1,720,971 research outputs found
Methodological studies on the precision of variety trials with sugar beet – effect of sample size and head rows
No full textYield Potential of Sugar Beet – Have We Hit the Ceiling?
No full textThe yield of sugar beet has continuously increased in the past decades. The question arises, whether this progress will continue in the future. A key factor for increasing yield potential of the crop is breeding progress. It was related to a shift in assimilate partitioning in the plant toward more storage carbohydrates (sucrose), whereas structural carbohydrates (leaves, cell wall compounds) unintendedly declined. The yield potential of sugar beet was estimated at 24 t sugar ha-1. For maximum yield, sufficient growth factors have to be available and the crop has to be able to fully utilize them. In sugar beet, limitations result from the lacking coincidence of maximum irradiation rates and full canopy cover, sink strength for carbon assimilation and high water demand, which cannot be met by rainfall alone. After harvest, sugar losses during storage occur. The paper discusses options for a further increase in yield potential, like autumn sowing of sugar beet, increasing sink strength and related constraints. It is prospected that yield increase by further widening the ratio of storage and structural carbohydrates will come to its natural limit as a certain cell wall stability is necessary. New challenges caused by climate change and by prolonged processing campaigns will occur. Thus breeding for improved pathogen resistance and storage properties will be even more important for successful sugar beet production than a further increase in yield potential itself
New Generation of Resistant Sugar Beet Varieties for Advanced Integrated Management of Cercospora Leaf Spot in Central Europe
No full textCercospora leaf spot (CLS) epidemics in sugar beet have been increasing in recent years causing higher use of fungicides. Concomitantly, the availability of effective fungicides is at risk because of resistance development in the fungus, the lack of new active ingredients as well as restrictive approval practices. A key option for an integrated management of CLS is cultivation of resistant varieties. Because of the yield penalty in resistant varieties, acceptance in commercial practice so far has been low. The aim of our study was to characterize recent sugar beet varieties registered in Germany in terms of resistance and tolerance to CLS and their value for integrated pest management. The genetic basis of CLS resistance in varieties is protected by intellectual property rights even after variety registration and not open to the public due to economic competition. To gain reliable data for cultivation, varieties have to be tested for their resistance traits under field conditions at varying levels of infection with Cercospora beticola. In collaboration with variety related stakeholders, 15 sugar beet varieties were tested in 49 field trials in Germany from 2014 to 2016 for their yield response to CLS. The trials were set up in a split-plot design with and without infection (i.e., with and without fungicide). The classification of varietal reaction to CLS is based on symptomatic leaf area (susceptibility) and the resulting relative yield loss (tolerance). Since the relation between both parameters varied among varieties, it was used as an additional parameter to describe tolerance. On this basis, three groups of varieties were identified. They can be characterized as a susceptible, a resistant and a presumably tolerant cluster. A comparison of the data with an older dataset originating from 2009 to 2011 revealed that yield performance of recent varieties with resistance to C. beticola caught up with susceptible varieties due to breeding progress. They showed no yield penalty in the absence of the disease and better economic performance than susceptible varieties. It is assumed that these varieties will allow a substantial reduction of fungicide use for an advanced integrated pest management under central European conditions
Crop protection in sugar beet cultivation in Germany - Analysis of opportunities and challenges
No full textPflanzenschutz im Zuckerrübenanbau in Deutschland – Situationsanalyse 2018
No full textDie Kontrolle von Schaderregern ist eine wesentliche Voraussetzung zur Sicherung der Erträge von Kulturpflanzen. Diese Situationsanalyse stellt das Auftreten von Unkräutern, Krankheiten und tierischen Schädlingen im Zuckerrübenanbau in Deutschland dar und erläutert die Verfahren zu ihrer Kontrolle. Wesentlicher Baustein des integrierten Pflanzenschutzes, der in der EU maßgeblich ist, sind Sorten mit Resistenz- oder Toleranzeigenschaften, z.B. gegenüber Rizomania oder Nematoden. Zur Bekämpfung von Schad- erregern werden auch chemische Pflanzenschutzmittel eingesetzt, deren aktuelle und mittelfristige Verfügbarkeit gezeigt ist. Hier steht der Zuckerrübenanbau derzeit vor großen Herausforderungen, insbesondere durch den Wegfall der neonicotinoiden Saatgutbeizungen ab 2019. Neben der Zulassungssituation, die auch noch weitere Wirkstoffe betrifft, spielt auch die Entwicklung von resistenten Schaderregern eine entscheidende Rolle für die Verfügbarkeit effizienter chemischer Bekämpfungsverfahren. Konsequenzen für den zukünftigen Pflanzenschutz im Zuckerrübenanbau werden aufgezeigt. Für eine längerfristige Nutzung der vorhandenen Wirkstoffe ist ein spezifisches Resistenzmanagement unerlässlich
Crop protection in sugar beet cultivation in Germany - Analysis of opportunities and challenges
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Selectivity of foramsulfuron + thiencarbazone-methyl and classic herbicides in sensitive and non-sensitive sugar beet genotypes
No full textA new herbicide for sugar beet cultivation using the ALS-inhibiting active ingredients foramsulfuron and thiencarbazone-methyl is under approval in the EU member states. Sugar beet genotypes that are non-sensitive to this herbicide are currently under development. Selectivity of the ALS-inhibiting herbicide and yield response of the non-sensitive genotypes might be relevant to meet the requirements for variety registration. To evaluate these issues, six field trials were conducted in Germany in 2013 and 2014. Classic herbicides and the ALS-inhibitor herbicide were applied in dosages of up to fourfold the authorised (or applied for) application rates. The ALS-inhibitor herbicide did not cause any significant phytotoxicity and had no effect on leaf area index at a single, double or fourfold dosage. By contrast, classic herbicides had significant negative effects at the single dosage. At fourfold dosage, they caused 41% phytotoxicity and reduced leaf area index by 35%. The relative yield difference between ALS-inhibitor and classic herbicide treatments was 8.6% and 17.4% of white sugar yield at double and fourfold dosage respectively. The ALS-inhibitor herbicide thus showed higher selectivity than the classic herbicides. In the registration process, the resulting yield advantage could balance a possible yield penalty of non-sensitive genotypes. The introduction of a new system for weed control could improve application flexibility and control of troublesome weeds in sugar beet.KWS SAAT S
Duration of Soil Activity of Foramsulfuron Plus Thiencarbazone-methyl Applied to Weed Species Typical of Sugar Beet Cultivation
No full textThe duration of the soil activity of an acetolactate synthase-(ALS) inhibiting herbicide which is currently under approval for sugar beet cultivation was determined in a field trial series in Germany in 2013 and 2014. The herbicide containing foramsulfuron (FSN; 50 g L−1) and thiencarbazone-methyl (TCM; 30 g L−1) was applied in different dosages (25+15, 37.5+22.5 and 50+30 g FSN+TCM ha−1) to the bare soil. Five weed species (rapeseed, common lambsquarters, wild chamomile, blackgrass, barnyardgrass) were sown at 5, 10, 15 and 20d after application. The duration of the soil activity was assessed by determining percent weed control in the treated plots. The longest duration was observed after applying 50+30 g FSN+TCM ha−1, but the influence of environment was much stronger than the dosage effect. The mean duration of soil activity was 10 to 15 d in 2013 and longer than 20 d in 2014. Differences among weed species in their response to the herbicide treatments were small.</jats:p
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