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Gene Expression under Short-Term Low Temperatures: Preliminary Screening Method to Obtain Tolerant Citrus Rootstocks
Get PDFClimate change and global warming are leading to a change in weather patterns toward hot and cold waves. Citrus fruits are a tropical or subtropical crop whose growth is altered by changes in weather patterns. Thus, in the present work, two experiments are evaluated to obtain a screening method to select citrus rootstocks that help us to select new low-temperature-tolerant plant materials. One cold experiment was carried out with the Poncirus trifoliata and Citrus macrophylla rootstocks at 4 °C for 4, 8, 24 and 56 h. A second experiment was performed at 4 °C for 5 days with subsequent acclimatization lasting 0, 5, 10 and 24 h. The expression of the cold response genes CAMTA1, CAMTA3, CAMTA5, CBF1, ICE1 and COR413 IM1 was quantified. The results showed that the best rootstock selection strategy was the second experiment, as a higher expression of the genes CAMTA3, CAMTA5, CBF1 and COR413 IM1 was seen in the tolerant genotype P. trifoliata. We quantified the gene expression of proline biosynthesis P5CS1, dOAT and the proline transporters PROT1 and PROT2; the concentration of the amino acid proline in leaves was also quantified. These results once again showed that the best experiment to differentiate between tolerant and sensitive rootstocks was the second experiment with acclimation time
Irrigation water saving strategies in Citrus orchards: Analysis of the combined effects of timing and severity of soil water deficit
Get PDFThe knowledge of the crop response to soil water deficit is essential to predict the actual crop water requirements under limited soil water conditions. The mathematical schematization of the crop response under RDI can allow identifying the exact irrigation timing. The threshold of soil water status below which crop transpiration decreases represents a key parameter for the water stress functions. The main objective of this paper was to investigate the effects of several RDI treatments, applied during the three stages of fruit growth, on soil-plant-water relations of drip-irrigated mandarin trees. Experiments were carried out in seven irrigation treatments: a control, irrigated at 125% of potential evapotranspiration measured in weighting lysimeters, ETlys, during the whole year, and six RDI treatments in which 25% and 50% of ETlys were applied during each of the three stages of fruit growth. The critical threshold of soil water status expressed in terms of soil water depletion below which predawn (PLWP) and midday (MSWP) leaf water potential is affected by decreasing soil water content, were identified. The dependency of crop water status from the climate forcing, occurring under soil water contents higher than the critical threshold was also demonstrated. Moreover, a strong relationship between water stress integral (Smswp) evaluated during the three stages of fruit growth, and the corresponding amount of water applied (irrigation and precipitation) was observed after normalizing the variables. The robust relationship between these two variables (R2 = 0.83) confirmed that the water stress integral represents a good indicator of the plant-water relationship and allows the prediction of the total irrigation depth to be applied to achieve a desired stress level during the fruit growth. Moreover, this relationship depends on the irrigation schedule adopted to regulate the deficit, which includes the irrigation variables, such as irrigation dose and its variabilit
Effects of the irrigation regimes on grapevine cv. Bobal in a Mediterranean climate: I. Water relations, vine performance and grape composition
Get PDFClimate change scenarios are predicting an increase in temperature as well as more scarce and torrential rainfall episodes. Due to this, an imbalance between grape technological and phenolic maturity is being observed detrimentally affecting grapes composition. In semi-arid areas, irrigation management is a main field practice to influence grape ripening. The goal of the present study was to investigate in Vitis vinifera L. cv. Bobal grapevine responses to three watering regimes: (I) Rainfed, (II) deficit irrigation (DI) replacing only 35% of the estimated crop evapotranspiration (ETc) and (III) full irrigation (FI) replacing 100% ETc. In the mid-summer, rainfed grapevines showed different degrees of water stress determined by midday stem water potentials (Ψstem) ranging from −1.1 to −1.4 MPa depening on the season. Rainfed plants had in all seasons less vigor and production and, at harvest, higher concentrations of total soluble solids (TSS) and grape phenolics compounds, as well as lower pH, with respect to the other water regimes studied. DI grapevines, generally, had intermediate values between Rainfed and FI, which presented extreme values of the studied parameters respect to Rainfed. The effects observed on grape color parameters and phenolic compounds with the Rainfed regime were mainly due to a dehydration of the berry, which lowered the yield and the weight of the berry compared to the irrigated treatments. The lower TSS accumulation in the DI berries with respect to the Rainfed, will favor obtaining wines with lower alcohol content, currently more demanded by the consumers. Besides, despite the differences obtained between water regime treatments in the TSS accumulation, the extractability of the anthocyanins was similar, which is interesting since anthocyanin extraction from grapes is prerequisite to the formation of stable red wine pigments. Although the most convenient irrigation strategy might depend to the wine style to be obtained, DI is a strategy that can help to close the gap in the imbalance between the technological and phenolic maturity, positively affecting vine yield and performance with respect to the rainfed strategy
Efecto de diferentes estrategias de riego sobre la nutrición, la calidad y el pardeamiento interior de la corteza de la granada.
