321 research outputs found

    Effect of organic, low-input and conventional production systems on pesticide and growth regulator residues in wheat, potato and cabbage

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    The Nafferton factorial systems comparison (NFSC) experiments facilitate the investigation of effects of, and interaction between, three production system components - a) rotational position, b) fertility and c) crop protection management - in organic, conventional and low-input crop management systems. This paper presents first results on pesticide and growth regulator residues observed over a period of two years. Residues were only detected for three (Chlormequat, Chlorothalonil and Aldicarb) of the 28 pesticides used in the experiments. As expected, residue levels were affected by the crop protection practices, but significant effects of fertility management practices were also detected. This indicates that the human health risks associated with pesticide residues may increase in low input systems which attempt to reduce the environmental impact of conventional farming systems by switching to organic matter based fertilisation regimes

    N released from organic amendments is affected by soil management history

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    A ryegrass bioassay was conducted to investigate the effect of soil management history on nitrogen mineralisation from composted manure and pelleted poultry manure. Soils were used from 2 field experiments comparing conventional and organic/low input management systems. When composted manure was added, soils which had received high rates of composted FYM under biodynamic management released a greater amount of nitrogen for plant uptake than those with a history of mineral or fresh manure fertilisation, suggesting that biological preconditioning may result in greater efficiency of composted FYM as a nitrogen source for plants. “Native” N mineralisation was found to be related to total soil N content

    Effect of organic, low-input and conventional production systems on yield and diseases in winter barley

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    The effect of organic, low-input and conventional management practices on barley yield and disease incidence was assessed in field trials over two years. Conventional fertility management (based on mineral fertiliser applications) and conventional crop protection (based on chemosynthetic pesticides) significantly increased the yield of winter barley as compared to organic fertility and crop protection regimes. Severity of leaf blotch (Rhynchosporium secalis) was highest under organic fertility and crop protection management and was correlated inversely with yield. For mildew (Erysiphe graminis), an interaction between fertility management and crop protection was detected. Conventional crop protection reduced severity of the disease, only under conventional fertility management. Under organic fertility management, incidence of mildew was low and application of synthetic pesticides in “low input” production systems had no significant effect on disease severity

    Low temperature/short duration steaming as a sustainable method of soil disinfection

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    This report was presented at the UK Organic Research 2002 Conference. Soil samples containing resting structures of fungal crop pathogens (Verticillium dahliae, Sclerotinia sclerotiorum, Sclerotium cepivorum, Pythium ultimum), potato cyst nematodes (Globodera rostochiensis and Globodera pallida) and weeds (Chenopodium album and Agropyron repens) were treated with aerated steam in the laboratory at temperatures ranging from 50–80oC in a specially constructed apparatus. Steaming at 50 or 60oC for three minutes, followed by an eight-minute resting period in the steamed soil and immediate removal from the soil thereafter, resulted in 100% kill of all weeds, fungi and nematodes. Low temperature/ short duration soil steaming could become a sustainable alternative to chemical or high-temperature steam soil disinfestation

    Effect of Climate, Crop Protection, and Fertilization on Disease Severity, Growth, and Grain Yield Parameters of Faba Beans (<em>Vicia faba</em> L.) in Northern Britain: Results from the Long-Term NFSC Trials

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    \ua9 2024 by the authors. Faba beans are one of the most suitable grain legume crop for colder, maritime climates. However, there is limited information on the effect of changing from conventional to organic production methods and potential impacts of global warming on the health and performance of faba bean crops in Northern Europe. We therefore assessed the performance of faba beans grown with contrasting crop protection (with and without pesticides) and fertilization (with and without P and K fertilizer input) regimes used in organic and conventional production in seven growing seasons. Conventional crop protection and fertilization regimes had no effect on foliar disease severity, but resulted in small, but significant increases in faba bean yields. The overall yield gap between organic and conventional production regimes was relatively small (~10%), but there was substantial variation in yields between growing seasons/years. Redundancy analysis (RDA) showed that climate explanatory variables/drivers explained the largest proportion of the variation in crop performance and identified strong positive associations between (i) temperature and both straw and grain yield and (ii) precipitation and foliar disease severity. However, RDA also identified crop protection and variety as significant explanatory variables for faba bean performance. The relatively small effect of using P and K fertilizers on yields and the lack of a measurable effect of fungicide applications on foliar disease severity indicate that the use of these inputs in conventional faba beans may not be economical. Results also suggest that the yield gap between organic and conventional faba bean production is significant, but smaller than for other field crops

    The influence of organic and conventional fertilisation and crop protection practices, preceding crop, harvest year and weather conditions on yield and quality of potato (Solanum tuberosum) in a long-term management trial

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    The effects of organic versus conventional crop management practices (fertilisation, crop protection) and preceding crop on potato tuber yield (total, marketable, tuber size grade distribution) and quality (proportion of diseased, green and damaged tubers, tuber macro-nutrient concentrations) parameters were investigated over six years (2004–2009) as part of a long-term factorial field trial in North East England. Inter-year variability (the effects of weather and preceding crop) was observed to have a profound effect on yields and quality parameters, and this variability was greater in organic fertility systems. Total and marketable yields were significantly reduced by the use of both organic crop protection and fertility management. However, the yield gap between organic and conventional fertilisation regimes was greater and more variable than that between crop protection practices. This appears to be attributable mainly to lower and less predictable nitrogen supply in organically fertilised crops. Increased incidence of late blight in organic crop protection systems only occurred when conventional fertilisation was applied. In organically fertilised crops yield was significantly higher following grass/red clover leys than winter wheat, but there was no pre-crop effect in conventionally fertilised crops. The results highlight that nitrogen supply from organic fertilisers rather than inefficient pest and disease control may be the major limiting factor for yields in organic potato production systems

