ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
Not a member yet
2747 research outputs found
Sort by
Acta Horticulturae
No full textNew low and medium vigour Prunus rootstocks compatible with peach cultivars were evaluated under controlled and in field conditions against biotic and abiotic stress factors. Most rootstocks exhibited different levels of resistance to the root-knot nematode Meloidogyne javanica. The plum hybrids ‘PAC 9801-02’ and ‘Krymsk®2’ were the only rootstocks that exhibited resistance to the lesion nematode, although ‘Krymsk®2’ is not compatible with peach. All rootstocks showed a high sensitivity to crown gall. The low vigour plums ‘Evrica’ and ‘Krymsk®1’, and the hybrid peach ‘PADAC 9907-23’ were sensitive to iron chlorosis. The rest showed different levels of tolerance. All plum-based materials were moderately tolerant to tolerant to root asphyxia, whereas peach-based rootstocks were sensitive with the exception of the peach almond hybrid ‘PAC 0009-01’. Most plums tend to emit an excessive number of root and crown suckers. From the agronomic standpoint, ‘PAC 0009-01’ and ‘PAC 9801-02’ present a better overall performance taking into account the combined traits
Estudio de las bases para el cultivo sostenible del arroz
Get PDFLa utilización de la siembra directa y la inundación del arrozal durante la mayor parte de su ciclo de cultivo constituyen la forma más intensiva de cultivo de arroz en el mundo. Esta intensificación puede ser muy gravosa para el ambiente si se producen pérdidas provenientes de los elevados "inputs" aplicados al suelo agrícola. En los arrozales europeos el elevado uso de los fertilizantes nitrogenados puede contaminar el agua y ser causa de la pérdida progresiva de la calidad del suelo como consecuencia del efecto perjudicial sobre los microorganismos del suelo, particularmente sobre las cianobacterias fijadoras de N2 (Roger y Kulasooriya, 1980; Fernández Valiente y col. 1997). La necesidad de preservar los recursos naturales induce a mejorar el sistema de cultivo del arroz en términos de estabilidad, sostenibilidad y respeto al medio ambiente. En este sentido la Política Agraria Común de la Unión Europea trata de incentivar la puesta en práctica de técnicas agrícolas que reduzcan la contaminación. La mayor parte de los arrozales españoles forman parte de Parques Naturales de alto valor ecológico como la Albufera de Valencia, el Coto de Doñana y el Delta del Ebro, que en su conjunto suponen las zonas húmedas más importantes de España y de Europa, con una consiguiente mayor preocupación por los problemas ambientales. De hecho, se estima que los arrozales que rodean o forman parte de los espacios naturales tienen gran importancia ecológica, funcionando como zona semi-natural de depuración de aguas (Fores y Comin 1992). El estudio de estos agro-ecosistemas está, por tanto, directamente relacionado con una gestión más realista de estos espacios naturales
Acta Horticulturae
No full text‘Garbi’ (‘Fortune’ × ‘Murcott’) and ‘Safor’ (‘Fortune’ × ‘Kara’) are the Valencian Institute of Agrarian Research’s most recent citrus cultivars to be released for commercial production. Those two new cultivars are late-maturing triploid mandarins, and they were studied and tested in the Plant Protection and Biotechnology Center in the IVIA. During two seasons the postharvest behavior of both cultivars were evaluated in the Postharvest Technology Center. The effect of storage temperature on quality of ‘Garbi’ and ‘Safor’ mandarins were studied. Fruit were stored up to 30 days at 1, 5, or 9°C, and then fruit were stored at 20°C during 6 days simulating shelf-life. The incidence of chilling injury was evaluated; ‘Garbi’ mandarins were more sensitive to chilling injury than ‘Safor’ mandarins when stored at 1 or 5°C. However, this sensitivity was lower than that shown by ‘Fortune’ mandarins in previous studies. ‘Safor’ mandarins did not show symptoms of chilling injury at any storage temperature studied, when the fruit were previously coated. For both mandarin cultivars, fruit quality, including firmness, weight loss, soluble solids, titratable acidity, and ethanol content were not affected by storage at low temperature
Gestational losses in a rabbit line selected for growth rate
No full textPrenatal death can occur due to several genetic and environmental factors which alter normal embryo development, maternal environment to support normal fertilisation, development of embryos, placenta and foetus, or affect the necessary relationship between embryo and endometrium. The aim of this work was to study gestational losses and progesterone, 17 (beta-estradiol and IGF I serum levels in a rabbit line selected for growth rate (paternal line). In this study, a maternal line well characterised in previous studies was used as a reference line. A total of 211 laparoscopies were carried out, and the number of corpora lutea and implanted embryos at 12(th) days, total born and live born were recorded per female. To analyse the endocrine levels, blood serum was collected from 54 females with implanted embryos at 12(th) and 24(th) day of gestation (27 from each line). The paternal line showed the lowest ovulation frequency, number of implanted embryos, total born and live born (0.70, 11.3, 7.4, and 6.4 vs 0.86, 12.8, 11.1 and 10.6 for maternal line, respectively) and consequently, the highest implantation, gestational, foetal and perinatal losses (0.31, 