Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
Not a member yet
3042 research outputs found
Sort by
Genotype × environment interaction for grain yield of some lentil genotypes and relationship among univariate stability statistics
Get PDFLentil (Lens culinaris Medik.) is traditionally grown as a rain fed crop, particularly in the Middle East; its seed is a rich source of protein for human consumption in developing countries such as Iran and others. The stability of 11 different lentil genotypes was investigated using 19 univariate stability parameters. Field experiments were conducted in 20 rain-fed environments in Iran’s lentil producing areas to characterize genotype by environment (GE) interactions on seed yield of 11 lentil genotypes. Combined analysis of variance across environments indicated that both environment and GE interactions significantly influenced genotype yield. Several statistical methods and techniques were used to describe the GE interaction and to define stable genotypes in relation to their yield. The results of these different stability methods were variable. However, most showed genotype FLIP 92-12L was stable and genotype Gachsaran was unstable. Genotypes identified as superior differed significantly from local cultivars and can be recommended for use by farmers in semi-arid areas of Iran. Principal component analysis was used to obtain an understanding of relationships among stability techniques. It showed the parameters studied could be grouped in five distinct classes. Clustering of the genotypes indicated that there were two genotypic groups in this group of genotypes
Influence of spacing on the initial production of hedgerow ‘Arbequina’ olive orchards
Get PDFA new type of olive (Olea europaea L.) orchard, based on high-density hedgerows harvested by vineyard type straddleharvesters has appeared in recent years. This system greatly simplifies olive harvesting, which has a high labour demand in standard olive orchards. There are, however, no specific low-vigour olive cultivars or dwarfing rootstocks adapted to this system, as exist in other fruit crops. It is therefore crucial to select the optimum density for maximum production without causing serious competition problems. In this study we present initial results of the effect of densities, ranging from 780 to 2,580 olive trees ha-1, on the production of an ‘Arbequina’ olive hedgerow orchard during the first seven years after planting. There were no significant differences in fruit characteristics (oil content and moisture) among density treatments. Density had a linear negative influence on fruit yield tree-1. In contrast, accumulated yield ha-1, for both fruit and oil yield, showed a linear increase with increased density, with coefficients of determination ranging from 0.37 to 0.72. Accumulated oil yield at high density was up to 5,000 kg ha-1 more than at the low densit
The role of knowledge management tools in supporting sustainable forest management
Get PDFAim of study: Knowledge Management (KM) tools facilitate the implementation of knowledge processes by identifying, creating, structuring, and sharing knowledge through use of information technology in order to improve decision-making. In this contribution, we review the way in which KM tools and techniques are used in forest management, and categorize a selected set of them according to their contribution to support decision makers in the phases of problem identification, problem modelling, and problem solving.Material and Methods: Existing examples of cognitive mapping tools, web portals, workflow systems, best practices, and expert systems as well as intelligent agents are screened for their applicability and use in the context of decision support for sustainable forest management. Evidence from scientific literature and case studies is utilized to evaluate the contribution of the different KM tools to support problem identification, problem modelling, and problem solving.Main results: Intelligent agents, expert systems and cognitive maps support all phases of the forest planning process strongly. Web based tools have good potential to support participatory forest planning. Based on the needs of forest management decision support and the thus-far underutilized capabilities of KM tools it becomes evident that future decision analysis will have to consider the use of KM more intensively. Research highlights: As the problem-solving process is the vehicle for connecting both knowledge and decision making performance, the next generation of DSS will need to better encapsulate practices that enhance and promote knowledge management. Web based tools will substitute desktop applications by utilizing various model libraries on the internet.Keywords: best practices; cognitive mapping; expert systems; intelligent agents; web portals; workflow systems; Decision Support Systems.
