10 research outputs found

    Effects of Cropping System (Organic and Conventional) on the Fiber Quality Index, Spinning Consistency Index and Multiplicative Analytic Hierarchy Process of Cotton (Gossypium hirsutum L.)

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    Markets for organically produced high quality cotton (Gossypium hirsutum L.) are projected to increase. Field experiments were conducted in Palamas, Karditsa in Central Greece, to compare the effects of two cropping systems on fiber quality of three cotton cultivars. The experiments, conducted during three years, were laid out in a split plot design with four replicates, two main plots (organic and conventional system) and three sub-plots (cotton cultivars). Findings suggest that fiber quality index (FQI), spinning consistency index (SCI) and multiplicative analytic hierarchy process (MAHP) are three indices that could be integrated in a useful protocol for the evaluation of different cropping systems for cotton cultivation. In particular, our results indicate that in general there was not any superiority of conventional compared to the organic cropping system regarding fiber quality as shown by the above mentioned indices. Regarding the length of the cotton fiber, this was positively correlated with micronair and the uniformity index of the cotton fiber. The organic system resulted to higher values of SCI than the ones of the conventional (1547.9 and 1522.3, respectively). The present 3-years study shows that organic cultivation of cotton can ensure high fiber quality and this was clearly confirmed by means of the several important indices

    Effect of Different Types of Fertilization on Vigna unguiculata subsp. sesquipedalis Crop

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    A field experiment was conducted at Pylos, Greece to compare the effect of different types of fertilization on yardlong bean (Vigna unguiculata subsp. sesquipedalis) crop. The conventional treatment plots were fertilized with an inorganic fertilizer, whereas the organic treatments plots received organic compost. Data analysis confirmed no significant correlation between plant height and type of fertilization, but there was significant correlation between length of pods and type of fertilization. In particular, morphological characteristics of yardlong bean were enhanced by inorganic fertilization in comparison with the organic fertilization.  Organic farming increased significantly the number on root nodules in comparison with conventional farming

    Effect of Biocyclic Humus Soil on Yield and Quality Parameters of Processing Tomato (Lycopersicon esculentum Mill.)

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    A field experiment was conducted to evaluate the effects of biocyclic humus soil, a newly found apparently carbon stabilized form of organic matter with significantly different characteristics from common composts or other forms of organic matter (humus), on yield and quality of processing tomato. The experiment was laid out in a completely randomized design with three replications and three fertilization treatments (untreated, inorganic fertilizer and biocyclic humus soil). The highest fruit yield (116.8 t/ha) was obtained by using biocyclic humus soil. There were no treatment effects on fruit firmness (4.34-4.60 kg/cm2), total soluble solids (4.29-4.76 °Brix) and total acidity (0.25-0.31 g citric acid/100 g fruit) content of fruits. In conclusion, the tomato plants grown in biocyclic humus soil had 45% more yield than in conventional plots, and this big difference is probably related to the fact that the humus soil as a substrate provides an optimum environment for plant growth

    Effect of organic and inorganic fertilization on weed flora and seed yield in black mustard [Brassica nigra (L.) Koch] crops

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    Crop production practices affect weed communities in agricultural systems. Field experiments were conducted to determine the effects of organic and inorganic fertilization on weed flora and seed yield in black mustard [Brassica nigra (L.) Koch] crops. The experiments, conducted at two sites (Athens and Agrinio, Greece) during 2019, were laid out in a randomized complete block design with three replicates and three fertilization treatments (untreated, compost fertilizer and inorganic fertilizer). The results of the present study indicated that the total weed density and biomass in the black mustard crops were significantly influenced by fertilization. The highest leaf area index (4.76-4.84 m2 m-2) and canopy interception of incident photosynthetically active radiation (PAR) (93.56-94.98%) were observed under inorganic fertilization at 90 days after sowing. At both experimental sites, the total weed density and biomass were significantly higher under inorganic fertilizer treatment at 45 DAS. The highest densities of the weed species Sinapis arvensis, Chenopodium album and Malva sylvestris were found in the plots treated with inorganic fertilizer. The seed yield was also affected by fertilization, with the highest values (1352-1456 kg ha-1) observed in the plots treated with inorganic fertilizer. In conclusion, the different fertilization practices affected both the weed density and weed biomass; in particular, inorganic fertilization led to the development of he highest weed density. Furthermore, the highest seed yields were recorded under inorganic fertilization in both the experimental areas

    Weed-Species Abundance and Diversity Indices in Relation to Tillage Systems and Fertilization

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    Weeds pose a major threat to world agriculture by reducing detrimentally crop yield and quality. However, at the same time, weeds are major interacting components of the agroecosystems. Abundance and diversity of weeds vary significantly among the several communities. In order to evaluate each community's structure and the interactions among them, several population indices are used as key tools. In parallel, various cultivation and land management strategies, such as tillage and fertilization, are commonly used in terms of integrated weed management. Estimating the response of weed species on those practices is crucial for both biodiversity maintenance and alternative weed control methods. Many experiments have confirmed the fundamental role of tillage intensity and nutrition supply in weed species' abundance and diversity. For instance, in some studies, the abundance of perennial weeds was doubled under reduced tillage intensity. In addition, higher values of Shannon-Weiner and Pielou indices were reported in the PK fertilization treatment compared to the control and NK fertilization treatments. The objective of this paper is to provide a brief overview of the key results of these experiments and summarize the part of the literature related to the effect of tillage systems and fertilization on weed species abundance and diversity. Such knowledge could contribute to the sound design and implementation of integrated weed management programs which in turn may lead to a decrease in the density of serious and noxious weeds and an increase in the overall balance of agroecosystems

    Dissimilar welding between conventional and high strength low alloy naval steels with the use of robotic metal cored arc welding

