ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
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El estudio del viroma del olivo mediante secuenciación masiva permite el avance de la taxonomía viral y plantea nuevos interrogantes
Get PDFSe ha descrito por primera vez la secuencia completa de 16700 nt del virus asociado al amarilleamiento de la hoja de olivo (OLYaV), un closterovirus que no estaba asignado a género y de cuyo genoma solo se conocían 4605 nt. El descubrimiento de la organización del genoma y las relaciones filogenéticas con todos los miembros de la familia Closteroviridae en las proteínas compartidas (ORF1a, ORF1b, HSP70h, HSP90h y CP) ha permitido la propuesta y creación del nuevo género Olivavirus compuesto por este virus y otras dos especies virales no asignadas a género, que comparten su proximidad filogenética en todas las proteínas, la codificación de una proteína de la familia de las taumatinas y la ausencia de la proteína menor de la cápsida (CPm)
Efecto de la bomba de pistones de los pulverizadores hidraúlicos sobre la viabilidad de los conidios de Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) y su infectividad sobre Ceratitis capitata Wiedemann (Diptera: Tephritidae)
Get PDFBeauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) es una especie de hongo entomopatógeno ampliamente utilizada para el control de diferentes plagas. Actualmente, existen diferentes formulados comerciales. Su aplicación se realiza utilizando los mismos pulverizadores que para los plaguicidas químicos. Las diferentes partes de estos equipos (bombas, filtros, boquillas, etc.) pueden producir daños a los conidios presentes en la mezcla, disminuyendo su eficacia en el control de plagas. Una de las bombas más utilizadas en los pulverizadores es la bomba de pistones. El objetivo de este trabajo fue estudiar el efecto de estas bombas sobre la viabilidad de los conidios de B. bassiana y su
infectividad sobre Ceratitis capitata Wiedemann (Diptera: Tephritidae)
Presence of cover crops for the conservation of overwintering natural enemies in citrus orchards: friends or foes for spring and summer pest control?
Get PDFWintertime in subtropical areas such as the Mediterranean citrus growing regions has always been considered a critical period for natural enemies. During winter, the major part of citrus pests are not present, and furthermore, citrus trees do not offer any nutritional sustenance for natural enemies. Under this situation, natural enemies either, abandon citrus orchards or suffer severe undernourishment, letting citrus orchards unprotected in early spring, a key period due to the arrival of many citrus pests. Cover crops can offer food resources and shelter to natural enemies and, through well-managed, may represent a sustainable tool to avoid this undesirable biocontrol imbalance
Infraestructuras ecológicas como estrategia de conservación de la entomofauna útil asociada al agrosistema de los cítricos y su acción reguladora sobre plagas claves de este cultivo en Canarias
Get PDFEl presente estudio está enmarcado dentro del proyecto LIFE18 CCA/ES/001109, encaminado a instaurar estrategias de control sostenible de Trioza erytreae (Del Guercio) (vector del HLB) y otras plagas de importancia para la citricultura, en el contexto del Pacto Verde Europeo. El objetivo se ha centrado en el diseño y gestión de infraestructuras ecológicas como estrategia de Control Biológico por Conservación para aumentar la biodiversidad de la entomofauna útil asociada al agrosistema de los cítricos. Los ensayos se han desarrollado en 5 áreas de cultivo de cítricos, localizadas en diferentes zonas citrícolas, norte y sur de Tenerife y Gran Canaria
Melaza contaminada por insecticidas sistémicos: riesgos para los insectos beneficiosos
Get PDFEl control de plagas en agricultura se basa mayoritariamente en el uso de insecticidas que pueden producir efectos nocivos en insectos beneficiosos. En varios estudios recientes, se ha demostrado que la melaza excretada por los hemípteros que se alimentan de plantas tratadas con insecticidas sistémicos puede contaminarse con dichos insecticidas, y resultar tóxica para los insectos beneficiosos que se alimentan de ella. Esta ruta de exposición ha sido demostrada para tres especies de plantas distintas, cinco insecticidas sistémicos y cuatro especies de hemípteros, por lo que puede ser una ruta de exposición muy común en diferentes agroecosistemas donde el néctar es un recurso escaso y la melaza es la principal fuente de alimentación para los insectos beneficiosos
