Bygbladplet, biologi og bekæmpelse

Bygbladplet udvikler med års mellemrum kraftige angreb i modtagelige sorter, som kan give op til 30-40% udbyttetab. - Svampen er udsædsbåren, ligesom den smitter via halmrester, vinterbyg og spildkornsplanter af byg. - Udsædsbåren bygbladplet kan medføre kraftige bladangreb senere på sæsonen. - Kornpartier med over 15% angrebne kerner bør ikke bruges ubejdset som udsæd. - Bygbladplet fremmes af fugtige forhold, men kan godt udvikle sig alene som følge af dug om natten. Optimale temperaturer for svampen er 15-25° C. - Især i vårbyg varierer sorternes modtagelighed over for bygbladplet. Valg af sorter med god resistens er vigtig for at mindske risikoen for angreb. - Sorternes modtagelighed kan også variere fra mark til mark, fordi der findes forskellige smitteracer af bygbladplet. - Dyrkningsmæssige foranstaltninger som brug af sund udsæd, pløjning og et sædskifte med 2 år mellem bygafgrøder reducerer mængden af smitstof og dermed risikoen for angreb. - Det er muligt at bekæmpe kerneangreb ved bejdsning og bladangreb ved hjælp af svampemidler

Anvendelse af ufuldstændige blokforsøg

I forsøg med mange forsøgsled, forsøg på uensartede arealer og forsøg, som af praktiske grunde skal opdeles på mindre enheder, vil det ofte være fordelagtigt at anvende blokke, som ikke indeholder alle forsøgsled. Sådanne ufuldstændige blokke kan konstrueres efter flere forskellige principper. I enfaktorielle forsøg anvendes oftest metoder, som sikrer, at alle par af forsøgsled kan sammenlignes med den samme (og bedst mulige) sikkerhed, mens man i flerfaktorielle forsøg oftest anvender metoder, som sikrer, at de mest interessante effekter (hoved- og/eller vekselvirkninger) kan estimeres bedst muligt. Artiklen viser tre eksempler på anvendelse af ufuldstændige blokforsøg: 1) Sortsforsøg i ærter (enfaktoriel), 2) Frøavlsforsøg med strandsvingel (trefaktoriel) og 3) Forsøg med svampemidler i byg (tofaktorielt split-plot). For hver af disse vises den benyttede plan samt effekten af at benytte planen i stedet et randomiseret blokforsøg med fuldstændige blokke

Biological activity of glucosinolate derived compounds isolated from seed meal of Brassica crops and evaluated as plant and food protection agents

Glucosinolates are amino acid derived allelochemicals characteristic of plants of the order Capparales. These compounds are present in seeds of agriculturally common Brassica crops in varying quantities depending on the species (ref). The use of the remaining seed cake after oil extraction has traditionally been limited by the concentration of these compounds. However, the extraction of glucosinolates from seed meal is nowadays possible and it further contributes to an increased quality of the seed meal for feed (Sørensen et al., this conference). Glucosinolates are hydrolysed by endogenous enzymes (myrosinases; EC 3.2.1.147) and a number of compounds are produced depending on the parent glucosinolate and the environmental conditions.1 Among these compounds, oxazolidine-2-thiones are known for their antinutritional effects on monogastric animals, whereas isothiocyanates are fungicidal, nematocidal and herbicidal.2,3 The possibility for using glucosinolates as precursors for environmental friendly biocides therefore exists, which could contribute to increase the value of the Brassica seed meal

Sustainability of European winter wheat- and maize-based cropping systems: Economic, environmental and social ex-post assessment of conventional and IPM-based systems

