Spanish Journal of Agricultural Research
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Effect of cultivar and year of harvest on the mineral composition of Algerian extra-virgin olive oils
No full textAim of study: To evaluate the effect of cultivar and year of harvest on the content of mineral elements of Algerian extra virgin olive oils.Area of study: Technical Institute of Arboriculture of Fruits and Vine (TIAFV), Bejaia, Algeria.Material and methods: The mineral contents of extra virgin olive oils from ten cultivars during two consecutive campaigns 2014/2015 and 2015/2016 were determined using atomic absorption spectrometry and absorption in a graphite furnace after microwave-assisted acid digestion. Principal component analysis was applied to correlate the mineral content with cultivar type and year of harvest.Main results: Mean concentrations for Fe, Zn, Cu, Na, K, Mg, As and Co in samples were observed in the range of 1.640-13.213, 1.546-32.866, 1.375-3.337, 19.666-104.720, 4.573-117.133, 0.120-2.560, 0.006-0.146 and 0.002-0.051 μg g-1, respectively. The first three principal components retained 76.25% of the variance. The determinants of the effect of cultivar type and year of harvest were Fe and Na; Mg, Co and As, respectively.Research highlights: The study showed that mineral composition of the olive oils was mainly determined by the cultivar and the year of harvest
Phenological diversity in a World Olive Germplasm Bank: Potential use for breeding programs and climate change studies
No full textAim of study: Crop phenology is a critical component in the identification of impacts of climate change. Then, the assessment of germplasm collections provides relevant information for cultivar selection and breeding related to phenology, being the base for identifying adaptation strategies to climate change.Area of study: The World Olive Germplasm Bank located at IFAPA Centre “Alameda del Obispo” (WOGB-IFAPA) in Cordoba (Southern Spain) was considered for the study.Material and methods: Data gathered for nine years on flowering and ripening time of olive cultivars from WOGB-IFAPA were evaluated. Thus, full flowering date (FFD) for 148 cultivars and ripening date (RD) for 86 cultivars, coming from 14 olive growing countries, were considered for characterization of olive phenology and for calibration/validation of phenological models.Main results: The characterization of WOGB-IFAPA has allowed the identification of cultivars with extreme early (‘Borriolenca’) and late (‘Ulliri i Kuq’) flowering as well as the ones with extreme early (‘Mavreya’) and late (‘Gerboui’) ripening dates. However, the very limited inter-cultivar variability, especially for FFD, resulted in a non-optimal simulation models performance. Thus, for FFD and RD the root mean square error was around 6 and 24 days, respectively. The limited inter-cultivar variability was associated to the low average temperatures registered during winter at WOGB-IFAPA generating an early accumulation of the chilling requirements, thus homogenizing FFD of all the analyzed cultivars.Research highlights: The identification of cultivars with early FFD and late RD provides useful information for breeding programs and climate change studies for identifying adaptation strategies
New estimates of total factor productivity, technical and efficiency changes for the global agricultural economy
No full textAim of study: The accuracy of international and intertemporal comparisons of total factor productivity (TFP) growth requires the use of indicators that satisfy transitive and multiplicative properties, such as the Färe-Primont index (FPI). This paper compares the evolution of TFP in global agriculture.Area of study: Worldwide.Material and methods: The evolution of TFP in global agriculture was measured by the traditional Malmquist index (MI) and by the FPI, with alternative measurements of input capital.Main results: We found a significantly lower TFP growth with the FPI. New estimates of TFP growth for 1961-2015 show that output oriented scale-mix efficiency drives TFP growth, with an important technological change between 1996 and 2000 and another in 2014. Regional comparisons reveal heterogeneous trends in efficiency, linked to institutional reforms and agricultural R&D.Research highlights: More realistic figures and global comparisons of agricultural productivity provide a better understanding to implement better policies. Available measures of capital stock do not yield significant differences in TFP estimations, but the precise identification and estimation of the heterogeneous drivers and burdens is fundamental for boosting agricultural productivity and its benefits on global food security
Sophorolipids: A review on production and perspectives of application in agriculture
