1,721,237 research outputs found
The essential symbiosis of mycology and plant pathology: present and future needs
Get PDFCITATION: Crous, P. W. 1995. The essential symbiosis of mycology and plant pathology : present and future needs. South African Journal of Science, 91(10):502-504.The original publication is available at https://journals.co.zaCorrect disease diagnosis is essential for plant pathologists striving to combat plant
disease. To support them, mycologists are integrating traditional and molecular techniques.
Attention must therefore be given to harnessing the power of molecular genetics
to provide rapid methods of identification, and to study the adaptability of plant pathogens
in terms of virulence and sensitivity to fungicides. To combat African plant diseases
effectively, better co-operation bem'een mycologists and plant pathologists is essential.https://journals.co.za/content/sajsci/91/10/AJA00382353_9062ArticlePublisher's versio
Fungicide sensitivity of phaeomoniella chlamydospora, the causal organism of petri grapevine decline
Get PDFCITATION: Groenewald, M., Denman, S. & Crous, P. W. 2000. Fungicide sensitivity of phaeomoniella chlamydospora, the causal organism of petri grapevine decline. South African Journal of Enology & Viticulture, 21(2):59-61, doi:10.21548/21-2-2206.The original publication is available at http://www.journals.ac.za/index.php/sajevTwelve fungicides, benomyl, chlorothalonil, fenarimol, fosetyl-Al, iprodione, kresoxim-methyl, mancozeb, metalaxyl, prochloraz manganese chloride, quintozene, tebuconazole and thiram were screened in vitro for their ability to inhibit mycelial growth of Phaeomoniella chlamydospora, the causal organism of Petri grapevine decline. Isolates of Pa. chlamydospora were obtained from different geographical areas in the Western Cape province. The effective concentration at which 50% of mycelial growth was inhibited (EC50) was calculated for each fungicide. Benomyl, fenarimol, kresoxim-methyl, prochloraz manganese chloride and tebuconazole were the most effective in inhibiting mycelial growth of Pa. chlamydospora with ECso values ranging from 0.01 to 0.05 μg/mL. Data obtained in this study represent the base-line sensitivity of local isolates to these fungicides, which is important for monitoring the development of pathogen resistance to fungicides.http://www.journals.ac.za/index.php/sajev/article/view/2206Publisher's versio
Fungal Planet description sheets: 128-153
No full textCrous, P. W. et al.-- 56 pages.Novel species of microfungi described in the present study include the following from Australia: Catenulostroma corymbiae from Corymbia, Devriesia stirlingiae from Stirlingia, Penidiella carpentariae from Carpentaria, Phaeococcomyces eucalypti from Eucalyptus, Phialophora livistonae from Livistona, Phyllosticta aristolochiicola from Aristolochia, Clitopilus austroprunulus on sclerophyll forest litter of Eucalyptus regnans and Toxicocladosporium posoqueriae from Posoqueria. Several species are also described from South Africa, namely: Ceramothyrium podocarpi from Podocarpus, Cercospora chrysanthemoides from Chrysanthemoides, Devriesia shakazului from Aloe, Penidiella drakensbergensis from Protea, Strelitziana cliviae from Clivia and Zasmidium syzygii from Syzygium. Other species include Bipolaris microstegii from Microstegium and Synchaetomella acerina from Acer (USA), Brunneiapiospora austropalmicola from Rhopalostylis (New Zealand), Calonectria pentaseptata from Eucalyptus and Macadamia (Vietnam), Ceramothyrium melastoma from Melastoma (Indonesia), Collembolispora aristata from stream foam (Czech Republic), Devriesia imbrexigena from glazed decorative tiles (Portugal), Microcyclospora rhoicola from Rhus (Canada), Seiridium phylicae from Phylica (Tristan de Cunha, Inaccessible Island), Passalora lobeliaefistulosis from Lobelia (Brazil) and Zymoseptoria verkleyi from Poa (The Netherlands). Valsalnicola represents a new ascomycete genus from Alnus (Austria) and Parapenidiella a new hyphomycete genus from Eucalyptus (Australia). Morphological and culture characteristics along with ITS DNA barcodes are also provided.Fundação para a Ciência e a Tecnologia, Portugal is thanked for grant SFRH/BD/46038/2008 (M. Couthinho) and PEst-OE/BIA/UI0457/2011 (A.J.L. Phillips). The contribution of L. Marvanová is part of the project MSM 0021622416 of the Ministry of Education, Youth and Sports, Czech Republic.Peer Reviewe
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
In vitro screening of fungicides against phomopsis viticola and diaporthe perjuncta
Get PDFCITATION: Mostert, L., Denman, S. & Crous, P. W. 2000. In vitro screening of fungicides against phomopsis viticola and diaporthe perjuncta. South African Journal of Enology & Viticulture, 21(2):62-65, doi:10.21548/21-2-2210.The original publication is available at http://www.journals.ac.za/index.php/sajevPhomopsis viticola is the cause of Phomopsis cane and leaf spot disease of grapevines, while Diaporthe perjuncta is associated with bud mortality. The efficacy of nine fungicides (azoxystrobin, flusilazole, folpet, fosetyl-Al + mancozeb, kresoxim-methyl, mancozeb, penconazole, spiroxamine and trifloxystrobin) against isolates of P. viticola and D. perjuncta was determined in vitro using the mycelial growth test. Additionally, azoxystrobin, folpet, kresoxim-methyl, mancozeb, propineb and trifloxystrobin were tested for their ability to inhibit spore germination in vitro. Ten isolates of P. viticola and three of D. perjuncta were used in the mycelium inhibition tests, and five isolates of P. viticola in the spore germination tests. The effective concentration at which mycelial growth was inhibited by 50% and at which 50% of the spores (EC50 value) were inhibited from germinating was calculated for each isolate/fungicide combination. In the mycelium growth test flusilazole, penconazole and trifloxystrobin gave better inhibition at lower concentrations than folpet and fosetyl-Al + mancozeb. No significant differences in the mean ECso values were detected among azoxystrobin, flusilazole, kresoxim-methyl, penconazole, spiroxamine and trifloxystrobin. There were also no significant differences among the mean EC50 values of azoxystrobin, kresoximmethyl and mancozeb. Flusilazole and penconazole inhibited mycelial growth at the lowest mean EC50 values obtained. Kresoxim-methyl and trifloxystrobin inhibited spore germination at lower concentrations than folpet or mancozeb. Folpet required the highest concentration to inhibit 50% germination and was significantly different from mancozeb and propineb. There were also no significant differences among the mean EC50 values of mancozeb, propineb and azoxystrobin. The mean EC50 values of the strobilurin fungicides were not significantly different from one another. These results indicate that the strobilurin fungicides inhibited mycelial growth and spore germination of P. viticola. Trials need to be conducted to verify these findings under field conditions.http://www.journals.ac.za/index.php/sajev/article/view/2210Publisher's versio
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
- …
