Time filter

Source Type

Baux A.,Forschungsanstalt Agroscope Changins Wadenswil ACW
Agrarforschung Schweiz

In the last 20 years, the yield of mid-early forage maize increased by 2 dt dry matter/ha/ year. Varieties with major agronomical problems such as lodging were eliminated. The improvement of quality, and more specifically the content of digestible organic matter (DOM), is more difficult to evaluate, as it is highly influenced by environmental condition. Both yield and quality vary among locations and years. Dry matter content at harvest only influences the DOM up to 30%, when seed filling is not complete and therefore grain content too low. This is one more reason not to harvest variety trial too soon, so that the late varieties can reach the minimum DM content (30%). Data from several locations were compared. For example, differences appeared between Changins (Nyon, VD) and Reckenholz (Zurich, ZH): in Changins, summers are warmer and dryer. Satisfying dry matter content for harvest was usually reached 2 to 4 weeks earlier than in Reckenholz. Yields were lower but with similar content of DOM. DOM was less correlated to grain content in Reckenholz (R2=0.01, ns) than in Changins (R2=0.21***), where plants are smaller and ear development seems to be able to compensate the lower digestibility of the rest of the plant. New varieties showed significant improvement compared to older ones, especially for yield and quality parameters such as DOM. Variety trials over 20 years allowed these improvement to be available for the farmers. Source

Gebhard C.-A.,Hochschule fur Agrar | Buchi L.,Forschungsanstalt Agroscope Changins Wadenswil ACW | Liebisch F.,ETH Zurich | Sinaj S.,Forschungsanstalt Agroscope Changins Wadenswil ACW | And 2 more authors.
Agrarforschung Schweiz

This study evaluated 27 legumes as cover crops, sowed in pure or mixed stands, with the aim to outline their agrosystemic services. The results show important behavior variations among the different legumes. The amount of aerial biomass built from August until the first frost achieve between 0.4 and 5.9 t DM/ha. From 377 to 850 degrees-days are necessary to reach 50 % of soil cover. The nitrogen accumulated by the legumes is mainly due to symbiotic nitrogen fixation and vary from a few kg to 150 kg N/ha. The ability of legumes to compete with weeds is closely correlated with the amount of biomass produced (R2 = 0.93). It is analogous to the aptitude of association tested on legumes in mixtures with oat and phacelia. Five species (grass pea, faba bean, hairy vetch, common vetch and pea) are found to be very dominant and reach more than 80 % of biomass in mixture with phacelia and about 70 % with oat. These species are also those producing the highest biomass, covering soil most rapidly, and fixing high quantity of nitrogen. Many other legumes (fenugreek, lentil, white lupin, soybean, berseem clover, persian clover, crimson clover, hungarian vetch) show less competitive performance and offer a good complement for species associations. Source

Speiser B.,Research Institute of Organic Agriculture FiBL | Stolze M.,Research Institute of Organic Agriculture FiBL | Oehen B.,Research Institute of Organic Agriculture FiBL | Gessler C.,ETH Zurich | And 9 more authors.
Agronomy for Sustainable Development