Get PDFEl granado (Punica granatum L.) es un frutal tradicional en zonas subtropicales cálidas y semi-áridas, recientemente considerado como cultivo alternativo. La disponibilidad de agua para el riego es un factor limitante en el sureste peninsular español, la zona de producción más importante de la granada en España. En los últimos años se está observando una alteración fisiológica en la granada que ocasiona el pardeamiento de la cara interior de la corteza y que se muestra más aparente tras la conservación en cámara frigorífica. El presente ensayo trata de determinar el efecto manejo de riego sobre la nutrición de la planta, la calidad de la fruta y el pardeamiento interior de la corteza del fruto. Los tratamientos ensayados (T1 a T6) han sido de aplicación de dos dosis de riego (para reponer el 100% de la ETc y de riego deficitario sostenido (RDS, restricción del 50 % durante todo el ciclo de cultivo) con el empleo en las líneas portagoteros de emisores de diferente caudal (8, 4 y 2 L/h, respectivamente). Se ha realizado
el análisis de macro y microelementos minerales en el fruto y los parámetros de calidad de la fruta de color exterior de la corteza y del zumo (CIELab*), SST (ºBrix), pH, acidez titulable e índice de madurez del zumo y el índice de pardeamiento de la corteza. En los resultados obtenidos, no se encontraron diferencias significativas en los parámetros medidos debidas al caudal del emisor. El RDS aumentó la coloración externa del fruto, el rendimiento en zumo y el índice de madurez, redujo el espesor de la corteza y no afectó al color del zumo. El riego deficitario redujo la afección de pardeamiento interno tras la conservación
Retos y posibilidades a los que se enfrenta el sector ornamental de la Comunitat Valenciana
Get PDFEl sector ornamental en España se asocia mayoritariamente con el cultivo de planta viva, en maceta y contenedor, y algo menos con el de flor cortada, aunque también ha tenido su relevancia. Son cultivos muy intensivos en mano de obra y recursos, con altos niveles de inversión y tecnología, y que reportan un importante valor a las cuentas finales de la producción agraria, principalmente por el componente exportador. Los viveristas de la Comunitat Valenciana concentran más de un tercio de la superficie nacional y son un claro referente para todo el sector español. Este trabajo tuvo como principal objetivo detectar las expectativas de futuro que perciben estos empresarios, con el fin de percibir en qué áreas hay que seguir trabajando para garantizar la continuidad del sector ornamental. Se recopilaron 33 encuestas realizadas en una sesión conjunta a viveristas valencianos. Con sus respuestas se ha realizado un análisis DAFO que ha permitido identificar los retos y posibilidades a las que se enfrenta el sector ornamental en dicha Comunidad. La aportación recabada tiene un valor especial dado el rol profesional que asumen, más elevado que otros productores agrarios. En general, son personas con un alto conocimiento técnico del cultivo, pero como actúan de forma directa en el resto de fases de la cadena de valor, también tienen información relevante en las cuestiones comerciales. Con los resultados obtenidos del estudio se puede concluir que son cultivos con una gran demanda de mano de obra, generando empleo cualificado por la alta tecnificación que requiere y que los mayores desafíos se centran en los de naturaleza legal y medioambiental. Habría que hacer un esfuerzo por transmitir a los consumidores la
relevancia de aceptar un mayor precio por producciones de alta calidad, procedente de cultivos que generan mucha riqueza en el territorio
Polyphenol content in apricot fruits
Get PDFApricot (Prunus armeniaca L.) species is one of the most important Mediterranean fruits. The fruits are important in the diet of Asian and Mediterranean countries in which the apricot is used as fresh and dried fruit, being an important source of nutrients. Despite of the amount of genetic resources and diversity studies available into the species, there are a few studies focused on fruit quality. Among the different compounds of fruit quality, polyphenols are classified as the most abundant antioxidants in nature, being important as a source of health benefits as well as a potential source of natural products for the food industry. The important role of polyphenols in human nutrition, outline these compounds as the most relevant for defining fruit quality. In this study, the polyphenol content on fruits from different apricot varieties included elite cultivars and hybrids from the IVIA breeding program have been compared for identifying the genotypes with relevant contribution to fruit quality. The most important compounds obtained in terms of quantity were: phenolic acids and flavonoids. Results identified the PPV resistant cultivar ‘Goldrich’ as the best cultivar for increasing the content of antioxidants in the varieties of the breeding program
