oil Madrid” (Spain)OLIVE OIL MADRID” (SPAIN)

The present work proposes a methodology to select the most suitable areas for olive cultivation under rainfed conditions in the Madrid Region (Central Spain). This methodology is based on an analysis of the significant edaphoclimatic parameters that characterize the study region matched with the crop requirements of the olive tree, in the framework of the Land Suitability Classification system. A key component of the proposed methodology is the selection and rating of edaphic and climatic parameters as limitations associated with olive crop requirements in rainfed conditions. The climatic parameters considered are: average temperature of the absolute minimum of the coldest month (during dormancy and growth periods), average temperature of the minimum in the phenological stages of flowering, growth and ripening, mean relative humidity in spring and autumn, and average annual sunshine hours. The edaphic parameters considered (both extrinsic and intrinsic to soil profiles) include: slope, stoniness and rockiness, drainage, presence of perched water table, infiltration rate, effective depth, available water retention capacity (AWC), cation exchange capacity (CEC), pH, base saturation, active lime, salinity, Ca/K antagonism and organic matter content. For each of these parameters, five levels of severity have been established, from "very unfavorable" (excluded) to "very favorable" (optimal), establishing specific limits within each of these ranges to compare them with the requirements of olive trees. The final phase of the evaluation is the allocation of Suitability Categories to certain areas of interest for olive growing, established according to soil and climate criteria, on the basis of Land Mapping Units defined on the studied territory. The interest of an edaphoclimatic assessment in this geographical area lies in its marginal location with respect to the main olive groves in the Iberian Peninsula, and in the variety of existing climatic and edaphic conditions, some of them generally considered as limiting the cultivation of the olive grove, as well as in an evident current expansion of this crop. The most relevant edaphic limitations derive especially from a low available water capacity, and locally, by factors such as acid pH, Ca/K antagonism or high active lime. The exclusionary limitations derive, to a great extent, from climatic characteristics, associated with low temperatures combined with high relative air humidity. This methodology is expected to serve as a basis for the delimitation of new areas on which the implantation of the olive grove may be foreseen within a period, like the present one, of remarkable expansion of this crop.

Olive crops and rural development: Capital, knowledge and tradition

AbstractOlive‐growing territories are undergoing a strong challenge within globalization. New methods of planting worldwide are reducing costs and improving harvesting processes. In turn, the international value chain of olive oil is being increasingly managed in a professional way, giving rise to new and better olive oils that are opening new niches in new and old markets. Will traditional olive oil Mediterranean regions be able to adapt their model of production in order to face a new situation in the market? The answer is conditioned by the struggle between the knowledge of the sector and the regional traditions.

Fruit, mesocarp, and endocarp responses to crop load and to different estimates of source: sink ratio in olive (cv. Arauco) at final harvest

Abstract The annual fluctuations in olive crop load due to alternate bearing and other factors often lead to large differences in fruit size and oil content between years at harvest. A better understanding of how fruit parameters respond to the different leaf: fruit (i.e., source: sink) ratios that occur with contrasting crop loads would provide important information for crop management. Thus, the primary objectives of this study conducted with the cv. Arauco in three growing seasons were to: 1) determine the weight and size responses of the fruit and its main tissues, mesocarp (pulp) and endocarp (pit), to crop load; and 2) obtain relationships between different estimates of the source: sink ratio versus various fruit and oil parameters. Fruit thinning was performed by hand on uniform trees with high initial crop loads four weeks after full bloom the first season to obtain different crop loads at harvest. The thinning percentages the first season were 24%, 48% and 87%, along with an unthinned control. The same trees were then monitored the following two seasons without any further thinning. Fruit were sampled at harvest each season to determine fruit and tissue weights and diameters, oil weight per fruit, and oil concentration (%). Fruit weight was reduced 30–40% by high crop loads in each growing season with the mesocarp being much more affected than the endocarp. Oil weight per fruit (−50%) showed a somewhat greater reduction than fruit weight to crop load due to both fruit diameters and fruit oil concentration being decreased at high crop loads. Fruit and tissue weights and oil weight per fruit all displayed bilinear functions versus source: sink ratio when the source was expressed as canopy volume (a surrogate for leaf area) and sink on both a fruit number and glucose equivalent (GE) basis. Source limited fruit growth at both medium and high crop loads due to limited photoassimilate availability based on the bilinear functions, and the slope of the endocarp response to source: sink ratio was 15 times less than that of the mesocarp when expressed on a GE basis. A quantitative comparison with previously published studies indicated that maximum fruit weight appears to be obtained in olive between 1–2 m2 of leaf area per kg of GE. The bilinear relationships of source: sink ratio versus fruit weight observed in this study could contribute to crop modelling, and further research concerning how and when the mesocarp and endocarp respond to crop load is needed to aid crop management in obtaining sufficient fruit size and quality for table olive cultivars.

