Suchergebnisse

Der Beitrag untersucht den Stellenwert gesellschaftlich relevanter Thematiken in deutschsprachigen Songtexten der zurückliegenden fünf Jahrzehnte. Dabei zeigt sich, dass neben individuellen Befindlichkeiten auch politische, sozialkritische oder umweltbezogene Themen signifikant angesprochen werden. Wir kontrastieren Songtexte mit anderen Testsorten und wenden dabei quantitative Methoden auf umfangreiche, breit stratifizierte Datensamples an, um die Phänomenbeschreibungen präzisierbar, generalisierbar und reproduzierbar zu machen. Das longitudinale Korpusdesign bietet Potenzial für diachrone Vergleiche. Im Sinne eines erweiterten "Mixed Methods"-Ansatzes exploriert die Studie zudem ausgewählte Aspekte qualitativ und bettet sie in den zeitlichen Kontext ein.

The beet cyst nematode Heterodera schachtii (BCN) is an important parasite compromising yield of sugar beet. Standard sugar beet varieties are susceptible to BCN and strongly support BCN reproduction. Another type of variety is resistant to BCN. Although resistance leads to reduced nematode infestation levels, the yield potential of available resistant varieties is low. Tolerant varieties form a third type; high yield is produced with and without BCN infestation. However, so far it has remained unknown whether tolerant sugar beet varieties support or reduce BCN infestation and reproduction under field conditions. In order to address this question, the impact of five tolerant beet varieties on BCN population levels was investigated at 15 locations during a period of three years and compared to a resistant and a susceptible variety. The results demonstrate that all tolerant varieties led to population levels that ranged between that of the susceptible and that of the resistant variety. According to the respective BCN reproduction, the different varieties were classified as moderately susceptible (MS) or highly susceptible (HS) or as moderately resistant (MR) or highly resistant (HR). Tolerant varieties differed in their host status but tended to respond moderately resistant. In conclusion, it is suggested to include the analysis of resistance level either in the official registration procedure for BCN-tolerant sugar beet varieties or to perform this analysis for all registered varieties as a kind of risk assessment.

Die Zuckerrübenerträge auf den landwirtschaftlichen Flächen der kreisfreien Städte Mainz, Worms und Frankenthal aus den Jahren 1951–2003 wurden mit ausgewählten Witterungsparametern korreliert. Für das Untersuchungsgebiet konnte ein signifikanter Zusammenhang zwischen Zuckerrübenertrag und Witterung nachgewiesen werden. Um den Einfluss des Faktors Züchtung, welcher maßgeblich für den Produktionsfortschritt verantwortlich ist und somit den Zusammenhang zwischen Ertrag und Witterung bzw. Klima verfälschen würde, auszublenden, wurden die Erträge von diesem bereinigt. Die züchtungsfortschrittsbereinigten Erträge korrelieren durchweg deutlich höher mit den Witterungsparametern als die real erzielten Erträge. Vor allem die Witterungsparameter der Monate Juni bis August, während der Hauptwachstumsphase der Zuckerrübe, klären einen großen Teil der Ertragsvarianz auf. Hohe Niederschlagssummen haben einen positiven, hohe Temperatursummen hingegen einen negativen Einfluss auf den erzielten Ertrag.

Für die Zukunft projizieren zugrunde gelegten Klima-

szenarien eine Fortsetzung der Trends der Vergangenheit, sodass der Klimawandel möglicherweise auch in Zukunft eher einen negativen Einfluss auf die Erträge haben dürfte. Der züchterische und produktionstechnische Fortschritt überkompensiert diese negativen Auswirkungen aktuell jedoch noch und lässt somit den möglichen Einfluss des Klimawandels als gering erscheinen, was aber real nicht zutrifft.

"Syndrome des basses richesses" (SBR) is a sugar beet disease, which primarily leads to the reduction of sugar content and yield and thus to large economic losses. Two non culturable and vector transmitted pathogens, a proteobacterium ("Candidatus Arsenophonus phytopathogenicus") as well as a phytoplasma ("Candidatus Phytoplasma solani") can cause SBR. SBR symptoms include chlorosis and necrosis of older leaves, necrosis of the vascular tissues of the beet and asymmetries of younger leaves. In 2018, it was shown that in addition to France Pentastiridius leporinus (L., 1761) it is the most important vector in Baden-Württemberg. This species has adapted from its natural host (reed) to the agricultural crop rotation of sugar beet and winter wheat. In 2018, P.leporinus was the most commonly caught Auchenorrhyncha species in sugar beet and 44% were loaded with the proteobacterium. The longest flight pattern of P. leporinus in sugar beet (from May 25th to September 5th) was detected. The first proof of a second generation led to the long flight pattern of this species. This article presents the development of the area of infestation and the proof of the two pathogens until 2018. In addition, previous findings as well as own results for the dissemination and control of SBR at Baden-Württemberg in 2018 are presented. Differences in susceptibility of sugar beet varieties were shown for the first time. One specific genotype showed no reduction in sugar content despite SBR infection. Variety selection could thus be a promising approach to control SBR in sugar beet.

From 2017 to 2020 an extensive monitoring for bacterial and viral yellowing diseases was carried out in southern and central Germany. The monitoring recorded for the first time the infestation of sugar beets with yellowing viruses and the disease "Syndrome Basses Richesses" (SBR). To map the yellowing virus infestation, samples were examined for the presence of several virus species (BYV, BtMV, poleroviruses). The disease SBR was investigated in this study using the more common γ-3 proteobacterium "Candidatus Arsenophonus phytopathogenicus". In this study samples were chosen, which showed yellowing symptoms. The coordination of the sampling was carried out by the Association of Hessian-Palatinate Sugar Beet Growers. Results clearly show the extent of the heavily infested area from SBR to southern Hesse, Rhine-Hesse and Franconia. The spread of SBR can be explained by the migration of the leafhopper Pentastiridius leporinus. Furthermore, the regional and parallel spread of mixed infections of both yellowing diseases was shown for the first time, which probably contributed to the strong sugar yield losses observed in practice. Causes and effects of mixed infections of both yellowing diseases require further research. Over the four-year study period, a continuous increase in SBR infections was observed. Therefore, the need for development of appropriate management systems to control SBR is very high.