Anwendung der Bekämpfungsschwellen und Warndienste in der Schweiz

Gemäss Direktzahlungsverordnung sind die Schweizer Landwirte verpflichtet, bei direkten Pflanzenschutzmassnahmen Schadschwellen sowie Empfehlungen von Prognose- und Warndiensten zu berücksichtigen. Um abschätzen zu können, wie gut diese Vorgabe im Feldbau noch befolgt wird, wurde 2013-2014 eine anonyme Umfrage bei Landwirten und Lohnunternehmern durchgeführt. Insgesamt wurden 477 Fragebogen zurückgeschickt, 456 konnten für die Auswertung berücksichtigt werden. Die Resultate zeigen, dass die Bekämpfungsschwellen bei Unkräutern und Ungräsern nur noch sehr bedingt angewendet werden. Als Gründe wurden die fehlende Zeit und eine bekannte Verunkrautung angegeben. Insgesamt deutlich besser sieht die Situation bei den Krankheiten aus. Am häufigsten wird die Bekämpfungsschwelle bei den Blattflecken in Zuckerrüben angewendet. 81% der Landwirte gaben an, die Bekämpfungsschwelle immer oder häufig anzuwenden. Am wenigsten Beachtung findet die Bekämpfungsschwelle von Rhizoctonia bei Kartoffeln. 47% der Befragten wenden die Schwelle nie oder selten an. Bei den Schädlingen wird die Bekämpfungsschwelle am häufigsten angewendet, insbesondere bei Schädlingen, welche ein hohes Schadenspotenzial haben und die Bekämpfungsschwelle einfach und präzis mit wenig Zeitaufwand erhoben werden kann. Dies ist zum Bespiel beim Rapsglanzkäfer der Fall. 92,6% der Antwortenden gaben an, die Schwelle immer oder häufig anzuwenden. Die vorhandenen Prognosesysteme Phytopre und Fusaprog sind vielen Landwirten nicht bekannt und werden wenig genutzt. Warndienste werden dagegen von sehr vielen Landwirten genutzt. 87% gaben an, dass sie die Warndienste in der Fachpresse immer oder häufig nutzen. Auch die kantonalen Beratungsdienste werden als Informationsquelle geschätzt. Die Studie zeigt auf, in welchen Bereichen zusätzliches Potenzial zur Verminderung von Risiken beim Einsatz von Pflanzenschutzmitteln besteht

Leveraging research partnerships to achieve the 2030 agenda : experiences from North-South cooperation

Transnational research partnerships are considered fundamental for supporting research and creating shared knowledge for sustainable development. They enable the acquisition and global sharing of high-quality information and create shared knowledge and capacity. This paper aimed to identify the enabling factors of such partnerships. In a survey carried out by the authors of this article, partnerships were perceived most beneficial when they provided access to new key features such as funding, technology and training. Compliance with research partnership principles, combined with funds and shared interests, was seen to further enhance the longevity of partnerships. Upon consulting the recent peer-reviewed literature, it became clear that research was lacking with regard to optimising the framework and performance of research partnerships, despite galloping technological progress in other areas of sustainable development. We believe that technological opportunities could be better harnessed to enable the concept of partnership to evolve and move towards transformative research for the advancement of sustainable development

Implications of Extreme Life Span in Clonal Organisms: Millenary Clones in Meadows of the Threatened Seagrass Posidonia oceanica

The maximum size and age that clonal organisms can reach remains poorly known, although we do know that the largest natural clones can extend over hundreds or thousands of metres and potentially live for centuries. We made a review of findings to date, which reveal that the maximum clone age and size estimates reported in the literature are typically limited by the scale of sampling, and may grossly underestimate the maximum age and size of clonal organisms. A case study presented here shows the occurrence of clones of slow-growing marine angiosperm Posidonia oceanica at spatial scales ranging from metres to hundreds of kilometres, using microsatellites on 1544 sampling units from a total of 40 locations across the Mediterranean Sea. This analysis revealed the presence, with a prevalence of 3.5 to 8.9%, of very large clones spreading over one to several (up to 15) kilometres at the different locations. Using estimates from field studies and models of the clonal growth of P. oceanica, we estimated these large clones to be hundreds to thousands of years old, suggesting the evolution of general purpose genotypes with large phenotypic plasticity in this species. These results, obtained combining genetics, demography and model-based calculations, question present knowledge and understanding of the spreading capacity and life span of plant clones. These findings call for further research on these life history traits associated with clonality, considering their possible ecological and evolutionary implications

Effects of Increased Nitrogen Deposition and Precipitation on Seed and Seedling Production of Potentilla tanacetifolia in a Temperate Steppe Ecosystem