Phenology and abundance of Enoicyla pusilla in conifer stands
Get PDFAim of Study. We study the abundance of Enoicyla pusilla (Burmeister) in pine plantations and the effects of silvicultural thinning on insect population. This species is considered a rare member of the order Trichoptera, reported as absent or occasional in conifer forests. It has been suggested that the proliferation of conifer plantations may be a threat for this species by favoring population isolation. Area of study. Plantations of native and non-native pines in Galicia (NW of Spain).Material and Methods. We used different traps systems, including 28 pitfall traps, to compared populations of insects in 14 thinned and unthinned plots of Pinus pinaster and P. radiata distributed across 3 forest stands. Traps were checked every 15 days during one year.Main results. We caught 1.219 larvae of E. pusilla. It was the third most abundant species captured in pitfall traps. Larval activity extended from January to late July. They were more abundant in the stands of P. radiata, probably because the denser foliage produced limits sunlight and helped to maintain litter moisture. Additionally needles of P. radiata had lower toughness and higher nitrogen content, which probably makes it a higher quality resource for the detritivorous larvae. Thinning did not affect larvae population.Research highlights: Although managed forests cannot match the biodiversity value of native mixed species stands, if managed appropriately, they may provide habitat for native fauna while also allowing for forest productionKey words: caddisfly; Pinus pinaster; Pinus radiate; plantations; thinning
Estrategias empresariales, rentabilidad y eficiencia productiva
No full textThe strategy choices of market-oriented companies are a topic now under wide investigation in the analysis of business performance antecedents. The purpose of this study is to examine the outcomes of the combination of three different organizational strategies (market orientation, innovativeness and entrepreneurial orientation) on business performance indicators. Models using profitability and efficiency indicators are proposed with the specific aim of obtaining a deeper analysis of the relative roles played by each. The empirical work takes place in the agro-food industry in the Ebro Valley, one of Spain’s most competitive regions. The estimates from profitability quantile and truncated regressions of the efficiency scores reveal that market orientation has a positive effect on economic and productivity performance. The impact of pro-active, innovation-seeking, and risk-averse entrepreneurship is nevertheless more debatable, despite some influence of these entrepreneurial styles on observed performance values. This enables conclusions regarding the possibility of combining a market-oriented business culture with innovation and entrepreneurial activity with a view to obtaining business performance gains.La elección de las estrategias de las empresas orientadas al mercado es uno de los temas que ha mostrado mayor interés en los últimos años dentro del análisis de los logros empresariales. En este trabajo se pretende estudiar las consecuencias de la combinación de distintas estrategias de la organización orientación al mercado, orientación a la innovación y orientación emprendedora, sobre distintos tipos de resultados empresariales. En concreto, se proponen distintos modelos que analicen el efecto de dichos comportamientos empresariales sobre los resultados de rentabilidad y de eficiencia. La investigación empírica se realiza en el sector agroalimentario de una de las zonas españolas más competitivas, el Valle del Ebro. Los resultados muestran en las estimaciones de rentabilidad por cuantiles y en las regresiones truncadas de la eficiencia el efecto positivo de la orientación al mercado en los resultados económicos y productivos de las empresas. Sin embargo, es más discutible la implicación de la búsqueda de innovación y de la proactividad y aversión al riesgo del empresario sobre dichos resultados, aunque se observa que estos modos empresariales afectan a los valores obtenidos. Por lo tanto, es posible concluir sobre la idea de adopción de una cultura empresarial orientada al mercado combinada con otras actividades de innovación y emprendimiento, con el fin de mejorar el resultado empresarial.
Effect of energy concentration on growth performance and carcass quality of Iberian pigs reared under intensive conditions
Get PDFIn total, 192 Iberian pigs were used to investigate the effects of net energy (NE) concentration of the diet on growth performance and carcass quality of castrated females (CF) and castrated males (CM). From 30 to 112 kg body weight (BW), three diets were formulated with similar digestible amino acid content per kcal of NE but differing in energy concentration (2,045, 2,175 and 2,305 kcal NE kg-1 from 30 to 81 kg BW and 2,175, 2,305 and 2,445 kcal NE kg-1 from 81 to 112 kg BW). From 112 kg to slaughter (148 kg BW), all pigs received a common finisher diet. Each treatment was replicated eight times and the experimental unit was a pen with four pigs. A decrease in NE concentration of the diet increased feed intake (p<0.05) and tended to impaired feed conversion ratio (p<0.10), whereas carcass and meat quality traits were not affected. Castrated males ate more feed and grew faster but had less fat thickness at the gluteus medius muscle than CF (p<0.05). However, no differences in carcass and meat quality traits between genders were detected. We conclude that a reduction in NE content of the grower diets did not affect growth rate and therefore, it not a valuable alternative to avoid excess of BW at slaughter in Iberian pigs reared under intensive management conditions. Also, both genders can be used for the production of high quality carcasses destined to the dry-cured industry