In order to ensure higher sustainability of winter wheat and maize production in Europe, cropping systems featuring different levels of Integrated Pest Management (IPM) need to be tested in the field and validated for their sustainability before being adopted by farmers. However, the sustainability evaluation of cropping systems is difficult to perform effectively due to the complex economic, social and environmental dimensions of sustainability. Within the EU research project PURE, nine long-term experiments were conducted in various European regions from 2011 to 2014, comparing two IPM levels against the conventional system (CS) in winter wheat- and maize-based cropping systems. IPM1 encompassed some pesticide use in semi-diverse crop rotations while IPM2 favoured reduced- and non-chemical methods in diverse rotations. The modified DEXiPM (DEXi Pest Management) model for arable cropping systems was used for ex-post assessments to compare the economic, environmental and social sustainability of these systems. The assessments showed that in six out of nine trials the CS was overall unsustainable because of low evaluation of the environmental sustainability that was mainly due to high pesticide use and simplified crop rotations where the choice of crops is primarily market-driven. In contrast, six IPM1 and five IPM2 systems could be classified as sustainable, achieving ‘medium’ or ‘high’ scores for all three sustainability dimensions. Differences in the socio-economic conditions across countries and/or climatic and soil conditions across experimental trials highlighted that IPM is based on general principles that must be adapted to address specific local conditions. Overall, IPM systems included more diverse crop rotations and practices compared to the CS, promoting IPM-based strategies with less pesticide use but also a reduced reliance on pesticides that could partially compensate for any yield reductions by the savings on pesticide and application costs. It is recommended that the results of the study should be disseminated to policy-makers, advisors and farmers and that their implementation should be considered on a regional level. Regional policies to encourage the adoption of more sustainable systems based on IPM principles, as well as better support by more closely involving the regional advisory services for the general implementation of IPM is further recommended. Ex-post analysis with DEXiPM also identified the constraints of the IPM1 and IPM2 systems evaluated as not sustainable. These were related to i) environmental issues for those IPM1 systems that still relied mainly on pesticide use and had less diverse crop rotations, and ii) economic issues for IPM2 systems, mainly due to the choice of less profitable crops in the rotation, as well as to yield penalties caused by the very low pesticide use or replacing pesticides with less effective non-chemical methods. The identification of these constraints is a valuable input to the local and regional discussion on how to adopt IPM and develop more sustainable cropping systems

A post-market, prospective, multi-center, single-arm clinical investigation of Phasix™ mesh for VHWG grade 3 midline incisional hernia repair

BACKGROUND: Incisional heia is a frequent complication of midline laparotomy. The use of mesh in hernia repair has been reported to lead to fewer recurrences compared to primary repair. However, in Ventral Hernia Working Group (VHWG) Grade 3 hernia patients, whose hernia is potentially contaminated, synthetic mesh is prone to infection. There is a strong preference for resorbable biological mesh in contaminated fields, since it is more able to resist infection, and because it is fully resorbed, the chance of a foreign body reaction is reduced. However, when not crosslinked, biological resorbable mesh products tend to degrade too quickly to facilitate native cellular ingrowth. Phasix™ Mesh is a biosynthetic mesh with both the biocompatibility and resorbability of a biological mesh and the mechanical strength of a synthetic mesh. This multi-center single-arm study aims to collect data on safety and performance of Phasix™ Mesh in Grade 3 hernia patients. METHODS: A total of 85 VHWG Grade 3 hernia patients will be treated with Phasix™ Mesh in 15 sites across Europe. The primary outcome is Surgical Site Occurrence (SSO) including hematoma, seroma, infection, dehiscence and fistula formation (requiring intervention) through 3 months. Secondary outcomes include recurrence, infection and quality of life related outcomes after 24 months. Follow-up visits will be at drain removal (if drains were not placed, then on discharge or staple removal instead) and in the 1st, 3rd, 6th, 12th, 18th and 24th month after surgery. CONCLUSION: Based on evidence from this clinical study Depending on the results this clinical study will yield, Phasix™ Mesh may become a preferred treatment option in VHWG Grade 3 patients. TRIAL REGISTRATION: The trial was registered on March 25, 2016 on clinicaltrials.gov: NCT02720042

Population genomics of post-glacial western Eurasia.

Western Eurasia witnessed several large-scale human migrations during the Holocene <sup>1-5</sup> . Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes-mainly from the Mesolithic and Neolithic periods-from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a 'great divide' genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 BP, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 BP, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a 'Neolithic steppe' cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations

On the origin and evolution of the material in 67P/Churyumov-Gerasimenko

International audiencePrimitive objects like comets hold important information on the material that formed our solar system. Several comets have been visited by spacecraft and many more have been observed through Earth- and space-based telescopes. Still our understanding remains limited. Molecular abundances in comets have been shown to be similar to interstellar ices and thus indicate that common processes and conditions were involved in their formation. The samples returned by the Stardust mission to comet Wild 2 showed that the bulk refractory material was processed by high temperatures in the vicinity of the early sun. The recent Rosetta mission acquired a wealth of new data on the composition of comet 67P/Churyumov-Gerasimenko (hereafter 67P/C-G) and complemented earlier observations of other comets. The isotopic, elemental, and molecular abundances of the volatile, semi-volatile, and refractory phases brought many new insights into the origin and processing of the incorporated material. The emerging picture after Rosetta is that at least part of the volatile material was formed before the solar system and that cometary nuclei agglomerated over a wide range of heliocentric distances, different from where they are found today. Deviations from bulk solar system abundances indicate that the material was not fully homogenized at the location of comet formation, despite the radial mixing implied by the Stardust results. Post-formation evolution of the material might play an important role, which further complicates the picture. This paper discusses these major findings of the Rosetta mission with respect to the origin of the material and puts them in the context of what we know from other comets and solar system objects