1,720,959 research outputs found
Morpho‐physiological and agronomic responses of wheat varieties under artificial shade in agroforestry systems
Full text linkBACKGROUND: Solar radiation is a primary constraint in silvoarable agroforestry, with yield losses near the trees well documented in temperate climates. However, genetic variability for shade tolerance remains largely unexplored. This 2-year field trial investigated the impact of artificial shading – using nets that reduced photosynthetically active radiation (PAR) by moderate (−30%) and severe (−50%) levels relative to full sun – on the morpho-physiology and yield of common wheat. During the first growing season, three varieties were evaluated: the modern variety, Bologna, and two old, tall varieties, Piave and Terminillo. In the second season, only Bologna was retested under the same shading treatments, to further assess its performance.
RESULTS: Shading treatments delayed crop phenology from heading onward. They were associated with a prolonged canopy stay-green, with effects accentuated by increasing shading severity. In the first year, moderate shading increased Bologna's grain yield by 8% (P ≤ 0.05) and raised protein content by 0.7%. In the second year, drier conditions and reduced radiation from March–June – causing more severe limitation of PAR, the amount of sunlight available for photosynthesis – led to a 40% yield loss. Old varieties suffered yield reductions due to lodging (−43% in Terminillo,−66% in Piave), yet showed notable increases in mineral content (up to +48% Mg in Piave) and grain protein (+1.7% in Terminillo and +3.4% in Piave). Under shaded conditions, increased gliadin content led to enhanced gluten accumulation, potentially improving dough extensibility.
CONCLUSIONS: Although nets can mimic shading in wheat effectively, these results highlight the need to extend varietal screening to identify suitable genotypes and key morpho-physiological traits to optimize wheat cultivation in shaded environments such as agroforestry systems, with further validation in specific emerging models
Phytohormonal Regulation of Abiotic Stress Tolerance, Leaf Senescence and Yield Response in Field Crops: A Comprehensive Review
Full text linkField crops are expected to be increasingly threatened by climate change, which will negatively impact plant development, growth and yield. Phytohormones play a crucial role in regulating specific signalling pathways to induce rapid adaptive responses to environmental stresses. Exogenous phytohormone application alters hormonal balance, thereby enhancing plant adaptation to adverse conditions. While several studies have advanced our understanding of the use of phytohormones in field crops, yield responses and species-specific application strategies remain inconsistent and rarely assessed under field conditions. The application of cytokinins (CKs), abscisic acid (ABA), and gibberellic acid (GA) has been shown to maintain prolonged photosynthetic activity, stabilize plasma membrane, and reduce lipid peroxidation and ion accumulation under salinity stress in wheat. Additionally, inhibitors of ethylene synthesis and receptors can mitigate stress symptoms under drought and heat stress, which typically accelerates senescence and shortens the grain-filling period in cereal crops. In this way, exogenous application of CKs, GA, and ethylene inhibitors can delay senescence by sustaining leaf photosynthetic activity and postponing nutrient remobilization. However, these benefits may not consistently translate into improvements in grain yield and quality. This review explores the molecular mechanisms of phytohormones in abiotic stress tolerance, delineates their specific functions and evaluates experimental findings from field applications. It also summarizes the potential of phytohormone applications in field crops, emphasizing the need for species-specific investigations on application timing and dosages under open-field conditions to optimize their agronomic potential
Effects of foliar-sprayed bio-fertilizer with N-fixing Methylobacterium symbioticum on morpho-physiological traits of maize under varying N fertilization rates
Full text linkNitrogen (N) fertilization remains a critical challenge in sustainable agriculture. Plant growth-promoting bacteria offer a promising strategy to enhance nitrogen use efficiency and improve cereal crop productivity while reducing reliance on synthetic inputs. This open-field study evaluated the morpho-physiological effects of foliar application of Methylobacterium symbioticum (MS) on maize in NE Italy. Following a baseline application of liquid digestate (300 kg N ha-¹) to all plots, four treatments were compared: N300 (digestate only, serving as the control); N300 + MS (digestate with MS); N350 (digestate with 50 kg ha-¹ chemical N); and N320 + MS (digestate with 20 kg ha-¹ chemical N and MS). ESEM imaging confirmed colonization of leaf surfaces by M. symbioticum. Its application significantly promoted aboveground growth and delayed leaf senescence by improving chlorophyll retention, increasing seasonal average SPAD from 46.9 in control to 49.4 (+5.3%, N300 + MS) and 48.8 (+4.1%, N320 + MS), likely mediated by the ascertained ACC-deaminase activity of MS. Root electrical capacitance showed treatment-specific effects, with the highest readings under the N320 + MS treatment (+54% vs. control at flowering). Yield responses were non-linear with respect to N dose, with N300 + MS showing a 12% (1,364 g/m²) and N320 + MS a 6% non-significant increase vs. control. MS-treated plants also exhibited a non-significant 5% increase in grain protein content, but significantly higher aboveground N accumulation. It is concluded that, this microbial inoculation strategy can enhance N use efficiency, particularly under reduced synthetic fertilization, presenting an environmentally-friendly and sustainable agricultural strategy for maize cultivation
