1,724,074 research outputs found
Evaluation of S-734 and BAS 9052 for Control of Johnsongrass (Sorghum halepense) in Soybeans (Glycine max)
Full text linkJohnsongrass is one of the more limiting factors in soybean production and is the most serious weed problem in the Southeastern United States. Actually, different herbicides are used in johnsongrass control, and still there are new herbicides which are being tested. Two experimental herbicides for johnsongrass control in soybeans are BAS 9052 and S-734.
The experiments were conducted in 1980 and 1981 with the objective to evaluate the effectiveness of S-734 alone and in combination with mefluidide and BAS 9052, BAS 9052 applied early or late postemergence, trifluralin, alachlor, and fluchloralin for seedling and rhizome johnsongrass control.
In both areas S-734 was applied at 0.8, 1.1, and 1.7 kg/ha, S-734 at rates of 0.8, 1.1, and 1.7 kg/ha was combined with mefluidide at 0.3 kg/ha, S-734 at rates of 1.1 and 1.7 kg/ha was also combined with BAS 9052 at 0.6 kg/ha, BAS 9052 was applied at 0.6, 0.8, and 1.1 kg/ha early or late postemergence. Trifluralin and fluchloralin were applied at rate of 1.1 kg/ha in seedling study and 2.2 kg/ha in rhizome study. Alachlor was applied at rates of 3.4 and 4.5 kg/ha in seedling study.
The results of the experiments showed that there were similarities and differences in the response of rhizome and seedling johnsongrass to the treatments. The control of johnsongrass, and the resulting soybean yields, was higher in the seedling area than in the rhizome area. There were no differences among rates of herbicides.
Good seedling johnsongrass control was obtained with all treatments although there were differences among herbicides. In 1980 there were differences between BAS 9052 applied early and late postemergence, but there were no differences in 1981. BAS 9052 might be used as a late postemergence application for best seedling johnsongrass control. There were no differences among herbicides on soybean yields.
In both years good rhizome johnsongrass control was obtained with BAS 9052 applied early or late postemergence. Poor rhizome johnsongrass control was obtained with S-734, trifluralin, and fluchloralin. High soybean yields were obtained with BAS 9052
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
Evaluation of BAS 9052 & BAS 9021 for Control of Johnsongrass (Sorghum Halpense) in Soybeans (Glycine Max)
Full text linkThe lack of adequate weed control is one of the major problems encountered in soybean production. Johnsongrass presents one of the most serious weed control problems in the Southeastern United States. numerous herbicides are used in an effort to control johnsongrass, and research is still being conducted to find new herbicides for this purpose. Two of these herbicides are BAS 9021 [6,6-dimethyl-2,4-dioxo- 3[1-[2-(propenyloxy)amino]butylidene]-cyclohexane] and BAS 9052 [2-(n-ethoxybutyrimidoyl)-5-(2-ethylthiopropy1)-3- hydroxy-2-cyclohexen-1-one].
In 1978, johnsongrass control with BAS 9021 at 1.1 and 1.7 kg/ha in sim-le early postemergence or late postemergence applications, or in each of two split applications, was evaluated using the herbicide alone, with a nonionic surfactant, or a nonphytotoxic crop oil. The split applications gave johnsongrass control ranging from 49, to 81,. Late postemergence applications of 1.7 kg/ha of BAS 9021 were as Food as split applications. As a group, the addition of oil or surfactant gave increased control over the herbicide alone.
In 1979 BAS 9021 and BAS 9052 were compared with mefluidide [N-[2,4-dimethyl-5[[(trifluoromethyl)sulfonyl]amino]phenyl]acetamide]and alachlor (2-chloro-2\u276\u27-diethyl-N-(methoxymethyl)acetamide] for seedling johnsongrass control. The BAS materials were compared with mefluidide, trifluralin]α, α, α trifluoro-2,6-dinitro-N,N-dipropyl-p-toliuidine], fluchloralin [N-(2-chloroethyl)-2,6-dinitro-n-propyl- 4-(trifluoromethyl)aniline] and trifluralin plus vernolate [S-propyl dipropylthiccarbamate] for rhizomic johnsongrass control.
In both experiments BAS 9021 was applied at 1.1 and 1.7 kg/ha in each of two applications. BAS 9052 was applied at rates of 0.6 to 1.1 kg/ha early postemergence, late postemergence or in split applications. Mefluidide was applied at rates of 0.3 to 0.6 kg/ha either early postemergence or in split applications. All postemergence herbicide applications contained an oil concentrate at a rate of 2.4 L/ha.
Alachlor for seedling control was applied preemergence at 3.4 and 4.5 kg/ha. Preplant incorporated applications of trifluralln and fluchloralin were made at rates of 2.2 kg/ha and vernolate at 2.8 kg/ha was combined with —1 and 2.2 kg/ha of trifluraiin for rhizomic johnsongrass control.
In the seedling area, all BAS treatments gave 88% or better johnsongrass control. In the rhizomic area split applications of BAS 9052 tended to result in the best johnsongrass control. Ratings were taken both 8 and 11 weeks after planting. Soybean yields were generally better with higher johnsongrass control.
Mefluidide caused apparent soybean injury, resulted in poor johnsongrass control and lowered soybean yields. All preplant incorporated treatments gave poor johnsongrass control and low soybean yields. Alachlor gave fair johnsongrass control but resulted in high soybean yields
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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