bluuebunny/crossref_metadata_2025 huggingface dataset:
Managed vs. unmanaged. Structure of beech forest stands (Fagus sylvatica L.) after 50 years of development, Central Bohemia
Authors: Bilek L. , Remes J. , Zahradnik D.
Published: December 2011

In this study, the structure and spatial patterns of adjacent beech (Fagus sylvatica L.) forest stands, both those having undergone intensive management and those without management intervention over the last 50 years were analyzed. Data was collected from six 1ha permanent research plots. Four plots were established in varying parts of the reserve, comprising entirely of even-aged managed forest stands; two 1-ha permanent plots were located in a non-interventional stand. For each woody stem, basic dendrometrical data and coordinates were measured. The total volume of dead wood (standing and fallen) and its classes of decay were recorded. The structure and species diversity of forest stands were analyzed using skewness and the coefficient of variation of dbh distribution, the Gini index, the Shannon index, the mingling index, the Pielou index of segregation and the Hopkins-Skellam, Pielou-Mountford, Clark-Evans aggregation indices, the diameter differentiation index and Ripley K function. The diameter distribution of the managed stands was generally normal, albeit with a large diameter range and with a typical flat diameter curve. A general lack of giant trees, lower rates of coarse woody debris (from 0.2 to 0.5% of the total living volume) and random tree distribution were also confirmed. Within the investigated area, the diameter differentiation and Gini indices along with the degree of skewness and the coefficient of variation made it possible to monitor the shift from even-aged forest management to spontaneous forest development. In general, spontaneous development was marked mainly by aggregated tree distribution in the middle and lower layer, and a shift from normal to reversed J-shaped dbh distribution. The total volume of deadwood in one of the unmanaged plots amounted to 48.10 m3/ha (9.5% of living wood volume). The use of adequate structural and spatial analysis as indicators of natural forest development are discussed.
Understanding long-term hunting statistics: the case of Spain (1972-2007)
Authors: Martínez-Jaúregui M. , Arenas C. , Herruzo A.C.
Published: December 2011

Hunting is assuming a growing role in the current European forestry and agroforestry landscape. However, consistent statistical sources that provide quantitative information for policy-making, planning and management of game resources are often lacking. In addition, in many instances statistical information can be used without sufficient evaluation or criticism. Recently, the European Commission has declared the importance of high quality hunting statistics and the need to set up a common scheme in Europe for their collection, interpretation and proper use. This work aims to contribute to this current debate on hunting statistics in Europe by exploring data from the last 35 years of Spanish hunting statistics. The analysis focuses on the three major pillars underpinning hunting activity: hunters, hunting grounds and game animals. First, the study aims to provide a better understanding of official hunting statistics for use by researchers, game managers and other potential users. Second, the study highlights the major strengths and weaknesses of the statistical information that was collected. The results of the analysis indicate that official hunting statistics can be incomplete, dispersed and not always homogeneous over a long period of time. This is an issue of which one should be aware when using official hunting data for scientific or technical work. To improve statistical deficiencies associated with hunting data in Spain, our main suggestion is the adoption of a common protocol on data collection to which different regions agree. This protocol should be in accordance with future European hunting statistics and based on robust and well-informed data collection methods. Also it should expand the range of biological, ecological and economic concepts currently included to take account of the profound transformations experienced by the hunting sector in recent years. As much as possible, any future changes in the selection of hunting statistics should allow for comparisons between new variables with the previous ones.
Environmental variability and its relationship to site index in Mediterranean maritime pine
Authors: Bravo-Oviedo Andrés , Roig Sonia , Bravo Felipe , Montero Gregorio , Del-Río Miren
Published: December 2011

Environmental variability and site productivity relationships, estimated by means of soil-site equations, are considered a milestone in decision making of forest management. The adequacy of silvicultural systems is related to tree response to environmental conditions. The objectives of this paper are to study climatic and edaphic variability in Mediterranean Maritime pine (Pinus pinaster) forests in Spain, and the practical use of such variability in determining forest productivity by means of site index estimation. Principal component analysis was used to describe environmental conditions and patterns. Site index predictive models were fitted using partial least squares and parsimoniously by ordinary least square. Climatic variables along with parent material defined an ecological regionalization from warm and humid to cold and dry sites. Results showed that temperature and precipitation in autumn and winter, along with longitudinal gradient define extreme site qualities. The best qualities are located in warm and humid sites whereas the poorest ones are found in cold and dry regions. Site index values are poorly explained by soil properties. However, clay content in the first mineral horizon improved the soil-site model considerably. Climate is the main driver of productivity of Mediterranean Maritime pine in a broad scale. Site index differences within a homogenous climatic region are associated to soil properties.
Effects of the sequence wildfire-harvesting-coppice sprout selection on nutrient export via streamfloe in a small E. globulus watershed in Galicia (NW Spain)
Authors: Fernández Cristina , Vega José A. , Bara Salvador , Alonso Margarita , Fonturbel Teresa
Published: December 2011

