1,720,959 research outputs found
The antimicrobial actitity of water extracts from Labiatae.
No full textIn vitro antimicrobial activity of water extracts of oregano, rosemary and sage were tested against five different fungi (Phytophthora cactorum, Verticillium dahliae, Fusarium oxysporum f.sp. lycopersici, Phoma tracheiphila and Botrytis cinerea). Infusion, decoction and maceration methods were used to obtain the extracts. Their inhibent effect on radial fungal growth was determined at three different concentrations (500 mL/L, 50 mL/L and 5 mL/L). After 4, 8 and 12 days the radial growth of the species was measured and fungitoxicity was recorded in terms of percent colony inhibition. The data obtained showed that while the extracts of rosemary and sage were less effective against all fungi tested at all concentrations and by all extraction methods used, oregano extract showed a strong antifungal activity at higher concentration by infusion and decoction methods
Monitoraggio visivo su palmacee potenziali ospiti del Punteruolo rosso e del Castnide delle palme presenti in Sicilia
No full textUse of natural products for the control of powdery mildew of rose plants
No full textPowDery mildew caused by Podosphaera pannosa (Wallr. Fr.) De Bary on roses in greenhouse cultivation is usually controlled by chemical products. Aiming to lower the use of chemical treatments, in vitro and in planta assays were carried out using some natural products. The inhibitory effect of essential oils extracted from oregano inflorescences (Origanum heracleoticum L.) and cloves (Syzygium aromaticum L. Merril et L.M. Perry), was evaluated by in vitro tests. Essential oil at 0.5, and 0.125 ml/L concentration was added to conidia suspension (8 x 105 conidia/ml). After 2, 4, 8, 12, 24 and 48 hours, 400 conidia for each treatment and control were evaluated and the germination percentage calculated. The treatments showed the full inhibition of P. pannosa conidia germination in all cases. In planta assay was carried out in a greenhouse on roses grown in a soilless system. Concentrations of 0.25 and 0.5 ml/L of oregano and cloves essential oils, emulsified, plus an additive compound at 0.5 ml/L; and NaHCO3 at 5 g/L were sprayed on rose plants in an experimental block design. Each treatment was repeated 4 times. All the natural products were compared with usual chemical treatments and with an untreated control. All sprays were applied every 7 days. Diffusion and incidence of powDery mildew were checked during the assay. At the end of the assay biometric data were evaluated. The results show an inhibitory activity of both essential oils at higher concentration and of NaHCO3 treatment; this last one showed the best inhibition. Significant differences were found in comparison with chemical treatments and the control. No toxicity phenomena were found at either concentration of the essential oils treatments. The NaHCO3 treatment showed slight phytotoxicit
Efficacy of the fungicide valiphenal against crown rot of rose caused by Phytophthora citrophthora
No full textCrown and root rot caused by soilborne species of Phytophthora are common diseases of container-grown ornamental plants in nursery. Crown rot of Rose caused by P. citrophthora has been recently reported in Sicily (southern Italy). Valiphenal (IR 5885) is a systemic dipeptide fungicide of the valinamide class of compounds and is active against Oomycetes. This new fungicide is under development by the italian agrochemical company ISAGRO against powdery mildews of grapevine, potatoes and vegetables. In this study, the efficacy of Valiphenal and other experimental active ingredients was tested for the first time against crown rot of Rose. Phosetyl-Al (Aliette) was used as a reference product. Minigreffe plants of ‘Red France’ Rose on Rosa indica-major as rootstck, grown in pots (diameter 16 cm) in a plastic-house were used in all experiments. Plants were wound inoculated on the stem with agar plugs taken from P. citrophthora colonies growing on potato dextrose agar. Wounds were sealed with Parafilm and symptoms were evaluated at various time intervals after inoculation. Valiphenal, alone or mixed with biostimulants, such as the leaf organic fertilizer Siapton, was applied as foliar spray at the dose of 0.75 g/l a. i., 7 days before the inoculation. In all experiments Valiphenal proved to be as effective as Phosetyl-Al in reducing the length of the cankers on the stems of inoculated plants. Five months after the inoculation, plants treated with Valiphenal or Phosetyl-Al did not show symtoms of stem dieback whereas all nontreated control plants wilted. The addition of Siapton increased the efficacy of Valiphenal but results were not consistent among experiments. No symptoms of phytotoxicity were observed on treated plants
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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