1,721,021 research outputs found
Spatial and temporal variability of spring barley yield and quality quantified by crop simulation model
No full textNitrogen fertilization is the most critical agronomic input affecting barley production and farm profitability. The strict quality requirements for malting barley are challenging to achieve for farmers. In addition, soil variability and weather conditions can affect barley yield and quality. Thus, the objectives of this study are to (a) quantify the variability of soil properties, and (b) use spatial data in a crop simulation model, quantifying the impacts of climate−soil interactions on the barley crop yield and grain quality. Based on historical yield maps, a commercial field was divided into different yield stability zone levels. The Decision Support System for Agrotechnology Transfer model was used to evaluate soil and crop spatial data. The bulk density affected the soil water content and soil mineral N and hence the crop-growing conditions in each yield stability zone. Our observed and simulated results showed that 120 kg N ha−1 is the optimal rate to increase grain yield while still keeping within the grain N% requirements for malting quality. This study shows the great value of integrating crop modeling with on−farm experimental data for improving understanding of the factors which affect site−specific N fertilization of barley
Effects of compost and defatted oilseed meals as sustainable organic fertilisers on cardoon (Cynara cardunculus L.) production in the Mediterranean basin
Full text linkCardoon (Cynara cardunculus L.) is considered as one of the most suitable energy crops for Southern Europe. The aim of this work was to outline the effects of organic fertilisers on the productivity and the global warming potential (GWP) on cardoon production. Six fertilisers (N 100 kg ha −1 , N 50 kg ha −1 , Compost 30 t ha −1 , Compost 15 t ha −1 + N 25 kg ha −1 , 3 t ha −1 of defatted oilseed meals of sunflower, 3 t ha −1 of defatted oilseed meals of Brassica carinata), and unfertilised control, were evaluated on two cultivars (‘Gobbo di Nizza’ and ‘Altilis 41’) in a split-plot experiment. Defatted oilseed meal of sunflower recorded higher total dry weight (+10%), seed yield (+17%), nitrogen use efficiency (+14%) and better GWP (−66%) compared to the other organic fertilisers and performing as well as N 100 kg ha −1 . Altilis 41 cultivar showed the highest aboveground total dry weight (10 t ha −1 y −1 ), seed yield (1.7 t ha −1 y −1 ), stalk dry weight (7 t ha −1 y −1 ) and head dry weight (3 t ha −1 y −1 ). Our results highlighted that by combining suitable cultivar and fertilisation strategies, it could be possible to increase the production sustainability of C. cardunculus
Agronomic Comparisons of Heirloom and Modern Processing Tomato Genotypes Cultivated in Organic and Conventional Farming Systems
No full textThe yield and fruit quality of processing tomatoes (Solanum lycopersicum L.) have increased markedly over the past decades. The aim of this work was to assess the effects of the organic (OFS) and conventional farming systems (CFS) on the main agronomic parameters involved in processing tomato yield components and fruit quality traits of heirloom and modern genotypes. Marketable yield increased from heirloom to modern genotypes, both in OFS and in CFS, showing a difference of ≈20 t per hectare in favor of CFS. Total fruit yield (TY) was not improved from heirloom to modern assessed genotypes, and a difference of ≈35 t per hectare was observed in favor of CFS. In both farming systems, the highest marketable yield of modern genotypes was due to a higher number of fruits per plant, harvest index, nitrogen agronomic efficiency (NAE), and fruit water productivity. Moreover, the main growth parameters involved in the yield differences between OFS and CFS were the number of leaves per plant, the average fruit weight, the normalized difference vegetation index (NDVI), and NAE. It is noteworthy that fruit quality improvement in terms of color and brix per hectare was paralleled by a decrease of tomato pH in both farming systems. According to our results, we conclude that to reduce the current yield gap between OFS and CFS, agronomic and breeding efforts should be undertaken to increase leaf area index, fruit number per plant, and NAE for better genotype adaptation to organic farming systems
Grafting and Plant Density Influence Tomato Production in Organic Farming System
Full text linkThe tomato is a key crop cultivated worldwide for the fresh and processing markets. Only a small percentage of the tomatoes processed by industries were produced following the guidelines of the organic farming system. Potential reasons for the limited share of organic tomato production are probably related to the lower yield obtained in organic farming in comparison with conventional farming. In this study, the use of the cherry tomato genotype 'Tomito' as a rootstock and two different plant densities (2.5 and 1.25 plant m(-2)) were evaluated in order to improve the agronomic performances of the commercial processing tomato genotype 'H3402 & PRIME; cultivated in the organic farming system. Agronomic and quality parameters were assessed at harvest time. The plant density influenced the plant biometric parameters, mass and marketable yield, and fruit health and quality. The use of a rootstock improved the marketable yield per plant (more than 59%), with the quality of the fruit decreasing the number of sunburnt fruits (-27.7%). The use of the 'Tomito' as a rootstock and a plant density of 2.5 plant m(-2) are the better choices to achieve good performances in optimal environmental conditions. However, further studies are required to validate these results both in other environments and using different scions
