1,720,961 research outputs found
Long-term evaluation of yield components of young olive trees during the onset of fruit production under different irrigation regimes
No full textAbstract A four-year study was conducted on young
Olea europaea L. trees to investigate the effect of deficit
irrigation starting from the onset of fruit production. Subsurface
drip irrigation was used to supply 100% (FI),
46–52% (DI), or 2–6% (SI) of tree water needs. Tree
growth was reduced by deficit irrigation, whereas, return
bloom was not. Per tree fruit yield of DI trees was 68% that
of FI, but fruit yield efficiency based on tree size was
similar between treatments. Fruit set and the number of
fruits of FI trees were similar to those of DI trees and
significantly higher than in SI trees. No significant differences
in fruit fresh weight were found between FI and DI.
The oil yield and oil yield efficiency of the DI treatment
were 82 and 110% that of FI trees, respectively. A level of
about 50% deficit proved sustainable to irrigate trees for oil productio
PRODUCTIVITY OF OLIVE TREES WITH DIFFERENT WATER STATUS AND CROP LOAD
No full textA field experiment was conducted over two growing seasons to determine the combined effect of crop load and
irrigation on yield components of olive trees (Olea europaea L. ‘Leccino’) planted at 6 m 3.8 m in a sandy-clay soil.
Different crop loads were established by manual thinning of fruits. Drip irrigation was managed to maintain pre-dawn
leaf water-potentials (PLWP) within the following ranges: (i) higher than –1.1 MPa (FI; fully irrigated); (ii) between
–1.0 and –3.3 MPa (DI; deficit irrigated); or (iii) below –1.2 MPa, but not lower than –4.2 MPa (SI; severe deficit
irrigated).The irrigation period lasted from 6 – 16 weeks after full bloom (AFB) in 2003, and from 5 – 19 weeks AFB
in 2004. In 2003, full bloom was on 26 May; in 2004, it was on 3 June. Neither irrigation regime nor crop load affected
flowering or flower quality the following Spring. The combined fruit yields [on a fresh weight (FW) basis] over both
years in SI and DI trees were 49.0% and 81.6% of FI trees, respectively.The oil yields of SI and DI trees were 52.5%
and 81.2% of FI trees, respectively. Fruit FWs in FI trees were greater than those of DI or SI trees at 8 weeks AFB.At
harvest, FI trees bore the largest fruits, and SI trees the smallest fruits. The FWs of individual fruits at harvest in the
FI and DI treatments decreased as crop load increased, but no such relationship was apparent for SI trees. The oil
content of the mesocarp increased as PLWP increased from approx. –3.5 MPa to –1.5 MPa.The oil content of FI trees
at harvest decreased from 53.1% to 45.7% dry weight as fresh fruit yield increased from 5 – 25 kg dm–2 trunk crosssectional
area. However, crop load did not have any effect on the oil content of the mesocarp in DI trees. Fruit
maturation was delayed by irrigation. Maturation index also decreased (indicating delayed maturation) as the crop
load on FI or DI trees increased, but did not vary with crop level in SI trees
The effect of irrigation on fruit development of olive cultivars 'Frantoio' and 'Leccino'
No full textA field study was conducted on mature trees of two olive cultivars (`Frantoio' and `Leccino') in Tuscany (Italy) to assess differences between irrigated and rainfed trees in fruit growth parameters and the cellular processes determining mesocarp growth. Reference evapotranspiration, calculated by the Penman-FAO equation, was multiplied by a crop coefficient of 0.55 or 0.65 to determine the amount of irrigation water. The fresh weight and dry weight of fruits and their tissues were monitored at approximate two-week intervals. At 9 (end of massive endocarp sclerification) and 20 weeks after full bloom (AFB) fruit anatomical parameters were measured in transverse equatorial sections using image analysis. Fruits from irrigated trees showed greater equatorial diameter and mesocarp transverse area than those from rainfed trees of both cultivars at 9 and 20 weeks AFB. Irrigation significantly increased the size of mesocarp cells of both cultivars at 9 and 20 weeks AFB, and cell number in `Leccino' at 9 weeks AFB
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
