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Economic prospects of pomegranate growing in the Spanish Mediterranean region
Get PDFThe objective of this paper is to analyze origin price trends, as well as to determine the profitability of Spanish pomegranate farms through the evaluation of investments. This analysis is performed in parallel with mandarin, since citrus is one of the main tree crops with which it competes and shares territory. Although farmers in the Spanish Mediterranean have preferred to choose citrus in recent decades, its drop in value is encouraging the choice of alternative tree crops, and there will be areas, like the one studied here, where the interest in species with more favorable prospects, such as the pomegranate, will increase. This is possible if demand grows, supported by the notion that it is a healthy or functional food
Complete Genome Sequence of "Candidatus Portiera aleyrodidarum" BT-QVLC, an Obligate Symbiont That Supplies Amino Acids and Carotenoids to Bemisia tabaci
No full textThe genome of "Candidatus Portiera aleyrodidarum," the primary endosymbiont of the whitefly Bemisia tabaci (Mediterranean species), is reported. It presents a reduced genome (357 kb) encoding the capability to synthetize, or participate in the synthesis of, several amino acids and carotenoids, being the first insect endosymbiont capable of supplying carotenoids
Role for Rhizobium rhizogenes K84 Cell Envelope Polysaccharides in Surface Interactions
No full textRhizobium rhizogenes strain K84 is a commercial biocontrol agent used worldwide to control crown gall disease. The organism binds tightly to polypropylene substrate and efficiently colonizes root surfaces as complex, multilayered biofilms. A genetic screen identified two mutants in which these surface interactions were affected. One of these mutants failed to attach and form biofilms on the abiotic surface although, interestingly, it exhibited normal biofilm formation on the biological root tip surface. This mutant is disrupted in a wcbD ortholog gene, which is part of a large locus predicted to encode functions for the biosynthesis and export of a group II capsular polysaccharide (CPS). Expression of a functional copy of wcbD in the mutant background restored the ability of the bacteria to attach and form normal biofilms on the abiotic surface. The second identified mutant attached and formed visibly denser biofilms on both abiotic and root tip surfaces. This mutant is disrupted in the rkpK gene, which is predicted to encode a UDP-glucose 6-dehydrogenase required for O-antigen lipopolysaccharide (LPS) and K-antigen capsular polysaccharide (KPS) biosynthesis in rhizobia. The rkpK mutant from strain K84 was deficient in O-antigen synthesis and exclusively produced rough LPS. We also show that strain K84 does not synthesize the KPS typical of some other rhizobia strains. In addition, we identified a putative type II CPS, distinct from KPS, that mediates cell-surface interactions, and we show that O antigen of strain K84 is necessary for normal cell-cell interactions in the biofilms
Novel defenses of Protopulvinaria pyriformis (Hemiptera: Coccidea) against its major parasitoid Metaphycus helvolus (Hymenoptera: Encyrtidae): Implications for biological control of soft scales
No full textProtopulvinaria pyriformis (Cockerell) (Hemiptera: Coccidae), a scale native to South America, is a major pest of laurel, Laurus nobilis L., and a potential pest of other ornamental plants in urban green areas. We evaluated the potential of Metaphycus helvolus (Compere) (Hymenoptera: Encyrtidae), its major parasitoid, as a biological control agent against P. pyriformis. This parasitoid was imported from South Africa to control soft scales in Europe more than 20 years ago. Three factors limited its efficacy: (i) the scale frequently thwart parasitoid attack by removing its stylet and wiggling, a unique defense in soft scales, (ii) scale honeydew extended M. helvolus lifespan little more than water, and (iii) P. pyriformis did not encapsulate Metaphycus spp. eggs but immature parasitoids died during their prepupal stage, which may have been caused by laurel plant secondary compounds from laurel. This parasitoid mortality had not been previously reported in immature parasitoids of genus Metaphycus. These three novel aspects should be considered when choosing a suitable parasitoid in future soft scale biological control programs. (C) 2012 Elsevier Inc. All rights reserved
