Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Efecto de las mallas de sombreo en la mejora del clima nocturno de los invernaderos sin calefacción
No full textThe objective of this work was to study the effect of shading screens, normally used during the day for cooling purposes, on the night-time climate of unheated greenhouses. For this purpose, first a number of experimental measurements were taken during cold nights to characterise the greenhouse climate both with and without an aluminised external screen. Secondly a Computational Fluid Dynamic (CFD) model of greenhouse was developed. After validation of the model by comparison with experimental data, the model was used to simulate the greenhouse climate for different sky conditions ranging from cloudless to overcast nights. Simulations were performed for a greenhouse with internal and external shading screens and for the same greenhouse without screens. Experimental results showed the positive effect of an external shading screen, whose use increased night-time temperature and reduced the risk of thermal inversion. Its effect was much stronger under clear sky conditions. The CFD model supported this conclusion and provided a detailed explanation of the temperature behaviour of all the greenhouse types considered. CFD simulations proved that an aluminised screen placed inside the greenhouse at gutter height gave the greatest thermal increase. Therefore, external or internal screens can help to increase the sustainability of greenhouse production in areas with mild winter climates by enhancing the use of solar energy stored in the greenhouse soil during the previous day and released at night-time.El objetivo del presente trabajo fue evaluar el efecto de las mallas de sombreo, utilizadas habitualmente para refrigeración, sobre el clima nocturno de los invernaderos no calefactados. Con este fin se realizaron diversos ensayos experimentales para caracterizar el clima nocturno de un invernadero multitúnel con y sin malla externa aluminizada. En segundo lugar se procedió a desarrollar un modelo del clima nocturno del invernadero basado en lamediante dinámica de fluidos computacional CFD. Finalmente, tras validar el modelo con los datos experimentales, se procedió a simular el comportamiento del clima del invernadero para diferentes condiciones de clima nocturno variando entre noches con cielos totalmente despejados o totalmente cubiertos. Las simulaciones se realizaron para tres casos: invernadero sin malla, con malla interna y con malla externa. Los resultados experimentales mostraron el efecto positivo del uso de mallas de sombreo externas que permitieron incrementar la temperatura interior y reducir el riesgo de inversión térmica, siendo este efecto mucho más marcado en noches despejadas. El modelo de CFD coincidió con los resultados experimentales y permitió analizar en detalle las condiciones térmicas de los diferentes invernaderos evaluados. Las simulaciones con CFD mostraron que la malla aluminizada instalada en el interior del invernadero, a la altura de la canal, proporcionó el mayor incremento térmico nocturno. En conclusión, las mallas de sombreo externas o internas pueden ayudar a incrementar la sostenibilidad de la producción bajo invernadero en áreas de clima templado maximizando el uso de la energía solar almacenada en el suelo del invernadero durante el día y cedida al aire durante la noche siguiente
Inducción del enraizamiento de estaquillas de olivo utilizando bacterias productoras de auxinas
No full textSouthern Spain is the largest olive oil producer region in the world. In recent years organic agriculture systems have grown exponentially so that new alternative systems to produce organic olive cuttings are needed. Several bacterial isolates, namely Pantoea sp. AG9, Chryseobacterium sp. AG13, Chryseobacterium sp. CT348, Pseudomonas sp. CT364 and Azospirillum brasilense Cd (ATCC 29729), have been used to induce rooting in olive semi-hardwood cuttings of Arbequina, Hojiblanca and Picual cultivars of olive (Olea europea L). The first four strains were previously selected as auxin-producing bacteria and by their ability to promote rooting in model plants. They have been classified on the basis of their 16S rDNA gene sequence. The known auxin producer A. brasilense Cd strain has been used as a reference. The inoculation of olive cuttings was performed in two different ways: (i) by dipping cuttings in a liquid bacterial culture or (ii) by immersing them in a paste made of solid bacterial inoculant and sterile water. Under nursery conditions all of the tested bacterial strains were able to induce the rooting of olive cuttings to a similar or greater extent than the control cuttings treated with indole-3-butyric acid (IBA). The olive cultivars responded differently depending on the bacterial strain and the inoculation method. The strain that consistently gave the best results was Pantoea sp. AG9, the only one of the tested bacterial strains to express the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase. The