Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Mechanical properties of wood from Pinus sylvestris L. treated with Light Organic Solvent Preservative and with waterborne Copper Azole
No full textAim of study: To determine the effect on wood from Pinus sylvestris of treatment with preservatives on mechanical properties and to establish the relation between the penetration and compression strength.Area of study: SpainMaterial and Methods: 40 samples of defect-free wood from Pinus sylvestris L. were treated with Light Organic Solvent Preservative (Vacsol Azure WR 2601) and 50 with waterborne Copper Azole (Tanalith E 3492). 40 control samples were not treated (water or preservative). Mechanical resistance to static bending, modulus of elasticity and compression strength parallel to the grain were compared with untreated wood. Regression analysis between the penetration and compression strength parallel was done with the samples treated with waterborne preservative.Main results: The results indicate that the treated wood (with either product) presents a statistically significant increase in mechanical resistance in all three mechanical characteristics. The results obtained differ from earlier studies carried out by other authors.There was no correlation between parallel compression strength and the degree of impregnation of the wood with waterborne Copper Azole . The most probable explanation for these results concerns changes in pressure during treatment.The use of untreated control samples instead of samples treated only with water is more likely to produce significant results in the mechanical resistance studies.Research highlights: Treated wood presents a statistically significant increase in MOE, modulus of rupture to static bending and parallel compression strength.There was no correlation between parallel compression strength and the degree of impregnation with waterborne preservative.Keywords: Light Organic Solvent Preservative; MOE; parallel compression; static bending; waterborne Copper Azole; wood technology
Short Communication. An efficient axillary shoots propagate system for the living fossil plant - Wollemi pine (Wollemia nobilis)
No full textAim of study: The aim of the work was to determine the optimum axillary shoot induction system by optimizing different factors.Area of study: The different factors which were pretreatment methods, media types, kinds of cytokinins and dark treatmentMaterial and methods: After pretreating and sterilizing, the stems of Wollemi pine which about 3cm long were cultured on three kinds of media (GD, DCR AND ms) with different concentration and type of cytokines (BA, ZT and TDZ), as well as dark treatment (0, and 4 weeks) and then exposure to tissue culture room. The experiments were randomized block designed and the results were analyzed with ANOVA.Main results: Rapid freezing in liquid nitrogen was the most effective pretreatment method, dark treatment for the first 4-weeks of stem explants cultured in induction media could increase the frequency of axillary shoot induction significantly. The highest frequency of axillary shoot induction (63%) was obtained when explants were cultured in 1/2GD medium with 6.8 μM TDZ combining 4-weeks dark treatment. Research highlights: The optimized conditions for shoot production in vitro can be useful for conservation in vitro of Wollemia nobilis.Keywords: Wollemia nobilis; in vitro conservation; tissue culture; an endangered relict conifer
Limitations to adopting regulated deficit irrigation in stone fruit orchards: a case study
Get PDFFruit production development is resulting in large commercial orchards with improved water management standards. While the agronomic and economic benefits of regulated deficit irrigation (RDI) have long been established, the local variability in soils and climate and the irrigation system design limits its practical applications. This paper uses a case study approach (a 225 ha stone fruit orchard) to unveil limitations derived from environmental spatial variability and irrigation performance. The spatial variability of soil physical parameters and meteorology in the orchard was characterized, and its implication on crop water requirements was established. Irrigation depths applied during 2004-2009 were analysed and compared with crop water requirements under standard and RDI strategies. Plant water status was also measured during two irrigation seasons using stem water potential measurements. On-farm wind speed variability amounted to 55%, representing differences of 17% in reference evapotranspiration. During the study seasons, irrigation scheduling evolved towards deficit irrigation; however, the specific traits of RDI in stone fruits were not implemented. RDI implementation was limited by: 1) poor correspondence between environmental variability and irrigation system design; 2) insufficient information on RDI crop water requirements and its on-farm spatial variability within the farm; and 3) low control of the water distribution network
Effect of season and stocking density during transport on carcass and meat quality of suckling lambs
Get PDFMany factors related to transport to abattoir affects meat quality, but scarce information is available in suckling lambs. Thus, the aim of this work was to evaluate the effects of season and stocking density on carcass and meat quality of suckling lambs during commercial transport to the abattoir. A factorial design (2 × 3) was used: two seasons (winter and summer) and three stocking densities (SD; 0.08, 0.12 and 0.20 m2 animal-1). Meat quality variables were measured in the M. longissimus at 24 h post-mortem and after 5 days of refrigerated storage. Lambs transported in summer showed lower liver weight (p<0.001), h* (p<0.05), deoxymyoglobin content (p<0.001), pressed juice (p<0.01), shear force (p<0.001) and firmness (p<0.001), and higher initial pH (p<0.001), L*, b*, C* (p<0.001) and a* (p<0.01), as well as metmyoglobin and oxymyoglobin content (p<0.001), than those transported in winter. The effect of season was dependent on storage time, being colour changes more evident at 24 h than after 5 days of storage, whereas lipid oxidation was only observed in stored meat, which may be explain because the natural antioxidative system decreases with time after slaughter. Scarce effect of SD was found on the carcass and meat quality parameters, thus under our experimental conditions the three SD studied appear to be suitable for suckling lambs transport. However, both carcass and meat quality were within the normal commercial range
Residue management practices and planter attachments for corn production in a conservation agriculture system