Pest survey card on Elsinoë australis, E. citricola and E. fawcettii
Get PDFThis pest survey card was prepared in the context of the EFSA mandate on plant pest surveillance (M-2020-0114), at the request of the European Commission. Its purpose is to guide the Member States in preparing data and information for Elsinoë australis, E. citricola and E. fawcettii surveys. These are required to design statistically sound and risk-based pest surveys, in line with current international standards. The fungi E. australis, E. citricola and E. fawcettii are clearly defined taxonomic entities causing scab on citrus. Elsinoë australis, E. citricola and E. fawcettii are Union quarantine pests. The import of citrus plants is prohibited while general requirements are in place for the import of citrus fruit, which are the main pathway for entry of these pests into the EU. Elsinoë australis and E. fawcettii produce ascospores in the leaf litter and conidia on lesions in plant tissues that can be disseminated by rain splash and wind, but dispersal distances are not known. Mild temperatures and wetness are necessary for infection and lesions appear after four to six days. The commercial citrus species most relevant for the EU are susceptible to these three fungi. Due to the wide availability of host species and climatic suitability, all citrus-growing areas in the EU are considered potentially suitable for their establishment. Long-distance spread is likely to occur through the movement of infected plant material. To increase the likelihood of detecting the three fungi, visual examination of symptoms should be preferentially conducted in autumn before the harvest period. Symptoms caused by E. australis, E. citricola and E. fawcettii are non-specific, so visual examination should be followed by molecular tests to identify the pests. Based on the analyses of the information on the pest–host plant system, the various units that are needed to design a survey should be defined and tailored to the situation in each Member State
Two Better Than One? Potential Effects of Intraguild Predation on the Biological Control of Ceratitis capitata (Diptera: Tephritidae) by the Parasitoid Aganaspis daci (Hymenoptera: Figitidae) and the Predator Pseudoophonus rufipes (Coleoptera: Carabidae)
Get PDFThe use of more than one species to manage a single insect pest is a common practice among biological control programs. However, the beneficial effects of natural enemies are not always additive, which in many cases may be attributed to interspecific interactions such as intraguild predation (IGP). Herein, we investigated the potential IGP between two relevant natural enemies of the Medfly (Ceratitis capitata), the predator Pseudoophonus rufipes and the parasitoid Aganaspis daci, as well as the possible implications of this phenomenon in their efficiency as biocontrol agents. To this end, we assessed their functional responses and different demographic parameters when acting alone and together against C. capitata under laboratory conditions. Coexistence led to a switch in the functional response of both species, from type III to type II in A. daci and the opposite in P. rufipes. Regarding demographic parameters, coexistence resulted in higher parasitoidism and population reduction by A. daci only at low host densities, probably due to competition pressure. In the same circumstances, P. rufipes reduced its predatory activity, rejecting those larvae that were presumably parasitized and causing negligible IGP. At high Medfly densities, A. daci efficiency decreased, and the reduced encounter probability enhanced the predatory activity by P. rufipes. As a result of these trends, Medfly population reduction reached almost 100% at all densities, which suggests an additive effect of both natural enemies and recommends combined releases of these agents as a strategy for the control of the Medfly
Postharvest chitosan-arginine nanoparticles application ameliorates chilling injury in plum fruit during cold storage by enhancing ROS scavenging system activity
