ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
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Programa de mejora genética del melocotonero en la Comunidad Valenciana
No full textDebido a la extensa variabilidad presente en China, este país es considerado como el centro de origen de la especie por diversos autores (Watkins, 1976). La especie fue difundida por el mediterráneo por los romanos que la introdujeron a través de Persia.
Posteriormente se difundió por toda Europa. Después del descubrimiento de América fue introducida en América por los exploradores portugueses y españoles. China es el país del mundo con una mayor riqueza en germoplasma de la especie. Las mayores colecciones mundiales de melocotón se encuentran en Nanjing, Zhengzhou y Beijing (Wang et al, 2002). En melocotón existe una gran diversidad en forma, color, tamaño y contenido en azucares del fruto. El germoplasma originario de las republicas exsoviéticas, e Irán se ha utilizado en gran medida para secado por lo que la selección llevada a cabo ha dado lugar a variedades de alto contenido en azúcares
Diagnosis of Xanthomonas axonopodis pv. citri, causal agent of citrus canker, in commercial fruits by isolation and PCR-based methods
No full textAims: To show the results of the detection of an EU quarantine organism, Xanthomonas axonopodis pv. citri (Xac), in citrus fruits imported from countries where this bacterium is present, using an integrated approach that includes isolation, pathogenicity assays and molecular techniques. Methods and Results: Citrus fruits with canker-like symptoms, exported to Spain from South American countries were analysed by several methods. Bacterial isolation, three conventional polymerase chain reaction (PCR) protocols, and real-time PCR with SYBR Green or a TaqMan probe, were compared. Canker-like lesions were disrupted in PBS buffer, and the extract used for bacterial isolation and DNA extraction followed by PCR amplification. Canker lesions, identified by PCR, showed viable bacteria in eleven of fifteen fruit samples. In 16 out of 130 lesions analysed from these samples, Xac was isolated, and pathogenicity on grapefruit leaves confirmed. By real-time PCR, using SYBR green or a Taqman probe, Xac was detected in 58 and 80 lesions respectively. By conventional PCR the bacterium was detected in 39–52 lesions depending on the protocol employed. Conclusions: An integrated approach for reliable detection of Xac in lesions of fruit samples, employing several techniques and with real-time PCR using a TaqMan probe as the fastest and most sensitive screening method, has been established and validated and is proposed as a useful tool for the analysis of Xac on fresh fruits. Significance and Impact of the Study: This work faces up to the real threat of the importation of citrus fruits that can harbour quarantine bacteria and will be useful in diagnostic laboratories for the analysis of commercial fresh fruits from countries where citrus canker is present
Irrigation water pricing policy and its effects on sustainability of table grape production in Spain
Get PDFIn Spain, production of table grapes is located principally in two very and provinces of the Mediterranean region, which, although geographically close, have very distinct entrepreneurial behavior. The objective of this study was to determine the effects of availability and price of irrigation water on the sustainability of grape operations. First, shadow prices of irrigation water were obtained by applying compromise programming; calculations were performed for the current productive context, and another calculation was performed for the adoption of a series of technological improvements. Also, water demand curves were calculated to analyze the repercussions of applying an increasing tariff, such as that proposed by the current European Water Framework Directive. The results show that it is necessary to increase the technological level of the production phase to guarantee the sustainability of Spanish table grape production units. The most relevant improvements are changing surface irrigation for drip irrigation, perfecting the training structures, covering the fields with screens or plastic, introducing apirena varieties, and earlier harvesting. The resulting shadow prices for irrigation water are very high, indicating that in these production units water availability has a greater effect than price. However, the real prices the farmers could pay do not coincide with the shadow price but with that deducted from the demand curves, which were obtained by simulating the effects of implementing a water-pricing policy. For the farmer to obtain a minimal profit, even though the proposed technological improvements are adopted, the price could not surpass 0.6 epsilon m(-3) in the area with the least technology and 1.1 epsilon M-3 in that with the highest level of technology
Fecundity and development of Cirrospilus coachellae (Hymenoptera: Eulophidae), a parasitoid of Marmara gulosa (Lepidoptera: Gracillariidae)
No full textThe biology of Cirrospilus coachellae Gates (Hymenoptera: Eulophidae), an ecto-parasitoid of the larvae of Marmara gulosa Guillen & Davis (Lepidoptera: Gracillariidae) was studied in the laboratory. In total, 120.3 +/- 21.2 adults were produced per female at 26 degrees C. Females survived an average of 23.5 +/- 4.4 d and parasitized an average of 49.8 +/- 10.2 hosts over their lifetime. C. coachellae is a facultatively gregarious parasitoid with up to eight parasitoids developing per host with an average of 2.5 +/- 0.1 in the laboratory. A female-biased sex ratio of 0.31 (male/total) was exhibited. Development times decreased with increasing temperatures from 23.7 +/- 0.2 d at 20 degrees C to 9.2 +/- 0.1 at 29 degrees C. Estimated lower and upper development thresholds were 14.1 and 36.7 degrees C, respectively. Maximal development rate occurred at 31.3 degrees C, and 138 degree-days was required to complete the cycle
Optimization of an aroma sensor for assessing grape quality for wine making
Get PDFControl of the raw material has considerable influence on final wine quality. The objective of this work was to develop a sensor capable of assessing grape juice quality in the cellar. Sensor response was compared with conventional chemical analysis using multivariate data techniques. The aroma sensor array is composed of 14 metal oxide sensors (MOS) gas transducers plus a temperature and a relative humidity sensor. This work showed that the sensor could detect rotten flavours in grape juice
Otras alternativas a la quema de paja de arroz: incorporación directa al suelo y aplicación en forma de compost
Get PDFEl destino que tradicionalmente se ha dado a la paja en los campos de arroz del
Parque Natural de la Albufera, ha sido la quema. Pero esta práctica, tan apreciada por los
arroceros por su facilidad de realización y por sus efectos fitosanitarios, produce serios
problemas de salubridad en las zonas circundantes a la ciudad de Valencia, así como
considerables daños medioambientales.
