ReDivia - Repositorio Digital de l'Instit Valencià d'Investigacions Agràries
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Caracterización nutricional de variedades tradicionales valencianas de pimiento
Get PDFLa erosión genética provocada en los cultivos al primar producción sobre calidad ha derivado en pérdida de biodiversidad, lo que compromete la seguridad alimentaria mundial. Los agricultores, a través de un proceso histórico de selección, han ido diferenciando variedades tradicionales de cultivo, fuente de biodiversidad agrícola que además favorece el desarrollo de la economía local. Por este motivo, su recuperación, cultivo y clasificación es clave para la economía y futuro alimentario. Dicha conservación requiere una descripción detallada de las características agronómicas, fenotípicas y de calidad nutricional como valor añadido. Este trabajo elabora una caracterización de los recursos fitogenéticos valencianos de cultivos de pimiento, Capiscum annum
La integración en el modelo de producción ecológica: valoración de los agricultores valencianos
Get PDFLa demanda de productos ecológicos ha incrementado de forma notable en los últimos años. Tanto desde la oferta como de la demanda se insta hacia un consumo agrícola responsable. En el mercado se detectan consumidores sensibles a prácticas respetuosas con el medioambiente, a la soberanía alimentaria y el uso eficiente de los insumos, a la selección de alimentos sanos y sin residuos. Por parte de las políticas públicas se tiende a una producción cada vez más cercana a la modalidad ecológica. Las estadísticas invitan a pensar que el mensaje llega. El presente trabajo se planteó con el objetivo de determinar cuáles son los aspectos que más motivan, o en su defecto frenan, la adopción de la producción ecológica (PE). Se contemplaron tanto los aspectos puramente agronómicos, como otros de mercado y gestión administrativa. Se efectuó un sondeo exploratorio a 300 participantes del primer eslabón de la cadena alimentaria en la Comunitat Valenciana, en el que se incluían mayoritariamente
agricultores. La muestra permitió distinguir entre productores que ya trabajaban en ecológico, otros que dudan si hacerlo y quienes se niegan a dar el cambio; y también entre agricultores de cultivos en secano frente a regadío. Los resultados muestran que los mayores temores se centran en aspectos como el tiempo que se necesita para reconvertir la plantación a ecológica, así como las dificultades burocráticas o las necesidades de formación. Como ventajas, el respeto al medio ambiente, o laproducción de alimentos saludables se perfilan como los de mayor relevancia. Se concluye que, aunque todos muestran un interés por el conocimiento de la PE es mayor la apuesta por la adopción en cultivos de secano frente a regadío y en aquellos productores que previamente han tenido algún contacto con ella
Eliciting tomato plant defenses by exposure to herbivore induced plant volatiles
Get PDFWhen zoophytophagous mirids (Hemiptera: Miridae) feed on tomato plants they activate both direct and indirect defense mechanisms, which include the release of herbivore induced plant volatiles (HIPVs). HIPVs are capable of activating defense mechanisms in healthy neighboring plants. In this work, we investigated which of these mirid-induced HIPVs are responsible for inducing plant defenses. Healthy tomato plants were individually exposed to eight HIPVs [1-hexanol, (Z)-3-hexenol, (Z)-3-hexenyl acetate, (Z)-3-hexenyl propanoate, (Z)-3-hexenyl butanoate, hexyl butanoate, methyl jasmonate and methyl salicylate] for 24 hours. Then, the expression level of defensive genes was quantified. All HIPVs led to increased expression of defensive genes by the plant when compared to unexposed tomato plants. In a further step, (Z)-3-hexenyl propanoate and methyl salicylate were selected to study the response of four tomato key pests and one natural enemy to tomato plants previously exposed to both HIPVs relative to unexposed control plants. Plants previously exposed to both HIPVs were repellent to Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), attractive to the parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae) and indifferent to Tetranychus urticae Koch (Acari: Tetranychidae). The volatiles emitted by plants previously exposed to both selected volatiles were also determined. Increased levels of C5 and C6 fatty acid-derived volatile compounds and β-ionone were detected, confirming that both HIPVs significantly activated the lipoxygenase pathway. These results are the starting point to advance the use of volatile compounds as defense elicitors in tomato crops
Optimization of postharvest technology for ‘Rojo Brillante’ persimmon and introduction of new varieties in the mediterranean area
Get PDFIn the last two decades, persimmon production in Spain has increased exponentially and the cultivation area has expanded almost eight-fold. The current production of persimmon is focused on the cultivar ‘Rojo Brillante’, which is appreciated worldwide due to the high quality of the fruit. Nevertheless, centralized production of this single cultivar implies a major commercial limitation as its high volume of production is concentrated in a relative short harvesting period. Furthermore, it also implies a high phytosanitary risk.
