Vorzüglichkeit des Clearfield®-Systems bei Raps unter verschiedenen Bewirtschaftungsintensitäten

In einem zweifaktoriellen Feldversuch mit Clearfield®-Raps (Brassica napus; Sorte PT228CL) sollte im Jahr 2014 auf der Versuchsstation Ihinger Hof geprüft werden, ob eine Vorzüglichkeit des Clearfield®-Systems bei verschiedener Bewirtschaftungsintensität vorliegt. Faktor 1 war die Bewirtschaftungsintensität mit den Varianten Normalsaat (NS; wendende Bodenbearbeitung, 50 Körner m-2, Reihenabstand 12 cm), Dünnsaat (DS; wendende Bodenbearbeitung, 25 Körner m-2, Reihenabstand 50 cm) und Strip-till (ST; 25 Körner m-2, Reihenabstand 50 cm). Faktor 2 war die Herbizidstrategie mit den Varianten Vorauflaufstrategie (VAS; Colzor® Trio (30 g l-1 Clomazone, 187,5 g l-1 Dimethachlor, 187,5 g l-1 Napropamid), appliziert einen Tag nach der Saat; Agil®-S (100 g/l Propaquizafop), appliziert ca. 3,5 Wochen nach der Saat) und Clearfield®-Strategie (CLS; Clearfield®-Vantiga® (375 g l-1 Metazachlor, 125 g l-1 Quinmerac, 6,25 g l-1 Imazamox) + Dash® E.C. (345 g l-1 Fettsäuremethylester, 205 g l-1 Fettalkoholalkoxylat, 46 g l-1 Ölsäure), appliziert am gleichen Tag wie Agil®-S). Die Variante NS erzielte im Mittel aller Herbizidstrategien mit 3,9 t ha-1 den höchsten Ertrag, signifikant mehr als die ertragsschwächste Variante Strip-till mit 3,6 t ha-1. Mit VAS war der Ertrag im Mittel der Bewirtschaftungsintensitäten mit 3,8 t ha-1 signifikant höher als mit CLS (3,7 t ha-1). Wechselwirkungen traten nicht auf. Die Unkrautdichte war insgesamt vergleichsweise niedrig (kein Auftreten von Sisymbrium officinale und Galium aparine) und dabei noch am höchsten in DS/CLS und ST/CLS mit 12,8 bzw. 13,9 Pflanzen m-2, dem rund 2 bis 3-Fachen der anderen Varianten. Clearfield®-Vantiga® zeigte bei vermutlich höherem Unkrautdruck in Dünnsaat (DS) und Stip-till (ST) eine Minderwirkung gegenüber Stellaria media und Ausfallgetreide (hier: Hordeum vulgare). Eine ökonomische Auswertung der Ergebnisse soll sich anschließen.Performance of oilseed rape in the Clearfield®-system in different cropping intensitiesA two-factorial field experiment should reveal the performance of Clearfield® oilseed rape under different cropping intensities. The experiment was conducted at the experimental station Ihinger Hof in 2014, with cropping intensity as factor 1 and herbicide strategy as factor 2, all treatments sown with variety PT228CL. Treatments of cropping intensities were “normal sowing” (NS; soil inversion tillage tillage, 50 seeds m-2, 12 cm row spacing), “reduced sowing density” (DS; soil inversion tillage, 25 seeds m-2, 25 cm row spacing) and striptill (ST; 25 seeds m-2, 25 cm row spacing). The two herbicide strategies were pre-emergence strategy (VAS; application of Colzor® Trio (30 g L-1 Clomazone, 187.5 g L-1 Dimethachlor, 187.5 g L-1 Napropamide) one day after sowing and of Agil® S (100 g/L Propaquizafop) 3.5 weeks after sowing) and Clearfield® strategy (CLS; application of Clearfield®-Vantiga® (375 g L-1 Metazachlor, 125 g L-1 Quinmerac, 6.25 g L-1 Imazamox) and Dash® E.C. (345 g L-1 fatty acid methyl ester, 205 g L-1 fatty alcohol alkoxylates, 46 g L-1 oleic acid) at the same day as Agil® S). NS resulted in the highest yield (3.9 t ha-1) which was significantly more than obtained by ST (3.6 t ha-1), the least-yielding intensity. There were no significant interactions of the effects. Weed density was highest in DS/CLS and ST/CLS with 12.8 and 13.9 plants m-2, respectively, and thus the two to threefold of the other treatments.The results indicate a lack of efficacy of Clearfield®-Vantiga® under the presumably higher weed pressure in DS and ST, specifically in controlling the weeds Stellaria media and volunteer cereals (in this case: Hordeum vulgare). An economic evaluation will follow

The Impact of Stress in Decision Making in the Context of Uncertainty

For a number of decades, different fields of knowledge, including psychology, economics, and neurosciences, have focused their research efforts on a better understanding of the decision-making process. Making decisions based on the probability of future events is routine in everyday life; it occurs whenever individuals select an option from several alternatives, each one associated with a specific value. Sometimes subjects decide knowing the precise outcomes of each option, but commonly they have to decide without knowing the consequences (because either ambiguity or risk is involved). Stress has a broad impact on animal behaviors, affects brain regions involved in decision-making processes, and, when maladaptive, is a trigger for neuropsychiatric disorders. This Mini-Review provides a comprehensive overview on how stress impacts decision-making processes, particularly under uncertain conditions. Understanding this can prove to be useful for intervention related to impairments to decision-making processes that present in several stress-triggered neuropsychiatric disorders.Foundation for Science and Technology . Grant Numbers: SFRH/SINTD/60129/2009 , PTDC/SAU-NSC/111814/2009; Programa Operacional Factores de Competitividade (COMPETE)].info:eu-repo/semantics/publishedVersio

Predicted contextual modulation varies with distance from pinwheel centers in the orientation preference map

In the primary visual cortex (V1) of some mammals, columns of neurons with the full range of orientation preferences converge at the center of a pinwheel-like arrangement, the ‘pinwheel center' (PWC). Because a neuron receives abundant inputs from nearby neurons, the neuron's position on the cortical map likely has a significant impact on its responses to the layout of orientations inside and outside its classical receptive field (CRF). To understand the positional specificity of responses, we constructed a computational model based on orientation preference maps in monkey V1 and hypothetical neuronal connections. The model simulations showed that neurons near PWCs displayed weaker but detectable orientation selectivity within their CRFs, and strongly reduced contextual modulation from extra-CRF stimuli, than neurons distant from PWCs. We suggest that neurons near PWCs robustly extract local orientation within their CRF embedded in visual scenes, and that contextual information is processed in regions distant from PWCs