No full textSophorolipids are bioactive molecules that have gained a lot of attention in the recent decades due to their unique functional properties of reducing surface and interfacial tension, emulsification and solubilization. They are mainly produced by the yeast Candida bombicola and are composed of a sugar moiety linked to a fatty acid chain. Sophorolipids are non-toxic, highly efficient and stable at extreme conditions and possess environmentally friendly characteristics over the chemical surfactants. This review is focused on the main characteristics of sophorolipids, fermentation processes, and their utilization in the agricultural field. In this context, sophorolipids are very suitable for use in agriculture, as enhancers of solubility and mobility of plant nutrients, which could result in increased plant biomass, root size and fruit yield. In addition, they could be used for biodegradation of oils, bioremediation of heavy metals in contaminated soils, and as potential biopesticides, to control phytopathogenic microorganisms in agriculture. The extensive use of chemical pesticides has led to widespread insecticide resistance and to hazards to human health and the environment due to their high toxicity. Thus, the introduction of a new biomolecule to control plant diseases and increase crop yield has become an interesting alternative. As a result of the demonstrated antimicrobial activity towards phytopathogenic bacteria and fungi, sophorolipids could be extensively explored in the agriculture field, as a sustainable and natural multifunctional agent for plant crops and soils
Host and environmental factors as determinants of equine piroplasmosis seroprevalence in Central Spain
No full textAim of study: To estimate equine piroplasmosis seroprevalence, identify associated risk factors and assess infection recentness.Area of study: Community of Madrid (Central Spain)Material and methods: Sera from 139 horses and 40 donkeys were examined by cELISA to evaluate Babesia caballi and Theileria equi seroprevalences and examine potential risk factors. They included species, gender, age, breed, colour coat, dedication, external parasite treatments, access to pasture, contact with other species, new introduction, tick infestation, farm altitude, land cover, soil type and climatic zone. A bivariate analysis was performed and significant variables were included in a logistic regression model to examine their independent contribution. In positive samples ELISA inhibition percentiles (EIPs) were used to assess whether infections were old or recent.Main results: True seroprevalence (95% CI), adjusted for test sensitivity and specificity was 19% (13-27) for T. equi and 1% (0-3) for B. caballi. In the bivariate analysis, T. equi seroprevalence varied significantly according to horse and farm-level explanatory variables; high seroprevalence groups generally had high EIPs suggesting recent infection. The multivariable analysis revealed that T. equi seroprevalence increased with age, it was higher in police horses compared to sporting, recreational and breeding animals and in those living in lower altitude where planosol soil type was predominant.Research highlights: T. equi seroprevalence in the area was significantly higher than B. caballi seroprevalence and depends on animal management and environmental factors that affect vector abundance and diversity. Identified risk factors must be considered to improve tick and tick-borne disease control and prevention
Effect of stocking density and use of environmental enrichment materials on the welfare and the performance of pigs in the growth and finishing phases
No full textAim of study: To evaluate the effects of stocking density and the use of environmental enrichment (EE) objects on the welfare and the performance of pigs in the growing and finishing phases.Area of study: The southern region of Brazil.Material and methods: A total of 240 pigs, 120 immunocastrated males and 120 females, with an initial weight of 22.38 ± 2.38 kg and mean age of 65 days, were submitted to two stocking densities conditions (0.85 and 1.28 m²pig) with and without EE for 117 days. The experimental design was a 2×2×2 factorial (two categories, two densities, and two EE conditions), with six replicates. Performance variables and behavior were evaluated.Main results: For stocking density, there was a significant difference in the finishing phase from 148 to 161 days of age for the final weight (FW), average daily weight gain (ADWG), and feed conversion rate (FCR). For the EE factor, there was no difference in any of the phases or in the overall period. In the overall period, the higher availability of space improved the results of FW (140.56 kg vs 136.63 kg), ADWG (1.005 kg vs 0.974 kg), and FCR (2.05 vs 2.10). There was no effect of EE, stocking densities, or their interaction on the frequency of different behaviors of the pigs in the growth and finishing phases.Research highlights: There was no effect of interactions between enriched environments, stocking densities, and sex for animal performance and behavioral frequencies; however, differences between the factors were observed separately. The higher availability of space improved the results of FW, ADWG, and FCR
