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

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

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

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

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

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

Reaction dynamics in Pb+Pb at the CERN/SPS: from partonic degrees of freedom to freeze-out

We analyze the reaction dynamics of central Pb+Pb collisions at 160 GeV/nucleon. First we estimate the energy density pile-up at mid-rapidity and calculate its excitation function: The energy density is decomposed into hadronic and partonic contributions. A detailed analysis of the collision dynamics in the framework of a microscopic transport model shows the importance of partonic degrees of freedom and rescattering of leading (di)quarks in the early phase of the reaction for E > 30 GeV/nucleon. The energy density reaches up to 4 GeV/fm^3, 95% of which are contained in partonic degrees of freedom. It is shown that cells of hadronic matter, after the early reaction phase, can be viewed as nearly chemically equilibrated. This matter never exceeds energy densities of 0.4 GeV/fm^3, i.e. a density above which the notion of separated hadrons loses its meaning. The final reaction stage is analyzed in terms of hadron ratios, freeze-out distributions and a source analysis for final state pions.Comment: 10 pages, 7 figures, Proceedings of the Erice School on Nuclear Physics in Erice, Sicily, Italy, September 17 -25 1998; to be published in Progress in Particle and Nuclear Physics Vol. 4

Phase chaos in the anisotropic complex Ginzburg-Landau Equation

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.

Topological Lensing in Spherical Spaces

This article gives the construction and complete classification of all three-dimensional spherical manifolds, and orders them by decreasing volume, in the context of multiconnected universe models with positive spatial curvature. It discusses which spherical topologies are likely to be detectable by crystallographic methods using three-dimensional catalogs of cosmic objects. The expected form of the pair separation histogram is predicted (including the location and height of the spikes) and is compared to computer simulations, showing that this method is stable with respect to observational uncertainties and is well suited for detecting spherical topologies.Comment: 32 pages, 26 figure

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu