1,721,013 research outputs found
Strategie di contenimento delle malattie degli ortaggi
No full textI funghi sono la principale causa di deterioramento in post raccolta. Bisogna prevenire le infezioni e contenerle ricorrendo a trattamenti termici o biologici
Biological Control of Postharvest Diseases by Microbial Antagonists
No full textThe postharvest phase has been considered a very suitable environment for successful
application of biological control agents (BCAs), since the first work on the biological
control of brown rot disease of stone fruit was reported by Pusey and Wilson
[1]. Sure enough, the conditions of constant temperature and high humidity seem to
offer more chances to BCAs, increasing their antifungal activity [2]. BCAs are living
organisms and act following different antagonistic strategies depending on
pathogens, host and environment. Knowledge of their modes of action is therefore
essential to enhance their viability and increase their potentiality in disease control.
In general, antagonists used for biocontrol of postharvest diseases are yeasts and
bacteria, and to a lesser extent fungi, and they have been widely reviewed [3–7].
Antagonists can display a wide range of modes of action, at different stages of
their activity, relating to different hosts, pathogens; sometimes-different modes act
simultaneously, and it is therefore difficult to establish which individual mechanism
has contributed to a specific antifungal action. Considerable information is available
with respect to their efficacy, their application under storage conditions, and their
mixture with safe substances or according to the formulation. However, the mechanisms
by which BCAs exert their activity against pathogens have not yet been fully
elucidated [5] and sometimes, in order to achieve maximum effectiveness in postharvest
phase, were combined with physical and chemical methods including heat
treatments, gamma or UV-C irradiation, and controlled atmosphere (CA).
The bottleneck of the biocontrol matter remains the BCAs formulation often
done in association with private companies, due to the high costs of production and
the regulatory barriers to BCAs registration in different countries that often do not encourage their dissemination. Also, a formulation often could reduce the activity
of antagonists with respect to the fresh cells [2]
Use of algae in strawberry management
No full textIn agriculture, extracts from algae are used for their stimulant effects on plant vigor and productivity but little is known on their effect against fungal pathogens. However, the recent EU restriction on synthetic pesticides made the management of fungal plant pathogens difficult and greatly stimulated the research of alternative solutions to chemicals. Applications of extracts from algae can help limit disease spread in several crops and the development effective alternatives to chemical treatment in crop protection and nutrition management. In particular, for strawberry, the management of a number of serious diseases in open field and greenhouse in soil or soilless cultivation has become difficult due to recent restrictions in agrochemical use and the lack of effective alternatives. This review provides an overview of the most recent findings on the potential use of extracts of algae for strawberry management, concerning both their biostimulant effects and antifungal properties against pathogens. The existing reports on this topic show the strong potential of algae extracts application on plants both as biostimulants and bioprotectants against fungal pathogens. Further investigation is needed to fully uncover the interesting and exploitable antifungal properties of extracts from algae and to clarify the mechanism of action of extracts and singular components against pathogens
How siderophore production can influence the biocontrol activity of Aureobasidium pullulans against Monilinia laxa on peaches
Full text linkIn the present study Aureobasidium pullulans strains L1 and L8 were shown both in vitro and in vivo to compete
for iron with Monilinia laxa through the secretion of siderophores (1.2 and 1.4 mg ml−1, respectively) and
to prevent postharvest fruit decay of peaches. The two strains reduced mycelial growth and conidial germination
of M. laxa specially in presence of lower iron concentrations (5 and 10 μg l−1 FeCl3), confirming a better
efficacy when nutrients are scarce. In in vivo assay, A. pullulans L1 and L8 strains inhibited pathogen virulence,
reducing by 83.5% and 84.4% on average respectively the peach lesion diameter for each tested iron solutions
(5, 10, 20 μg l−1 FeCl3,). The highest iron solution slowed down the antagonists’ action and conversely increase
the pathogen aggressiveness. Results shows that A. pullulans L1 and L8 strains compete with M. laxa for iron, so
revealing new biocontrol aspects. Both strains showed the capability to decrease the accumulation of iron competing
with some fungal pathogens and reducing their virulence. These results provide new perspectives for the
use of biocontrol agents in agriculture
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
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