An experimental study was carried out between 1987 and 1999, to assess the effect of the sequence wildfire-clearfelling-coppice sprout selection thinning, on streamflow nutrient export in a Eucalyptus globulus Labill. watershed in Galicia (NW Spain). The effects of such a sequence on nutrient export via streamflow had not been previously evaluated. A wildfire in 1989 caused a significant increase in nutrient exports in streamflow during the following two years. No significant effect was observed the third year after wildfire. After clearfelling in 1992, inputs via precipitation compensated for nutrient exports in streamflow, except for K the first year following harvest and NO3- during the three years after this operation. Coppice sprout selection thinning in 1995 had less effect on nutrient exports than wildfire or harvest. The results presented here could may help in evaluating the effects of current intensive forest management and perturbations that affect eucalypt stands in NW Spain.
Germination and emergence variability of alfalfa (Medicago sativa L.) landraces collected in Southern Tunisia oases
Authors: Benabderrahim M. A. , Haddad M. , Hamza H. , Ferchichi A.
Published: December 2011

Variability in germination under controlled conditions with and without salt, seeds characteristics and field emergence were evaluated for 20 landraces of Medicago sativa ssp sativa, a forage legume collected from three sites in Tunisia. Highly significant differences were recorded among the landraces (p < 0.001) for all the characters studied except tegument colour. Number of seeds produced per plant ranged between 378 and 460 seeds g–1. Emergence responses of seeds were different among landraces and sites and their values ranged between 12 to 45%. Salt stress (150 mM) caused substantial reduction in final and rate of germination of all the landraces with an average decline of 62.4 and 69.7%, respectively. Final germination values ranged from 26.5 to 75.75% when supplied distilled water. However, final germination values ranged from 10.75 to 32.5% when the seeds were exposed to saline water (150 mM). Rate of germination ranged from 12.75 to 63.25% and from 6.25 to 21.25% at non-saline and salt stress, respectively. Cluster analysis separated the 20 landraces into four clusters. Three landraces in the first cluster had the lowest germination and the greatest field emergence. One landrace composed the second cluster and showed both high germination and field emergence. Two landraces in the third cluster presented greater germination and low emergence. The other landraces constituted the fourth cluster and had intermediates emergence and germination.
Effects of abandoning long-term goat grazing on species composition and species richness of pastures at La Gomera, Canary Islands
Authors: Arevalo J. R. , De Nascimento L. , Fernandez-Lugo S. , Saro I. , Camacho A. , Mata J. , Bermejo L.
Published: December 2011

Goat grazing management is a powerful ecological force structuring plant communities which effects are highly different depending on factors such as climatic conditions, grazing intensity, type of plant community, etc. Pastures in the Canary Islands have important heritage, socioeconomic and landscape values because they are the remains of traditional livestock management and a key element of local economy. An experimental study of goat grazing exclusion has been carried out in an area of La Gomera Island to determine the main effects of grazing abandonment on species richness and species composition. The species composition of La Gomera pastures is more sensitive to grazing than to climatic variability, though effects in the species richness in relation to grazing were not detected. Because the pasture origin in this area involved artificial, removing of non useful plants in order to provide land for agriculture more than 300 years ago, and using it for pastures around 80 years ago, the sustainable use has maintained this rich plant community. Grazing abandonment can have a negative effect on the pastures’ diversity, as grazing has been a strong force in the maintenance of certain species. Public promotion of this primary activity is suggested to allow the continuation with minimal effects on the vegetation composition. This will help to conserve the high diversity of this area and the promotion of natural values as well as traditional and sustainable human activities.
Introduction of cry1Ab gene into cotton (Gossypium hirsutum) enhances resistance against Lepidopteran pest (Helicoverpa armigera)
Authors: Khan G. A. , Bakhsh A. , Riazuddin S. , Husnain T.
Published: December 2011

The significant breakthrough in plant biotechnology is the development of techniques to transform genes from unrelated sources into commercially important crop plants to develop resistance against insect pests. A local cotton cultivar MNH-93 was transformed through Agrobacterium tumefaciens strain C58C1 assisted by bombardment with tungsten particles. The Agrobacterium strain contained the recombinant binary vector pKMAB harboring cry1Ab under 35S promoter. Neomycin phosphotransferase (nptII) gene was used as a selectable marker at a concentration of 50 mg L–1. The transformation efficiency remained 0.26%. The primary transformants were analyzed for transgene integration and expression through PCR and Southern Blotting and Western dot blot. The gene copy number was determined by Southern analysis in order to find out the cry1Ab integration sites. The Bt protein being produced in the transgenic plants was quantified using ImageQuant software, which ranged from 0.00 to 1.35% of the total protein. The positive plant seeds obtained from T0 progeny were further raised under greenhouse and field conditions to evaluate their field performance. Leaf biotoxicity assays were performed to determine the efficacy of introduced gene. The results showed that transgenic lines in T1 progeny have appreciable level of resistance (40-60%) against lepidopteran pests in both green house and field conditions.
Validation of two discriminant strategies applied to NIRS data spectra for detection of animal meals in feedstuffs
Authors: Soldado A. , Quevedo J. R. , Bahamonde A. , Modroño S. , Martinez-Fernandez A. , Vicente F. , Perez-Marin D. , Garrido-Varo A. , Guerrero J. E. , De la Roza-Delgado B.
Published: December 2011

