1,720,962 research outputs found
Short-term soil amendment by sewage sludge anaerobic digestate in a tomato monoculture suppresses Fusarium vascular wilt disease by changing the taxonomic characteristics of soil microbiota
Full text linkDigestate incorporation into topsoil determines soil fertility improvement by changing composition and structure of soil microbiota. However, how microbiota responds to short-term soil amendment by sewage sludge anaerobic digestate (SSD) for suppressing Fusarium vascular wilt disease is unknown. This study compares the effects of three SSD-based treatments to suppress Fusarium oxysporum f. sp. lycopersici (Fol) in a long-term cherry tomato monoculture under field condition in a 3-year trial. Three sampling sites with two application times (two bulk soils at 3–12 weeks after amendment and one tomato rhizosphere soil at 12 weeks post-amendment) were chosen. Three digestate typologies (liquid, centrifuged, and dried) having physicochemical features and heavy metals content below the legal limits were tested at 50 l, 3.5 kg and 2.5 kg m−2y−1 dose, respectively. Fusarium wilt disease was measured for three consecutive years by severity index and Fol abundance in tomato vascular tissue was assessed by ITS rDNA gene sequencing. Fol abundance and taxonomic structure of Fusarium community in the rhizosphere were determined at specie level at the end of the trial by ITS rDNA and EF1α rDNA genes sequencing, respectively. The taxonomic structure (α-, β-diversity) of soil bacterial community (SBC) was characterized from phylum up to genus level at the end of the trial in all the sites by 16S rRNA gene sequencing. The results showed that dry SSD reduced disease severity in field up to 18 % and Fol abundance in tomato up to 0.9 ITS copies g−1 tissue. Fol abundance was decreased in the rhizosphere up to 0.0027 ng μl−1 DNA, while the Fusarium community shifted between treated-soils and un-amended. The SBC composition (α-diversity) changed in the rhizosphere by applying dry digestate, while the SBC structure (β-diversity) shifted either among treatments or sites. Bacterial members related to Fol suppression (Bacillus, Chitinophaga, Flavihumibacter, Flavobacterium, Pseudomonas and Terrimonas) increased in the rhizosphere (P < 0.01, P < 0.001) more than in the bulk soils by applying both dewatered-SSDs. Thus, digestate soil amendment carried out for three consecutive years has affected tomato Fusarium wilt severity by changing the taxonomic characteristics of fusaria and bacteria communities of the amended soil
Maize Yield Response, Root Distribution and Soil Desiccation Crack Features as Affected by Row Spacing
Full text linkPlant density is among the most critical factors affecting plant yields and resource use efficiency since it drives the exploitation of the available resources per unit area, root distribution and soil water losses by direct evaporation from the soil. Consequently, in fine-textured soils, it can also affect the formation and development of desiccation cracks. The aim of this study, carried out on a sandy clay loam soil in a typical Mediterranean environment, was to investigate the effects of different row spacings of maize (Zea mais L.) on yield response, root distribution and the main features of desiccation cracks. The field experiment compared bare soil and soil cropped with maize using three plant densities (6, 4 and 3 plants m−2), obtained by keeping the number of plants in a row constant and varying the distance between the rows (0.5–0.75–1.0 m). The highest kernel yield (16.57 Mg ha−1) was obtained with the greatest planting density (6 plants m−2) with a row spacing of 0.5 m; significantly lower yields were recorded with spacings of 0.75 and 1 m, with a decrease of 8.09% and 18.24%, respectively. At the end of the growing season, soil moisture in the bare soil was on average 4% greater in comparison to the cropped soil and was also affected by row spacing, decreasing with the decrease in the inter-row distance. An inverse behaviour was observed between soil moisture and both root density and desiccation crack size. Root density decreased to the increase in soil depth and to the increase in distance from the row. The pluviometric regime occurred during the growing season (total rainfall of 343 mm)-resulted in the formation of cracks of reduced size and with an isotropic behaviour in the bare soil, whereas in the cultivated soil, the cracks were parallel to the maize rows and increased in size with decreasing inter-row distance. The total volume of the soil cracks reached a value of 135.65 m3 ha−1 in the soil cropped with a row distance of 0.5 m, and was about ten times greater in comparison to the bare soil and three times greater in comparison to a row spacing of 1 m. Such a volume would allow a recharge of 14 mm in the case of intense rainy events on soil characterised by low permeability
Exploring Aegilops caudata: A Comprehensive Study of the CslF6 Gene and β-Glucan
Full text linkIn the quest for sustainable and nutritious food sources, exploration of ancient grains and wild relatives of cultivated cereals has gained attention. Aegilops caudata, a wild wheatgrass species, stands out as a promising genetic resource due to its potential for crop enhancement and intriguing nutritional properties. This manuscript investigates the CslF6 gene sequence and protein structure of Aegilops caudata, employing comparative analysis with other grass species to identify potential differences impacting β-glucan content. The study involves comprehensive isolation and characterization of the CslF6 gene in Ae. caudata, utilizing genomic sequence analysis, protein structure prediction, and comparative genomics. Comparisons with sequences from diverse monocots reveal evolutionary relationships, highlighting high identities with wheat genomes. Specific amino acid motifs in the CslF6 enzyme sequence, particularly those proximal to key catalytic motifs, exhibit variations among monocot species. These differences likely contribute to alterations in β-glucan composition, notably impacting the DP3:DP4 ratio, which is crucial for understanding and modulating the final β-glucan content. The study positions Ae. caudata uniquely within the evolutionary landscape of CslF6 among monocots, suggesting potential genetic divergence or unique functional adaptations within this species. Overall, this investigation enriches our understanding of β-glucan biosynthesis, shedding light on the role of specific amino acid residues in modulating enzymatic activity and polysaccharide composition
