Influence à long terme du travail du sol sur la densité des levées d'adventices en situation de non désherbage

1993 ◽  
Vol 71 (7) ◽  
pp. 919-926 ◽  
Author(s):  
F. Dessaint ◽  
R. Chadoeuf ◽  
G. Barralis
Keyword(s):  
Amaranthus Retroflexus ◽  
Avena Fatua ◽  
The Other ◽  
Simultaneous Increase ◽  
Stellaria Media ◽  
Alopecurus Myosuroides ◽  
Galium Aparine ◽  
Thlaspi Arvense ◽  
Term Evolution

The sprouting of weeds was followed over a 9-year period (1977 – 1978 to 1985 – 1986) in a triennial rotation alternating between two spring cultures (barley–pea) and one winter culture (wheat) grown on two agricultural plots. The plots, one superficially worked while the other tilled, did not undergo any weeding treatment. A simultaneous increase in sprouting was observed in both plots at the beginning of the second rotation. However, this increase was greater on the superficially worked plot. The modifications within the adventitious community are qualitative in the first rotation, but become essentially quantitative at the beginning of the second rotation. Some species increase in density (Alopecurus myosuroides, Avena fatua, Galium aparine, Fallopia convolvulus, Sinapis arvensis, Thlaspi arvense) while others decrease (Amaranthus retroflexus, Kickxia spuria, Stellaria media). Key words: community, long term evolution, factorial analysis of correspondences, weeds. [Journal translation]

scholarly journals Weed infestation of a spring wheat (Triticum aestivum L.) crop under the conditions of plough and ploughless tillage

2012 ◽  
Vol 64 (3) ◽  
pp. 133-140
Author(s):  
Andrzej Woźniak
Keyword(s):  
Spring Wheat ◽  
Chenopodium Album ◽  
Dry Weight ◽  
Amaranthus Retroflexus ◽  
Avena Fatua ◽  
Stellaria Media ◽  
Tillage Systems ◽  
Galium Aparine ◽  
Tillage System ◽  
Weed Infestation

A field experiment was conducted in the period 2007- 2009 in the Uhrusk Experimental Farm (Lublin region) belonging to the University of Life Sciences in Lublin. Different tillage systems - plough and ploughless tillage - were the experimental factors. In the plough tillage system, tillage involved skimming done after the harvest of the forecrop and autumn ploughing. In the ploughless tillage system, only the herbicide Roundup 360 SL (active substance - glyphosate) was applied after the harvest of the forecrop. In both tillage treatments, spring tillage involved field cultivating and the use of a tillage assembly consisting of a cultivator, cage roller, and harrow. The present experiment evaluated weed infestation of the crop expressed by the number and air-dry weight of weeds and their species composition. Under the conditions of ploughless tillage, air-dry weight of weeds in the spring wheat crop was shown to increase significantly compared to plough tillage. The tillage systems under comparison did not differentiate the number of weeds per 1 m<sup>2</sup>. Spring wheat sown using plough tillage was colonized most extensively by the following weed species: <i>Avena fatua</i> L., <i>Stellaria media</i> (L.) Vill., <i>Galium aparine</i> L., <i>Amaranthus retroflexus</i> L., <i>Chenopodium album</i> L., and <i>Consolida regalis</i> Gray. In the ploughless tillage treatments, the following weeds were predominant: <i>Stellaria media</i> (L.) Vill., <i>Avena fatua</i> L., <i>Fallopia convolvulus</i> (L.) A. Löve, <i>Papaver rhoeas</i> L., <i>Amaranthus retroflexus</i> L., <i>Galium aparine</i> L., and <i>Chenopodium album</i> L.

