6,798 research outputs found

    Nectria galligena as the cause of a collar rot disease in organically grown Topaz apple trees

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    Symptoms resembling collar rot were detected in organically managed Topaz trees aged 3-10 years, occur-ring one to several years after planting of the orchard. Trees were killed within the same growing season in which symptoms were first observed. The disease commonly progressed as a complete covered canker at the base of the tree trunk. Isolation attempts were negative for Phytophthora and other Oomycetes, but con-sistently yielded Nectria galligena. The possibility of latent (endophytic) infections of N. galligena as the cause of delayed collar rot symptoms is briefly discussed

    Diplodia seriata, cause of black fruit rot in organically grown apples in Holland, Belgium and Northern Germany

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    A fruit rot resembling Gloeosporium infections but appearing on fruits prior to harvest was noticed in organic apple orchards in Holland, Belgium and Northern Germany in 2007. Infections were most commonly observed on ‘Elstar’, but other cultivars were also affected. Fruit colonisation progressed in two steps, whereby a latent stage of sunken black lesions in immature fruits gave rise to a rapidly spreading firm brown rot upon fruit ripening. Isolation experiments from both stages consistently yielded a single species of fungus identified as Diplodia seriata, formerly known under the teleomorph name Botryosphaeria obtusa. Lesions of D. seriata were also seen on leaves as necrotic light brown spots surrounded by a purple halo, and occasionally on small twigs as cankers. Fruit mummies on apple twigs were heavily colonised by D. seriata and are thus likely to carry inoculum for fruit infections during late summer or in the following growing season

    Prvo priopćenje o vrsti Puccinia distincta McAlpine, novoj europskoj hrđi na tratinčicama (Bellis perennis L.) iz Hrvatske

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    Severe rust infections on wild and cultivated daisies (Bellis perennis L.) were found in April and May 2000 in an isolated coastal location of Croatia between Lovran and Opatija. The pathogen was identified as Puccinia distincta McAlpine which has been spreading rapidly across Europe for the past four years and may be of Australian origin. In the current paper, we describe the diagnostic features of P. distincta using Croatian material, and suggest spraying with myclobutanil-containing fungicides to protect ornamental daisies in flowerbeds. Without such treatments, it may no longer be possible to grow daisies in areas affected by P. distincta.Teška infekcija hrđe na divljim i uzgajanim tratinčicama (Bellis perennis L.) otkrivena je u travnju i svibnju 2000. na izoliranom priobalnom području izme|u Lovrana i Opatije. Patogena gljiva bila je determinirana kao Puccinia distincta McAlpine, koja se protekle četiri godine brzo širi po Europi, a možda dolazi iz Australije. U ovom prikazu opisujemo dijagnostičke značajke gljive P. distincta primjenjujući materijal iz Hrvatske i predlažemo prskanje fungicidima na osnovi miklobutanila kako bismo zaštitili dekorativne tratinčice u cvjetnim nasadima. Bez takvih tretmana postoji mogućnost da na područjima zaraženim s P. distincta više neće biti moguć njihov uzgoj

    Risiko und Prävention angeborener Herzfehler

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    Konzept zur Reduktion der Regenfleckenkrankheit - Ermittlung von Parametern zur Biologie der Erreger unter westeuropäischen Klimabedingungen als Grundlage für die Weiterentwicklung eines Prognosemodells

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    Ziel des dreijährigen Projekts war es, Schlüsselparameter der bisher unter europäischen Bedingungen nur wenig erforschten Regenfleckenkrankheit (RFK) zu erarbeiten. In den Regionen Altes Land und Bodensee dominierte in allen drei Versuchsjahren (2007 – 2009) ein und derselbe RFK-Erreger, Peltaster sp.. Weitere RFK-Erreger sowie der Erreger der Fliegenschmutzkrankheit (FSK), Schizothyrium pomi, kamen nur sporadisch vor und sind wahrscheinlich für die Bekämpfung der Symptome derzeit ohne Bedeutung. In beiden Regionen ist die RFK fast ausschließlich auf ökologisch bewirtschaftete Anlagen beschränkt. Eine Besiedlung von Obstanlagen durch RFK-Erreger findet zunächst von außen statt, kann dann aber in den darauf folgenden Jahren durch endogenes Inokulum getragen werden. Fruchtmumien spielen eine Rolle als endogene Infektionsquellen. Umfangreiche Versuche zur Präzisierung der Infektionsbedingungen haben ergeben, dass eine Besiedlung der jungen Früchte bereits zum sehr frühen Zeitpunkt (T-Stadium, BBCH 74) und danach während des gesamten weiteren Saisonverlaufs erfolgen kann. Die Stärke der Symptomausprägung zur Ernte ist in erster Linie davon abhängig, wie lange die Früchte den natürlichen Infektionsbedingungen ausgesetzt waren. Je später in der Saison Infektionen stattfinden, desto weniger Zeit haben die RFK-Pilze für die Besiedlung und Ausbreitung auf der Frucht, so dass späte Infektionen i.d.R. nicht mehr zu starken Befallsgraden führen. Zur Ausprägung von RFK-Symptomen ist Blattfeuchte, auch in Form von Taubildung, ausreichend, jedoch wird die Symptomausbildung mit zunehmenden Niederschlagsmengen deutlich beschleunigt. Sind erste RFK-Symptome in einer Anlage sichtbar, verkürzt sich die zur Inkubation notwendige kumulative Blattnässedauer von etwa 250 auf unter 150 Stunden. Die RFK-Erreger scheinen eine mehrwöchige Trockenphase unbeschadet überdauern zu können. Apfelsorten zeigen deutliche Unterschiede in der Ausprägung der RFK-Symptome. Die Ursachen hierfür müssen in weiteren Untersuchungen geklärt werden