For developing qualitative or quantitative applications with spectroscopic data, such as near infrared spectroscopy (NIRS), different methodologies have been proposed in the mathematical statistical and computer science literature. Useful chemometrical alternatives have emerged, such as support vector machines (SVM), widely used for modeling multivariate and non-linear systems. These methods are usually compared using the classification performance and the success of results. The aim of the present work was to develop and validate a robust, accurate and fast discriminant methodology based on NIRS data to detect presence of animal meals in feedstuffs. A linear method, modified partial least square (PLS) analysis and one non-linear method (SVM) were studied. Results showed that modified PLS model allows obtaining coefficients of determination for cross validation around 0.97. Applying SVM strategy no false negatives were detected during training step. With both strategies the lowest percentage of misclassified samples on external validation was achieved with SVM, 0% with certified standard samples containing from 0.05% to 4% of animal meals. These results show SVM strategy as a robust method of classification for detecting animal meals in feedstuffs using NIRS methodology.
Survival percentage, photosynthetic abilities and growth characters of two indica rice (Oryza sativa L. spp. indica) cultivars in response to iso-osmotic stress
Authors: Nishimura T. , Cha-um S. , Takagaki M. , Ohyama K. , Kirdmanee C.
Published: December 2011

The aim of this study was to investigate pigment degradation, chlorophyll fluorescence diminution, photosynthetic ability and growth reduction in two rice cultivars, in response to either iso-osmotic salt stress or water-deficit stress. Seedlings of rice cultivars RD6 and KDML105 were photo-autotrophically grown in MS media and subsequently exposed to –0.23 (control), –0.40 or –0.67 MPa iso-osmotic NaCl (salt stress) or mannitol (water-deficit stress) for 14 days. The survival percentage of the two rice cultivars reduced dramatically when subjected to –0.67 MPa NaCl treatment. Chlorophyll a (Chla), chlorophyll b (Chlb), total carotenoids (Cx+c), maximum quantum yield of PSII (Fv/Fm) and photon yield of PSII (ΦPSII) in the stressed seedlings were significantly lower when compared to seedlings in the control group (without mannitol or NaCl), leading to low net-photosynthetic rate (Pn) and growth reduction. In addition, the growth characters of plantlets in the salt stress conditions were more sharply reduced, and the physiological changes greater than those in water-deficit stress conditions. On the other hand, non-photochemical quenching in the leaves of stressed plantlets increased significantly, especially in response to iso-osmotic salt stress. In the present study, overall growth performance and physiological characters of KDML105 grown under iso-osmotic stress were better than those of RD6.
Evaluation of the use of low-cost GPS receivers in the autonomous guidance of agricultural tractors
Authors: Alonso-Garcia S. , Gomez-Gil J. , Arribas J. I.
Published: December 2011

This paper evaluates the use of low-cost global positioning system (GPS) receivers in the autonomous guidance ofagricultural tractors. An autonomous guidance system was installed in a 6400 John Deere agricultural tractor. A lowcostGPS receiver was used as positioning sensor. Three different control laws were implemented in order to evaluate the autonomous guidance of the tractor with the low-cost receiver. The guidance was experimentally tested with the tracking of straight trajectories and with the step response. The total guidance error was obtained from the receiver accuracy and from the guidance error. For the evaluation of the receiver’s accuracy, positioning data from several lowcost receivers were recorded and analyzed. For the evaluation of the guidance error, tests were performed with each control law at three different speeds. The conclusions obtained were that relative accuracy of low-cost receivers decreases with the time; that for an interval lower than 15 min, the error usually remains below 1 m; that all the control laws have a similar behavior and it is conditioned by the control law adjustment; that automatic guidance with lowcost receivers is possible with speeds that went up to 9 km h–1; and finally, that the total error in the guidance is mainly determined by the receiver’s accuracy.
Short communication. Use of proleptic shoots in the cutting propagation of Protea ‘Susara’ (Proteaceae)
Authors: Rodriguez-Perez J. A. , Vera-Batista M. C. , De Leon-Hernandez A. M. , Rodriguez-Hernandez I.
Published: December 2011

This study analyses the influence of auxin and wounding on the rooting of stem cuttings of Protea ‘Susara’ (P. magnifica × P. susannae) prepared from proleptic shoots. Two assays were carried out. Terminal cuttings, 10-15 cm long, treated with 4000 mg L–1 of indole-3-butyric acid (IBA) and wounded or not were used in the first experiment. The combination of wounding + IBA did not significantly improved rooting compared with the use of IBA alone (70% and 53.3% of transplantable cuttings, respectively). Three levels of IBA (0, 2,000 and 4,000 mg L–1 ) , with or without wounding, and cuttings including the total length of the shoot were used in the second assay. At the end of the trial (24 weeks), wounded cuttings treated with 2,000 mg L–1 or 4,000 mg L–1 of IBA yielded 90% of transplantable cuttings. The combination of wounding + IBA significantly favoured rooting in comparison with the use of IBA or wounding alone.
Selectivity and weed control efficacy of some herbicides applied to sprinkler irrigated rice (Oryza sativa L.)
Authors: Cavero J. , Zaragoza C. , Cirujeda A. , Anzalone A. , Faci J. M. , Blanco O.
Published: December 2011