In this context, this Thesis addresses two main objectives: 1) Optimization of pre- and postharvest technology in order to guarantee the quality of ‘Rojo Brillante’ persimmon after cold storage and transportation to overseas markets. 2) Evaluation of the behavior of foreign varieties of persimmon under Mediterranean conditions in order to extend the varietal range
New Trends in Disease and Pest Management: Challenges and Opportunities
Get PDFHorticultural and field crops are affected by a number of pests and diseases caused by arthropods, bacteria, fungi, oomycetes, viruses, virus-like organisms, and nematodes. The geographical range of most of these pests and pathogens is expanding as a result of growing global trade and environmental change [1]. Perennial horticultural crops are grown for a number of years; thus, long-term strategic decisions on pest and disease management are critical. Cultivar and rootstock selection as well as orchard planning should be defined prior to crop establishment. Short-term tactical decisions, such as spraying of plant protection
products and cultural practices, should also be planned and implemented for proper pest and disease management [2]. Field crops are cultivated over large areas and management strategies should carefully consider the spatial dimensions and complex interactions with the surrounding landscape
Shaping the biology of citrus: II. Genomic determinants of domestication
Get PDFWe performed genomic analyses on species and varieties of the genus Citrus to identify several determinants of domestication, based on the pattern of pummelo [Citrus maxima (Burr. f) Merr] and mandarin (Citrus reticulata Blanco) admixture into the ancestral genome, as well as population genetic tests at smaller scales. Domestication impacted gene families regulating pivotal components of citrus flavor (such as acidity) because in edible mandarin varieties, chromosome areas with negative Tajimas values were enriched with genes associated with the regulation of citric acid. Detection of sweeps in edible mandarins that diverged from wild relatives indicated that domestication reduced chemical defenses involving cyanogenesis and alkaloid synthesis, thus increasing palatability. Also, a cluster of SAUR genes in domesticated mandarins derived from the pummelo genome appears to contain candidate genes controlling fruit size. Similarly, conserved stretches of pure mandarin areas were likely important as well for domestication, as, for example, a fragment in chromosome 1 that is involved in the apomictic reproduction of most edible mandarins. Interestingly, our results also support the hypothesis that various genes subject to selective pressure during evolution or derived from whole genome duplication events later became potential targets of domestication
Dairy Cows Activity under Heat Stress: A Case Study in Spain
Get PDFHeat stress plays a role in livestock production in warm climates. Heat stress conditions impair animal welfare and compromise the productive and reproductive performance of dairy cattle. Under heat stress conditions, dairy cattle modify their behavior. Thus, the assessment of behavior alterations can be an indicator of environmental or physiological anomalies. Moreover, precision livestock farming allows for the individual and constant monitoring of animal behavior, arising as a tool to assess animal welfare. The purpose of this study was to evaluate the effect of heat stress on the behavior of dairy cows using activity sensors. The study was carried out in Tinajeros (Albacete, Spain) during the summer of 2020. Activity sensors were installed in 40 cows registering 6 different behaviors. Environmental conditions (temperature and humidity) were also monitored. Hourly data was calculated for both animal behavior and environmental conditions. Temperature and Heat Index (THI) was calculated for each hour. The accumulated THI during the previous 24 h period was determined for each hour, and the hours were statistically classified in quartiles according to the accumulated THI. Two groups were defined as Q4 for no stress and Q1 for heat stress. The results showed that animal behavior was altered under heat stress conditions. Increasing THI produces an increase in general activity, changes in feeding patterns and a decrease in rumination and resting behaviors, which is detrimental to animal welfare. Daily behavioral patterns were also affected. Under heat stress conditions, a reduction in resting behavior during the warmest hours and in rumination during the night was observed. In conclusion, heat stress affected all behaviors recorded as well as the daily patterns of the cows. Precision livestock farming sensors and the modelling of daily patterns were useful tools for monitoring animal behavior and detecting changes due to heat stress