    An observational prospective study of topical acidified nitrite for killing methicillin-resistant Staphylococcus aureus (MRSA) in contaminated wounds

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    Background Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune response. When nitrite is exposed to low pH, NO is generated and has been used as an NO delivery system to treat skin infections. We demonstrated eradication of MRSA carriage from wounds using a topical formulation of citric acid (4.5%) and sodium nitrite (3%) creams co-applied for 5 days to 15 wounds in an observational prospective pilot study of 8 patients. Findings Following treatment with topical citric acid and sodium nitrite, 9 of 15 wounds (60%) and 3 of 8 patients (37%) were cleared of infection. MRSA isolates from these patients were all sensitive to acidified nitrite in vitro compared to methicillin-sensitive S. aureus and a reference strain of MRSA. Conclusions Nitric oxide and acidified nitrite offer a novel therapy for control of MRSA in wounds. Wounds that were not cleared of infection may have been re-contaminated or the bioavailability of acidified nitrite impaired by local factors in the tissue

    Phonon-assisted radiofrequency absorption by gold nanoparticles resulting in hyperthermia

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    It is suggested that in gold nanoparticles (GNPs) of about 5 nm sizes used in the radiofrequency (RF) hyperthermia, an absorption of the RF photon by the Fermi electron occurs with involvement of the longitudinal acoustic vibrational mode (LAVM), the dominating one in the distribution of vibrational density of states (VDOS). This physical mechanism helps to explain two observed phenomena: the size dependence of the heating rate (HR) in GNPs and reduced heat production in aggregated GNPs. The argumentation proceeds within the one-electron approximation, taking into account the discretenesses of energies and momenta of both electrons and LAVMs. The heating of GNPs is thought to consist of two consecutive processes: first, the Fermi electron absorbs simultaneously the RF photon and the LAVM available in the GNP; hereafter the excited electron gets relaxed within the GNP's boundary, exciting a LAVM with the energy higher than that of the previously absorbed LAVM. GNPs containing the Ta and/or Fe impurities are proposed for the RF hyperthermia as promising heaters with enhanced HRs, and GNPs with rare-earth impurity atoms are also brought into consideration. It is shown why the maximum HR values should be expected in GNPs with about 5-7 nm size.Comment: proceedings at the NATO Advanced Research workshop FANEM-2015 (Minsk, May 25-27, 2015). To be published in the final form in: "Fundamental and Applied NanoElectroMagnetics" (Springer Science + Business Media B.V.

    Abschätzung der Auswirkungen der Krautfäule auf den Bio-Kartoffelbau in verschiedenen Europäischen Ländern, sowie Inventar der angewendeten Anbau- und Pflanzenschutzstrategien

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    Problemstellung/Ziele Die Kraut- und Knollenfäule (Phytophthora infestans) ist die Krankheit, die im biologischen (aber auch konventionellen) Kartoffelanbau in Europa die größten Probleme verursacht. Unter günstigen klimatischen Bedingungen breitet sich die Krankheit sehr rasch aus und kann große Ertragsausfälle verursachen. Innerhalb von Europa variiert der durch P. infestans verursachte wirtschaftliche Schaden stark zwischen den Regionen. Dies hängt von verschiedenen Faktoren ab, aber in biologisch bewirtschafteten Anbausystemen immt man an, dass die klimatischen Bedingungen, die verwendeten Sorten sowie die agronomischen Maßnahmen wie Bodenbearbeitung oder die Verwendung von Pflanzenschutzmitteln eine wichtige Rolle spielen. Die Reduktion oder das Verbot des Kupfereinsatzes im biologischen Kartoffelanbau wird deshalb auch unterschiedliche Auswirkungen in den verschiedenen Europäischen Regionen haben. Als Teilprojekt des EU-finanzierten Projektes Blight-MOP (QLRT 31065) wurde eine detaillierte Studie der ökonomischen und gesetzlichen Rahmenbedingungen und ein Inventar der Anbausysteme in 7 Ländern durchgeführt, um (i) Ein Inventar der derzeitigen Anbautechniken zu erstellen, (ii) die Auswirkungen von P. infestans auf Erträge und Wirtschaftlichkeit zu evaluieren und die Auswirkungen eines Kupferverbotes abzuschätzen und um (iii) Pflanzenschutzstrategien von Bioproduzenten zu identifizieren, die bereits jetzt ohne den Einsatz von Kupfer auskommen. Fazit: Diese Betriebsanalyse weist darauf hin, dass eine Optimierung der Einzelmassnahmen und die regionsspezfische Integration von Massnahmen zu einer substanziellen Verbesserung des Anbauerfolges führen können. Die Betriebsanalyse zeigt auch, dass Kupfer bislang eine wichtige Rolle bei der Ertragsbildung gespielt hat. Ein Kupferverbot ohne Angebot von praxistauglichen Alternativlösungen (wie sie innerhalb von Blight-MOP und anderen Projekten erarbeitet werden) würde demnach zu einer starken Destabilisierung des biologischen Kartoffelanbaues und vermutlich zu einer Angebotsvernappung führen. Andere Teilprojekte des Blight-MOP Projektes zielen auf die Verbesserung von anbautechnischen Massnahmen und die Entwicklung von Ersatzprodukten für Kupfer ab
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