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Bohren C.,Institute For Pflanzenbauwissenschaften Ipb | Wirth J.,Institute For Pflanzenbauwissenschaften Ipb
Agrarforschung Schweiz | Year: 2015

According to a survey conducted in 26 countries, yellow nutsedge (Cyperus esculentus L.) belongs to the most dangerous weeds in Europe due to its high reproductive capability, its weediness (local abundance) and low success of control. Unintentional spread of tubers from field to field by machinery and crop waste is an important element of the invasion. Visible plants in a field weakly indicate the real rate of infestation. A single treatment with a sustainable control effect does not exist. In field trials, we tested the efficacy of different herbicides. Herbicides alone are not enough for a good nutsedge control in most of vegetable and field crops. Highly effective herbicides are selective in a few crops only. Incorporation of herbicides after application can support their effect. Repeated soil cultivation during the period of tuber formation (May to July) as well as competition by fast-growing dense (cover) crop stands (from July onwards) can reduce the number of tubers in the soil. Our results show clearly that successful measures for the reduction of tuber numbers can quickly be wiped out by subsequent ineffective control strategies. © 2015, A M T R A - Association pour la Mise en Valeur des Travaux de la Recherche Agronomique. All rights reserved.

Schoneberg A.,Institute For Pflanzenbauwissenschaften Ipb | Perren S.,Institute For Pflanzenbauwissenschaften Ipb | Naef A.,Institute For Pflanzenbauwissenschaften Ipb
Agrarforschung Schweiz | Year: 2015

Robust apple and pear varieties are an important tool in sustainable fireblight management. Two artificial inoculation methods are used for assessing a pome-fruit cultivar’s susceptibility to fireblight: shoot inoculation and blossom inoculation. Since 2013, Agroscope has for the first time been in a position to conduct artificial blossom inoculation tests on an outdoor trial plot that is unique in Switzerland. A correlation analysis was used to test both methods as to their comparability. A weakly positive correlation was detected, which was nevertheless not significant. Cultivars with low susceptibility in the shoot inoculation in the greenhouse also often proved to be robust in the blossom inoculation. With some cultivars, however, susceptibility in the shoot inoculation was markedly under-or overestimated compared to susceptibility in the blossom inoculation. For better transferability of the results to practice, the most promising candidate cultivars from the shoot inoculation should therefore also be tested outdoors by means of artificial blossom inoculation. The combination of the two test methods and the additional observations on the susceptibility of the cultivars from practice will allow us to make reliable recommendations of fireblight-tolerant varieties for Swiss pome-fruit production. © 2015 Agrarforschung Schweiz. All rights reserved.

Levy L.,Institute For Pflanzenbauwissenschaften Ipb | Ellemsi Y.,Institute For Pflanzenbauwissenschaften Ipb | Pellet D.,Institute For Pflanzenbauwissenschaften Ipb
Agrarforschung Schweiz | Year: 2015

Wheat viscosity is a qualitative characteristic of cereals. Certain studies indicate positive effects for human health linked to high viscosity, such as the lowering of cholesterol or a reduction in cancer risks. Where the feeding of livestock is concerned, however – especially monogastric animals – low levels of viscosity are desirable. In fact, among other things, a high viscosity reduces enzymatic activity in the animal’s gut, slows down the passage of the alimentary bolus, and reduces the rate of absorption of the feed. To counteract these disadvantages, the industry enriches forage mixtures with enzymes. The viscosity of 48 varieties of wheat was analysed, with 24 varieties being tested during the three years of the trial. Although this trait is highly dependent upon variety, it also varies according to the pedoclimatic conditions of the crop. Seventy per cent of the varieties studied have an average viscosity that is suitable for feed. Viscosity is linked to practically no other agronomic or qualitative characteristic (particularly kernel yield). Despite this, a sub-sample of 11 varieties shows a negative correlation between viscosity and protein content. The results of this study show that producers have access to varieties with highly contrasting viscosities. In-depth knowledge of the viscosities of the different varieties and their targeted usage might contribute to a reduction in the use of enzymes in the mixtures, especially where the breeders themselves produce the raw material for feeding their livestock. © 2015, AMTRA - Association pour la Mise en Valeur des Travaux de la Recherche Agronomique. All rights reserved.