Ursachen der selektiven Wirkung der Photosynthesehemmer Phenmedipham und Bentazon/ Causes of the Selective Action of the Photosynthetic Inhibitors Phenmedipham and Bentazon

1979 ◽  
Vol 34 (11) ◽  
pp. 926-930 ◽  
Author(s):  
H. Börner
Keyword(s):  
Beta Vulgaris ◽  
General Pattern ◽  
Amaranthus Retroflexus ◽  
Matricaria Chamomilla ◽  
Stellaria Media ◽  
Senecio Vulgaris ◽  
Alopecurus Myosuroides ◽  
Galium Aparine ◽  
Combined Action ◽  
Photosynthetic Inhibitors

Abstract The different sensitivity of broad-leave weeds against the photosynthetic inhibitors phenmedipham and bentazon could be explained by the combined action of herbicide uptake and decomposition. In spite of fast uptake of phenmedipham by Beta vulgaris, this plant was not injured, because the herbicide was metabolized very rapidly. The transformation of phenmedipham by Galium aparine, Matricaria chamomilla, Centaurea cyanus, Stellaria media and Amaranthus retroflexus was reduced compared to Beta vulgaris. These plants survived, with the exception of Amaranthus, first of all because of a reduced uptake of the herbicide. The other weeds investigated (Galinsoga ciliala, G. parviflora, Sinapis alba, Capsella bursa-pastoris, Sinapis arvensis, Senecio vulgaris) were extremely sensitive against phenmedipham because they could not protect themselves neither by a reduced uptake nor an increased metabolism. The grass weeds Alopecurus myosuroides and Avena fatua are resistant against the herbicide because of the protected growing point and the missing basipetal translocation of the compound. Also the susceptibility of rice, soybeans, wheat and some weeds to bentazon is the result of penetration and metabolism of the herbicide in plants. Susceptible plants (Chrysanthemum segetum, Matricaria chamomilla, Xanlhium pensilvanicum) are nearly unable to detoxify bentazon. whereas in resistant plants (rice, soybeans, wheat) a substantial amount of absorbed bentazon was converted to different metabolites. Only Echinochloa crus-galli, which is more resistant, and Galium aparine, which is more susceptible, when they adsorbed the same quantity of bentazon, deviate from this general pattern.

Sea surface temperatures, salinity and pH reconstructions over the last 1,2 Ma in South Indian Ocean using the unique combination of Mg/Ca, d18O and ∆47 in planktonic foraminifera

2021 ◽  
Author(s):  
Marion Peral ◽  
Thibaut Caley ◽  
Bruno Malaizé ◽  
Erin McClymont ◽  
Thomas Extier ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Transfer Function ◽  
Planktonic Foraminifera ◽  
The Other ◽  
Unique Combination ◽  
South Indian Ocean ◽  
Term Evolution ◽  
South Indian ◽  
Clumped Isotope

