Zur Reaktion des Roggens in langjähriger Monokultur bei differenzierter Mineral- und Stallmistdüngung

Veränderungen in der Futterqualität von Phalaris arundinacea wurden in Abhängigkeit vom Schnittzeitpunkt im 1. Aufwuchs und variierter Nachwuchsdauer im 2. Aufwuchs untersucht. Daraus ließen sich die optimalen Nutzungszeitspannen von Phalaris arundinacea bestimmen. Überflutungen beeinflussen ebenfalls die Länge der optimalen Nutzungszeitspannen und die Futterqualität. Bei Phalaris arundinacea stieg der Rohfaser‐ und Ligningehalt sowie der K/N—Quotient mit zuneymendem physiologischen Alter an, wogegen der Rohprotein‐ und Kaliumgehalt sank.     

Effects on boar semen quality after infection with porcine reproductive and respiratory syndrome virus: a case report

The effect of porcine reproductive and respiratory syndrome virus (PRRSV) on semen quality was examined in a group of 11 spontaneously infected boars in a commercial boar stud. Semen samples were collected 4 weeks prior to 4 weeks post-infection (wpi). Infection with PRRSV of the European genotype subtype 1 (EU-1) was verified by specific quantitative real-time polymerase chain reaction (RT-PCR) in 36% of the serum samples. All boars seroconverted before 4 wpi and remained in normal condition throughout the study. Comparison of the percentage of morphologically intact spermatozoa revealed an increase of acrosome-defective spermatozoa (P = 0.012) between −4 and 4 wpi. Significant deleterious effects on semen quality were detected for membrane integrity when semen had been stored for 2 days after sampling. Analysis of sperm subpopulations in a thermoresistance test on day 7 after sampling revealed alterations in the percentage of circular, progressively motile spermatozoa (P = 0.013), in the percentage of non-linear, progressively motile spermatozoa (P = 0.01), and on the amplitude of lateral sperm head displacement (P = 0.047). There was no difference in the incidence of mitochondrially active spermatozoa (P = 0.075). Investigation of routine production data between pre- and post-infection status showed no differences on ejaculate volume (P = 0.417), sperm concentration (P = 0.788), and percentage of motile spermatozoa (P = 0.321). This case report provides insights into a potential control strategy for PRRSV outbreaks in boar studs.     

Isolation of Vibrio vulnificus and atypical Vibrio from surface water of the Baltic Sea in Germany

From 1995 to 1997 several defined species like V. alginolyticus, V. anguillarum, V. cholerae (non O1 and non O139), V. mimicus, V. parahaemolyticus and V. vulnificus were isolated during a survey to determine the presence of V. vulnificus in the brackish water of the Baltic Sea in Germany. Moreover atypical Vibrio isolates were detected. Four isolates belonging to a group of atypical Vibrio and possibly representing a new species in the genus Vibrio were characterized in detail. All four strains were isolated from surface costal waters. Based on 16S rDNA sequence analysis they showed the highest relatedness to the species V. navarrensis and V. vulnificus. The strains did not harbor the species specific hemolysin gene vvhA from V. vulnificus as shown by PCR and hybridization experiments. Moreover, they differed in at least two biochemical parameters tested from the hitherto described Vibrio species. All these strains induced hemolysis on washed blood agar dishes and showed phase variations on Luria Bertani agar dishes. Because of the similarity to the eel pathogen V. vulnificus, we infected eels with one of the four atypical strains (CH-291), but no pathogenicity for eels could be detected. Furthermore, Vero cell tests with supernatants of bacterial cultures did not reveal secreted Vero cell cytotoxic compounds. This indicates a nonpathogenic nature of these strains.     

Landscape Diagnosis on Different Space and Time Scales – A Challenge for Landscape Planning

Landscape diagnosis provides a bridge between scientific knowledge and socio-economic issues that is needed to meet the demands of sophisticated landscape planning and management. The diagnostic assessment of landscape functions (capacities, goods and services supported by the landscape) at different spatio-temporal scales is a valuable tool that can solve the transformation problem. A variety of landscape classification systems – including biophysical and landscape units – can be applied as a spatial reference system. Examples are described from the multitude of approaches to assess landscape functions that can be employed in landscape diagnosis. The theoretical and methodological aspects of the approach are illustrated using examples both from Germany and the Czech Republic. The examples focus on landscape functions such as groundwater recharge, regulation of water balance, and resistance to wind erosion. In addition, the rarity of and threats to landscape types, landscape aesthetic values, and the landscape character and landscape persistence are discussed.     

Control of late blight in organic potato production: evaluation of copper-free preparations under field,growth chamber and laboratory conditions

In order to replace copper fungicides in organic potato production, 53 copper-free preparations (CFPs) based on natural compounds, including plant extracts and microorganisms, and five copper preparations were evaluated for their potential to control Phytophthora infestans, the pathogen that causes late blight of potatoes. In in vitro assays, 30% of the CFPs inhibited indirect germination of sporangia, 26% mycelial growth and in growth chamber experiments, 21% efficiently reduced foliar blight of tomato plants. In micro-plot field trials with applications twice a week, the copper preparations were the most effective and reduced foliar blight by 99%. Of the CFPs tested, Oekofluid P, Mycosin and other sulphuric clays, and C-2000 reduced late blight the most, from 63% to 37%. In small-plot trials in 2001, 2002 and 2004, 27 CFPs with different formulations and four copper preparations were examined. In 2004, copper preparations at full and reduced rates and sulphuric clays were applied either weekly or according to the decision support system Bio-PhytoPRE. With Bio-PhytoPRE, copper preparations reduced foliar blight of potatoes by 23–77% and increased tuber yield by 2–28%, depending on the copper rate applied and year. With CFPs, maximal efficacy was 17% and no effect on tuber yield was observed. In vitro and in vivo trials showed that the rainfastness and the persistence of CFPs was low compared with copper preparations. This indicates that the failure of CFPs under field conditions is probably due to a lack of stability under prevailing environmental conditions and not to a lack of efficacy. Until stable formulations for CFPs are developed, an optimised and restricted use of copper fungicides using a decision support system could help to control late blight in organic potato production and to reduce copper input into the environment.     

Der Bambusbohrer,Dinoderus minutus Fabr., in Deutschland!

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