1,721,029 research outputs found
La selezione clonale della Malvasia in Sardegna
No full textLa Malvasia, in Sardegna, è diffusa su circa 300 ettari impiantati prevalentemente nella costa occidentale della Planargia su siti calcarei a quote tra il livello del mare ed i 300 metri. Il clima è arido, con inverni miti ed estati molto calde; le precipitazioni medie sono di 600 mm con 74 giorni piovosi. Nell’Isola, la Malvasia è presente con diverse tipologie clonali che si caratterizzano per il grappolo spargolo di grandezza media e molto allungato. Gli acini piccoli o medi hanno buccia sottile e consistente di color giallo carico, sapore semplice o lievemente aromatico. Il lavoro di selezione clonale e sanitaria è stato avviato già negli anni ’70, con l’isolamento di 33 presunti cloni che, successivamente, non hanno superato tutti i controlli sanitari previsti dalla legislazione allora vigente. L’indagine è proseguita nei decenni successivi con l’ulteriore individuazione di accessioni interessanti che sono state esaminate in situ e propagate ed allevate in campi di confronto. Nel periodo 1998- 2005 sono state saggiate in laboratorio circa 1400 piante, selezionate nell’ambito di differenti popolazioni, relativamente alla presenza di specie virali ritenute pregiudizievoli alla certificazione (GFLV, GLRaV-1, GLRaV-2, GLRV –3, GVA, GFkV). Sono risultati mediamente più frequenti l’agente induttore della ′′maculatura infettiva′′ (GFkV) con il 95% dei casi, seguito dal virus 3 dell’′′accartocciamento fogliare′′ (GLRV-3) e dall’agente della ′′butteratura del Kober′′ (GVA) con valori rispettivamente del 71 e 53%. Il virus 1 (GLRaV-1) associato all’ ′′accartocciamento fogliare′′ ed il GFLV, agente dell’ ′′arricciamento della vite′′, sono stati identificati in proporzioni del 28 e dell’8%. Saggi eseguiti su un campione di 387 piante per la presenza di GLRaV-2, induttore di ′′disaffinità di innesto′′, hanno dato una positività pari al 28%. I riscontri globali assumono ulteriore rilevanza alla luce delle infezioni plurime frequenti in natura. Nell’indagine una particolare attenzione è stata rivolta ad alcuni biotipi risultati affetti dalla sola maculatura infettiva. Fra queste, tre tipologie sono state verificate per il profilo ampelografico e genetico, utilizzando sei marcatori SSR e propagate su due portinnesti in un campo sperimentale allestito ad Oristano, presso l’azienda agraria dell’Università Sassari. Per un triennio è stata seguita l’evoluzione delle principali fasi fenologiche (ripresa vegetativa, fioritura, invaiatura e maturazione). Su 15 piante, che hanno costituto le ripetizioni di ciascuna accessione, è stata determinata la fertilità potenziale e reale delle gemme e, durante l’inverno, è stato quantificato il legno asportato con la potatura. Dall’invaiatura, inoltre, sono stati prelevati cinque grappoli per ripetizione, al fine di determinare il tenore in solidi solubili totali e in acidità. Alla raccolta è stata valutata la produzione di tutti i ceppi presenti e sui grappoli è stato effettuato un completo rilievo morfologico e chimico, determinando, oltre ai solidi solubili totali e all’acidità totale, il pH e le concentrazioni in acido malico e tartarico. Alle valide caratteristiche agronomiche, ed in particolare alle produzioni e alle peculiarità qualitative, non hanno però fatto riscontro le esenzioni sanitarie (presenza di GFkV) previste per la certificazione. Tuttavia, alla luce delle recenti norme (DM 7/07/2006), varate in accordo alla associazione dei Costitutori Italiani (ACOVIT), le accessioni citate ed ulteriori presunti cloni, successivamente individuati, potrebbero avere, in tempi brevi, un adeguato riconoscimento certificativo.The cv Malvasia is spread in Sardinia over 200 ha cultivated mainly in the west costal region called Planargia. The sanitary and genetic improvement efforts started in the 1970 and went on with the following decades using the European standardized methodologies. 1400 biotypes were first identified, by a preliminary field selection work and laboratory assay, and then screened for the presence of the following virus, all detrimental for the achievement of the certification status: GFLV, GLRaV-1, GLRaV-2, GLRaV–3, GVA, GVB, GFkV. The research confirms the difficulty to identify, in the field, virus-free vines to be certified. Biotypes affected only by Fleck were analyzed in detail. Among them, three selections were characterized for their ampelographic and genetic traits using six SSR markers. The selections were then grafted onto two rootstocks and were cultivated in an experimental field. The phenological, productive and qualitative analysis, carried out during three years, evidenced their agronomic value, while the virus-free status was not confirmed. Nevertheless, as a result of a recent Italian rule on grape propagation (DM 7/07/2006), established with the agree of the Italian grape varieties breed association (ACOVIT), these selections and some other potential clones could be certified in the next future
Verifica della suscettibilità di portainnesti di vite americana a Xylophylus ampelinus (Panag.) Willems et al., attraverso inoculazioni artificiali
No full textDistribution of Kober stem grooving and Rupestris stem pitting of grapevine in symptomless cv Torbato scions
No full textMolecular characterization of stolbur phytoplasma infecting weeds, vegetables and grapevine, based on vmp1 gene variability.
No full text
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
Prove di lotta contro l'oidio del carciofo nel biennio 1994-95 in Sardegna
No full textTWO YEARS OF FIELD TRIALS AGAINST POWDERY MILDEW OF ARTICHOKE IN SARDINIA
The results of field trials carried out in Sardinia against Leveillula taurica (Lév.) Arn. f. sp. Cynarae Jacz., the causal agent of powdery mildew of Artichoke (Cynara scolymus L.), are reported. The new triazole fungicide Bromuconazole was compared with other chemicals (Hexaconazole, Penconazole, Triadimefon, Triadimenol and Pyrazophos) used against this disease.Most fungicides, with the exception of pyrazophos, were effective in preventing or blocking the diesease
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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