The aim of this study was to provide an ex ante assessment of the sustainability of genetically modified (GM) crops under the agricultural conditions prevailing in Switzerland. The study addressed the gaps in our knowledge relating to (1) the agronomic risks/benefits in production systems under Swiss conditions (at field and rotation/orchard level), (2) the economic and socio-economic impacts associated with altered farming systems, and (3) the agro-ecological risks/benefits of GM crops (at field and rotation/orchard level). The study was based on an inventory of GM crops and traits which may be available in the next decade, and on realistic scenarios of novel agricultural practices associated with the use of GM crops in conventional, integrated, and organic farming systems in Switzerland. The technology impact assessment was conducted using an adapted version of the matrix for "comparative assessment of risks and benefits for novel agricultural systems" developed for the UK. Parameter settings were based on information from literature sources and expert workshops. In a tiered approach, sustainability criteria were defined, an inventory of potentially available, suitable GM crops was drawn up, and scenarios of baseline and novel farming systems with GM crops were developed and subsequently submitted to economic, socio-economic, and agro-ecological assessments. The project had several system boundaries, which influenced the outcomes. It was limited to the main agricultural crops used for food and feed production and focused on traits that are relevant at the field level and are likely to be commercially available within a decade from the start of the project. The study assumed that there would be no statutory restrictions on growing GM crops in all farming systems and that they would be eligible for direct payments in the same way as non-GM crops. Costs for co-existence measures were explicitly excluded and it was assumed that GM foods could be marketed in the same way as non-GM foods at equal farm gate prices. The following model GM crops were selected for this study: (1) GM maize varieties with herbicide tolerance (HT), and with resistance to the European corn borer (Ostrinia nubilalis) and the corn rootworm (Diabrotica virgifera); (2) HT wheat; (3) GM potato varieties with resistance to late blight (Phytophthora infestans), to the nematode Globodera spp., and to the Colorado beetle (Leptinotarsa decemlineata); (4) HT sugar beet with resistance to "rhizomania" (beet necrotic yellow vein virus; BNYVV); (5) apples with traditionally bred or GM resistance to scab (Venturia inaequalis), and GM apples with stacked resistance to scab and fire blight (Erwinia amylovora). Scenarios for arable rotations and apple orchards were developed on the basis of the model crops selected. The impact assessments were conducted for the entire model rotations/orchards in order to explore cumulative effects as well as effects that depend on the farming systems (organic, integrated, and conventional). In arable cropping systems, herbicide tolerance had the most significant impact on agronomic practices in integrated and conventional farming systems. HT crops enable altered soil and weed management strategies. While no-till soil management benefited soil conservation, the highly efficient weed control reduced biodiversity. These effects accumulated over time due to the high proportion of HT crops in the integrated and conventional model rotations. In organic production systems, the effects were less pronounced, mainly due to non-use of herbicides. Traits affecting resistance to pests and diseases had a minor impact on the overall performance of the systems, mainly due to the availability of alternative crop protection tools or traditionally bred varieties. The use of GM crops had only a minor effect on the overall profitability of the arable crop rotations. In apple production systems, scab and fire blight resistance had a positive impact on natural resources as well as on local ecology due to the reduced need for spray passages and pesticide use. In integrated apple production, disease resistance increased profitability slightly, whereas in the organic scenario, both scab and fire blight resistance increased the profitability of the systems substantially. In conclusion, the ecological and socio-economic impacts identified in this study were highly context sensitive and were associated mainly with altered production systems rather than with the GM crops per se. © 2012 INRA and Springer-Verlag, France. Source

Schurch S.,Forschungsanstalt Agroscope Changins Wadenswil ACW | Cordette T.,University of Picardie Jules Verne
Agrarforschung Schweiz

Baseline sensitivity of septoria leaf blotch to SDHI fungicides Since recently, a new class of fungicides is available to control Septoria leaf blotch of wheat, the so-called carboxamides or SDHI. The risk of resistance development in Mycosphaerella graminicola to SDHI fungicides is estimated to be medium to high. Therefore the implementation of an anti-resistance strategy is necessary to preserve the efficacy of these fungicides. Sensitivity studies may be necessary in case field efficacy weakens. Thus, a method was established to conduct large-scale sensitivity tests in our laboratory. The sensitivity to three SDHI active substances (boscalid, bixafen and isopyrazam) of 117 Swiss M. graminicola strains was measured in vitro. These data describe the baseline sensitivity (initial sensitivity level prior to the introduction of the fungicides) and may be used in case of control failures to detect potential shifts in sensitivity. At the moment, to prevent resistance emergence and build up, SDHI fungicides are applied on cereals only once per crop and are used only in mixtures with partners having a different mode of action. Source

Vermathen M.,University of Bern | Marzorati M.,University of Bern | Baumgartner D.,Forschungsanstalt Agroscope Changins Wadenswil ACW | Good C.,Forschungsanstalt Agroscope Changins Wadenswil ACW | Vermathen P.,University of Bern
Journal of Agricultural and Food Chemistry

1H HR-MAS NMR spectroscopy was applied to apple tissue samples deriving from 3 different cultivars. The NMR data were statistically evaluated by analysis of variance (ANOVA), principal component analysis (PCA), and partial least-squares-discriminant analysis (PLS-DA). The intra-apple variability of the compounds was found to be significantly lower than the inter-apple variability within one cultivar. A clear separation of the three different apple cultivars could be obtained by multivariate analysis. Direct comparison of the NMR spectra obtained from apple tissue (with HR-MAS) and juice (with liquid-state HR NMR) showed distinct differences in some metabolites, which are probably due to changes induced by juice preparation. This preliminary study demonstrates the feasibility of 1H HR-MAS NMR in combination with multivariate analysis as a tool for future chemometric studies applied to intact fruit tissues, e.g. for investigating compositional changes due to physiological disorders, specific growth or storage conditions. © 2011 American Chemical Society. Source

Discover hidden collaborations