Advances in Hazelnut (Corylus avellana L.) Rootstocks Worldwide

Studies on hazelnut (Corylus avellana L.) rootstocks have been limited to date. However, the use of vigorous, non-suckering rootstocks for this species could increase the cost-effectiveness of orchards by reducing the annual need to prune suckers, thus facilitating mechanical harvesting, and reducing orchard management costs and environmental impact. Seedlings of the non-suckering Turkish tree hazel (C. colurna L.) have been used traditionally in Serbia. In the 1970s, the United States Department of Agriculture in Corvallis, Oregon (USA) released the first two non-suckering clonal rootstocks—‘Dundee’ and ‘Newberg’—from open-pollinated seeds of C. colurna. Moreover, selection of C. avellana cvs. with few suckers is continuing. Trials carried out in different countries with own-rooted and grafted plants have shown good performance of grafted hazelnuts. Currently, some nurseries in several countries are propagating hazelnut rootstocks and grafting trees for planting commercial orchards. Interest in these cultivar/rootstock combinations is increasing, and more new orchards of grafted trees are expected to be planted in the coming years.info:eu-repo/semantics/publishedVersio

Hazelnut production and prospects in Spain

For many years, Spain was the fourth largest hazelnut producer worldwide, after Turkey, Italy and the USA. However, Spanish production currently occupies the tenth place with 10,500 t in 2017, due to the reduction of land used for cultivation, coupled with the growing importance of other producing countries: Azerbaijan, China, Georgia, Chile, Iran and France. In Europe, with 16% of world hazelnut production, in 2017, Italy is the main producer country (81%), followed by France and Spain, producing 6,7% and 6,5%, respectively. The hazelnut tree (Corylus avellana L.) grows wild in Spain. In 2017, the total cultivated area dedicated to this species was 12,806 ha, mainly (82%) concentrated in Tarragona, southern Catalonia. Finally, it is worth highlighting the sector's great investment in fruit processing technology. Currently, the main cooperatives offer semi-finished products to many European chocolate industries and have their own production of roasted products, in shell and flour, for direct sale.info:eu-repo/semantics/publishedVersio

Hazelnut Kernel Size and Industrial Aptitude

Kernel size is the main hazelnut quality parameter for the consumption market. However, industrial purposes are the main destination for the main hazelnut cultivars. This work aims to identify industrial aptitude relationships to kernel size, and qualitative nut and kernel traits eligible to enhance hazelnut’s commercial value. The qualitative hazelnut traits of cv “Negret” and “Pauetet” were assessed via in-shell and shelled nut sizes for two years. In-shell hazelnuts were tested for weight, shape, percent kernel, yield and shell thickness. Kernels were measured for shape, weight, roasting aptitude, skin color, moisture content and water activity, free acidity, fat content, crude protein, total sugars, minerals, fatty acid composition, α-tocopherol and oil stability. In-shell hazelnut traits significantly differed between cultivars, sizes and storage period. Shell thickness and nut roundness increased almost linearly with nut caliber, whereas kernel percentage decreased. Kernel roundness increased linearly with caliber. The blanching and roasting aptitude of “Negret” increased linearly with caliber, whereas no significant trend was observed for “Pauetet”. Significant differences between cultivars were confirmed for water activity, oil acidity and skin color. Regarding chemical composition, fat content increased linearly with caliber in both cultivars, and α-tocopherol followed the same trend in “Negret”. The sugar content tended to decrease with caliber, whereas crude protein, fiber and minerals did not show any significant relationship with kernel size. Unsaturated and polyunsaturated fatty acids fitted to linear models related to caliber, showing differences between cultivars. Unsaturated fatty acids increased with caliber, whereas polyunsaturated fatty acids decreased, and the oil stability increased linearly with kernel size. These results show that some hazelnut key traits change significantly with kernel size. The linear models presented could be a powerful tool for the confectionery industry to modulate the industrial value of given hazelnut batches.info:eu-repo/semantics/publishedVersio

Almond Fruit Drop Patterns under Mediterranean Conditions

Almond is an important tree nut crop worldwide, and planted areas have been increasing year after year. While self-fertility is one of the key factors when it comes to improved almond productivity of new cultivars, yield is also affected by the number of flowers produced, pollination, fruit set, fruit drop, and fruit weight. Almond fruit drop patterns of 20 Mediterranean almond cultivars were studied over three years. In addition, fruit drop patterns of two scion cultivars ‘Marinada’ and ‘Vairo’ budded onto eight to 10 different rootstocks managed with three different pruning strategies were studied for two years. Cumulative flower and fruit drop ranged from 50% to 90% among cultivars and treatments, and there were up to four fruit drop events during the growing season, the main one occurring from 20–60 days from full bloom (DFFB). Subsequent drops were at 100 DFFB, 120–140 DFFB, and the last one at 160–180 DFFB. The later drops were less apparent. In general, about half of the cumulative drop was comprised of buds and flowers, and the remaining percentage was fruit that dropped 20 or more days after full bloom. Furthermore, different fruit drop patterns were observed depending on the cultivar. For late- and extra-late flowering cultivars, cumulative fruit drop began to decrease earlier, with most of the drops occurred already at full bloom, whereas the opposite was observed for the early flowering cultivars. Rootstocks also had an important effect on the fruit drop pattern, with different effects depending on the scion cultivar. Tree management, such as type of pruning, also had an important effect on the rate of fruit drop and cumulative drop. Therefore, each combination of cultivar × rootstock × pruning type will require different strategies in order to reduce the fruit drop and optimize crop loads.info:eu-repo/semantics/publishedVersio

Towards the integral management of library collections at the Technical University of Catalonia (UPC)

Peer Reviewe

Los sistemas operativos en la EGB

La utilización de un entorno operativo sencillo y muy visual reduce el tiempo de aprendizaje de las operaciones básicas del sistema operativo. Se analizan los sistema operativos y la adaptación de éstos a las necesidades y capacidades de los niños y niñas de EGB, a partir de las estancias de informática realizadas en Torrebonica

Mechanical properties of highly textured porous Ni-YSZ and Co-YSZ cermets produced from directionally solidified eutectics

It is well known that several ceramic materials develop an usual; and sometimes unique; combination of properties as a result of mixing different phases with similar expansion coefficients. Sometimes they are elastically stiff, have low thermal expansion coefficients, and are resistant to chemical attack. As this paper will show, their mechanical properties are also enhanced. Nanoindentation is used to measure the mechanical properties for each phase of NiO-YSZ and CoO-YSZ eutectics produced by the laser floating zone technique, and also the analogues Ni-YSZ and Co-YSZ cermets produced by reduction from the eutectic precursors. The different tests have been performed at 100 nm, in order to obtain an imprint lower than the size of the secondary phase and extract the hardness and Young's modulus. Moreover, several tests have been performed at 2000 nm of indentation range to obtain the response of each material. The different imprints have been visualized by Atomic Force Microscopy