results are also discussed in terms of potential commercial interest and nursery feasibility performance of these strains.El sur de España es el mayor productor mundial de aceite oliva. En los últimos años hay una gran demanda de sistemas de producción ecológicos, por lo que es necesario encontrar sistemas de estaquillado ecológicos. Se han utilizado los aislamientos bacterianos Pantoea sp. AG9, Flavobacterium sp. AG13, Chryseobacterium sp. CT348, Pseudomonas sp. CT364 y Azospirillum brasilense Cd para inducir el enraizamiento en estaquillas de olivo (Olea europaea L.)de los cultivares Arbequina, Picual y Hojiblanca. Todas ellas han sido seleccionadas por producir auxinas y promover el enraizamiento en plantas modelo, y han sido clasificadas en base a la secuenciación del ADNr 16S. Como referencia se ha utilizado la cepa Cd de A. brasilense, productora de auxina. La inoculación se ha realizado de dos maneras diferentes: sumergiendo las estaquillas en el cultivo bacteriano o mediante inmersión en una pasta de inoculante sólido mezclado con agua estéril.Todas las estirpes bacterianas fueron capaces de producir, bajo condiciones de invernadero, un porcentaje de enraizamiento similar al producido por el ácido 3-indol-butírico (IBA). Se han observado diferentes respuestas según el cultivar de olivo y el método de inoculación utilizado. La cepa más efectiva ha sido AG9, que es la única que posee actividad 1-aminociclopropano-1-carboxilato (ACC) desaminasa. Los resultados se discuten en base a su interés comercial y a su facilidad de manejo en el vivero
Compost versus vermicompost as substrate constituents for rooting shrub cuttings
Get PDFThe feasibility of composted (C), composted plus vermicomposted (V1) and straight vermicomposted (V2) tomato crop waste as component of rooting media for Euonymus japonicus ‘Microphylla’ and Lavandula angustifolia vegetative propagation was studied. Mixes of C, V1 and V2 with coir fibre (CF) at the proportions 100:0, 75:25, 50:50, 25:75, 0:100 (v:v) were assayed. Physical, physico chemical and nutritional characteristics of all materials and mixes were determined and correlated with cutting rooting and growth performances. The compost and the two vermicomposts were markedly different from CF. They had higher bulk density and lower total porosity than CF. Compost had lower water holding capacity and shrinkage in response to drying than vermicomposts and CF. Compost and vermicomposts were alkaline materials whilst CF was almost neutral. Electrical conductivity (EC) was low in CF and vermicomposts, and high in compost due to the high mineral contents, mainly of K+, SO42– and Na+ in this material. EC and the ions contributing to it (K+, SO42–, Na+) showed highly significative inverse correlations with rooting percentage for the two species and with root and shoot growth but only for E. japonicus. Due to its high EC, compost C (average rooting = 22.5%) performed worse than vermicomposts V1 (av. rooting = 97%) and V2 (av. rooting = 98%) whilst the latter performed similarly to CF control (av. rooting = 100%). Thus vermicomposts appeared to be more appropriate than compost as rooting media constituent
Summer deficit irrigation in a hedgerow olive orchard cv. Arbequina: relationship between soil and tree water status, and growth and yield components
Get PDFStem water potential (Phi-stem) is a useful tool for irrigation scheduling in tree crops, provided threshold values for growth and production are determined for each physiological period. Four irrigation treatments were evaluated in a hedgerow olive orchard. Control (CON) was irrigated using soil water sensors to maintain the root zone close to field capacity. Severe water deficits were applied by irrigating at 30% CON from end of fruit drop to end of July (DI-J) or from end of July until beginning of oil synthesis (DI-A). Less severe water deficit was applied in July and August by irrigating at 50% CON (DI-JA). Continuous measures of soil moisture, Phi-stem and shoot length were recorded in all treatments. Fruit dry weight and oil content were measured at the end of the experimental period and at harvest. Relative extractable soil water to 0.8 m depth (REW) and Phi-stem were highly correlated and influenced by irrigation treatment. Shoot growth, fruit characteristics and oil production were correlated to Phi-stem. Shoot growth was reduced by 50% relative to CON by irrigating at Phi-stem of -1.3 MPa. Fruit dry matter and oil content (g fruit-1) were linearly reduced as mean summer Phi-stem decreased. Oil production was highly related with Phi-stem in August but not in July. Water can be saved in July by irrigating at Phi-stem of -2.9 MPa but Phi-stem should be maintained higher than -2.0 MPa in August to prevent decrease of oil production
Riego por surcos en el cultivo de la chufa en Valencia (España). I: Respuesta productiva a dos estrategias de riego