Identification of Key Strategies for Olive Crop Production and Technical Requirements for their Implementation with the World Class Manufacturing Approach

Identification of Key Strategies for Olive Crop Production and Technical Requirements for their Implementation with the World Class Manufacturing Approach

Residual biomass potential in olive tree cultivation and olive oil industry in Spain: valorization proposal in a biorefinery context

Olive crop and olive oil industry generates several residues, i.e., olive tree pruning biomass (OTPB), extracted olive pomace (EOP) and olive leaves (OL) that could be used to produce high-added value products in an integrated biorefinery. OTPB is generated in the field as a result of pruning operation to remove old branches; EOP is the main residue of the pomace olive oil extracting industry after extraction with hexane of residual oil contained in olive pomace; and OL comes from the olive cleaning process carried out at olive mills, where small branches and leaves are separated by density. In this work, an analysis of the potential of OTPB, EOP and OL residues was addressed by estimating the production volumes at national level and the spatial distribution of these residues using geographic information system software. Information provided by public institutions and personal surveys to the industries was evaluated. Moreover, chemical analysis of the residues was undertaken and the results used to make a first assessment of valorization into biofuels such as bioethanol and bio based chemicals. Results show that close to 4.2 million tons/year of EOP, OL and OTPB derived from olive oil industry and olive tree cultivation in Spain could be available as a raw material for biorefineries in Spain. The analysis of the chemical characteristics indicates the relevant potential of these feedstocks for the production of bioethanol and other compounds such as phenols based on suitable processing and conversion routes, although techno-economic evaluations must be tackled to refine this approach.

Effect of the Super Absorbent Polymer Stockosorb® on leaf turgor pressure, tree performance and oil quality of olive trees cv. Chemlali grown under field conditions in an arid region of Tunisia

The effects of soil amendment with the hydrophilic polymer Stockosorb® on the physical properties of the soil as well as on physiological parameters (turgor pressure, stomatal conductance, chlorophyll fluorescence) and yield (vegetative growth, fruit characteristics, oil yield and quality) of an established olive crop cultivated under rainfed conditions, were investigated in Tunisia during the 2014 growing season.Stockosorb® hydrogel was applied by injection in the soil around olive trees (TS) and compared to a control plot (TC) without hydrogel application. The results showed that water content was generally higher in hydrogel amended soils compared to the control soil. The seasonal leaf patch output pressure (Pp) readings revealed that trees with Stockosorb® treatment had the highest water status and were moderately stressed in comparison to control trees which were severely stressed due to the poor water status during the vegetative growth and fruiting period. The application of Stockosorb® in the root zone of olive trees significantly increased midday stomatal conductance (gs) and the maximal quantum efficiency (Fv/Fm). Shoot growth, oil yield and rainwater use efficiency were strongly improved by the Stockosorb® amendment to the soil, however oil quality still within the threshold limits set for an ‘Extra virgin' classified olive oil.

Chemosensory characterization of virgin olive oils obtained from organic and conventional practices during fruit ripening

AbstractThe current increase in demand for organic products by consumers, including virgin olive oils (VOO), makes it necessary to study the characteristics of these types of foods. Moreover, the higher quality of organic products versus that of conventional products is controversial. In this regard, the chemosensory qualities of several virgin olive oils produced from fruit grown in an experimental orchard at four different stages of maturation under organic and conventional management systems were analysed. The resulting oils were subjected to sensory and chemical analyses. According to the data organic virgin olive oils showed higher concentrations of volatile compounds synthesized throughout lipoxygenase (LOX) pathway, responsible for green grass and olive fruity sensory attributes and showed lower concentrations of phenols, related to bitter and pungent attributes. Sensorily, conventional oils were more bitter and richer in green‐leaf character, while organic oils were sweeter. Multivariate analysis showed that 10 sensory descriptors and 6 compositional parameters clearly discriminate between Picual and Hojiblanca cultivars and between organic and conventional samples. These results could be useful to clarify the different sensory characteristic between virgin olive oils obtained by conventional and organic olive crops.