Effect of storage length at 16 degrees C prior freezing on boar sperm quality and cholesterol content after thawing in samples pre-treated or not with cholesterol-loaded cyclodextrin (CLC)
No full textRelationships between agronomic factors and epidemics of Phytophthora branch canker of citrus in southwestern Spain
No full textPhytophthora branch canker, caused by Phytophthora citrophthora, has been an increasing problem in clementine (Citrus reticulata) production in Spain during last years. The disease was particularly severe in the new citrus-growing areas of the southwestern coastal areas in Huelva Province. Recent studies revealed that disease emergence was not related to either genetic drift or host specificity changes in P. citrophthora population. Therefore, the possible association of agronomic factors with the disease was investigated. A total of 110 orchards were selected arbitrarily from the main citrus-growing areas in Huelva Province. The presence of branch cankers together with agronomic factors including soils, cultivars, rootstocks, irrigation, pruning, techniques to improve fruit production, fungicide treatments, presence of brown rot of fruit and frost damage were recorded. Logistic regression analysis was used to detect correlations between the agronomic factors studied and disease prevalence. Phytophthora branch canker was significantly associated with mature clementine orchards. Sweet orange and hybrid cultivars as well as young clementine orchards were less affected by the disease. Although disease was less frequent in Salorthid soils, alternative high resolution procedures are required to draw conclusions about the effect of soil properties on disease prevalence. As in other Phytophthora-induced diseases, soil flooding during the rainy season was correlated positively with the prevalence of branch cankers. Improving fruit production by branch scoring showed a strong positive correlation with Phytophthora branch canker. This is the first time that girdling has been associated with Phytophthora disease epidemics on a fruit tree crop, but further research is needed to determine the cause of this relationship. Cultural practices including pruning, regulated deficit irrigation, additional phosphonate sprays, and abiotic and disease factors such as frost damage and presence of brown rot of fruit were not significantly correlated with disease prevalence
Cítricos: Cultivo, Poscosecha e Industrialización
No full textDesde el momento en que los frutos cítricos son recolectados hasta su comercialización y consumo se inicia
un proceso de deterioro natural, que conducirá a la
pérdida del producto en un corto periodo de tiempo si
se no se realizan procesos de manipulación y conservación para evitarlo.
En Colombia, las pérdidas en el periodo poscosecha
de los cítricos son muy elevadas. Para reducir estas
pérdidas es necesario entender los factores biológicos
y medioambientales relacionados con el deterioro del
fruto y conocer la tecnología poscosecha más apropiada para retrasar la senescencia y mantener la calidad
del producto lo mejor posible. La manipulación poscosecha tiene como objetivo mantener las cualidades
de los productos desde que son cosechados hasta que
llegan al consumidor, garantizando la calidad organoléptica y nutricional, mejorando la presencia externa
y siempre aplicando las normas y recomendaciones
vigentes.
Normalmente, los frutos cítricos tras la recolección
son transportados a las centrales de manejo (o empacadoras) donde son sometidos al proceso de confección para su presentación al mercado o bien expuestos a tratamientos poscosecha específicos como desverdización o frigoconservación. Uno de los problemas de competitividad
que presenta la cadena citrícola, es el hecho de que la
fruta nacional no cumple con los estándares que impone la demanda
interna o el acceso a nuevos mercados externos. Esto se debe principalmente
al deficiente manejo poscosecha que existe en todas las regiones
del país, comenzando por una cosecha inadecuada, deficiente
selección, clasificación y almacenamiento, e insuficiente tecnología
para mejorar presentación, lo que finalmente se traduce en abundantes
desechos y pérdidas.