Get PDFBackground: Plum (Prunus domestica L.) has a short shelf-life period due to its high respiration rate and is sensitive to low storage temperatures, which can lead to the appearance of chilling injury symptoms. In this investigation, we applied new coating treatments based on chitosan (CTS) and arginine (Arg) to plum fruit (cv. ‘Stanley’). Results: Fruit were treated with distilled water (control), Arg at 0.25 and 0.5 mM, CTS at 1% (w/v) or Arg-coated CTS nanoparticles (CTS-Arg NPs) at 0.5 and 1% (w/v), and then stored at 1 °C for days. The application of CTS-Arg NPs at 0.5% attenuated chilling injury, which was accompanied by accumulation of proline, reduced levels of electrolyte leakage and malondialdehyde, as well as suppressed the activity of polyphenol oxidase. Plums coated with CTS-Arg NPs (0.5%) showed higher accumulation of phenols, flavonoids and anthocyanins, due to the higher activity of phenylalanine ammonia-lyase, which in turn resulted in higher DPPH scavenging capacity. In addition, CTS-Arg NPs (0.5%) treatment delayed plum weight loss and retained fruit firmness and ascorbic acid content in comparison to control fruit. Furthermore, plums treated with CTS-Arg NPs exhibited lower H2O2 accumulation than control fruit due to higher activity of antioxidant enzymes, including CAT, POD, APX and SOD. Conclusions: The present findings show that CTS-Arg NPs (0.5%) were the most effective treatment in delaying chilling injury and prolonging the shelf life of plum fruit
Selección de material vegetal autóctono en habas de verdeo (Vicia faba var. Major)
Get PDFEl haba (Vicia faba var. major) es un cultivo tradicional muy arraigado en las huertas alicantinas, siendo su destino principal la producción para el mercado de consumo en fresco. El material vegetal que se suele emplear procede mayoritariamente de selecciones de los propios agricultores, aunque algunas empresas productoras de semillas comercializan sus propias selecciones. En el año 2008 desarrollamos trabajos previos que mostraron un mejor comportamiento productivo por parte del material propagado por los agricultores de la zona comparado con el de varias empresas. El objetivo principal de este trabajo fue
seleccionar semillas autóctonas que pudieran entrar a formar parte del «Catálogo de Variedades Locales de Interés Agrario Valenciano». Hemos estudiado 6 cultivares de ciclo temprano, tipo “Cuarentena” y 6 de ciclo intermedio, tipo “Muchamiel”, durante dos campañas consecutivas. El diseño estadístico fue de bloques al azar con 3 repeticiones por tratamiento. Se llevó a cabo el control de las producciones y varios calibrados de las vainas. Realizado el análisis estadístico de los resultados, no aparecieron diferencias significativas (al 95 %) entre la producción comercial de los distintos cultivares, excepto en el segundo ciclo de “Muchamiel”. Sí que se encontraron diferencias en cuanto a precocidad y tamaño de las vainas. A la vista de estos datos, seleccionamos el cv tipo “Cuarentena” codificado como C1 y el cv. tipo “Muchamiel” codificado como M2, procedente, ambos provenientes de agricultores de Elche. Estas selecciones pasaran a formar parte de la colección del «Catálogo de Variedades
Locales de Interés Agrario Valenciano», multiplicándose en cultivo ecológico para su puesta a disposición de los agricultores interesados en su cultivo
Assessing almond response to irrigation and soil management practices using vegetation indexes time-series and plant water status measurements
Get PDFCurrent water scarcity scenario has led to the implementation of sustainable agricultural practices intended to improve water use efficiency. The present work evaluates during three agricultural campaigns (2018-2020) the response of a young almond orchard to two management practices in terms by combining remote sensing indexes (Normalized Difference Vegetation Index, NDVI; and Soil Adjusted Vegetation Indexes, SAVI) and physiological/ morphological measurement (stem water potential, Ψstem; trunk perimeter and canopy diameter). The management practices included (I) sustained deficit irrigation and (II) soil management. Severe deficit irrigation resulted in lower vegetation indexes (VI) values, Ψstem and tree dimensions (13 %, 23 % and 14 % lower, respectively) than those obtained for full irrigation strategy; whereas moderate deficit irrigation did not affect any of the parameters analysed. The presence of vegetation cover in the inter-row resulted in a VIs increase (19-42 %) and in lower tree dimensions (reductions of 7-8 % for trunk perimeter and 0.34-0.37 m for canopy diameter) when compared to bare soil treatment, but did not have any influence on Ψstem. The present study proves the suitability of remote sensing and physiological measurements for assessing almond response to the different management practices