Sprinkler irrigation can reduce the irrigation water needed to grow rice. However, most available information on weed control with herbicides is related to flood irrigated rice because this is the main growing method. Field experiments were conducted at Zaragoza (Spain) during two years to study weed control and tolerance of sprinkler irrigated rice to several herbicides. The main weeds were Atriplex prostrata Bouchér ex DC., Cyperus rotundus L., Echinochloa crus-galli (L.) Beauv. and Sonchus oleraceus L. Rice cv Guadiamar was tolerant to preemergence (PRE) application of clomazone at 0.36 kg ha-1 and oxadiazon at 0.5 kg ha–1. PRE application of pendimethalin at 1.32 kg ha–1 combined with clomazone at 0.36 kg ha-1 decreased rice yield. Postemergence (POST) application of bentazon at 1.6 kg ha–1 + MCPA at 0.25 kg ha–1 did not injure rice but POST application of azimsulfuron at 0.025 kg ha–1 produced visual crop injury. Only treatments that controlled grassy weeds since rice was planted and by more than 80% at harvest time lead to acceptable rice yield (> 5,000 kg ha–1). Clomazone applied PRE at 0.36 kg ha–1 provided good control of grassy weeds (> 80%) and the highest rice yield, so it is recommended as a selective and efficacious PRE treatment for weed control of annual weeds in sprinkler irrigated rice. The perennial purple nutsedge was difficult to control at high plant densities (> 150 plants m–2) and the recommended herbicide is azimsulfuron applied at POST at 0.02 kg ha–1.
The effects of the combination of salinity and excess boron on the water relations of tolerant tomato (Solanum lycopersicum L.) cv. Poncho Negro, in relation to aquaporin functionality
Authors: Contreras C. , Montoya A. , Pacheco P. , Martinez-Ballesta M. C. , Carvajal M. , Bastias E.
Published: December 2011

As elevated levels of boron (B) are accompanied by conditions of excessive salinity with drastic consequences for crops,it is crucial to find a crop that is tolerant to these conditions. In this work, the interaction between salinity and excess Bwith respect to aquaporin-mediated changes by blockade of mercury and water relations were studied as well as the osmotic adjustment of the plants. The treatments, for tomato ‘Poncho Negro’ cultivated hydroponically in a controlled environment chamber, were control (75 and 150 mM) NaCl and/or 5 mg L–1 or 20 mg L–1 B. Hydraulic conductance (L0) of detached exuding root systems exhibits large variations in response to abiotic stimuli. No additive (synergic) effects of B and salinity were observed. Under salinity, the plants increased their turgor, compensating for the decrease in the leaf water potential through the reduction in the leaf osmotic potential by the accumulation of soluble sugars and proline. The involvement of Hg2+-insensitive aquaporins or the osmotic gradient as the main force for water flow through the apoplastic pathway must be contemplated. Finally, all the data reveal the tomato cv. Poncho Negro to be a germplasm of agronomic interest and a good alternative for cultivation areas with high content of salts and the excess B of the soil and irrigation water.
Physiological, biochemical and histopathological effects of fermentative acidosis in ruminant production: a minimal review
Authors: Xu Y. , Ding Z.
Published: December 2011

Rumen acidosis is increasingly recognized as a significant disorder in ruminants that increases the morbidity and mortality of animals, especially for dairy cattle and sheep. Acidosis is not just D-lactate which disturbs the acid-base status and the severity of acidosis is related to many factors and not only due to the level of lactic acid production, resulting in difficulties in diagnosing acidosis. Therefore, an understanding of the physiological, biochemical, and histopathological effects of rumen acidosis is fundamental for developing effective methods of prevention and treatment of fermentative acidosis. The present review evaluates the physiology, biochemistry, and pathophysiology of fermentative acidosis as well as gives a conclusion and look-forward. The information will benefit the health and welfare of ruminants and contribute to modern systems of ruminant production.
Physico-mechanical characteristics of rose petals dealing with the pneumatic harvest of Rosa damascena
Authors: Yilmaz D. , Ekinci K.
Published: December 2011

For the design of harvesting machines is important the study of characteristics dealing with the harvest of crops. This study focused on some physico-mechanical characteristics of rose petals, which are important for pneumatic harvest mechanization of Rosa damascena Mill. These characteristics are terminal velocity, picking force, mass, projection area, density, and drag coefficient of rose petals. The petals were handpicked at 06:30 a.m. (S1), 08:30 a.m. (S2), 10:30 a.m. (S3), and 12:30 p.m. (S4) at four different dates in 2009, June 5 (H1), June 11 (H2), June 17 (H3), and June 23 (H4), covering the potential flowering period. Terminal velocity of rose petals varied between 1.572 and 1.257 m s–1; the picking force from 0.501 to 1.005 N; the mass measured from 0.049 to 0.122 g; projection area from 13.830 cm2 for H1S4 to 7.071 cm2 for H4S1; drag coefficient from 0.790 for H2S1 to 0.287 for H1S4. The results of the study indicate that as far as terminal velocity of rose petals is concerned the harvest of R. damascena should be executed towards the end of H4 and S4. On the other hand, the magnitude of the picking force, the density, and the drag coefficient of rose petals decrease when the harvesting hour increases from H1 to H4 and the harvesting date increases from S1 to S4, which makes necessary to increase aspiration pressure.
Short communication. Susceptibility of Phoenix theophrasti (Palmae: Coryphoideae) to Rhynchophorus ferrugineus (Coleoptera: Curculionidae) and its control using Steinernema carpocapsae in a chitosan formulation
Authors: Dembilio O. , Karamaouna F. , Kontodimas D. C. , Nomikou M. , Jacas J. A.
Published: December 2011

