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Effects of application phytostim biostimulant on growth, yield postharvest quality, and metabolites of two amaranth species
Get PDFThesis (M. Agricultural Management (Plant Production)) -- University of Limpopo, 2024Amaranthus species are indigenous crops in South Africa, commonly consumed as leafy
vegetables. It has been consumed for many decades by the rural community population
for its nutritional and nutraceutical properties. However, the crop is still not
commercialized due to limited productivity in the country. There is scant information on
the cultivation of Amaranthus species and its improvement as compared to the exotic
crops such as spinach and lettuce. Thus, it is pertinent to find ways of improving the crop
in terms of yield, and postharvest quality attributes. This study was aimed at establishing
the information on the effect of different concentrations of Phytostim® biostimulant on
growth, yield, and postharvest quality of Amaranthus cruentus and Amaranthus caudatus.
The objectives of this study was to (1) investigate the effects of different concentrations
of Phytostim® biostimulant on growth and yield attributes, (2) to investigate the interactive
effect of Phytostim® biostimulant concentrations and storage period on postharvest shelf life quality attributes, nutritional components, and secondary metabolites of the two
Amaranthus species. The different concentrations of Phytostim® biostimulant used in this
study were 0, 0.5, 1, 1.5, 2.5, 3, 4.5, and 6% while untreated plants (0%) were used as
control in all the objectives.
To achieve objective one: four-week-old seedlings of Amaranthus species were grown in
a greenhouse condition following a Randomized Complete Block Design (RCBD) for a
period of eight weeks (60 days). Different concentrations of Phytostim® biostimulant were
foliar-applied after every 14-day until harvest. Growth and yield attributes (stem diameter,
plant height, number of branches, number of leaves per plant, fresh and dried leaf mass
per plant) data were collected at harvest. It was observed that Phytostim® biostimulant
significantly affected (p<0.05) growth and yield attributes of amaranth. On the growth
attributes, Phytostim® biostimulant increased the plant height by 97 cm and 110 cm at
1.5 % concentrations in both Amaranth species. While on the stem diameter increased
by 13 mm and 17 mm. On the number of branches, it increased by 30 and 44. On yield
parameter, highest biomass obtained was 74.23 g and 85.93 g per plant.
On the second objective: the harvested leafy vegetables of amaranth were separated into
uniform bundles of 100 g weight in a well-ventilated punnet and stored at ambient
temperature for 0, 3, and 6 days for assessment of weight loss, color, and visual quality.
During these storage period, a total of 5 g per replicate was sampled at three days
intervals and oven dried at 40 ºC for 72 h for analysis of nutrient components and
secondary metabolites such as mineral elements, amino acids, protein, and phenolic
compounds. It was observed that Phytostim® biostimulant and storage days significantly
affected (p<0.05) some of postharvest quality and nutritional components of amaranth.
Weight loss in 2.5% biostimulant was 20.85%, and 30.89% at day 6 in A. cruentus and
A.caudatus. These in terms of color, the leaves that maintained a good color quality was
at 0.5 % (h° = 148.21 and a*= -12.29) for A. cruentus. At the end of storage period (6d)
the leaves maintained a good color quality was at 2.5% (h° = 124.14 and a* = -10.66) in
A. caudatus. The obtained results revealed that weight loss%, color, and visual quality of
amaranth were significantly (p<0.05) influenced by different concentrations of Phytostim®
biostimulant and storage time. All the above-mentioned postharvest attributes were
improved at 2.5% concentrations of Phytostim® biostimulant in comparison to control.
Moreover, the study further revealed that different concentrations of Phytostim®
biostimulant significantly (p<0.05) influenced the mineral elements (Mg, Ca, Fe, K, Zn, N,
Cu, Se, and Mn), amino acids (His, Leu, Lys, Met, Phe, Thr, Val, Ala, Arg, Asp, Glu, Gly,
Pro and Ser) and protein content of the studied leaves. The nutrients components were
enhanced at 2.5% concentrations of Phytostim® biostimulant as compared to the control
and other concentrations of Phytostim® biostimulant. Thus, it can be concluded that
Phytostim® biostimulant can be recommended to be used effectively by farmers at 2.5%
for up to 6 days or less in preserving the high-quality characteristics of Amaranth species
during ambient temperature.
On the last stage of this study, the untargeted phenolic compounds were determined
using the Liquid Chromatograph Mass Spectrometer (UPLC-MS). A total of 12 phenolic
compounds were detected in the studied leaves. Phenolic compounds of the treated
plants were significantly higher in comparison to the phenolic compound of the untreated
plants. Principle Component Analysis and Orthogonal Partial Least Squares-Discriminant
Analysis showed that Phytostim® biostimulant is the main factor responsible for the
variation in the studied crop. The major identified phenolic metabolites were members of
the coumarin glucoside, glucuronic acid, and flavonoid-3-glycosides. Predominant
phenolic compound quantified was rutin in both species. This objective spotted
Phytostim® biostimulant concentrations at 3% to be the best for enhancing secondary
metabolites. Therefore, overall recommendation these objectives suggest that
Phytostim® biostimulant concentrations starting from 1.5% up to 3% could be used to
improve the yield, nutrients, and secondary metabolites
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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