    Foetal echocardiographic assessment of borderline small left ventricles can predict the need for postnatal intervention

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    Abstract Background We sought to prospectively determine foetal echocardiographic factors associated with neonatal interventions in borderline hypoplastic left ventricles. Methods Foetuses were included who had a left ventricle that was 2-4 standard deviations below normal for length or diameter and had forward flow across the mitral and aortic valves. Factors associated with an intervention in the first month of life or no need for intervention were sought using univariate and multivariate logistic regression models. Results From 2005 to 2008, 47 foetuses meeting the criteria had an additional diagnosis (+foetal coarctation/+transverse arch hypoplasia): atrioventricular septal defect 7 (+2/+0), double outlet right ventricle 2 (+0/+0), Shone's complex 19 (+9/+4), and ventricular disproportion 19 (+13/+11; 4 both). There were seven pregnancies terminated, three foetal demises, and five had compassionate care. There were 32 livebirths that either had a biventricular repair (n = 20, n = 2 dead), univentricular palliation (n = 2, both alive), or no intervention (n = 9). Overall survival of livebirths to 6 months of age was 79%. Factors associated with early intervention on first foetal echocardiogram were: obstructed or retrograde arch flow (p = 0.08, odds ratio 3.3), coarctation (p = 0.05, odds ratio 11.4), and left ventricle outflow obstruction (p = 0.05, odds ratio 12.5). Neonatal factors included: Shone's diagnosis (p = 0.02, odds ratio 4.9), bicuspid aortic valve (p = 0.005, odds ratio 11.7), and larger tricuspid valve z-score (p = 0.05, odds ratio 3.6). A neonatal factor associated with no intervention was a larger mitral valve z-score (mean −3.8 versus −4.2 intervention group, p = 0.04, odds ratio 2.8). Discussion The need for early intervention in foetuses with borderline hypoplastic left ventricle can be predicted by foetal echocardiograph

    NMR and conductivity studies of the mixed glass former effect in lithium borophosphate glasses

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    Alkali ion charge transport has been studied in a series of mixed glass former lithium borophosphate glasses of composition 0.33Li2O + 0.67[xB2O3 + (1 – x)P2O5]. The entire concentration range, 0.0 ≤ x ≤ 1.0, from pure glassy Li2P4O11 to pure glassy Li2B4O7 has been examined while keeping the molar fraction of Li2O constant. Electrical conductivity measurements and nuclear magnetic resonance techniques such as spin relaxometry, line shape analysis, and stimulated-echo spectroscopy were used to examine the temperature and frequency dependence of the Li+ ion motion over wide ranges of time scale and temperature. By accurately determining motional time scales and activation energies over the entire composition range the ion dynamics and the charge transport are found to be fastest if the borate and the phosphate fractions are similar. The nonlinear variation of the charge conduction, the most notable feature of the mixed glass former effect, is discussed in terms of the composition dependence of network former units which determine the local glass structure

    Phase chaos in the anisotropic complex Ginzburg-Landau Equation

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    Of the various interesting solutions found in the two-dimensional complex Ginzburg-Landau equation for anisotropic systems, the phase-chaotic states show particularly novel features. They exist in a broader parameter range than in the isotropic case, and often even broader than in one dimension. They typically represent the global attractor of the system. There exist two variants of phase chaos: a quasi-one dimensional and a two-dimensional solution. The transition to defect chaos is of intermittent type.Comment: 4 pages RevTeX, 5 figures, little changes in figures and references, typos removed, accepted as Rapid Commun. in Phys. Rev.
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