The invasive red palm weevil, Rhynchophorus ferrugineus Oliv. (Coleoptera: Curculionidae) is the most destructive pest of palms in the world. It has been reported on 19 palm species belonging to 15 different genera. The host status of theCretan Date Palm, Phoenix theophrasti, remains unclear. Therefore, the present study was carried out to ascertain the host status of this protected palm species. Additionally, the efficacy of entomopathogenic nematodes in a chitosan formulation to control this pest in P. theophrasti was assessed. Our results showed that healthy 4-yr-old P. theophrasti palms were not infested by adult females after 9 days exposure in a population density of 3 adults per plant. However, infestation was successful when neonate larvae were artificially introduced in palms. Therefore, natural populations of P. theophrasti could be at risk. Gummy secretion was observed in both naturally and forced infested palms indicating the existence of antibiosis in this species. Curative applications with the entomopathogenic nematode Steinernema carpocapsae in a chitosan formulation in early infested P. theophrasti palms managed to reduce insect’s activity and could help the palms to recover.
Evaluating the RUSLE model and developing an empirical equation for estimating soil erodibility factor in a semi-arid region
Authors: Vaezi A. R. , Sadeghi S. H. R.
Published: December 2011

Soil erodibility is one of six factors in the revised universal soil loss equation (RUSLE) that reflects the ease with which the soil is detached by splash during rainfall and/or by surface flow. This study was therefore carried out to assess applicability of the RUSLE model in estimating erodibility factor (K) and develop an appropriate equation to predict this factor in soils of the semi-arid region in Iran. Thirty six dry-farming lands were considered in a 900 km2 agricultural zone in Hashtroud, northwest of the country. Soil loss was measured at 108 unit plots under natural rainfall events for a 2-year period from March 2005 to March 2007. The K-factor was estimated using the mean geometric diameter of soil particles (Dg) and measured based on the mean annual soil loss per unit rainfall-runoff erosivity factor (R). Based on the results, the estimated K values varied from 0.0316 and 0.0485 t h MJ–1 mm–1 and the measured K values were ranged from 0.0014 to 0.0050 t h MJ–1 mm–1. The measured K values were almost 14 fold smaller than the estimated values on average. There was no considerable correlation between the measured K-factor and Dg (R2 = 0.05). Multi-regression analysis showed that the measured K-factor was significantly related to the aggregate stability and permeability (R2= 0.90, p < 0.001). Although Dg was positively correlated with the soil permeability (R2 = 0.42), it did not strongly affect the measured K-factor (R2 = 0.05) because of its negative effect on aggregate stability (R2 = 0.64)
Evaluation of nitrate leaching in a vulnerable zone: effect of irrigation water and organic manure application
Authors: Ruiz-Ramos M. , Gabriel J. L. , Vazquez N. , Quemada M.
Published: December 2011

Sustainable agricultural practices are needed to minimize nitrate leaching. The crop-soil simulation model STICS coupled with a geographic information system was used to estimate the amount of NO3 – leaching and to assess the ability of alternative management practices to reduce NO3 – leaching in a nitrate vulnerable zone (NVZ) in La Rioja, Spain. Model performance was examined by comparing the simulations and measurements of irrigated grapevine crops (variety Tempranillo) over various soil types. The measurements were obtained from five pilot plots over a period of three years and included the mineral nitrogen, the water content of the soil profiles and the nitrogen content of the crops. The simulated and measured values were in satisfactory agreement with each other. Then, eight management scenarios were simulated, combining two NO3 – concentrations of irrigation water and four levels of organic manure applications. The simulations identified good agricultural practices (GAP) for mitigating NO3 – pollution. High soil mineral nitrogen (SMN) and water pollution were driven by both the NO3 – concentration of irrigation water and the level of organic manure application. The use of aquifer water for irrigation would lead to diminish aquifer pollution at the expense of maintaining high SMN, non desirable for grape quality production. River water would offer an opportunity for the recovery of soils and the improvement of underground water quality if the application of organic manure was limited according to soil type. Differences in NO3 - leaching of the NVZ soils depended more on their ability to store N than on their annual drainage.
Modelization of the spatial distribution of corn head smut (Sporisorium reilianum Langdon and Fullerton) in Mexico
Authors: Sanchez-Pale J.R. , Ramirez-Davila J.F. , Gonzalez-Huerta A. , De Leon C.
Published: December 2011

