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Silky bent grass (Aperaspica-venti (L.) P. Beauv.) is a common weed of cereal crops widely spread in Northern and Easthern Europe (Germany, Czech Republic,...), Northern Asia, Siberia and Canada. Up to now, no resistant case has b...
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Silky bent grass (Aperaspica-venti (L.) P. Beauv.) is a common weed of cereal crops widely spread in Northern and Easthern Europe (Germany, Czech Republic,...), Northern Asia, Siberia and Canada. Up to now, no resistant case has been detected in Belgium but some chemical weeding failures have been observed in Wallonia fields.During summer 2011, 37 seed samples of Apera spica-venti were collected in Wallonia and submitted to resistance tests in controlled conditions. Three modes of action were tested: acetyl coenzyme-A carboxylase inhibitors (pinoxaden and cycloxydim), acetolactate synthase inhibitors (mesosulfuron+iodosulfu-ron, pyroxsulam and sulfometuron) and photosynthesis inhibitors (isoproturon). One susceptible standard population was included in the test in order to validate it and to permit wild populations classification according to "R" rating system developed by Moss et al (2007).Most of populations were susceptible but some populations showed resistance to at least one of the three tested modes of action.
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В 2008-2009 гг. проведено экологическое испытание 5 видов и 16 сортов газонных трав. Установлено, что наиболее качественные газоны ф...
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В 2008-2009 гг. проведено экологическое испытание 5 видов и 16 сортов газонных трав. Установлено, что наиболее качественные газоны формировалиполевица побего-образующая и мятлик луговой сорта Impact Другие сорта мятлика лугового, а также сорт овсяницы красной Audubon подходят для создания обыкновенных городских газонов. Газоны из райграса пастбищного сортов Сакини и Плейер, фестулолиума сорта ВИК 90, овсяницы красной сорта Эхо имели невысокую общую декоративность и сорта этих трав нецелесообразно использовать для создания газонных травостоев.
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Anguina agrostis is one of the most economically damaging plant-parasitic nematodes. In this paper, a real-time PCR system for rapid identification of juveniles of A. agrostis was developed based on ITS-DNA with species-specific T...
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Anguina agrostis is one of the most economically damaging plant-parasitic nematodes. In this paper, a real-time PCR system for rapid identification of juveniles of A. agrostis was developed based on ITS-DNA with species-specific TaqMan probe and primers. Four related species, A. agrostis (two populations), A. tritici, A. wevelli and Ditylenchus destructor, were used to verify the specificity of this detection. Both of the two A. agrostis populations were positively detected and all of the non-yl agrostis populations were negative. One tenth of the DNA from a single second-stage juvenile of Anguina agrostis was detectable in this assay.
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BACKGROUND: This study investigates the mechanisms of resistance to acetolactate synthase-inhibiting herbicides in populations of Apera spica-venti (L.) P.B. from the Czech Republic. RESULTS: The proportion of resistance due to mu...
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BACKGROUND: This study investigates the mechanisms of resistance to acetolactate synthase-inhibiting herbicides in populations of Apera spica-venti (L.) P.B. from the Czech Republic. RESULTS: The proportion of resistance due to mutant acetolactate synthase (ALS) alleles was estimated by genotyping individuals from each of three populations for the eight ALS mutations known to confer resistance. Four resistance-conferring ALS mutations were identified: Pro-197-Ala, Pro-197-Thr, Trp-574-Leu and previously unreported Trp-574-Met substitution. Two populations (R1, R3) have amino acid substitution at positions Pro-197 and Trp-574. Individuals from the R3 population had two different resistance alleles. In the R2 population, only the resistant Trp-574-Met substitution was detected. Ten other single point mutations were identified, but these were not related to resistance. The cytochrome malathion decreased chlorsulfuron resistance in the resistant populations that were examined. Although malathion increased mortality, the GR_(50) values were too high to conclude that non-target-based mechanism was the main one for the resistance in Apera spica-venti populations tested in this study. CONCLUSIONS: Individuals of Apera spica-venti populations tested in this study possess the target-site ALS resistance mutation and an additional so far unknown resistance mechanism(s).
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Durch mehrjahrige, landerübergreifende Ringversuche konnte gezeigt werden, dass unter bestimmten Voraussetzungen die zugelassenen Aufwandmengen von Monitor, Attribut und Atlantis WG zur Kontrolle des Windhalms um 25% reduziert we...
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Durch mehrjahrige, landerübergreifende Ringversuche konnte gezeigt werden, dass unter bestimmten Voraussetzungen die zugelassenen Aufwandmengen von Monitor, Attribut und Atlantis WG zur Kontrolle des Windhalms um 25% reduziert werden konnen. Eine Reduktion auf 50% der Aufwandmenge ist nur moglich, wenn die Anwendung in Form einer Tankmischung vorgenommen wird und durch den Tankmischungspartner eine Windhalmteilwirkung erzielt wird. Die Aufwandmengenreduzierungen sind nur mit dem Einsatz von Formulierungshilfsstoffen vorzunehmen. Weiterhin konnen hohe Wirkungsgrade nur erreicht werden, wenn der Getreidebestand eine normale Konkurrenzkraft entfaltet. In kurzstrohigen Sorten und lückigen Getreidebestanden nimmt die Streubreite der Wirkungsgrade deutlich zu. Der erzielte Wirkungsgrad hangt starker von den Witterungsbedingungen nach der Applikation als von der Befallsstarke des Windhalms ab.Mit den vorliegenden Ergebnissen kann der Einsatz von verminderten Aufwandmengen dieser Sulfonylharnstoffe als ein Baustein in das Pflanzenschutzreduktionsprogramm integriert werden. Um Resistenzen vorzubeugen, sollten in getreidereichen Fruchtfolgen undWeizenmonokulturen die verminderten Aufwandmengen nur alternierend mit anderen Herbizidgruppen eingesetzt werden.