Discrimination of common defects in loquat fruit cv. ‘Algerie’ using hyperspectral imaging and machine learning techniques
Get PDFLoquat (Eriobotrya japonica L.) is an important fruit for the economy of some regions of Spain that is very susceptible to mechanical damage and physiological disorders. These problems depreciate its value and prevent it from being exported. Visible (VIS) and near infrared (NIR) hyperspectral imaging was used to discriminate between external and internal common defects of loquat cv. ‘Algerie’. Two classifiers, random forest (RF) and extreme gradient boost (XGBoost), and different spectral pre-processing techniques were evaluated in terms of their capacity to distinguish between sound and defective features according to three approaches. In the first approach the fruit pixels were classified into two classes, sound or defect, with a 97.5% rate of success; in the second the defective features were considered internal or external defects, achieving a 96.7% rate of success; and in the third approach each type of defect, i.e. purple spot, bruising, scars and flesh browning, were considered separately with a correct classification rate of 95.9%. The results indicated that the XGBoost classifier was the best method in all cases
Sustainable Management Methods of Orchard Insect Pests
Get PDFThe current need for sustainable resource management is increasingly urgent, as demand for agricultural commodities is rising rapidly as the world’s population grows. However, agricultural intensification is one of the main drivers of the global biodiversity crisis and global decline in insects [1,2]. Additionally, an impressive amount of research has been published regarding the many detrimental effects of pesticides, which had been the main approach developed for pest control in the first half of the previous century, but which has been progressively replaced by the use of biopesticides and other sustainable methods (biological, physical and other non-chemical methods) to provide satisfactory pest control and implementing Integrated Pest Management (IPM)
Rootstock effect on fruit quality, anthocyanins, sugars, hydroxycinnamic acids and flavanones content during the harvest of blood oranges ‘Moro’ and ‘Tarocco Rosso’ grown in Spain
Get PDFThe physico-chemical quality parameters (external and internal color, firmness, acidity, total soluble solids, anthocyanins, sugars, hydroxycinnamic acids and flavanones) of ‘Moro’ and ‘Tarocco Rosso’ blood oranges grafted onto eight different rootstocks at three harvest time were studied. The rootstocks were ‘Carrizo’, ‘C-35’, ‘Cleopatra’ mandarin, ‘Citrus volkameriana’, ‘Citrus macrophylla’, ‘Swingle’ citrumelo, ‘Forner-Alcaide 5’ and ‘Forner-Alcaide 13’. All studied parameters were highly rootstock/scion-dependent and showed changes throughout harvest. The content of the main anthocyanins revealed their relation with internal fruit color in both cultivars. The rootstocks that led to fruit with the lowest anthocyanins displayed the least sucrose content. The differences detected in the amount of hydroxycinnamic acids (chlorogenic, ferulic and sinapic) and flavanones (hesperidin, narirutin and didymin) related to anthocyanins content, explained phenylpropanoid pathway
Volume Rate Adjustment for Pesticide Applications against Aonidiella aurantii in Citrus: Validation of CitrusVol in the Growers’ Practice
Get PDFAonidiella aurantii is one of the most damaging armored scales in citrus crops worldwide.
To control this pest, high water volume rates are conventionally used. In order to rationalize the
pesticide applications in citrus, IVIA developed CitrusVol, a tool that recommends the optimal
volume rate based on the vegetation, the pest or disease and the active ingredient. In this study
the objectives were: (I) validate CitrusVol as a tool to adjust the spray volume to control A. aurantii
and (II) quantify its environmental and economical advantages. For this, the spray volume adjusted
with CitrusVol was compared with the one conventionally used by farmers in 18 applications in
seven orchards during two years. The following parameters were evaluated: (I) spray distribution
in the canopy, (II) A. aurantii males trapped per day, and (III) number of scales per fruit at harvest.
CitrusVol reduced the spray volume and the amount of pesticide by 35% on average. Despite this
reduction, a satisfactory spray distribution was achieved, and the volume was found to control the
pest in a comparable way to the conventional volume. Moreover, CitrusVol saved per application
and on average 31.25 h/100 ha of spray operating time, 241.83 L/100 ha of fuel consumption and
consequently, the reduction of emissions of CO2 was 631.18 kg/100 ha. Therefore, CitrusVol allows
for efficient, low-input and low-impact pesticide applications