En este capítulo se discute sobre los cambios fisiológicos que ocurren
tras la cosecha, los requisitos de calidad exigidos por el mercado así
como el proceso de manipulación poscosecha a los que se somete los
frutos cítricos. Con ello se pretende suministrar al lector el conocimiento
necesario para poder realizar la comercialización del fruto manteniendo
la calidad exigida por el consumidor
Increasing energy and lysine in diets for growing-finishing pigs in hot environmental conditions: Consequences on performance, digestibility, slurry composition, and gas emission
No full textThe influence of dietary nutrient concentration on growth performance, manure composition, and gas emission was studied in pigs in hot environmental conditions. A total of 64 intact males and 64 females [(Landrace x Large White) x Pietrain] weighing 63.1 +/- 9.7 kg were divided into 2 dietary treatments: high (HD: 14.39 MJ of DE/kg and 1.11% Lys) and low (LD: 13.97 MJ of DE/kg and 1.01% Lys) in energy and Lys contents. Pigs were allocated to 32 split-sex pens with 4 pigs/pen and 16 pens/treatment. Average productive performance was recorded for 41 d (phase 1). After phase 1, 12 females of 103.3 +/- 3.15 kg (6 per treatment) were selected and housed individually, and feces and slurry were collected during 3 and 4 consecutive days, respectively, to calculate nutrient digestibility and measure gas emissions (phase 2). For gas emission measurements, slurry was pooled by treatment and stored for 76 d. Initial composition of slurry and pH were analyzed. Maximum and minimum temperatures registered in the barn throughout the growing period were 35.1 and 18.1 degrees C, respectively. Animals fed the HD diet grew more efficiently than pigs fed the LD diet (G:F, 0.43 vs. 0.40; SEM = 0.01; P < 0.05). Fat digestibility was greater in HD compared with LD pigs (88.0 vs. 84.9%; SEM = 0.9; P < 0.05). Slurry from pigs fed the LD diet showed greater DM, OM, total N, and VFA contents than slurry from pigs fed the HD diet. Cumulative NH3, CO2, and especially CH4 emissions were greater in the HD slurry compared with the LD slurry (192 vs. 210 g of NH3/m(3); 2,712 vs. 3,210 g of CO2/m(3); 1,502 vs. 2,647 mL of CH4/kg of OM). Increasing feed density in the present study led to a more efficient growth, a decreased nutrient concentration in the slurry, and a greater gas emission
Physico-Chemical, Sensory and Nutritional Quality of Oranges Cv. Valencia Coated with Chitosan
Get PDFApplying waxes and natural coatings, such as chitosan, to citrus fruits lengthens their post-harvest shelf life. Although coating induces changes in the internal atmosphere, there is no information regarding the effects on their nutritional compounds. The objective of this study was to evaluate the effect of chitosan on the physiology and quality of 'Valencia' oranges (Citrus sinensis). Chitosan was applied in three proportions of solid content (CS) (0.6, 1.2 or 1.8 %). The results with chitosan were compared with those obtained with a commercial wax (CC) made of 10 % CS polyethylene/shellac and a control without coating. After 5, 9 and 16 weeks of refrigeration at 5 degrees C followed by one week at 20 degrees C, physico-chemical, sensorial and nutritional quality of the oranges was assessed. After five weeks under refrigeration, CC and 0.6 % chitosan reduced weight loss by 10 % with respect to the control. When storage was prolonged, 0.6 % chitosan was less effective than CC in reducing weight loss, but maintained internal CO2 and O-2 levels close to those of uncoated oranges, unlike CC, which restricted gaseous exchange, increased internal CO2 and decreased internal O-2 significantly with respect to uncoated fruits. Chitosan at 1.2 and 1.8 % CS modified the internal atmosphere with levels of CO2 and O-2 similar to those of oranges coated with CC. Nevertheless, the coating that most restricted gaseous exchange did not deteriorate the flavor of the fruits. Application of the coatings did not affect nutritional quality of the fruits, and flavonoids increased during storage
HS-SPME study of the volatile fraction of Capsicum accessions and hybrids in different parts of the fruit
No full textThe fruit volatile fraction of 8 Capsicum annuum and 2 Capsicum chinense accessions as well as 6 intra-specific and 2 inter-specific hybrids developed from crossings between them was isolated by headspace-solid phase microextraction (HS-SPME), and analized by gas chromatography-mass spectrometry (GC-MS). Samples of fruit flesh and placenta plus seeds were analysed separately. Several terpenoids, esters, alkanes, as well as other minor compounds relevant for the aroma, including 3-isobutyl-2-methoxypyrazine, methyl salicylate, and alpha-ionone, were identified. Remarkable differences, both qualitative and quantitative, were found for the volatile composition of the parent accessions. In hybrids a number of compounds comprised between or higher than in the corresponding parents was detected, while intermediate or transgressive inheritance for both total and individual volatiles was observed. Differences between fruit flesh and placenta/seeds were mostly quantitative, as we could not detect compound-specificity in these tissues. In most cases, both total and individual volatiles were higher in the placenta/seeds samples. This effect was particularly important in hybrids, with levels of total volatiles in the placenta up to 14-fold those of the fruit flesh. Our results suggest that there are ample opportunities for improving the aroma of Capsicum peppers by means of hybridization