&lt;p&gt;The Mid-Pleistocene transition (MPT) took place between 1,200 Ma and 800 ka (still debated). During this transition, the Earth&amp;#8217;s orbitally paced ice age cycles intensified, lengthened from &amp;#8764;40 000 (&amp;#8764;40 ky) to &amp;#8764;100 ky, and became distinctly asymmetrical while Earth&amp;#8217;s orbital variations remained unchanged. Although orbital variations constitute the first order forcing on glacial-interglacial oscillations of the late Quaternary, they cannot explain alone the shifts in climatic periodicity and amplitude observed during the MPT. In order to explain the MPT, long-term evolution of internal mechanisms and feedbacks have been called upon, in relation with the global cooling trend initiated during the Cenozoic, the expansion of Antarctic and Greenland Ice Sheet and/or the long-term decline in greenhouse gases (particularly CO2). A key point is therefore to accurately reconstruction of oceanic temperatures to decipher the processes driving climate variations.&lt;/p&gt;&lt;p&gt;In the present work, we studied the marine sediment core MD96-2048 taken from south Indian Ocean (26*10&amp;#8217;482&amp;#8217;&amp;#8217; S, 34*01&amp;#8217;148&amp;#8217;&amp;#8217; E) in the region of the Agulhas current. We compared 5 paleothermometers: alkenone, TEX86, foraminiferal- transfer function, Mg/Ca and clumped isotope. Among these approaches, carbonate clumped-isotope thermometry (&amp;#8710;&lt;sub&gt;47&lt;/sub&gt;) only depends on crystallization temperature, and the &amp;#8710;&lt;sub&gt;47&lt;/sub&gt; relationship with planktonic foraminifer calcification temperature is well defined. Since Mg/Ca is not only controlled by temperature but is also affected by salinity and pH. The classical d&lt;sup&gt;18&lt;/sup&gt;O in planktic is dependent on SST and d&lt;sup&gt;18&lt;/sup&gt;Osw, which is regionally correlated with the salinity in the present-day ocean. Assuming that the present-day d&lt;sup&gt;18&lt;/sup&gt;O&lt;sub&gt;sw&lt;/sub&gt;-salinity relation was the same during the MPT, we are able to separate changes in d&lt;sup&gt;18&lt;/sup&gt;O&lt;sub&gt;sw&lt;/sub&gt; from temperature effects and reconstruct past salinity. Combining d&lt;sup&gt;18&lt;/sup&gt;O, Mg/Ca and &amp;#8710;&lt;sub&gt;47&lt;/sub&gt; on planktonic foraminifera allow in theory to reconstruct SST, SSS and pH.&lt;/p&gt;&lt;p&gt;Here, we measured d&lt;sup&gt;18&lt;/sup&gt;O, Mg/Ca and &amp;#8710;&lt;sub&gt;47&lt;/sub&gt; on the shallow-dwelling planktonic species Globigerinioides ruber ss. at the maximal of glacial and interglacial periods over the last 1.2 Ma. Our set of data makes it possible to estimate the long-term evolution of SST, salinity and pH (and thus have an insight into the atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentration) across the MPT. Frist, strong differences are observed between the 5 derived-SST: the alkenone and TEX86 recorded the higher temperatures than the other SST proxies. Alkenone derived-SST do not show glacial-interglacial variations within the MPT. The Mg/Ca and transfer function derived-SST show a good agreement each other, while the clumped-isotope derived-SST are systematically colder than the other derived-SST. Then, our &amp;#8710;&lt;sub&gt;47&lt;/sub&gt;-SST, salinity and pH results clearly show that amplitude of glacial-interglacial variations was insignificant between 1.2 and 0.8 Ma (within the MPT) and increased after the MPT. Finally, we also discussed the potential to use this unique combination of proxies to reconstruct changes of atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentration.&lt;/p&gt;

scholarly journals Sustainability Science: Toward a Synthesis

2020 ◽  
Vol 45 (1) ◽  
pp. 331-386 ◽  
Author(s):  
William C. Clark ◽  
Alicia G. Harley
Keyword(s):  
Sustainable Development ◽  
Sustainability Science ◽  
Adaptive System ◽  
Complex Adaptive System ◽  
The Other ◽  
Multiple Contexts ◽  
Term Evolution ◽  
Complex Adaptive ◽  
Governance Arrangements

This review synthesizes diverse approaches that researchers have brought to bear on the challenge of sustainable development. We construct an integrated framework highlighting the union set of elements and relationships that those approaches have shown to be useful in explaining nature–society interactions in multiple contexts. Compelling evidence has accumulated that those interactions should be viewed as a globally interconnected, complex adaptive system in which heterogeneity, nonlinearity, and innovation play formative roles. The long-term evolution of that system cannot be predicted but can be understood and partially guided through dynamic interventions. Research has identified six capacities necessary to support such interventions in guiding development pathways toward sustainability. These are capacities to ( a) measure sustainable development, ( b) promote equity, ( c) adapt to shocks and surprises, ( d) transform the system into more sustainable development pathways, ( e) link knowledge with action, and ( f) devise governance arrangements that allow people to work together in exercising the other capacities.

Research on Uplink Semi-Persistent Scheduling in LTE System

2013 ◽  
Vol 791-793 ◽  
pp. 1952-1956
Author(s):  
Ji Ke Gao ◽  
De Min Zhang ◽  
Fa Tang Chen
Keyword(s):  
Online Games ◽  
The Other ◽  
Collision Probability ◽  
Evolution System ◽  
Term Evolution ◽  
Collision Processes ◽  
The Stability ◽  
New Applications ◽  
The Relationship