Get PDFSeed placement and failure to establish a uniform plant stand are critical problems associated with production of corn (Zea mays) following wheat (Triticum aestivum) in a conservation agriculture system in Iran. Our objectives were to evaluate the performance of a corn row- crop planter equipped with two planter attachments (smooth/toothed coulters) at six wheat residue management systems (three tillage systems and two levels of surface residue) at two forward speeds of 5 and 7 km h-1. Residue retained after planting, seeding depth, emergence rate index (ERI) and seed spacing indices were determined. The baled residue plots tilled by chisel plow followed by disc harrow (BRCD) resulted in minimum residue after planting as compared to other residue treatments. Furthermore, the maximum values of the ERI and uniformity of plant spacing pertained to this treatment. Other results showed that the ERI increased up to 18% for the toothed coulter as compared to the smooth coulter. The toothed coulter also established a deeper seed placement as compared to the smooth coulter. Planting at forward speed of 5 km h-1 resulted in deeper seeding depth as compared to a forward speed of 7 km h-1. However, lower values of miss and precision indices were obtained at forward speed of 7 km h-1, indicating a more uniformity of plant spacing. Results of this study showed that equipping the conventional planter with toothed coulter and planting in soil prepared under the BRCD residue management system can result in a satisfactory conservation crop production system
Short communication. Effects of adding different protein and carbohydrates sources on chemical composition and in vitro gas production of corn stover silage
Get PDFThe use of protein-rich by-products based in swine manure (SM), poultry waste (PW) or chemicals compounds as urea (U), as well as energy products like molasses (M) and bakery by-product (BB), is a viable method to produce good quality silage. In addition, the use of a bacterial additive can improve the fermentation characteristics of silage. The objective of this study was to determine chemical composition, in vitro gas production (GP) and dry matter disappearance (DMd), using different sources of protein and energy in silage. The silages were made using SM, PW or U as protein sources and M or BB as energy source, with corn stover and with or without a bacterial additive. The organic matter (OM) content was higher (p < 0.001) in silages with UBB, UM and SMBB compared with the rest of the treatments; meanwhile crude protein content was higher (p < 0.001) in silages with U. The addition of a bacterial additive increased (p < 0.05) OM content and decreased (p < 0.05) fiber content. Total GP was higher (p < 0.05) in silages containing BB, but DMd was higher (p < 0.05) in silages with U and SMBB. The inclusion of a bacterial additive decreased (p < 0.05) GP and DMd. The use of alternative sources of protein such as poultry and swine manure or urea, and of by-products of sugar industry and bakery is an alternative for silages based on corn stover. The results show that when properly formulated, the silages can provide more than 16% of crude protein and have DMd values above 60%
Conceptual design of a chickpea harvesting header
Get PDFInterest in the development of stripper headers is growing owing to the excessive losses of combine harvesters and costs of manually harvesting for chickpeas. The design of a new concept can enhance the mechanized process for chickpea harvesting. A modified stripper platform was designed, in which passive fingers with V-shape slots removes the pods from the anchored plant. The floating platform was accompanied by a reel to complete the harvesting header. Black-box modeling was used to redesign the functional operators of the header followed by an investigation of the system behavior. Physical models of the platform and reel were modified to determine the crucial variables of the header arrangement during field trials. The slot width was fixed at 40 mm, finger length at 40 mm, keyhole diameter at 10 mm and entrance width at 6 mm; the batted reel at peripheral diameter of 700 mm and speed at 50 rpm. A tractor-mounted experimental harvester was built to evaluate the work quality of the stripper header. The performance of the prototype was tested with respect to losses and results confirmed the efficiency of the modified stripper header for chickpea harvesting. Furthermore, the header with a 1.4 m working width produced the spot work rates of 0.42 ha h-1
Pressure and specific energy requirements for densification of compost derived from swine solid fraction
Get PDFCompost derived from swine solid fraction is a low density material (bulk density less than 500 kg m-3). This makes it costly to transport from production sites to areas where it could be effectively utilized for value-added applications such as in soil fertilization. Densification is one possible way to enhance the storage and transportation of the compost. This study therefore investigates the effect of pressure (20-110 MPa) and pressure application time (5-120 s) on the compaction characteristics of compost derived from swine solid fraction. Two different types of material have been used: composted swine solid fraction derived from mechanical separation and compost obtained by mixing the first material with wood chips. Results obtained showed that both the pressure applied and the pressure application time significantly affect the density of the compacted samples; while the specific compression energy is significantly affected only by the pressure. Best predictor equations were developed to predict compact density and the specific compression energy required by the densification process. The specific compression energy values based on the results from this study (6-32 kJ kg-1) were significantly lower than the specific energy required to manufacture pellets from biomass feedstock (typically 19-90 kJ kg-1)
Canary tomato export prices: comparison and relationships between daily seasonal patterns
Get PDFStatistical procedures are proposed to describe, compare and forecast the behaviour of seasonal variations in two daily price series of Canary tomato exported to German and British markets, respectively, over the last decade. These seasonal patterns are pseudo-periodic as the length of the seasonal period changes frequently in dependence of market conditions. Seasonal effect at a day in the harvesting period is defined as a spline function of the proportion of the length of such a period elapsed up to such a day. Then, seasonal patterns for the two series are compared in terms of the area between the corresponding spline functions. The ability of these models to capture the dynamic process of change in the seasonal pattern is useful to forecasting purpose. Furthermore, an analytical tool is also proposed to obtain forecasts of the seasonal pattern in one of these two series from the forecasts of the seasonal pattern in the other one. These procedures are useful for farmers in developing strategies related to the seasonal distribution of tomato production exported to each market
Price dependence in the principal EU olive oil markets
Get PDFThe objective of this paper is to assess the degree and the structure of price dependence in the principal EU olive oil markets (Spain, Italy and Greece). To this end, it utilizes monthly olive oil price data and the statistical tool of copulas. The empirical results suggest that prices are likely to boom together but not to crash together; this is especially true for the prices of the two most important players, Italy (importer) and Spain (exporter). The finding of asymmetric price co-movements implies that the three principal spatial olive oil markets in the EU cannot be thought of as one great pool