Sporisorium reilianum has caused significant economical damages in Mexico, in temperate and relatively dry areas, where maize is cultivated. The knowledge about the spatial distribution of this pathogen is basic to elaborate integrated management programs, and precise and efficient the development of sampling methods and control techniques. Unfortunately, in Mexico there are no studies on spatial behavior of this disease. For this reason, this study was developed to model S. reilianum spatial distribution by the year 2008; and also, to establish its spatial behavior with geostatistics techniques. The sampling method established 100 points for each of 30 locations of 27 municipalities in the State of Mexico. In each point, 500 plants were counted and those presenting symptoms of the disease were recorded. A geostatistical analysis was done in order to estimate the experimental semivariograms. It was adjusted to theoretical models (spherical, exponential or gaussian) with the program Variowin 2.2; later, it was evaluated through the crossed validation with the geostatistical interpolation method or kriging. Finally, aggregation maps of the disease were elaborated. The disease was found in 30 sampled locations; all of them presented an aggregated spatial pattern of the disease. Twenty one locations were adjusted to the spherical model, five to the exponential model and two to the Gaussian model. Aggregation maps were established in all models. It was observed that S. reilianum was not uniform in the assess areas. Results showed the spatial distribution of S. reilianum and real infestation in field using geostatistical techniques.
Irrigation return flows and phosphorus transport in the Middle Ebro River Valley (Spain)
Authors: Skhiri A. , Dechmi F.
Published: December 2011

Currently, there is an increased interest in the study of phosphorus (P) loss from soils aimed to understand and mitigate water eutrophication problems. The main objective of this study is to describe P losses in five irrigated agricultural watersheds considered as representative in terms of agricultural water management. Weekly water samples were collected during the 2007 hydrologic year (HY) at the watershed outlets and three P forms (total P, TP; total dissolved P, TDP; and particulate P, PP) were analyzed during irrigation (IS) and non-irrigation season (NIS). The P load per hectare was used to compare the study areas with other non-irrigated agricultural watersheds in Spain and Europe. Results indicate that most of the study areas showed increases in TP at higher flows. Annual TP concentrations were higher than the critical eutrophication threshold (0.02 mg L–1), with TDP being the dominant fraction. The TP was higher during the IS than during the NIS, except for the Arba River where seasonal TP concentration showed the highest values (0.237 and 0.275 mg L–1, respectively). Results also show that average TP yield (0.73 kg P ha–1 year–1) was higher than others reported on non-irrigated agricultural lands in Spain and Europe. This work is of great relevance and indispensable for guiding future research on P transfer aimed at establishing corrective measures to sustain irrigated agricultural productivity and surface water quality.
Use of CO2 balances to determine ventilation rates in a fattening rabbit house
Authors: Estelles F. , Fernandez N. , Torres A. G. , Calvet S.
Published: December 2011

Determining accurately the ventilation rates from rabbits houses, using non-expensive and non-invasive methods, is needed. The main aim of this work was to test the carbon dioxide balance as a method to determine the ventilation rate in fattening rabbit farms. In addition, the CO2 release rate from rabbit manure was measured, and the effect of CO2 concentration gradient between the inlet and outlet air of the building, on the method accuracy was characterized. To these aims, a fattening rabbit farm was evaluated during two periods and CO2 concentrations were simultaneously monitored in the inlet and outlet air by using a photoacoustic monitor. Ventilation rates were also directly determined by calibration of the exhaust fans and monitoring their operation times. CO2 emissions from manure were measured during two whole fattening periods, using a flux chamber and a photoacoustic monitor. The effect of CO2 concentrations gradient between the inlet and outlet of the farm on the accuracy of the balance was studied through statistical regressions. The CO2 emission from manure resulted in 13% of total CO2 emissions (considering both manure and animals). No statistically significant differences were found between measured and calculated ventilation rates. The effect of the CO2 gradient on the balance accuracy was statistically significant only in one of the trials. According to these results, the CO2 balance can be recommended for the determination of ventilation rates in fattening rabbit buildings.
The effects of amino acids fertilization incorporated to the nutrient solution on mineral composition and growth in tomato seedlings
Authors: Garcia A. L. , Madrid R. , Gimeno V. , Rodriguez-Ortega W. M. , Nicolas N. , Garcia-Sanchez F.
Published: December 2011

The aim of this research was to determine the effects on growth variables and leaf mineral concentration of tomato plants watered with nutrient solutions containing amino acids. Two separate experiments were then carried out to achieve this goal. In the first experiment, plants were watered with seven different nutrient solutions consisting of half-strength Hoagland solution supplemented with single (Alanine, Serine, Phenylalanine, Tyrosine) or combined (Ala + Ser; Phe + Tyr) amino acids, each at 0.2 mM of concentration. The control nutrient solution did not have any amino acids added. Relative to the control, growth variables were not affected by the presence of amino acids. In general, the mixture of Ala + Ser increased the leaf Ca2+ concentration, and the aliphatic amino acid treatments favoured an increase in leaf K+, Fe, Cu, and Mn concentrations. In addition, amino acids with hydroxyl groups in their structure, Ser and Tyr, increased Mg2+ concentration. In the second experiment, the nutrient solutions were supplemented with 0.05 mM of the same amino acids (T1). Control plants were irrigated with amino acid-free nutrient solution (T0). The concentration of Ca2+, K+, Mg2+, Fe, Cu, and Mn in the leaf also increased due the amino acids treatment. Chlorophyll contents in the leaves and amino acids compositions in the xylem sap and leaf water relation were also determined. In conclusion, the data reported in the two experiments point out that the application of amino acids to the nutrient solution has a beneficial effect on the leaf mineral status and on the chlorophyll concentration of the leaves.
Genetic variability and pollen effect on the transmission of the chemical components of the almond kernel
Authors: Font i Forcada C. , Kodad O. , Juan T. , Estopañan G. , Socias i Company R.
Published: December 2011