In LTE(Long Term Evolution) system, scheduling plays an important role in the process of allocating resource. LTE system puts forward semi-persistent scheduling (SPS) for new applications such as VoIP(Voice on Internet Protocol) and online games. Considering the problem of resource collision in SPS HARQ(Hybrid Automatic Repeat reQuest) process, we explore the relationship between uplink semi-persistent scheduling period and the number of semi-persistent transmissions, and propose two novel solutions. One is choosing specific uplink semi-persistent period for different uplink/downlink (UL/DL) configurations and the number of transmissions. The other is delaying collision processes for the configuration of small uplink period. The analysis proves that the two solutions can reduce the collision probability and improve the stability of LTE system.

scholarly journals Present and potential weed infestation of spring cereals in different cropping system

2013 ◽  
Vol 54 (1) ◽  
pp. 175-190
Author(s):  
Andrzej Wesołowski ◽  
Andrzej Woźniak
Keyword(s):  
Crop Rotation ◽  
Chenopodium Album ◽  
Soil Layer ◽  
Cropping System ◽  
Amaranthus Retroflexus ◽  
Stellaria Media ◽  
Galium Aparine ◽  
Weed Seeds ◽  
Spring Cereals ◽  
Weed Infestation

This paper presents the results of investigations on the weed infestation and vertical distribution of weed seed bank in rendzina under spring cereals cultivation in crop rotations and monoculture. Used herbicides (MCPA and <i>fenoxaprop-P-etylu</i>) decreased the number of weeds and species composition in comparison with harrowing. In the soil layer of 0-25 cm used in the monoculture there was found about 22,9% weed seeds more than in crop rotation. In the canopy of spring cereals the following weeds dominated: in crop rotation - <i>Chenopodium album, Echinochloa crus-galli and Veronica persica; and in monoculture - Stellaria media, Galium aparine</i> and <i>Chenopodium album</i>. In the soil layer of 0-25 cm used in crop rotation and monoculture the following weed seeds dominated : <i>Amaranthus retroflexus, Chenopodium album</i> and <i>Stellaria media</i>.

scholarly journals Видовой состав сорных растений в агрофитоценозах зерновых культур в географически отдаленных областях: Ленинградской (Северо-Западный регион) и Липецкой (Центрально-Черноземный регион)

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Н. Н. Лунева
Keyword(s):  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Silene Vulgaris ◽  
Raphanus Raphanistrum ◽  
Convolvulus Arvensis ◽  
Stellaria Media ◽  
Echinochloa Crusgalli ◽  
Polygonum Aviculare ◽  
Thlaspi Arvense ◽  
Fumaria Officinalis

Цель исследования – выявление различий в видовом составе сорных растений в посевах зерновых культур в географически отдаленных регионах (СЗР и ЦЧР). Произведен сравнительный анализ данных обследования 30 полей зерновых культур в ряде районов Ленинградской области в 2014-2016 гг. и 29 полей в районах Липецкой области в 2016-2018 гг., осуществленных по оригинальной методике автора. Использованы традиционные методы флористического анализа, а также распределение видов по классам постоянства встречаемости. Различия между сегетальными элементами флоры зерновых культур двух областей заключаются в более высоких показателях флористического богатства и таксономического разнообразия в Ленинградской области, а также различной очередностью семейств в первых двух «триадах» сравниваемых флористических спектров. Более глубокие отличия заключаются не только в наличии дифференциальных видов (63 вида в посевах зерновых культур только в Ленинградской области и 45 видов в посевах зерновых только в Липецкой области), но и в разных показателях встречаемости одинаковых видов, засоряющих посевы зерновых культур в обоих регионах. К более высоким классам постоянства встречаемости в Ленинградской области, чем в Липецкой, относятся виды: Chenopodium album L., Tripleurospermum inodorum (L.) Sch. Bip., Matricaria discoídea DC., Taraxacum officinale Wigg., Thlaspi arvense L., Stellaria media (L.) Vill., Elytrigia repens (L.) Nevski, Capsella bursa-pastoris (L.) Medik., Fumaria officinalis L. и Fallopia convolvulus (L.) A. Loeve, Achillea millefolium L., Artemisia vulgaris L., Sonchus arvensis L., Myosotis arvensis (L.) Hill., Silene vulgaris (Moench) Garcke, Plantago major L., Persicaria lapathifolia (L.) S.F. Gray, Polygonum aviculare L. На территории Липецкой области такими видами являются – Silene praténsis (Rafn) Godr,. Echinochloa crusgalli (L.) Beauv., Galeopsis tetrahit L., Galium aparine L., Convolvulus arvensis L. В засоренности посевов ячменя в разных областях также выявлены различия: зарегистрировано 42 вида сорных растений в посевах ячменя только Ленинградской области (среди которых доминирует Matricaria discoídea DC.) и 31 вид в посевах ячменя только в Липецкой области (среди которых доминируют Echinochloa crusgalli (L.) Beauv., и Amaranthus retroflexus L.). Из 29 одинаковых видов в посевах ячменя обеих областей, в Ленинградской области преобладают Chenopodium album L., Fumaria officinalis L., Tripleurospermum inodorum (L.) Sch. Bip., а в Липецкой Convolvulus arvensis L., Galeopsis tetrahit L., Raphanus raphanistrum L. Следовательно, фитосанитарный прогноз распространения видов сорных растений в посевах зерновых культур в целом, и в посевах ячменя, в частности, как и системы защиты от сорных растений будут отличаться в двух сравниваемых регионах.

