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Yield, harvesting efficiency and oil chemical quality of cultivars Arbequina and Arbosana harvested by straddle machine in two Apulian growing areas
No full textAbstract
Super-high-density olive culture is characterized by hedgerow trees with planting density ranging from 1200 up to 2000 trees ha-1, in order to allow continuous harvesting by straddle machines. The genotype cultivated is the key factor for both the agronomic and economic sustainability of this new cropping system. ‘Arbequina’ and ‘Arbosana’, together with a few others, are the most-used cultivars up to now. Yield, harvesting efficiency and oil quality are strongly affected by agronomical and environmental factors, among others. We report yields, harvesting efficiencies and chemical characteristics of oils of the cultivars ‘Arbequina’ and ‘Arbosana’ grown in two different pedoclimatic Apulian areas (southern Italy), with the same planting density, tree age, cropping practices and harvesting machine. Each cultivar was harvested at the same ripening stage for both sites. Site 1 was warmer and more arid than site 2. Mean harvesting efficiency was 98%; ‘Arbequina’ had higher harvesting efficiency with respect to ‘Arbosana’, due to different detachment force. The colder site reduced fruit yield and yield efficiencies of both cultivars but increased yield quality, by increasing both unsaturation level of fatty acids and polyphenol content of the extracted oil. The selection of appropriate growing areas was an important tool to define levels of both fruit yield and oil quality for the high-density olive orchards. Moreover, cultivar and harvesting time influenced not only the above-mentioned yield parameters, but also the performance of the straddle harvesters both in terms of harvesting efficiency and canopy damage
Different Weed Managements Influence the Seasonal Floristic Composition in a Super High-Density Olive Orchard
Get PDFWeed management is not yet environmentally, agronomically, economically and socially sustainable in olive orchards. It is necessary to study appropriate integrated weed management systems (IWMSs) based on the knowledge of weed population and effects of weeding practices over time. The aim of this study was to evaluate the effects of different weed managements on seasonal floristic composition of a super high-density olive orchard, also exploiting the essential principles of an IWMS. Five weeding techniques were compared: chemical control (CHI), mowing (MEC), plastic (nonwoven tissue, TNT and polyethylene, PEN) and organic (with de-oiled olive pomace, DOP) mulching. Weed monitoring was carried out on six dates in a three-year period. The infestation of each of the main 18 weed species recorded (%) and the total infestation (%) on each monitoring date were determined. Results underlined that all weeding practices investigated in this multi-year study affected the floristic composition, weed characteristics (hemicryptophytes, cryptophytes and therophytes) and seed bank. TNT and PEN were the most effective methods for weed management. Particularly, total infestation coefficient was significantly lowest when plots were managed with TNT (13.91%) and PEN (14.38%) and highest for MEC (141.29%). However, DOP also significantly reduced infestation compared to CHI and MEC. Therefore, DOP could constitute an excellent strategy for weed management in super high-density olive groves, since it also has the possibility of distributing mulching materials in a mechanized way in field and can result in improvement of soil fertility and the possibility of valorizing waste. Further studies should be carried out to investigate the mechanism of action (physical and allelochemical) of de-oiled pomace or other organic agro-industrial materials and the recovery time of these mulching materials in super high-density olive orchards
Attempts to Reduce the Systemic Spread of Xylella fastidiosa in Olive Trees by Pruning
Get PDFXylella fastidiosa subsp. pauca (Xfp) is the plant pathogenic bacterium causing the epidemic of olive quick decline syndrome decimating olive trees in the Apulia region (southern Italy). The lack of any effective therapeutic application for the control of this pathogen and its categorization as a regulated quarantine pathogen in many countries worldwide, impose mandatory eradication and containment measures. Based on current EU legislation, containment measures apply in those areas where the bacterium is widely established, such as in the Apulia region, and thus containment strategies to mitigate and cope with the infections are needed. We set up a field trial to assess if pruning interventions could limit and/or recover Xfp-infected trees by reducing the systemic spread of the bacterium and the severity of the desiccation phenomena typically compromising the crown of the highly susceptible cultivars, e.g., cv. Cellina di Nardò. Trees subjected either to major or light pruning interventions, including the removal of all the symptomatic branches, did not demonstrate a reduced bacterial colonization or development of symptoms. After two years of targeted pruning interventions, no significant amelioration of the sanitary status of the infected olive trees was recorded, suggesting that the sole application of these interventions is not effective to counteract the impact of the bacterium in the susceptible olive trees
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Electromagnetic Induction Measurements for Investigating Soil Salinization Caused by Saline Reclaimed Water