Short communication. Nitrogen content of residual alfalfa taproots under irrigation
Get PDFThe decomposition of alfalfa (Medicago sativa L.) residues can provide significant amounts of N to subsequent crops, but most of the data on this subject has been obtained from 1-2 year old alfalfa stands. The objective of this study was to determine the biomass of alfalfa taproots and their N content in irrigated alfalfa stands that are more than 2 years old. Twenty-two commercial irrigated alfalfa fields were evaluated in the Ebro Valley (Northeast Spain) from 2006 to 2010. The taproot biomass in the arable layer (0 to 30 cm depth) ranged from 1.8 to 10.1 Mg ha-1 and averaged 4.8 Mg ha-1. In contrast, the N concentration in alfalfa taproots was constant among fields and averaged 24.6 g N kg-1. The total amount of N contained in alfalfa taproots (0-30 cm depth) ranged from 47 to 96 kg N ha-1 in 55% of the fields, ranged from 97 to 200 kg N ha-1 in 22% of the fields, and exceeded 200 kg N ha-1 in 23% of the fields. The N content of the irrigated alfalfa taproots studied here is in the upper range previously reported in other areas, mainly with younger alfalfa stands. Based on the current finding, a classification of the quality of irrigated alfalfa stands is proposed to improve the estimates of the residual-N effects of alfalfa on subsequent crops
Nematode diversity in soil from a field trial with decomposing Bt cotton expressing Cry1Ac and Cry2Ab2 protein
Get PDFThe quality of decomposing plant materials may affect the soil community structure. The aim of the study was to determine the impact of decomposing Bt cotton and its isoline on soil nematode diversity. Bt cotton (06Z604D), isoline (99M03) and HART 89M (local non-Bt cotton cultivar) were planted for two seasons in a completely randomized block design in a confined field trial at Mwea, Kenya. After harvest the plant material was incorporated into soil and the nematode diversity was determined. The presence of Bt protein was evaluated using ELISA and insect bioassays. Abundance of bacteria feeding nematodes was significantly (p<0.05) high but to a smaller extent in the Bt cotton plots (53.7% and 52% in the first and second season respectively) than in isoline (42.8% and 45% in the first and second season respectively). Insect bioassays detected Bt protein in the Bt cotton plots during the entire decomposition period in both seasons. There were no significant differences in nematode trophic groups composition between isoline and HART 89M. The effect of Cry2Ab2 and Cry1Ac protein in decomposing Bt cotton litter on soil nematodes was minimal. The study provides a basis for future studies on the impact of genetically engineered plants on soil nematodes in Kenyan agroecosystems
Quality and efficiency of apple orchard protection affected by sprayer type and application rate
Get PDFThe goal of this work was to evaluate the potential of reduced application rates in apple trees as well as the potential of selective spray applications by using sensor-based tree detection techniques in Serbian fruit production. Their economical and biological effect was evaluated based on the quality and efficiency of the crop protection and techno-economic analysis. Results showed that during suitable weather conditions and with properly adjusted sprayer settings, a reduced application rate of 381 L ha-1 gave same quality of crop protection as a medium application rate of 759 L ha-1. A two-year efficiency trial on Venturia inaequalis and Podosphaera leucitricha infecting apple also showed that there was no significant difference in crop protection results for different types of orchard application techniques and application rates. The techno-economic analysis showed that selective application should be introduced in practice in areas >3-ha given that the cost of their introduction pays off after 2-3 seasons. Every subsequent season would give a clear economic profit. Besides the economic benefits, selective application technique also has a significant positive ecological effect due to reduction of spray losses and the amount of plant protection products used
Operations planning for agricultural harvesters using ant colony optimization
Get PDFAn approach based on ant colony optimization for the generation for optimal field coverage plans for the harvesting operations using the optimal track sequence principle B-patterns was presented. The case where the harvester unloads to a stationary facility located out of the field area, or in the field boundary, was examined. In this operation type there are capacity constraints to the load that a primary unit, or a harvester in this specific case, can carry and consequently, it is not able to complete the task of harvesting a field area and therefore it has to leave the field area, to unload, and return to continue the task one or more times. Results from comparing the optimal plans with conventional plans generated by operators show reductions in the in-field nonworking distance in the range of 19.3-42.1% while the savings in the total non-working distance were in the range of 18-43.8%. These savings provide a high potential for the implementation of the ant colony optimization approach for the case of harvesting operations that are not supported by transport carts for the out-of-the-field removal of the crops, a practice case that is normally followed in developing countries, due to lack of resources