Centenary celebrations meet a farewell party: British-Czech bilateral relations in the times of Brexit

2019 ◽  
Vol 21 (4) ◽  
pp. 689-708
Author(s):  
Monika Brusenbauch Meislova
Keyword(s):  
Long Term Evolution ◽  
The Other ◽  
Bilateral Relations ◽  
Term Evolution ◽  
The Future ◽  
The Times ◽  
British Embassy ◽  
Future Direction ◽  
The Uk

2019 marks an especially important year for British-Czech bilateral relations. As a year of both centenary celebrations of opening of the British Embassy in Prague and Brexit, it makes for a fascinating paradox: a symbol of a century-long continuity on one hand and a year of serious disruption on the other hand. Against this background, the overarching aim of this article is to investigate Brexit implications for British-Czech bilateral relations, placing this assessment in the context of the long-term evolution of these relations and relating it to debates within the scholarship on the effects of Brexit. At the same time, it addresses some of the wider political questions that will determine the nature of Brexit’s supposed effects on the future direction of individual bilateral relations between the UK and EU27 member states.

scholarly journals Weed Identification in Maize, Sunflower, and Potatoes with the Aid of Convolutional Neural Networks

2020 ◽  
Vol 12 (24) ◽  
pp. 4185
Author(s):  
Gerassimos G. Peteinatos ◽  
Philipp Reichel ◽  
Jeremy Karouta ◽  
Dionisio Andújar ◽  
Roland Gerhards
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Weed Management ◽  
Plant Protection ◽  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Species Discrimination ◽  
Weed Species ◽  
Stellaria Media ◽  
Alopecurus Myosuroides

The increasing public concern about food security and the stricter rules applied worldwide concerning herbicide use in the agri-food chain, reduce consumer acceptance of chemical plant protection. Site-Specific Weed Management can be achieved by applying a treatment only on the weed patches. Crop plants and weeds identification is a necessary component for various aspects of precision farming in order to perform on the spot herbicide spraying or robotic weeding and precision mechanical weed control. During the last years, a lot of different methods have been proposed, yet more improvements need to be made on this problem, concerning speed, robustness, and accuracy of the algorithms and the recognition systems. Digital cameras and Artificial Neural Networks (ANNs) have been rapidly developed in the past few years, providing new methods and tools also in agriculture and weed management. In the current work, images gathered by an RGB camera of Zea mays, Helianthus annuus, Solanum tuberosum, Alopecurus myosuroides, Amaranthus retroflexus, Avena fatua, Chenopodium album, Lamium purpureum, Matricaria chamomila, Setaria spp., Solanum nigrum and Stellaria media were provided to train Convolutional Neural Networks (CNNs). Three different CNNs, namely VGG16, ResNet–50, and Xception, were adapted and trained on a pool of 93,000 images. The training images consisted of images with plant material with only one species per image. A Top-1 accuracy between 77% and 98% was obtained in plant detection and weed species discrimination, on the testing of the images.

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