Single-nucleotide mosaicism in citrus: Estimations of somatic mutation rates and total number of variants
Get PDFMost of the hundreds of citrus varieties are derived from spontaneous mutations. We characterized the dynamics of single-nucleotide mosaicism in a 36-yr-old clementine (Citrus ×clementina hort. ex Tanaka) tree, a commercial citrus whose vegetative behavior is known in detail. Whole-genome sequencing identified 73 reliable somatic mutations, 48% of which were transitions from G/C to A/T, suggesting ultraviolet (UV) exposure as mutagen. The mutations accumulated in sectorized areas of the tree in a nested hierarchy determined by the branching pattern, although some variants detected in the basal parts were also found in the new growth and were fixed in some branches and leaves of much younger age. The estimate of mutation rates in our tree was 4.4 × 10−10 bp−1 yr−1, a rate in the range reported in other perennials. Assuming a perfect configuration and taking advantage of previous counts on the number of total leaves of typical clementine trees, these mutation determinations allowed to estimate for the first time the total number of variants present in a standard adult tree (1,500–5,000) and the somatic mutations generated in a typical leaf flush (0.92–1.19). From an evolutionary standpoint, the sectoral distribution of somatic mutations and the habit of periodic foliar renewal of long-lived plants appear to increase genetic heterogeneity and, therefore, the adaptive role of somatic mutations reducing the mutational load and providing fitness benefits
Mejoras en el diseño agronómico de la instalación de riego dirigidas al aumento de la productividad técnica y económica del agua en limonero temprano
Get PDFEl objetivo del trabajo fue incrementar la productividad en limonero temprano mediante mejoras en el diseño agronómico de la red de riego. El ensayo se llevó a cabo en una parcela experimental en Torre Pacheco (Murcia), en árboles adultos de limonero ‘Fino 49’ injertados sobre Citrus macrophylla Wester. Se han evaluado dos diseños del sistema de riego: diseño convencional (2L), con dos tuberías portagoteros (6 goteros árbol-1); y un diseño con mayor superficie mojada (3L), con tres tuberías (9 goteros árbol-1). Partiendo de los resultados agronómicos, se ha realizado un análisis económico comparativo entre dos diseños del sistema de riego. El diseño 3L fue el más productivo técnica y económicamente. El Producto Bruto Económico (PBE) fue un 14% superior en el diseño 3L respecto al 2L; el Producto Bruto Técnico (PBT) lo fue en un 6,2%. Este resultado se debe a dos motivos: por un lado y en mayor medida, al incremento en la proporción de limón de primer corte del diseño 3L y, por otro lado, a la disminución de limón derivado a la industria. El Margen Bruto (MB) sigue la misma pauta que el Producto Bruto (PB), ya que los costes diferenciales (CD) son de poca envergadura. El precio ponderado del kg de limón medio (PBE/PBT) es de 0,367 € kg-1 y 0,341 € kg-1, en 3L y 2L, respectivamente, y supone un ingreso de 2.631 € extras por hectárea y año a favor del sistema 3L. Por último, resaltar que el diseño 3L destaca principalmente por ser es más productivo económicamente, en relación al agua aplicada (€ m-3)
Non-polluting integrated control of citrus postharvest diseases
Get PDFPostharvest decay caused by fungal infections is among the most important causes of economic losses for the fresh citrus fruit sector worldwide. Major diseases include green and blue molds, caused by Penicilliumd igitatum and P. italicum, respectively, sour rot caused by Geotrichum citri-aurantii, anthracnose caused by Colletotrichum gloeosporioides, or brown rot caused by Phytophthora citrophthora