Evapotranspiration and its components over a rainfed spring maize cropland under plastic film on the Loess Plateau, China
No full textAim of study: To determine seasonal variations in evapotranspiration (ET) and its components; and ascertain the key factors controlling ET and its components in a rainfed spring maize field under plastic film.Area of study: Shouyang County in Shanxi Province on the eastern Loess Plateau, ChinaMaterial and methods: Eddy covariance system combined with micro-lysimeters and meteorological observing instruments were used in the field. The manual method was used to measure the green leaf area index (GLAI) during the growing season.Main results: In 2015 and 2016, the growing season ET accounted for 80% and 79% of annual ET, respectively. Soil evaporation (E) accounted for 36% and 33% of the growing season ET in 2015 and 2016, respectively. The daily crop coefficient increased with increasing GLAI until a threshold of ~3 m2 m−2 in the canopy-increasing stage, and decreased linearly with decreasing GLAI in the canopy-decreasing stage. At equivalent GLAI, daily basal crop coefficient and soil water evaporation coefficient were generally higher in the canopy-increasing and -decreasing stages, respectively. During the growing season, the most important factor controlling daily ET, T, and E was net radiation (Rn), followed by GLAI for daily ET and T, and soil water content at 10-cm depth for daily E; during the non-growing season, daily ET was mainly controlled by Rn.Research highlights: The daily crop coefficient and its components reacted differently to GLAI in the canopy-increasing and -decreasing stages
Influence of production system and finishing feeding on meat quality of Rubia Gallega calves
No full textAim of study: Beef quality is mainly affected by finishing feeding (FF) and production system (PS). The effects of PS (extensive, semi-extensive, traditional and intensive systems) and FF from Rubia Gallega calves were compared in terms of meat quality.Area of study: Galicia (NW Spain)Material and methods: Calves (n=10 per treatment) were slaughtered at nine months of age and meat samples were assessed in terms of meat quality attributes such as physicochemical, nutritional and sensory analysis performed by a trained panel.Main results: Meat chemical composition varied (p<0.01) with PS and FF. The semi-extensive system showed the lowest values (p<0.05) for cooking loss (22.8%) and for shear force (26.0 N) while the extensive system presented the lowest contents of saturated fatty acids (SFA) and the highest contents of linolenic acid (p<0.001). The SFA and polyunsaturated fatty acid (PUFA) contents varied with FF (p<0.05). The lowest and highest values for SFA and PUFA were displayed in extensive group finished with Pasture/Concentrate, meanwhile feedlot group finished with Concentrate/Straw showed and opposite trend. The n-6/n-3 ratio was lower than 4 for extensive and semi-extensive systems (p<0.001). In addition, tenderness and juiciness showed significant differences mainly due to FF.Research highlights: This study showed that meat of calves reared in extensive systems was the healthiest, regarding total fat and fatty acid composition. It can be concluded that finishing feeding, and PS affected meat quality. Hence the potential usefulness of these results is to improve meat quality and safety according to market demands
Electrocution and containment methods to reduce the activity of red palm weevil (Rhynchophorus ferrugineus, Ol.)
No full textAim of study: To evaluate the susceptibility of the Rhynchophorus ferrugineus to electric discharges, to eventually use this application in synergy with other methods as part of an integrated control strategy.Area of study: Worldwide.Material and methods: Three different electric voltage intensities were applied to R. ferrugineus to investigate the insect’s susceptibility in both adult and larval stages. The transmission and diffusion of electricity within a portion of the palm tree was tested. In addition, the suitability of containment materials for handling and transportation of plant residues was tested.Main results: The results of adult test showed that the total number of eggs laid per mating couple and the number of larvae born were about 1.5 times higher in the control compared to the electrified samples. The duration of the electric discharge on larvae had a small impact on the mortality rate, while the electric voltage showed a strong impact on mortality (87% for 10 V and 99% for 15 V). The presence of a significant electric current was observed in a viable portion of stem (distance from the source of electricity 10 cm) providing a direct current with 250 V tension. Among the materials tested for the transportation of palm residues, the aluminium net sheet showed the best results in the containment of both larval and adult individuals.Research highlights: Electrocution has proven to be a system which can help in the control of red palm weevil reducing the use of synthetic chemicals