Frei P.,Institute For Pflanzenbauwissenschaften Ipb | Gindro K.,Institute For Pflanzenbauwissenschaften Ipb
Agrarforschung Schweiz | Year: 2015

Leaf spot constitutes a threat to barley cultivation, leading to significant quantitative and qualitative yield losses. Although these symptoms can be due to physiological stress, they are primarily caused by infestation with the Ramularia collo-cygni fungus. In the absence of sporulation, these two types of leaf necrosis are practically impossible to tell apart. In order to control the pathogen Ramularia collo-cygni, Agroscope has launched a major study to learn more about its biology. The fungus was monitored by molecular analysis from the earliest stages of cultivation, allowing us to ascertain that it can be transmitted by seed. New forms of transmission of the disease have also been discovered whose roles in the epidemiology and survival of the fungus have yet to be determined. Fungicide trials have been conducted with different application strategies. These have shown that, in the absence of other leaf diseases in the crop, a single treatment from the BBCH 37 (flag-leaf) stage onwards is sufficient for the effective control of barley leaf spot. © 2015, A M T R A - Association pour la Mise en Valeur des Travaux de la Recherche Agronomique. All rights reserved.

Tschuy F.,Institute For Pflanzenbauwissenschaften Ipb | Wirth J.,Institute For Pflanzenbauwissenschaften Ipb
Agrarforschung Schweiz | Year: 2015

Herbicide resistance is a worldwide industrial agriculture problem that worsens from year to year. In certain northern European countries, black-grass is resistant to numerous different herbicides, and can scarcely be controlled in certain places. This phenomenon is also starting to emerge in Switzerland. Starting in 2011, and in order to monitor the appearance of new resistances and control their spread, Agroscope set up a monitoring programme at national level. This programme is important for the local development of prevention strategies in partnership with the cantonal plant-protection agencies. In Switzerland, the weed species currently affected by resistances are three monocotyledons (black-grass, loose silky bentgrass and Italian ryegrass) and a dicotyledon (lamb’s quarters). These have developed resistances to five different biochemical modes of action, defined at international level by the Herbicide Resistance Action Committee (HRAC). To prevent the appearance of new resistances and to best contain those that have already emerged, it is important to combine both cultural and phytosanitary control methods. © 2015 A M T R A - Association pour la Mise en Valeur des Travaux de la Recherche Agronomique. All rights reserved.

The cereals trade association has set up a harvest payment system based on the protein content of ‘TOP’ class wheats. Agroscope has implemented tests to study the impact of splitting the application of nitrogen fertiliser on wheat yield and quality. In Swiss soil and weather conditions, a 20-40-80 kg N/ha split – the third input being made at the CD-37 stage (flag-leaf sprouting) – yielded excellent results, both in terms of grain yield and protein content. Producers keen to produce grains with a high protein content may be tempted to choose the varieties highest in protein, and to manage them very intensively, with a significant third input at flowering; however, this strategy carries a very high risk of non-assimilation of the nitrogen by the plant, and of loss of grain yield. From an economic perspective, the most productive varieties are also the most profitable, even if they belong to lower quality categories. The study also highlighted the fact that in situations of low nitrogen availability, a high-straw variety developing a large number of spikes per m2 has the edge. By contrast, the size of the plant militates against grain formation in the more intensive systems. © 2016, AMTRA - Association pour la Mise en Valeur des Travaux de la Recherche Agronomique. All Rights Reserved.

According to Direct Payment regulations, Swiss farmers are obliged to take into account economic damage thresholds and the recommendations of forecasting and warning services before taking phytosanitary measures. In order to assess how well these requirements were being fulfilled in arable farming, farmers and agricultural contractors were anonymously surveyed in 2013-2014. Out of 477 returned questionnaires, 456 were evaluated. The results showed that control thresholds for weeds and grasses were only considered to a limited extent. Lack of time and a known weed infestation were given as reasons for this. Control thresholds were better respected in the treatment of disease. Most commonly, the control threshold was applied in treating leaf spot in sugar beets. Eighty-one per cent of farmers stated that they always or often used the control threshold for leaf spot. Least attention was paid to the control threshold in the treatment of Rhizoctonia in potatoes: 47% of respondents never or rarely used the threshold. The control thresholds were most often used when treating pests, especially pests with a high potential for causing damage, and for which the control threshold could be monitored easily and precisely, with little time expenditure. This was the case with pollen beetle: 92.6% of respondents stated that they always or often applied the threshold. The existing forecasting systems such as Phytopre and Fusaprog were unknown to many farmers and therefore not used. The warning services, on the other hand, were used by many farmers: 87% said that they always or often used the warning services in the trade press. The cantonal advisory services were also valued as a source of information. The study shows the areas in which there is still additional potential for reducing risks caused by the use of pesticides. © 2016, AMTRA - Association pour la Mise en Valeur des Travaux de la Recherche Agronomique. All Rights Reserved.