The responses of plant seeds and seedlings to changing atmospheric nitrogen (N) deposition and precipitation regimes determine plant population dynamics and community composition under global change.In a temperate steppe in northern China, seeds of P. tanacetifolia were collected from a field-based experiment with N addition and increased precipitation to measure changes in their traits (production, mass, germination). Seedlings germinated from those seeds were grown in a greenhouse to examine the effects of improved N and water availability in maternal and offspring environments on seedling growth. Maternal N-addition stimulated seed production, but it suppressed seed mass, germination rate and seedling biomass of P. tanacetifolia. Maternal N-addition also enhanced responses of seedlings to N and water addition in the offspring environment. Maternal increased-precipitation stimulated seed production, but it had no effect on seed mass and germination rate. Maternal increased-precipitation enhanced seedling growth when grown under similar conditions, whereas seedling responses to offspring N- and water-addition were suppressed by maternal increased-precipitation. Both offspring N-addition and increased-precipitation stimulated growth of seedlings germinated from seeds collected from the maternal control environment without either N or water addition. Our observations indicate that both maternal and offspring environments can influence seedling growth of P. tanacetifolia with consequent impacts on the future population dynamics of this species in the study area.The findings highlight the importance of the maternal effects on seed and seedling production as well as responses of offspring to changing environmental drivers in mechanistic understanding and projecting of plant population dynamics under global change

Early Developmental Responses to Seedling Environment Modulate Later Plasticity to Light Spectral Quality

Correlations between developmentally plastic traits may constrain the joint evolution of traits. In plants, both seedling de-etiolation and shade avoidance elongation responses to crowding and foliage shade are mediated by partially overlapping developmental pathways, suggesting the possibility of pleiotropic constraints. To test for such constraints, we exposed inbred lines of Impatiens capensis to factorial combinations of leaf litter (which affects de-etiolation) and simulated foliage shade (which affects phytochrome-mediated shade avoidance). Increased elongation of hypocotyls caused by leaf litter phenotypically enhanced subsequent elongation of the first internode in response to low red∶far red (R∶FR). Trait expression was correlated across litter and shade conditions, suggesting that phenotypic effects of early plasticity on later plasticity may affect variation in elongation traits available to selection in different light environments

Contrasting effects of grazing and hay cutting on the spatial and genetic population structure of Veratrum album, an unpalatable, long-lived, clonal plant species

1 Vegetation change induced by large herbivores is driven by the effects of grazers on populations of individual plant species. Short-term experimental or demographic studies may be insufficient when investigating the population responses of long-lived clonal plant species. 2 We therefore examined the effects of grazing on such a plant (Veratrum album) by comparing the spatial and genetic structure of populations in grasslands subject to long-term grazing or mowing for hay. 3 V. album is a locally dominant species that is avoided by large herbivores due to its toxicity. RAPD-phenotypes of a subsample of c. 50 shoots, and co-ordinates and dry weight of all shoots, were determined in a 5 10 m plot in each of four meadow and four pasture populations. 4 The breeding system of the genus Veratrum was previously unknown but our experimental finding that cross-pollinated but not self-pollinated or unpollinated flowers produced as many seeds as freely pollinated flowers suggested that V. album is a predominantly cross-pollinating species. 5 Both the spatial and genetic population structure differed markedly between the two grassland types. Clonal expansion of established plants in pastures led to populations consisting of larger shoots that were significantly more aggregated at a small spatial scale. Populations also had a higher proportion of flowering shoots, less seedling recruitment and a lower genotypic diversity in pastures than hay meadows. 6 The differences in population structure appear to be due to hay meadow populations reproducing primarily by seeds, whereas clonal reproduction accounts for half of the population growth in pastures. We suggest that, as livestock selectively avoids V. album shoots, grazing indirectly promotes plant growth, which results in an enhanced vegetative reproduction as well as a higher seed production. Experimental studies are, however, needed to determine why and how grazing adversely affects seedling recruitment. 7 Detailed information on population level responses of unpalatable dominant plant species, such as provided by the present study, may help us understand and predict vegetation change in response to changing levels of herbivory

Predicting adaptive evolution under elevated atmospheric CO2 in the perennial grass Bromus erectus

Increasing concentrations of CO2 in the atmosphere are likely to affect the ecological dynamics of plant populations and communities worldwide, yet little is known about potential evolutionary consequences of high CO2. We employed a quantitative genetic framework to examine how the expression of genetic variation and covariation in fitness-related traits, and thus, the evolutionary potential of a species, is influenced by CO2. In two field experiments, genotypes of the dominant grassland perennial Bromus erectus were grown for several years in plots maintained at present-day or at elevated CO2 levels. Under noncompetitive conditions (experiment 1), elevated CO2 had little impact on plant survival, growth, and reproduction. Under competitive conditions in plots with diverse plant communities (experiment 2), performance of B. erectus was reduced by elevated CO2. This suggests that the effect of CO2 was largely indirect, intensifying competitive interactions. Elevated CO2 had significant effects on the expression of genetic variation in both the competitive and noncompetitive environment, but the effects were in opposite direction. Heritability of plant size was generally higher at elevated than at ambient CO2 in the noncompetitive environment, but lower in the competitive environment. Selection analysis revealed a positive genotypic selection differential for plant size at ambient CO2, indicating selection favoring genotypes with high growth rate. At elevated CO2, the corresponding selection differential was nonsignificant and slightly negative. This suggests that elevated CO2 is unlikely to stimulate the evolution of high biomass productivity in this species