0.60, 0.40, and 0.15, respectively). Progesterone serum levels at 12(th) days of gestation were similar between lines; however, progesterone serum level at 24(th) day of gestation was significantly lower in the paternal line (4.8 vs 8.2 ng/mL). Serum levels of 17 beta-estradiol and IGF-I at 12(th) days of gestation were different between lines (14.6 vs 26.5 pg/mL, 237 vs 149 ng/mL for paternal and maternal lines respectively). These higher gestational losses of the paternal line could be explained by differences in 17 beta-estradiol level at 12(th) days of gestation and the possible effect on low progesterone serum levels at 24(th) days of gestation. Further studies in steroid production and bioavailability have to be done during oestrus and pregnancy related with metabolic activity of this line. (C) 2012 Elsevier Inc. All rights reserved
Modelling the spray deposition and efficacy of two mineral oil-based products for the control of California red scale, Aonidiella aurantii (Maskell)
Get PDFThe pattern and quantity of pesticide deposition may affect the efficacy of pesticide treatments. In this study we evaluated under laboratory conditions the efficacy of two petroleum-derived spray oils (PDSO) (Laincoil (R), an nC21 oil with a content of 83% w/v, Oil A, and Sunspray Ultrafine (R), an nC21 with a content of 85% w/v, Oil B, both with an unsulfonated residue of 92%) applied at 1.5% concentration at five volumes (0.5, 1, 2, 3 and 4 ml) against different stages of Aonidiella aurantii Maskell (Homoptera: Diaspididae). In parallel, we characterized the deposition pattern of treatments resulting from these five volumes and two PDSOs. The objective was to model deposition characteristics and efficacy as a function of the deposited volume in order to determine the optimum volume per unit surface that should be applied to control this pest. Different models that depend on the developmental stage and relate to the efficacy of the treatment as a function of the deposited volume have been obtained for both PDSOs, thus providing a scientific basis for product efficacy comparison. Furthermore, our results are also relevant to find an adequate trade-off between sprayed pesticide volume and expected efficacy. (C) 2011 Elsevier Ltd. All rights reserved
Evaluation of an oil dispersion formulation of imidacloprid as a drench against Rhynchophorus ferrugineus (Coleoptera, Curculionidae) in young palm trees
No full textBACKGROUND: The red palm weevil, Rhynchophorus ferrugineus (Olivier), is a phytophagous insect that feeds on soft succulent tissues of most palm species and is considered the main palm pest in the Middle East and the Mediterranean Basin. The aim of this study was to test the efficacy of imidacloprid oil dispersion (OD) as a drench in preventive and curative treatments against R. ferrugineus in Phoenix canariensis, Washingtonia robusta, Washingtonia filifera and Trachycarpus fortunei. RESULTS: Levels of infestation were highest in P. canariensis. There was no infestation in W. filifera. Mean efficacies of 100 and 94% were obtained in preventive and curative treatments respectively. High efficacies in preventive treatments (mean 95.4%) lasted for up to 45 days after application. CONCLUSION: The high efficacies and persistence of imidacloprid OD applied as a drench in young palms show the potential of this product for the management of R. ferrugineus. Copyright (C) 2011 Society of Chemical Industr
The Inhibiting Effect of Sulfate on Thermophilic Anaerobic Digestion of Cattle and Pig Waste Slurry
No full textSlurry acidification with sulfuric acid is a commonly used measure to reduce ammonia emissions from animal waste in Denmark. However, high sulfate content is an inhibiting factor in anaerobic digestion. The objective of this study was to investigate the sulfate concentration thresholds for inhibition of thermophilic anaerobic digestion of animal slurry We conducted a batch assay for 114 days using two types of slurry (pig and cattle) and ten different sulfate concentrations per type of slurry (0 to 5000 mg SO42- L-1). Added sulfate concentrations higher than 2.500 mg SO42- L-1 in pig slurry and higher than 2000 mg SO42- L-1 in cattle slurry caused reductions of more than 40% in Methane production and accumulations of volatile fatty acids throughout the study. The biogas produced contained large amounts of hydrogen sulfide (3.2% in pig slurry and 1.9% in cattle slurry) with concentrations peaking in the first 20 days and subsequently decreasing. Waste properties can affect the inhibitory threshold of the sulfate in anaerobic digestion. Our results provide specific sulfate inhibition thresholds for pig and cattle slurries, which differ from other sulfate-rich wastewaters
Efecto de las radiaciones gamma sobre yemas de caqui
Get PDFEn la última década, el cultivo del caqui (Diospyros kaki Thunb.) en España ha aumentado
significativamente. Esta expansión se debe principalmente al cv. Rojo Brillante, cultivar de alta
calidad organoléptica en el que se basa el 95% de la producción. Con la finalidad de evitar los
riesgos sanitarios y problemas de comercialización que supone el cultivo monovarietal, en el
Instituto Valenciano de Investigaciones Agrarias (IVIA) se inició un programa de mejora de
caqui que persigue la obtención de nuevos cultivares que mantengan la calidad del ‘Rojo
Brillante’, alta productividad y buen tamaño de fruto, y que amplíen su campaña de recolección.