Phytophthora palmivora: A New Pathogen of Olive Trees in Morocco

In spring of 2012, olive-trees with crown dieback, root rot and defoliation were observed in two years old olive tree in commercial plantations of tree nurseries in Sidi Taibi and in twenty to fifty years old field trees in Souk El Arbaa olive crops in Northwest of Morocco (Gharb area). The objective of this study was to isolate the responsible pathogen of the observed symptoms to the olive trees, to demonstrate its pathogenicity and fulfill the Koch´s postulate. Phytophthora palmivora was consistently isolated from roots (56%) and stems (73.6%) of the young olive trees and 85% from stems of field trees. Koch’s postulate was completed using two isolates of Phytophthora palmivora on 2-year old plants of Dahbia and Haouzia varieties grafted onto wild olive-trees. The affected branches percentages (Pab%) of the inoculated olive plants with the isolate 1 were higher (81.8% for Dahbia and 68% for Haouzia) than those what were inoculated with the isolate 2 (43% for Dahbia and 32% for Haouzia). The reisolation percentages (Pr%) of isolate 1 (84%) and isolate 2 (76%) in the roots of Dahbia variety were higher than isolate 1 (48%) and isolate 2 (55%) in roots of Haouzia variety. The reisolation percentage of isolate 1 in the stem of Dahbia (64%) was higher than that in the stem of Haouzia (41.33%). No significant difference was observed between the Reisolation percentages of isolate 2 in stem of Dahbia olive plants (38%) and in stem of Haouzia olive plants (33%). The pathogenicity of P. palmivora was demonstrated in the olive plants and this was the first report of this pathogen in Moroccan olive trees.

Behaviour of glyphosate in a reservoir and the surrounding agricultural soils

Glyphosate (GPS) is an herbicide currently used on olive crops in Spain, and can be transported to the nearby reservoirs currently used for human consumption. The purpose of this work was to study the behaviour and environmental fate of GPS in water and sediments of the Vibora Reservoir, its tributary river, and the surrounding agricultural soils to assess the risk of water pollution of this reservoir. The adsorption of GPS by different matrices was as follows: heading of the reservoir sediment (Cabecera)>tail sediment (Cola)>soils>Vibora sediment. The highest amount of oxides (especially Fe oxides) was observed in sediments from Cabecera and Cola whereas the lowest values were recorded on Vibora sediment. Results indicate that the highest GPS adsorption is due to the amorphous oxides and the edge sites of the clay minerals. Glyphosate adsorption increased with decreasing pH from 8 to 7. The desorption percentage of GPS from the four soils studied ranged only from 0.40 to 1.22%. Desorption was almost irreversible for Cabecera and Cola sediments, with values between 0 and 1.1%. Conversely, Vibora sediment presented about 20% desorption, probably due to its coarse texture and lower levels of amorphous oxides. Hockey-stick first-order kinetics was the best descriptor for water glyphosate dissipation at the Cabecera and Cola locations, and simple first-order kinetic for the water from the tributary Vibora River. The half-lives (DT50) were between 6.3 and 11.0days. The rapid degradation of GPS in surface waters and its practically irreversible sorption on these soils and sediments implies that GPS use in similar agricultural areas is of very low environmental risk. This manuscript also outlines the importance of the presence of photo-sensitizers in waters in the degradation routes of GPS in reservoirs.