Así mismo, en el Real Decreto 4/2001, de 12 de enero (MAPA, 2001), sobre
ayudas a la utilización de métodos de producción agraria compatibles con el medio
ambiente, se prohíbe la quema de rastrojos, salvo casos justificados por razones
sanitarias y para evitar problemas fitosanitarios graves.
Y por otra parte, en la Comunidad Valenciana se produce una cantidad importante
(unas 350.000 toneladas/año) de lodos de depuradora, que debido a su alto contenido en
materia orgánica y nutrientes esenciales (particularmente nitrógeno y fósforo) constituyen
un material enmendante del suelo de gran valor (Pomares, 1982), que es susceptible de
ser mezclado con un residuo lignocelulósico como es la paja de arroz, pudiendo
obtenerse un producto (compost) que además de contener altos niveles de materia
orgánica y nutrientes (Ferrer et al., 2001), resultaría estabilizado y suficientemente
higienizado para su uso como abono orgánico en los cultivos agrícolas.
Con vistas a obtener un aprovechamiento globalmente beneficioso que evite o
reduzca los riesgos ambientales que conlleva su quema, se iniciaron en el año 2002
sendos estudios de campo para evaluar la respuesta del cultivo del arroz a diferentes
manejos de la paja (quema, incorporación y recogida), y a la aportación de una parte de
la fertilización nitrogenada (25 y 50 %) en forma de un compost de paja de arroz y lodos
de depuradora
Combined postharvest X-ray and cold quarantine treatments against the Mediterranean fruit fly in 'Clemenules' mandarins
Get PDFIn the present work, survival of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) on artificially infested 'Clemenules' clementine mandarins (Citrus reticulata Blanco) was assessed on fruit subjected to integrated quarantine treatments consisting of irradiation with X-rays at doses of 0 (control), 30, 54, and 164 Gy followed by exposure to 1 degrees C for 0 (control), 3, 6, 9, or 12 days. Additionally, physico-chemical (rind color, firmness, and physiological disorders, soluble solids concentration, titratable acidity, maturity index, juice yield, and ethanol and acetaldehyde content) and sensory (sweetness, acidity, sensory maturity index, off-flavors, and mandarin-like flavor) fruit quality of 'Clemenules' clementines were assessed on X-irradiated fruit exposed to 1 degrees C for 0 (control), 6, or 12 days. Complete insect mortality with no negative effects on fruit quality after 7 days at 20 degrees C of shelf life was obtained on clementines firstly X-irradiated at 30 Gy and subsequently exposed to 1 degrees C for 2 days. This combination of treatments considerably reduced quarantine time if compared to standard cold quarantine treatments (1.1-2.2 degrees C for 14-18 days) and therefore showed promise as a potential commercial treatment for Spanish citrus exports
ACTA HORTICULTURAE
No full textThe gametophytic self-incompatibility (GSI) system in Rosaceae has been proposed to be controlled by two genes located in the S-locus: an S-RNase and a recently-described, pollen-expressed, S-haplotype-specific F-box gene (SFB). Fragments containing genes homologous to the S-RNase and F-box genes in Prunus species have been described. In apricot (Prunus armeniaca L.), these genes were identified recently. Three identified S-RNase alleles and the F-box allelic variants (SFB1, SFB2 and SFB4) allowed elucidation of the S-locus structure in apricot. In this paper, from the analysis of the S-locus, we carried out the molecular typing of several S-alleles in apricot. A primer pair developed from conserved regions identified in the apricot S-locus was used to amplify the first S-RNase intron. Fragments containing the second intron were obtained using two sets of primers designed from published Prunus avium S-cDNA sequences. These results confirm genotypes established by other methods and establish five self-(in)compatibility groups in apricot
Sustainable management for woody crops in Mediterranean dry-lands
Get PDFIn the large inland extensions of the Spanish Mediterranean, dry-farming is predominant and the main crops are olive, vine and almond. These species represent an agricultural activity that is fundamental to the continued inhabitation of these regions. The aim of this work is to determine the chances this agriculture has of continuing by following criteria of sustainability. Having chosen goals of an economic, social and environmental nature, almost-ideal cropping plans are obtained using the Compromise Programming. Moreover, given the important role played by water availability in this type of agriculture, the study is completed by determining the impact that an irrigation-water pricing policy would have, as outlined in the European Water Framework Directive. The study leads to the conclusion that, increasing mechanization may be the most straightforward strategy to ensure the sustainability of farms in Spanish dry-lands, and specially if the current trend of increasing irrigation-water prices is consolidated