En el caso del caqui, la mejora convencional se enfrenta a diferentes problemas como la
baja disponibilidad de variedades con flores masculinas, la herencia dominante de la astringencia
y la naturaleza hexaploide y nonaploide de los cultivares. Todo ello dificulta enormemente
los estudios genéticos y ha tenido como consecuencia la baja variabilidad comercial disponible.
Una de las estrategias elegidas en el IVIA para poder ampliar esta variabilidad ha sido la
mutagénesis inducida a través de la irradiación con rayos gamma, estrategia ya utilizada anteriormente
con éxito en otras especies frutales (Predieri, 2001)
Measurement of the colour index of early-season citrus fruits using computer vision
Get PDFAspect and colour of food surface is one of the first quality parameters evaluated by consumers and it is a key factor in the acceptance of a particular product for the consumers. In the Mediterranean area, early-season citrus fruit reach acceptable internal maturity standards for marketing, while the skin of the fruit is still green. A degreening treatment is widely used as a postharvest practice to improve the external colour. This treatment depends on the initial colour of the fruit. Therefore, an application where the inspection of the colour is needed is the assessment of these citrus fruits in order to determine accurately the colour of the citrus at harvest. The classification to determine if the fruit needs to be treated for degreening is based on the citrus colour index (CCI). In this work, the potential for the in-line CCI assessment of an industrial computer vision system is studied and compared with two other devices; a characterized computer vision system and a spectrocolorimeter used as reference in the analysis of colour on food. The results obtained prove that the industrial computer vision system predicts the colour index of citrus with a good reliability (R2 = 0.975) and is effective for classification of the fruit according to its colour
El proyecto Core Organic 2 Bio-Incrop: componentes, objetivos y trabajos en marcha
Get PDFCaídas de producción, desórdenes de crecimiento o incluso muerte de las plantas debido a enfermedades del suelo son comunes en cultivos plurianuales como los frutales. En estos casos, junto a la presencia de patógenos en el suelo, adquieren una especial relevancia los niveles de actividad y diversidad microbiológica del suelo. El mantenimiento de estos y el reconocimiento de su función dentro de los agrosistemas son fundamentales en la práctica de la agricultura ecológica. El proyecto BIO-INCROP pretende estudiar técnicas de cultivo capaces de incrementar la funcionalidad biológica del suelo, con
especial enfoque sobre la capacidad supresiva del suelo. Representando a dos de los principales ambientes agronómicos europeos, los trabajos se centrarán en manzano (en Italia, Austria, Alemania, Suiza y Turquía) y cítricos (España y Turquía). Los principales aspectos a investigar serán el uso de diferentes materiales orgánicos con capacidad para incrementar la vida microbiana del suelo, los tratamientos y prácticas con potencial para reducir la afección de enfermedades del suelo (cubiertas vegetales biodesinfectantes, biofumigación, solarización, plantación en zonas alternas, etc.) y el ensayo en condiciones controladas de productos autorizados para uso en agricultura ecológica con capacidad
desinfectante y estimulante de la vida microbiana del suelo (cepas específicas de hongos y bacterias, micorrizas, extractos, etc.). El proyecto está liderado por Luisa Manici, del CRA-CIN de Bolonia (Italia) y los trabajos en España por Rodolfo Canet, del CDAS-IVIA