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    The increasing trend of high strength low alloy steel application in the shipbuilding industry dictates the necessity for an investigation of their welds with conventional high strength steels. In this study, conventional and high strength low alloy naval steel plates 12 mm thick, were joined together in a butt joint configuration, using the metal cored arc welding technique and low heat input (1.0 kJ/mm). The weld was examined in terms of microhardness, microstructure, and tensile performance. The effect of multiple thermal cycles on the formation of primary and secondary microstructures was also discussed. The results revealed a smooth distribution of the microhardness across the different weld regions. Inside the heat affected zones (HAZs) and the weld metal various constituents were revealed, with ferrite in various forms (lath-like, acicular, semi-equiaxed, polygonal) appearing as the predominant phase, alongside martensite and austenite grains, and pearlite (lamellar and degenerated). The tensile testing indicated the base metal of the conventional high strength steel to be the weakest link of the weld, which was mainly attributed to its ferritic-pearlitic microstructure and the coarse grain size. The overall tensile performance of the weld remained at high levels, with a simultaneous reduction in the elongation after fracture in comparison to the base metals.The research was supported by Enterprise Ireland (EI) and SchuF Valve Technology GmbH (IP2018 0730

    Climate Change and Chances for the Cultivation of New Crops

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    Climate change is one of the greatest environmental, economic and social challenges in the history of mankind and nowadays is considered as the biggest environmental problem of the world. Climate change has a significant global impact and therefore Greece has to deal with its effects as well. Agriculture has been unfavourably affected in recent years, as the current and anticipated conditions in many cases seem to be rather prohibitive for the prosperity of the cultivated crops. On the contrary, these new conditions have made it possible for new plant species previously cultivated only in subtropical regions, to thrive in Greece. Moreover, economic reasons would make it rather necessary for the agricultural industry to cultivate alternative crops, which are thoroughly analysed in the present study. Based on Heating Degree Days (HDD) Greece is divided into four climatic zones. The variations in the mean maximum, mean minimum and mean temperature in each climate zone as well as the rainfall over the last 50 years (from 1964 to 2013) are reviewed in this paper. The outcome of this research is that it is not feasible for the studied alternative crops to thrive in all climate zones or vice versa. However, some of them and particularly crops such as quinoa, maca, psyllium, chia, cassava and pecan can be cultivated in all climate zones. It has also to be noted that adequate water is necessary for almost all the examined crops in order to achieve optimal growth and yield and therefore irrigations are rather necessary for specific species and climate zones

    Pulsed electromagnetic field: an organic compatible method to promote plant growth and yield in two corn types

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    Pre-sowing treatment of pulsed electromagnetic fields was used in corn seeds, in both indoor and outdoor conditions, in order to investigate the effect on plant growth and yield. The results of this research showed that pulsed electromagnetic fields can enhance plant characteristics, both under controlled environmental conditions and uncontrolled field conditions. The two varieties responded differently in the duration of magnetic field. Seeds were treated for 0, 15, 30, and 45 min with pulsed electromagnetic field (MF-0, MF-15, MF-30, and MF-45). Common corn variety performed better results in MF-30 treatment, while sweet corn variety performed better in MF-45 treatment. Magnetic field improved germination percentage, vigor, chlorophyll content, leaf area, plant fresh and dry weight, and finally yields. In the very interesting measurement of yield, seeds that have been exposed to magnetic field for 30 and 45 min have been found to perform the best results with no statistical differences among them. Another interesting finding was in root dry weight measurements, where magnetic field has a negative impact in MF-30 treatment in both hybrids, however without affecting other measurements. Enhancements on plant characteristics with economic impact on producer's income could be the future of a modern, organic, and sustainable agriculture

    Is There a Meaningful Serum Hepatitis B Virus DNA Cutoff Level for Therapeutic Decisions in Hepatitis B e Antigen-Negative Chronic Hepatitis B Virus Infection?

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    The diagnosis of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B indicating therapeutic intervention currently requires serum hepatitis B virus (HBV) DNA >= 2,000 IU/mL. We evaluated the severity of liver histology and the presence of histological indication for treatment in patients with HBeAg-negative chronic HBV infection focusing on those with low viremia and/or normal alanine aminotransferase (ALT). In total, 399 patients with increased ALT and detectable serum HBV DNA (chronic hepatitis B patients) and 35 cases with persistently normal ALT and HBV DNA >2,000 IU/mL (inactive carriers) were included. Histological indication for treatment (grading score >= 7 and/or stage >= 2 in Ishak’s classification) was found in 91% (185/203), 82% (75/91), 75% (47/63), and 62% (26/42) of chronic hepatitis B patients with HBV DNA >= 200,000, 20,000-199,999, 2,000-19,999, and <2,000 IU/mL, respectively (P < 0.001). Histological indication for treatment was more frequent in chronic hepatitis B patients with persistently elevated ALT (86% or 275/321), but it was also found in 74% (58/78) of those with transiently normal ALT (P = 0.025). All inactive carriers had HBV DNA <20,000 IU/mL. Histological indication for treatment was present in 17% (6/35) of inactive carriers always due to moderate (stage 2) fibrosis without active necroinflammation. Conclusion: HBeAg-negative chronic HBV patients with persistently or transiently increased ALT and HBV DNA >= 20,000 IU/mL almost always require therapeutic intervention, but histological indications for treatment are also present in the majority of such cases with HBV DNA < 20,000 and even < 2,000 IU/mL. In contrast, minimal histological lesions are observed in the majority of HBeAg-negative patients with persistently normal ALT and HBV DNA > 2,000 IU/mL, who may not require immediate liver biopsy and treatment but only close follow-up. (HEPATOLOGY 2008;48:1451-1459.
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