Plant Biostimulants in Sustainable Potato Production: an Overview
No full textIn modern agriculture, the reduction of environmental impact, ensuring both high and stable yield and high quality, is a primary goal. To avoid an excessive use of external inputs, without compromising crop performance, the increase of soil nutrient availability and nutrient use efficiency is fundamental in a sustainable potato production. In this framework, the use of plant biostimulants, such as humic substances, seaweed and microalgal extracts, hydrolysed proteins and amino acids and microorganisms, could give a great help to farmers. Due to the agronomic importance and the keen interest in these substances, the aim of this review was to survey and summarise the outputs derived from scientific published studies on the combination of potato and plant biostimulants. In the literature, several in vitro, growth chamber, glasshouse and field experiments were reported. Field experiments were conducted in different environmental conditions, using different genotypes, and all the applied plant biostimulants showed beneficial effects on both productive and qualitative potato parameters. Seaweed extract and humic substances could also reduce the normal dose of fertiliser without reducing yield. Among quality features, tuber size, contents of protein, vitamin C, starch and phenols are the principal parameters influenced by plant biostimulants. Weaknesses related to the use of plant biostimulants were shown and were related to different effectiveness of products due to their origin, production process and microbial species. In addition, product/strain-genotype interactions have been shown. Environmental factor, agricultural practice and timing of treatment can influence the effectiveness of both microbial and non-microbial plant biostimulants
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
Towards the Optimal Mineral N Fertilization for Improving Peeled Tomato Quality Grown in Southern Italy
No full textNitrogen (N) fertilization has often been used in excess by farmers to improve commercial yield and the profitability of processing tomato crops. However, N fertilizers greatly affect the overall tomato quality, including technological traits, nutritional characteristics, and mineral fruit composition. The aim of this work was to study the effects of increasing mineral N fertilization rates on processing tomato yield and quality when grown in Southern Italy conditions. The study was carried out at Battipaglia (Southern Italy) cropping cultivar “Messapico”, suitable for peeled tomato, and fruit quality was evaluated at the ripening stage. Results showed that N fertilization reduced sunburned fruits and resulted in increasing total yield, average fruit weight, as well as other fruit parameters (size, firmness, color indexes, pH, N, and calcium content). On the other hand, N fertilization negatively affected other fruit traits, such as dry matter and soluble solids content, total sugar index, ascorbic acid, and sodium content, while it had no effect on potassium and magnesium concentration in tomato fruits. Our results show that, in the investigated area, 200 kg N ha−1 is the best compromise to satisfy farmers and processors expectations, improve yield, and at the same time maintain good fruit quality attributes
Identification of the Volatile Components of Galium verum L. And Cruciata leavipes Opiz from the Western Italian Alps
No full textThe chemical composition of the volatile fraction from Galium verum L. (leaves and flowers) and Cruciata laevipes Opiz (whole plant), Rubiaceae, was investigated. Samples from these two plant species were collected at full bloom in Val di Susa (Western Alps, Turin, Italy), distilled in a Clevenger-type apparatus, and analyzed by GC/FID and GC/MS. A total of more than 70 compounds were identified, making up 92%–98% of the total oil. Chemical investigation of their essential oils indicated a quite different composition between G. verum and C. laevipes, both in terms of the major constituents and the dominant chemical classes of the specialized metabolites. The most abundant compounds identified in the essential oils from G. verum were 2-methylbenzaldheyde (26.27%, corresponding to 11.59 μg/g of fresh plant material) in the leaves and germacrene D (27.70%; 61.63 μg/g) in the flowers. C. laevipes essential oils were instead characterized by two sesquiterpenes, namely β-caryophyllene (19.90%; 15.68 μg/g) and trans-muurola-4(15),5-diene (7.60%; 5.99 μg/g); two phenylpropanoids, benzyl alcohol (8.30%; 6.71 μg/g), and phenylacetaldehyde (7.74%; 6.26 μg/g); and the green-leaf alcohol cis-3-hexen-1-ol (9.69%; 7.84 μg/g). The ecological significance of the presence of such compounds is 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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