1,720,962 research outputs found
A novel biological tool for the control of plant diseases caused by the bacterial pathogens Xanthomonas vesicatoria and X . fragariae
No full textThe management of bacterial plant diseases is nowadays limited to copper compounds, regulated by European Union since 2020, to reduce dependence on chemicals until reaching Zero-tolerance within 2030, or to few biological control agents (BCAs). In this study, the efficacy of the foliar fertilizer Probaction® (0.3% and 0.4%) was tested in vitro against strains of Xanthomonas vesicatoria (Xv), X. fragariae (Xf), Pseudomonas savastanoi subsp. savastanoi (Pss) and Erwinia amylovora (Ea). Probaction® was also tested in planta under controlled conditions against bacterial leaf spot of tomato (BLST) and towards strawberry angular leafspot (ALS) caused by Xv and Xf, respectively. On tomato plants cv. VF10, Probaction® (0.3%) was applied at the leaves or at the root apparatus, while on strawberry plants cv. Tea, Probaction® (0.4%) was treated at the leaves. After 24 h, the treated tomato or strawberry plants were inoculated by spraying the Xv or Xf suspension at the leaves; streptomycin sulphate (100 ppm) and sterile distilled water (SDW) were used as positive and negative controls, respectively. In vitro, Probaction® inhibited the growth of Xf, but it was not effective against Xv, Pss and Ea. In planta, the tomato plants treated at leaves or at roots showed a lower BLST severity (ca. 18 and 14 spots/leaf, respectively), compared to that on negative control plants (SDW, ca. 27 spots/leaf). On strawberry plants, Probaction® gave a relative protection (RP), related to SDW treated plants, of about 67%; while streptomycin sulphate, used as positive control, gave about 44%RP. In conclusion, the efficacy of Probaction® in reducing BLST severity, associated to its inability in inhibiting Xv growth in vitro, may suggest its role in triggering the plant immune response; while its direct efficacy in reducing ALS severity offers a valid alternative to chemicals in the disease management to reduce the Xf inoculum sources
Sustainable products to control the strawberry angular leafspot
No full textWithin the scope of the EU Regulation proposal on the sustainable use of pesticides to reduce dependence on chemicals until reaching Zero-tolerance by 2030, reliable and convenient alternatives to control the plant bacteriosis are investigated. Unfortunately, sustainable biocontrol agents are not always available or their economic impact on crop production is penalizing compared to the conventional products (e.g. heavy metals and antibiotics). In this study, the essential oils-based product Microsap® BIO 458 (458), the foliar fertilizer Probaction® and the resistance inducer Bion® (unregistered on strawberry) were tested in vitro against Xanthomonas fragariae (Xf, DISTAL 12191 strain), the causal agent of strawberry angular leafspot (ALS). Two experiments on young strawberry plants were carried out under controlled conditions by using 458 at 0.15% and 1%, Probaction® at 0.4% and Bion® treated once at 150 ppm and twice at 100 ppm against ALS. In vitro, all the tested products, except Bion®, resulted bactericidal. In vivo, all products reduced the ALS severity on strawberry plants, in particular, 458 at 0.15% and 1% gave a relative protection (RP) of about 40% and 34%, respectively; Probaction® gave 67% RP, while Bion® treated once and twice provided approx. 38% and 74% RP, respectively. Streptomycin sulphate (100 ppm) used as positive control gave RP of about 65% in the first experiment and of 44% in the second. All tested products showed their ability in reducing ALS severity and thus they offer a valid alternative to chemicals in the disease management to reduce the inoculum sources
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
Molecular identification of Fusarium species recovered from rice kernels in different growing areas of northern Italy in years 2003-2004.
No full textDispelling 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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