Green compost influences yield and quality of carrots (Daucus carota L.) by enhancing root rot suppression to Sclerotinia sclerotiorum (Lib. De Bary)
No full textThe aim of this research, carried out in Bari and Policoro (Southern Italy) from March to June 2018, was to evaluate the effects of two different green composts on yield, quality, and root rot suppression of carrot (Daucus carota L.) cv. Rubrovitamin when compared to a mineral fertilizer and a plant growing media of peat-pumice. Green composts obtained from the municipal solid waste (Biovegetal) and olive pomace by olive mill were used in outdoor crop as fertilizer to enhance root yield and quality and in glasshouse to evaluate root rot suppression against Sclerotinia sclerotiorum. A randomized complete block design with six replicates was used. A total of eight treatments was compared in outdoor (mineral fertilization, three levels of each compost and unfertilized control). A total of five treatments was used in glasshouse: carrot was cropped in a growing media made of peat and pumice and fertilized with the two composts at two different levels, compared to an un-sterile potting mix of 60% peat with 40% pumice used as control. In the carrot grown outdoors the different composts did not influence either the length of the phenological phases or the entire crop cycle, but the highest dose of olive pomace (30 Mg ha-1) favored the greatest root production with an increase of 19.9% if compared to the mineral fertilizer. Biovegetal at the highest dose (30 Mg ha-1) provided non-statistically differences in root production from that obtained with the mineral fertilization, as well as the lowest rate (15 Mg ha-1) of composted olive pomace supplemented with 50 kg N ha-1. The highest carotenoids content, total soluble solids and specific weight were recorded by the amendment with the highest composted olive pomace rate. Concerning the root rot suppression effect, Biovegetal showed to be more effective than composted olive pomace. Thus, the use of green compost could represent a useful alternative to mineral fertilization and soil-borne disease control by synthetic fungicides through an adding-value due to by-products reusing and waste recycling
Effects of organic fertilization from wet olive pomace on emmer wheat (Triticum dicoccum Shrank) grain yield and composition
Full text linkIn a circular economy framework, the evaluation of waste by-product use as fertilizer is essential to promote sustainable agriculture. Olive oil wet pomace can be a valuable alternative as organic fertilizer on cereal crops. Aim of the study is to evaluate the effects of organic (with olive oil waste pomace) fertilization, on grain yield, protein and polyphenol content of emmer wheat grown in Southern Italy. Different amounts, time and amount of application of organic fertilizer were compared to a traditional mineral fertilizer treatment. The chemical analysis, mainly grain protein content and phenolic acids contents, were carried out on the hulled seeds. Agronomic traits showed that the application of olive wet pomace at 140 Mg ha−1 in the first year and 70 Mg ha−1 in the second year, gave the best grain yield than an annual amount application of 70 Mg ha−1. No difference between organic and mineral fertilization was observed when the latter was carried 1 or 2 years before, and the organic fertilization increased grain protein content respect to mineral one. Polyphenol content was not significantly affected by fertilization treatments, while ferulic acid in the emmer grain recently fertilized with wet pomace showed a higher content than emmer fertilized 2–3 years before
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
Effects of mineral and organic fertilization with the use of wet olive pomace on durum wheat performance
Full text linkPurpose: Despite durum wheat accounts for only 5% of the global wheat production, it represents an economically important species, as a basic food and primary source of daily caloric intake in the Mediterranean basin area. By-products of agricultural processing, such as pomace, can be used to increase soil fertility, as they are indeed a source of important nutrients useful for crop growth. Methods: The present research was carried out on durum wheat, as part of a long-term experiment. The study aimed at assessing the effects of mineral and organic fertilization with the use of wet olive pomace on a 3-year trial with crops grown in succession (fava beans—wheat—spelt). A split-plot experimental design with three replicates was used. The cultivars (Aureo and Vespucci) were assigned to the main plots and the seven fertilization treatments to the sub-plots. Results: Our result showed that supplying wet olive pomace as soil improver was not sufficient to significantly improve soil fertility compared to the unfertilized control. However, when 60 kg ha−1 of nitrogen was supplied in coverage before tillering, in addition to 70 Mg ha−1 of wet olive pomace yield an increase of 66% in Aureo cv and of 222% in Vespucci cv, in comparison to the unfertilized crop. Conclusion: The best management of fertilizers, associated with the use of more nitrogen-use-efficient genotypes, is essential for the development of a sustainable agriculture
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