Certain types of bread products require a high protein content and well-defined rheological qualities. Although Swiss wheat varieties have a high protein content, said content fluctuates a great deal, and in some years is too low for breadmaking. From 2011 to 2013, a study was carried out on four varieties of wheat and seven nitrogen fertiliser application methods. The aim was on the one hand to analyse the influence of the nitrogen fertiliser (dose and splitting of application) on protein levels, and on the other to examine the relationship between the protein levels of the varieties and their rheological and baking qualities. The splitting of nitrogenous fertiliser applications into three rather than two doses not only significantly increases wet gluten content, but also substantially improves qualitative properties. A 20-40-80 kg N/ha split with a final dose when the flag-leaf appears is ideal for increasing wet gluten content without affecting either rheological quality or yield. This split can be recommended when cultivating ‘Top’ class varieties. The results also show that an increase in protein content does not necessarily improve gluten quality, since several parameters stagnate or decrease when nitrogen fertilisation is intensified. This observation can be explained by the stagnation in the proportion of glutenins, as well as by a decrease in gliadins in favour of albumins and globulins. No matter what nitrogenous fertilisation method is used, the variety ‘Runal’ always achieves the best protein levels. Despite its lower protein content, the variety ‘CH Claro’ obtains equivalent results to Runal in the rheological and baking tests. © 2016, AMTRA - Association pour la Mise en Valeur des Travaux de la Recherche Agronomique. All Rights Reserved.

Gibberella and fusarium ear rot of maize reduce grain yield qualitatively and quantitatively. Mycotoxins produced by the fungal pathogens that are responsible of these two diseases are a health threat for the animals fed with contaminated maize. One factor affecting disease severity and mycotoxin content, and therefore a potential management tool, is the susceptibility of the cultivated variety. This study aimed at establishing a methodology to evaluate this resistance level and then use is to test grain maize hybrids grown in Switzerland. A method using artificial inoculation of the ears at female flowering during at least three experimental years allowed to identify very susceptible, less susceptible and intermediate varieties. This ranking is a tool that maize growers may use while choosing a variety to manage the risk of Gibberella ear rot and of mycotoxin contamination. © 2016, AMTRA - Association pour la Mise en Valeur des Travaux de la Recherche Agronomique. All Rights Reserved.

Haner L.L.,Institute For Pflanzenbauwissenschaften Ipb | Courvoisier N.,Institute For Pflanzenbauwissenschaften Ipb | Herrera J.,Institute For Pflanzenbauwissenschaften Ipb
Agrarforschung Schweiz | Year: 2016

A ‘protein potential’ concept has been developed by analogy with the ‘grain yield’ concept, with the aim of better understanding the factors influencing wheat protein content and identifying the most stable varieties as well as the amount of protein that remains to be reached. The protein potential of 18 varieties of winter wheat covering all quality categories was established experimentally, and varied from 13.0% to 16.6%, according to the variety. Additional experimental data were used to evaluate the frequency at which the protein potential was achieved in the various conditions. Close to 5000 protein-content values stemming from practice (Fenaco GOF) also enabled a comparison of the performances of the varieties in both tests and practice. The analysis of these data demonstrated that the amount of nitrogen fertiliser applied as well as the splitting of applications influenced the rate of achievement of protein potential. Certain varieties are stable and others unstable, whether they are cultivated under test or practical conditions. The results from both sources are consistent, suggesting that the research data allow an accurate prediction of the performance of the varieties grown under practical conditions. © 2016 A M T R A - Association pour la Mise en Valeur des Travaux de la Recherche Agronomique. All rights reserved.

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