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Apera spica-venti (L) P. Beauv. is a common weed of cereal crops widely spread in Northern and Eastern Europe, Northern Asia, Siberia and Canada.Given the ability of Apera spica-venti to grow and develop in Wallonia and lack of sc...
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Apera spica-venti (L) P. Beauv. is a common weed of cereal crops widely spread in Northern and Eastern Europe, Northern Asia, Siberia and Canada.Given the ability of Apera spica-venti to grow and develop in Wallonia and lack of scientific knowledge of its biology, germination tests were performed on four populations. These laboratory tests were carried on according to the standards of the International Seed Testing Association (ISTA) in order to study three key factors (composition of water solution, presence/absence of pre-chilling and temperature) influencing the germination of the seeds.Germination tests showed that a solution containing 2 g/L of KNO3 and alternating night/day temperatures between 10°C and 30°C favorably influence the germination of Apera spica-venti. These results in controlled conditions are a premise for greenhouseand field tests.
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Investigation of molecular mechanisms of herbicide resistance to three modes of action was carried out in a population of Apera spica-venti with resistance to herbicides inhibiting acetolactate synthase (ALS), acetyl-CoA-carboxyla...
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Investigation of molecular mechanisms of herbicide resistance to three modes of action was carried out in a population of Apera spica-venti with resistance to herbicides inhibiting acetolactate synthase (ALS), acetyl-CoA-carboxylase (ACCase) and inhibitors of photosystem-II (PSII). Greenhouse experiments were conducted to detect and characterize resistance pattern to pyroxsulam (ALS inhibitor), pinoxaden (ACCase) and chlorotoluron (PSII) using the recommended rate of each herbicide alone and in tank-mix, sequential application and dose-response tests. Metabolic detoxification and/or reduced herbicide uptake and translocation studies were conducted using dose-response tests with the herbicides in combination with malathion. After treatment, leaves from surviving plants were collected for pyrosequencing to identify target-site mutations in specific regions of ALS, ACCase and psbA genes. Among 32 analysed plants, target-site mutations in specific regions were detected for ALS and ACCase gene, but no psbA mutations were found. Dose-response assay showed high resistance factors for pyroxsulam (RF = 269.4), pinoxaden (RF = 66.3), but lower for chlorotoluron (RF = 14.3). Testing for metabolic detoxification by pre-treatment with malathion resulted in an increased susceptibility to pinoxaden in all doses, some increased susceptibility to chlorotoluron at the highest doses and no difference for pyroxsulam. Our results indicate that while target-site mutations were present for ALS and ACCase sites of action, metabolic detoxification does play a role for pinoxaden resistance. This research provided key insights into the resistance mechanisms in Apera spica-venti and will be important for developing control strategies for this weed in the Czech Republic.
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Leaf and root tissue of Lolium perenne L., Agrostis capillaris L. and Festuca ovina L. grown under ambient (350 mu l l(-1) CO2) and elevated (700 mu l l(-1)) CO2 in a continuously C-14-labelled atmosphere and at two soil N levels,...
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Leaf and root tissue of Lolium perenne L., Agrostis capillaris L. and Festuca ovina L. grown under ambient (350 mu l l(-1) CO2) and elevated (700 mu l l(-1)) CO2 in a continuously C-14-labelled atmosphere and at two soil N levels, were incubated at 14 degrees C for 222 days. Decomposition of leaf and root tissue grown in the low N treatment was not affected by elevated [CO2], whereas decomposition in the high N treatment was significantly reduced by 7% after 222 days. Despite the increased C/N ratio (g g(-1)) of tissue cultivated at elevated [CO2] when compared with the corresponding ambient tissue, there was no significant correlation between initial C/N ratio and C-14 respired. This finding suggests that the CO2-induced changes in decomposition rates do not occur via CO2-induced changes in C/N ratios of plant materials. We combined the decomposition data with data on C-14 uptake and allocation for the same plants, and give evidence that elevated [CO2] has the potential to increase soil C stores in grassland via increasing C uptake and shifting C allocation towards the roots, with an inherent slower decomposition rate than the leaves. An overall increase of 15% in C-14 remaining after 222 days was estimated for the combined tissues, i.e., the whole plants; the leaves made a much smaller contribution to the C remaining (+6%) than the roots (+26%). This shows the importance of clarifying the contribution of roots and leaves with respect to the question whether grassland soils act as a sink or source for atmospheric CO2.
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