Application of the full nitrogen dose at decreasing rates by foliar spraying versus conventional soil fertilization in common wheat
Full text linkFoliar fertilization is increasingly recognized as a sustainable agronomic practice, yet its full potential to enhance nitrogen use efficiency (NUE), reduce application rates, and improve wheat grain quality remains largely underexplored. This study evaluated a two-year field trial comparing nitrogen fertilization applied solely through repeated foliar spraying at reduced doses (96, 80, and 64 kg N ha−1) using urea-ammonium-nitrate (UAN) compared to conventional soil fertilization at a standard rate of 160 kg N ha−1. Here it was demonstrated that foliar application at 96 kg N ha−1 achieved grain yields comparable to conventional fertilization (6.80 vs. 7.05 t ha−1) while slightly improving root and shoot growth. Reduced doses also significantly enhanced the glutenins-to-gliadins ratio, total glutenins content (+14 %), and nitrogen use efficiency (NUE: 118.1 vs. 47.5 kg grain DM kg−1 N supplied) but with a 14 % yield reduction at the lowest fertilizer dose (64 kg N ha−1).These findings demonstrate that foliar fertilization can maintain wheat productivity while reducing nitrogen input by up to 40 %, enhancing NUE and grain quality. This strategy also provides fertilizer savings and environmental benefits, with potential applications in drought-prone areas. Future research should focus on optimizing application rates and assessing long-term economic and environmental impacts
Evaluating the effects of hydrogel and glacial rockflour as soil ammendment and maize seed coating: early observations on soil properties and root growth.
No full textreservedEvaluating the effects of hydrogel and glacial rockflour as soil ammendment and maize seed coating: early observations on soil properties and root growth.Evaluating the effects of hydrogel and glacial rockflour as soil ammendment and maize seed coating: early observations on soil properties and root growth
Growth, Photosynthesis and Yield Responses of Common Wheat to Foliar Application of Methylobacterium symbioticum under Decreasing Chemical Nitrogen Fertilization
Full text linkCurrent agriculture intensifies crop cultivation to meet food demand, leading to unsustainable use of chemical fertilizers. This study investigates a few physiological and agronomic responses
of common wheat following the inoculation with plant growth-promoting bacteria to reduce nitrogen
inputs. A field trial was conducted in 2022–2023, in Legnago (Verona, Italy) on Triticum aestivum
var. LG-Auriga comparing full (180 kg ha−1
) and reduced (130 kg ha−1
) N doses, both with and
without foliar application at end tillering of the N-fixing bacterium Methylobacterium symbioticum.
Biofertilization did not improve shoot growth, while it seldom increased the root length density
in the arable layer. It delayed leaf senescence, prolonged photosynthetic activity, and amplified
stomatal conductance and PSII efficiency under the reduced N dose. Appreciable ACC-deaminase
activity of such bacterium disclosed augmented nitrogen retrieval and reduced ethylene production,
explaining the ameliorated stay-green. Yield and test weight were unaffected by biofertilization,
while both glutenin-to-gliadin and HMW-to-LMW ratios increased together with dough tenacity.
It is concluded that Methylobacterium symbioticum can amplify nitrogen metabolism at a reduced
nitrogen dose, offering a viable approach to reduce chemical fertilization under suboptimal growing
conditions for achieving a more sustainable agriculture. Further research over multiple growing
seasons and soil types is necessary to corroborate these preliminary observations
Phytoremediation of perfluoroalkyl and polyfluoroalkyl substances (PFAS): Insights on plant uptake, omics analysis, contaminant detection and biomass disposal
No full textThe unique properties of per- and polyfluoroalkyl substances (PFAS) have driven their pervasive use in different
industrial applications, leading to substantial environmental pollution and raising critical concerns about the
long-term impacts on ecosystem and human health. To tackle the global challenge of PFAS contamination, there
is an urgent need for sustainable and efficient remediation strategies. Phytoremediation has emerged as a
promising eco-friendly approach with the potential to mitigate the spread of these persistent contaminants.
However, addressing this complex issue requires interdisciplinary cutting-edge research to develop comprehensive
and scalable solutions for effective PFAS management. This review highlights recent advancements in
the detection, quantification, and monitoring of PFAS uptake by plants, providing a detailed description of PFAS
accumulation in several plant species. Besides, the physiological and molecular responses elicited by these pollutants are described. Leveraging omic technologies, including genomics, transcriptomics, and proteomics,
provides unprecedented insights into the plant-PFAS interaction. Novel approaches based on artificial intelligence
to predict this interaction and up to date disposal and valorization methods for PFAS-contaminated plant
biomass, are discussed here. This review offers an interdisciplinary approach to explore what has been discovered
so far about PFAS phytoremediation, covering the entire process from contaminant uptake to sustainable
disposal, providing a roadmap for future research
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
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