The chemical components of the almond kernel are traits contributing to almond quality and must be considered in breeding programs searching for high-quality almonds. Thus, total protein, oil content, fatty acid composition and tocopherol content were determined in 200 genotypes from four progenies from the almond (Prunus amygdalus Batsch) breeding program of Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Spain. All components showed significant differences among genotypes, as well also among progenies, showing a significant effect of the pollen parent in the average composition of each family. The protein content ranged between 8.4 and 24.7%, and the oil content between 37 and 67.5% of dry matter (DM). The major fatty acid was oleic, followed by linoleic. Alphatocopherol was predominant among the different tocopherol homologues (α, δ, and γ). Significant correlations were found among some components, such as total oil, oleic acid, and γ- and δ-tocopherol, but not with α-tocopherol. Heritability estimates were high for oil content and γ-tocopherol, medium for linoleic acid and α-tocopherol, and low for the rest of components. These results remark the importance of the genetic background of an individual for the quality profile of its kernels and the significant and positive effect of the pollen on the transmission of most chemical components of the almond kernel.
Ampelography and microsatellite DNA analysis of autochthonous and endangered grapevine cultivars in the province of Huesca (Spain)
Authors: Casanova J. , Mozas P. , Ortiz J. M.
Published: December 2011

The province of Huesca (Spain) is a traditional area for growing grapevines. There are archaeological evidences of their cultivation at least since the second century B.C. Nevertheless, in the last years the varietal diversity is markedly decreasing due to the rooting out of old plantations that are replaced with new broadly known varieties, since the market demands a certain standardization of the wine producing varieties. The objective of this study is to examine and characterise the existing varieties in the province of Huesca, mainly in vineyards planted before 1960. A total of 47 accessions were collected in 14 plots from 11 municipalities. Moreover 36 accessions from the region, planted at the Movera grapevine germplasm bank (Movera collection), located at Zaragoza (Spain) were included in the study. Ampelographic characterisation was carried out with 50 OIV descriptors for two consecutive years. Molecular characterisation was made with the following microsatellites: VVS2, VVMD5, VVMD7, VVMD27, VrZAG62 and VrZAG79. Ampelographic results were compared by cluster analysis. Most of the accessions were identified, being considered as new varieties: two white, Carrillera and Moscatel, and six red or black: Macicillo, Bomogastro, Angelina, Terrer, Parraleta Roja and Garnacha Gorda. Several new synonymies were detected, as Miguel for Vitadillo or Parrel for Trepat. Seven accessions remained unidentified. Out of the studied Vitis vinifera varieties, 23 were considered as endangered, indicating the valuable patrimony of the zone to be preserved.
Effect of feeding systems on live-weight, reproductive performance, milk yield and composition, and the growth of lambs in native Spanish Ojalada sheep
Authors: Miguel-Romera J. A. , Calvo-Ruiz J. L. , Ciria-Ciria J. , Asenjo-Martin B.
Published: December 2011

To produce lambs of the Ojalada breed, included within the Protected Geographical Indication “Lechazo de Castilla y Leon”, three feeding systems were compared (40 ewes/treatment): a) IND +CH+ C, ewes kept indoors and fed chopped straw plus concentrate, prepared on location and distributed mechanically (total mixed ration; TMR); b) IND + W+C, ewes kept indoors and fed whole straw in the form of large bales, plus concentrate (TMR); and c) GR + C, free-range grazing plus concentrate (control group). Live-weight, reproductive endpoints, milk production and composition (10 sheep from single lambing/treatment), and growth of lambs up to 35 days were assessed. Live-weight of ewes from the IND + CH + C group were similar to those in the GR + C group (p > 0.05). Treatments did not differ for fertility or prolificacy, except for fecundity in the IND +W+ C group compared to values for the IND + CH+ C and GR + C groups. The quantity of milk produced through 35 days did not differ (~1,300 mL d–1), with peak production in all three groups in the third week of lactation (~1,500 mL d–1). Milk chemical composition generally did not differ among treatments; only ewes in the IND +CH+C group presented greater protein content in the third week of lactation. Although treatments did not differ in live-weight at birth to 35 days, IND + CH+ C lambs differed in average daily gains, reaching 9 kg of live-weight (minimum weight for slaughter) at ages younger than the other groups whether from simple or double lambing. We can conclude that this type of production, keeping sheep closed and fed a TMR, is possible.
Short communication. Assessing lodging resistance in rice: A comparison of two indirect testing methods
Authors: Torro I. , Breto P. , Garcia-Yzaguirre A.
Published: December 2011