No full textChufa (Cyperus esculentus L. var. sativus Boeck.) is an important vegetable crop in Valencia (Spain), where its tubers are used to produce a refreshing drink called 'horchata'. Water is relatively inexpensive, there are no data regarding the volumes of water used to grow chufa, and the irrigation water use efficiency (IWUE) has neither been determined. The aim of this research was to compare the productive responses of the chufa crop to two irrigation strategies (IS). The volumetric soil water content (VSWC) was monitored with capacitance sensors. Trends in VSWC were used to determine the in situ field capacity (FC), beginning each irrigation event when the VSWC reached either approximately 45% (H1) or 60% (H2) of the FC at a soil depth of 0.10 m. The experiments were conducted over three consecutive seasons. An area velocity flow module measured the water flow. The yields, the water volumes used, and the IWUE were calculated. Plants were periodically sampled and the harvest index and relative growth rate were determined. The yield was affected by the year and by the IS. The greatest yields were obtained with the H2 strategy (on average 2.18 kg m-2 for H2 vs. 1.94 kg m-2 for H1; p≤0.01), and the average tuber weight (ATW) was affected (p≤0.01) by the year and IS interaction. IWUE was affected by the year, and none of the considered factors affected the harvest index (p≤0.05). It can be concluded that maintaining a higher VSWC would increase both yield and ATW without affecting IWUE.La chufa (Cyperus esculentus L. var. sativus Boeck.) es el cultivo hortícola más representativo de L’Horta Nord de Valencia (España). Sus tubérculos se utilizan en la elaboración de la horchata. No existen datos del volumen de agua utilizado en el cultivo, ni de la eficiencia en el uso del agua de riego (EUAR). El objetivo de este trabajo fue analizar la respuesta productiva de la chufa a dos estrategias de riego (ER). El contenido volumétrico de agua del suelo (CVAS) fue monitorizado mediante sensores de capacitancia, La evolución del CVAS fue utilizada para determinar los valores de capacidad de campo (CC), iniciándose cada riego, cuando el CVAS a 0,10 m de profundidad alcanzaba valores de 45% (H1) o 60% (H2) de la CC. Los experimentos se realizaron durante tres campañas consecutivas. Se calculó el rendimiento, el volumen de agua utilizado y la EUAR. Las plantas se muestrearon periódicamente y se determinó el índice de cosecha (IC) y la tasa de crecimiento relativo. El rendimiento fue afectado tanto por el año como por la ER. Los mayores rendimientos se obtuvieron con la estrategia H2 (2,18 kg m-2 en H2 frente a 1,94 kg m-2 en H1; p≤0,01) y el peso medio de los tubérculos (PMT) fue afectado (p≤0,01) por la interacción año-ER. La EUAR fue afectada por el año y ninguno de los factores analizados afectó al IC (p≤0,05). Se concluye que con los niveles más elevados de CVAS se aumentaría el rendimiento y el PMT, sin afectar a la EUAR
Utilization of milk minerals by Iberian suckling piglets
Get PDFLittle information is available concerning mineral metabolism in suckling piglets. The utilization of milk minerals and the mineral composition of Iberian (IB) suckling piglets were studied in two consecutive experiments at different ambient temperatures (trial 1, 27 ± 2°C; trial 2, 22 ± 2°C). Milk composition and the piglets’ performance were determined weekly over a 34 days lactation period and, at the end, body mineral contents were analyzed and mineral retention and bioavailability were calculated. The ash content in IB sows’ milk and in suckling IB piglets was found to be higher than that reported for lean genotypes. During lactation, mean ash content per unit of body weight gain in IB piglets (40.6 g kg-1) was 42% higher than that observed for lean breeds, and weaned IB piglets contained 60% more Ca (11-12.7 g kg-1 empty body weight) and P (7-7.5 g kg-1 empty body weight), compared with conventional pigs. Minerals from milk were retained by the IB piglet with an overall efficiency of 78.3%, 66.3% and 48.7% for Ca, P and Mg, respectively. Significant differences between trials were observed in the mineral fraction composition of the milk, which were reflected in piglet body composition at weaning, presumably due to differences in ambient temperature. Present findings underline genotype differences in mineral composition of sow’s milk and suckling piglets and may provide a useful starting point for formulating milk-replacer diets for IB piglets
Genetic diversity among Juglans regia L. genotypes assessed by morphological traits and microsatellite markers
Get PDFIn this study, genetic diversity was assayed among 16 accessions and five cultivars of Persian walnut (Juglans regia L.) using morphological traits and nine simple sequence repeat (SSR) markers. Samples were collected from Agriculture Research Center of Urmia city (North West Iran). Study on important morphological traits revealed genetic similarity of -0.6 to 0.99 based on CORR coefficient. The microsatellite marker system produced 34 alleles in range of 160-290 bp. The minimum (2) and maximum (7) number of alleles were obtained from WGA71 and WGA202 genetic loci, respectively. The mean number of alleles per locus was 4.25. Jaccard’s similarity coefficient ranged from 0.13 to 0.76. The results of this paper indicate high diversity among these genotypes which could be used for breeding management