Get PDFThis paper focused on the use of electromagnetic induction measurements in order to investigate soil salinization caused by irrigation with saline reclaimed water. An experimental activity was carried out during the growing season of tomato crop in order to evaluate expected soil salinization effects caused by different saline agro-industrial wastewaters used as irrigation sources. Soil electrical conductivity, strictly related to the soil salinity, has been monitored for three months by means of Electromagnetic Induction (EMI) measurements, and evident differences in the soil response have been observed. The study highlighted two aspects that can improve soil investigation due to the utilization of geophysical tools. First, EMI data can map large areas in a short period of time with an unprecedented level of detail by overcoming practical difficulties in order to massively sample soil. At the same time, repeated measurements over time allow updating real-time soil salinity maps by using accurate correlations with soil electrical conductivity. This application points out how integrated agro-geophysical research approaches can play a strategic role in agricultural saline water management in order to prevent soil salinization risks in medium to long-term periods
Two almond cultivars trained in a super-high density orchard show different growth, yield efficiencies and damages by mechanical harvesting
Get PDFModern almond growing travels on the tracks of super-high density (SHD). Born in 2010, it has already reached 6700 ha planted all over the world. This new cultivation system needs to define efficient agronomic techniques in order to identify it as a “Super-Efficient System”. Among these, the choice of cultivar is a crucial technique and a key factor for sustainability. The purpose of this study was to compare different cultivars in terms of vegetative, productive, and efficiencies parameters in order to gain applicable relevant knowledge about the SHD almond cultivation technique. For this, 3 years of research was carried out during 2017–2019, on a young almond grove made in 2014 with row spacing of 3.80 m × 1.20 m (2190 trees/ha), to evaluate the agronomic behavior of the two most planted cultivars in Italy, Guara-Tuono and Lauranne® Avijor, grafted on the Rootpac®20 dwarfing rootstock. The main biometric, productive, yield, mechanical harvesting efficiencies, and almond quality parameters were evaluated. Cv Lauranne® showed greater vigor, greater fruit yield, and damaged axes by mechanical harvesting, while higher values of yield efficiencies were observed for cv Tuono. Harvesting efficiency was related to canopy size and tree age. On the contrary, almonds quality parameters were strongly related to the cultivar, confirming the good performance of Tuono as varietal characters. Then, this cultivar seems to be the most suitable for an efficient SHD planting system, in line with the objectives of modern sustainable fruit growing. The better performance of cv Tuono could be related to the positive influence of the terroir as well
Re-shaping pruning improves the dynamic response of centuries-old olive trees to branch-shaker vibrations application
Get PDFIntroductionThe Mediterranean basin is home to centuries-old large olive trees; high-vigor cultivars are widespread, with training forms poorly adapted to mechanical harvesting by trunk/branch shakers. The significant quantity of leaves, the considerable tree height, and the presence of multiple dichotomous hanging branches reduce the transmission of vibrations applied by the branch-shaker machines. Thus, re-shaping pruning may improve the performance of this modern mechanical harvesting method by focusing on removing both the hanging branches and those forming dichotomies. The goal of this study was to evaluate the dynamic responses of large-sized olive trees to pruning (or not) through various field tests under different excitation forces. We hypothesized that more rational pruning could significantly increase vibration transmissions. MethodsTo assess the transmission of vibrations, tests were conducted before and after the pruning on representative trees. Tri-axial accelerometers packed in a small titanium housing were used. Trees were assessed before and after the re-shaping pruning. This study reports the first data about the dynamic behavior of centuries-old tree skeletons, in the context of very large-sized olive trees, while taking into account the effects of two different vibrations application modes: a realistic one represented by the system vibration head-tree, originated when the gripper of a shaking machine wrapped and fastened the main branch of the olive trees, and a more speculative one, represented by a single impulse of a short-duration force originated by a hammer. ResultsAfter pruning, spectral density increased 10 fold in the tertiary branches of pruned trees (ranging 1.0-10 m s(-2)) compared to that of not-pruned ones (ranging 0.1-1.0 m s(-2)) at frequency >50 Hz under vibration excitation. Moreover, vibrational decay times (120-150 ms) and amplitude (>10(-1) m s(-2)) were higher under single-impulse excitation. DiscussionA more rational pruning applied to ancient large-sized olive trees significantly increased the vibration transmission under both impulse and vibratory excitation forces, without affected their typical "look". Moreover, these insights are helpful in turn in achieving maximum fruit-removal efficiency. These insights could be applied to various horticultural conditions which would improve the economic sustainability of monumental olive trees, a key portion of the Mediterranean landscape and cultural heritage
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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