Rice lodging is still a problem in many countries, as all rice-growing countries have some varieties that get lodged. Direct evaluation of lodging resistance requires visual estimates in plots, but is not feasible in early generations of breeding programs, where genetic variability is too high. The aim of this study was to compare two methods for indirect evaluation of lodging resistance, especially in field conditions: the recovery ability after bending (measured as the tiller angle difference before and after bending); and, to test the sturdiness of the lower part of the plant, we have measured its resistance to pulling. Sixteen rice varieties and two F5 breeding lines were grown in plots and rows; 20 additional F5 breeding lines were only tested in rows. Visual estimates of plot lodging were significantly correlated with their tiller angle difference (r = 0.56*), but not with plant height or pulling resistance, although the latter was also correlated with visual lodging when only susceptible accessions were considered (r = –0.72*). Tiller angle difference was not significantly correlated with pulling strength, but it correlates with plant height (r = 0.56*). The scoring of tiller angle difference is simpler and less dependent on the evaluator than pulling resistance. It is concluded that it can be a valuable trait to select for resistance to lodging in early segregating generations of a pedigree breeding program
Short communication. Computer vision applied to saffron flower (Crocus sativus L.) processing
Authors: Perez-Vidal C. , Gracia L. , Gracia C.
Published: December 2011

This paper presents a computer vision system to obtain, using image analysis, the optimal cutting point of saffron flowers in order to obtain their stigmas. For this purpose, an effective and flexible computer program has been developed to process the flower image in order to obtain the cutting point to be sent to the cutting element. Furthermore, experimentation with real saffron flowers has been carried out in order to validate the developed application. In particular, the tests show that the method has good robustness and high success percentage in the flower characterization regardless the shape and size of the flower. The high image processing rate of the proposed method (20 computations s–1) would allow to greatly increase the production rate obtained with an automated cutting system compared to that obtained with the traditional hand method.
Pigouvian taxation to induce technological change and abate nonpoint pollution in the Ebro Basin, Spain
Authors: Esteban E. , Tapia J. , Martínez Y. , Albiac J.
Published: December 2011

The implementation of policies to control nonpoint pollution is a complicated task because the lack of information about the biophysical processes and the asymmetric information between social planner and polluters. The objective of this paper is to evaluate the efficiency of using an input tax instrument (water tax) with a non-uniform tax rate to abate nonpoint pollution. This water tax instrument generates a reduction in the pollution level, and induces farmers to adopt abatement practices such as better irrigation technology systems. The model presents theoretically and empirically the salinity pollution problems in the Ebro Basin (Northeast of Spain). Farmers are heterogeneous in crop types, irrigation technologies, and biophysical field characteristics. Because of this heterogeneity each farmer generates a different level of emissions, so farmers should be taxed differently. In this analysis, the social planner implements two tax rates according with farmers’ irrigation technology. Using a non-uniform tax rate, pollution emissions are reduced and farmers are induced to change their irrigation technology towards a more efficient one. The use of a more efficient irrigation technology increases social welfare and generates a cutback in the emission loads.
Assessing irrigation efficiency improvements by using a preference revelation model
Authors: Gutierrez-Martin C. , Gomez Gomez C. M.
Published: December 2011

This paper develops a general preference model to explain farmers’ decisions. Contrary to better known and most commonly used simulation models, the one presented in this paper allows to calibrate, simulate and explain farmers’ decisions without assuming linear preferences (as in many multi criteria decision models) or unobservable implicit cost functions (as in positive mathematical programming models). The model is calibrated for crop decisions in the Genil Cabra irrigated area in the Guadalquivir valley (South Spain) as the resulting empirical model is used to study how farmers react by adjusting these decisions when efficiency in the use of water is improved under different scenarios regarding water use rights. The main conclusion of the paper is that the potential water savings from enhancing irrigation technique (636 m3 ha–1) are overcome by increasing water demand due to higher per drop water productivity when sunflower is replaced by maize. For that reason water price increases and/or reduction of water use rights is a necessary condition to convert water savings through improved efficiency into lower water use and better conserved water sources.
Origin of a Tetragonal BiFeO3 Phase with a Giant c/a Ratio on SrTiO3 Substrates
Authors: Liu Huajun , Yang Ping , Yao Kui , Ong Khuong Phuong , Wu Ping , Wang John
Published: December 2011

A tetragonal BiFeO3 phase with giant c/a of approximately 1.25 has been of great interest recently as it potentially possesses a giant polarization and much enhanced electromechanical response. This super‐tetragonal phase is known to be a stable phase only under high compressive strains of above approximately 4.5%, according to first principle calculations. However, in previous work, this super‐tetragonal BiFeO3 phase was obtained in films deposited at high growth rate on SrTiO3 substrates with compressive strain of only around 1.5%. By detailed structure analysis using high resolution synchrotron X‐ray diffraction, atomic force microscopy, and transmission electron microscopy, the parasitic β‐Bi2O3 phase is identified as the origin inducing the formation of super‐tetragonal BiFeO3 phase on SrTiO3 substrates. In addition, ab initio calculations also confirm that this super‐tetragonal phase is more stable than monoclinic phase when Bi2O3 is present. Using Bi2O3 as a buffer layer, an alternative route, not involving strain engineering, is proposed to stabilize this promising super‐tetragonal BiFeO3 phase at low growth rates.