Fungal community in olive fruits of cultivars with different susceptibilities to anthracnose and selection of isolates to be used as biocontrol agents

Olive anthracnose is an important fruit disease in olive crop worldwide. Because of the importance of microbial phyllosphere to plant health, this work evaluated the effect of cultivar on endophytic and epiphytic fungal communities by studying their diversity in olives of two cultivars with different susceptibilities to anthracnose. The biocontrol potency of native isolates against Colletotrichum acutatum, the main causal agent of this disease, was further evaluated using the dual-culture method. Fungal community of both cultivars encompassed a complex species consortium including phytopathogens and antagonists. Host genotype was important in shaping endophytic but not epiphytic fungal communities, although some host-specific fungal genera were found within epiphytic community. Epiphytic and endophytic fungal communities also differed in size and in composition in olives of both cultivars, probably due to differences in physical and chemical nature of the two habitats. Fungal tested were able to inhibited C. acutatum growth (inhibition coefficients up to 30.9), sporulation (from 46 to 86%) and germination (from 21 to 74%), and to caused abnormalities in pathogenic hyphae. This finding could open opportunities to select specific beneficial microbiome by selecting particular cultivar and highlighted the potential use of these fungi in the biocontrol of olive anthracnose.

Дослідження аеродинамічних властивостей насіння олійних культур

Дослідження аеродинамічних властивостей насіння олійних культур

AN ECONOMIC STUDY FOR THE FACTORS AFFECTING ON THE PRODUCTION OF OLIVE CROP UNDER CONDITIONS OF THE DESERT ENVIRONMENT A CASE STUDY OF SOUTH SINAI GOVERNORATE

The research aims to study the factors affecting the production of olive crop in South Sinai. A simple random sample of olive farmers distributed among two categories of land acquisitions, First category is olive farmers with 10 Feddan or less, Second category is olive farmers with more than 10 Feddan. The research resulted in the following: -Production function of first category shows statistical significant positive relationship between production and working hours machinery, and effective units of nitrogen. Farmers in this category are producing in economic stage. -The second category shows significant positive relationship between production and working hours machinery, the human labor، amount of potassium units, and the nitrogen units.

Impacts of climate projections on water balance and implications on olive crop in Minas Gerais

ABSTRACT Minas Gerais is vulnerable to climate change, with negative impacts on water balance and changes in the cultivation of several crops. Currently, the olive crop has been an alternative source for farmers, especially those in the South of the state. However, there is no information on areas with climatic conditions suitable for olive cultivation, as well as the possible impacts of climate change. The aim of this study was to verify the impact of climate projections on water balance and agroclimatic zoning for olive cultivation in the Minas Gerais, based on current climate conditions (1980-2011), and different climate change projections for three future periods (2011-2040, 2041-2070 and 2071-2100). For the current climate, Minas Gerais showed 37% of suitable area, 15% of marginal area and 48% of unsuitable area for olive cultivation. For the period 2071-2100, only 4% was classified as suitable area, 6% as marginal area and 90% as unsuitable. Projections of climate change, of both temperature and rainfall, will affect the olive cultivation, substantially reducing the suitable area in the entire state.

Net ecosystem CO2 exchange in an irrigated olive orchard of SE Spain: Influence of weed cover

No-till management and the establishment of plant cover have been implemented in olive crops in recent years in order to prevent soil erosion and increase soil organic carbon. However, the effect of these conservation practices on the net CO2 exchange at the ecosystem scale has not been explored so far. In this study, we analyze the influence of resident vegetation cover (hereafter weeds) on the net ecosystem CO2 exchange (NEE) in an irrigated olive orchard located in Jaén (SE Spain) by using the eddy covariance technique. NEE was measured in the olive orchard under two treatments, one with weed cover in the alleys from autumn to spring, and another where weed growth was avoided by the application of a glyphosate herbicide. Our study demonstrates that the presence of weeds in the alleys increased carbon assimilation in the weed-cover treatment during the weed growing period (from December to April). However, the net ecosystem CO2 uptake decreased in the weed-cover treatment during late spring (May and June), after weeds were cut and left on the soil, compared to the weed-free treatment, probably due to an increase in soil respiration. On an annual basis, weed removal decreased net carbon uptake by 50% compared to the weed-cover treatment. The annual NEE was −140gCm−2y−1 in the weed-cover treatment and −70gCm−2y−1 in the weed-free treatment. In summary, our study demonstrates that, during the first year of differential treatment, maintenance of weed cover in olive groves has a positive effect on CO2 uptake and enhances the capacity of the agro-system to act as a net CO2 sink.