Development of two portable patternators to improve drift control and operator training in the operation of vineyard sprayers
Get PDFSpray drift can be defined as the quantity of plant protection product that is carried out of the sprayed area by the action of air currents during the application process. Efficacy of pesticide applications in orchards and vineyards is highly dependent on matching the canopy characteristics with the liquid distribution on a vertical plane, this being influenced by the type of sprayer, the nozzle orientation and air outlet adjustment. Two simple vertical patternators were designed and developed with the express purpose to be used in field conditions for the adjustment of vineyard canopy sprayers. Three different orchard sprayers were selected for comparative field trials of two new patternators with an already commercially available portable vertical patternator designed at University of Turin (Italy). The objective was to evaluate their efficiency in terms of spray recovery, symmetry and repeatability. Results show the ability of the two prototypes to measure the vertical distribution of liquid, as well as the important similarities between the liquid distribution profiles obtained with both patternators in comparison to the reference one. Trials conducted with the three different orchard sprayers show the suitability of this kind of tool, not only for research purposes but also for training activities and as part of the sprayer calibration process. Important benefits from both an economic and a sustainable point of view can be obtained regarding adequate liquid distribution according to the crop characteristics, this being especially interesting in field conditions
The effect of breed in a hot environment on some welfare indicators in feedlot cattle
Get PDFHeat stress has an important effect on the welfare of livestock and causes significant changes in biological functions. This study was carried out to investigate the behavioral differences of Brown Swiss (BS) and Holstein (H) feedlot cattle reared in a hot environment. All of the cattle were housed in a semi-open feedlot barn. The individual behavioral response variables measured were feeding, drinking, rumination, standing, resting, locomotor activity and elimination (urinating and defecating). For each animal, behavioral observations were recorded at 10 min intervals for 1 h starting at 06:00, 10:00, 13:00, 16:00, 20:00 and 23:00 h. The effect of breed, time of the day and hour of observation and the interactions of these factors were included in the model. The data were analyzed using the PROC GLM procedure in SAS. There were significant interactions between breed and time of observation for rumination (p0.05). BS cattle exhibited more frequent standing behavior at 13:00 h, whereas H cattle exhibited more frequent standing behavior at 16:00 h (p<0.01). The welfare of male H feedlot cattle was concluded to be more affected than that of male BS feedlot cattle when the ambient temperature was high (at 13:00 h)
Energy inputs-yield relationship and sensitivity analysis of pistachio (Pistacia vera L.) production in Markazi Region of Iran
Get PDFPistachio is considered as an important agricultural commodity in Iran and ranks top amongst all exported agricultural products. Conducting an overall energy audit and economic analysis of pistachio production can provide useful information to help implement management strategies for improving energy efficiency. A study was conducted during 2009 and 2010 to evaluate the overall energy inputs and outputs and to perform an economic analysis of pistachio production in the Iranian province of Markazi. The results revealed that the total energy input for pistachio production was 54305 MJ ha-1. Electricity, followed by diesel fuel and nitrogen fertilizer application were the highest contributors to energy input in pistachio orchards. The contribution of direct energy was higher than indirect energy and share of non-renewable energy was more than renewable energy. Net energy, energy use efficiency, energy productivity and specific energy were 7522 MJ ha-1, 0.86, 0.08 kg MJ-1 and 13.69 MJ kg-1, respectively. Econometric model based on Cobb-Douglas function indicated that impacts of electricity, diesel fuel and chemical fertilizer energy inputs on pistachio yield were positive while the impact of machinery was negative. The marginal physical productivity (MPP) value for diesel fuel was the highest among other variables, followed by energy inputs related to the chemicals and irrigation water. The results revealed that production of pistachios in Markazi Province, under current management practices, are not energy efficient and efforts should be made to improve energy use efficiency