scholarly journals Problems and perspectives in weed management

Author(s):  
Donato Loddo ◽  
J. Scott McElroy ◽  
Vittoria Giannini

Despite the wide use of herbicides in the past century, their use is decreasing due to rising resistance phenomena, absence of discovery of new modes of actions and more regulatory restrictions. On the other hand, several tactics and technologies have developed recently providing alternatives from mechanical, cultural, robotic and natural products use perspectives, that could profitably enhance weed management within the agroecosystem and usher in a new paradigm of weed management that integrates chemical and non-chemical weed management practices. In the next future, herbicide will remain an important tool for weed management and will be increasingly complemented by other innovative tactics and tools in a IWM perspective. This integrated approach would thus preserve the chemical and transgenic technology for future generations.

Author(s):  
Rimma M. Khaninova ◽  

The article discusses ballads of the Kalmyk poets Tseren Ledzhinov “Бальчгин туск баллад” (“A Ballad about the Mud”, 1941) and Sanzhar Baidyev «Башмгудин туск баллад» (“A Ballad about Boots”, 1967). The analysis of the two ballads in the original showed that neither the content nor the form of Ledzhinov’s poem fits the announced genre. The poem by Baidyev, on the other hand, is one of the interesting ballads of the Kalmyk poetry of the past century, it is experimental in terms of the plot and the characters. The original text of S. Badyev’s work is compared to its Russian translation “Boots” translated by D. Dolinsky and V. Strelkov. The comparison revealed that the author’s conception and manifestation were altered by the translators in the aspect of semantic context and genre identity.


Author(s):  
Vanessa Lopes Lourenço Hanes

Given the massive changes that Brazil has undergone in the past century, particularly in distancing itself linguistically from its former colonizer, this study is an attempt to determine the role of translation in the country's cultural evolution. Translational approaches have developed along opposing poles: on the one hand, a strong resistance to incorporating orally-driven alterations in the written language, while on the other, a slow, halting movement toward convergence of the two, and both approaches are charged with political and ideological intentionality. Publishing houses, editors and translators are gatekeepers and agents whose activities provide a glimpse into the mechanism of national linguistic identity, either contributing to or resisting the myth of a homogenized Portuguese language.


2019 ◽  
pp. 169-190
Author(s):  
Rachel Chrastil

What happens to our stuff when we die? How might we reimagine the family tree? Childlessness raises, among others, questions about legacy, inheritance, our relationship with future generations, our ability to shape the future, and the narratives we tell about the past and the future. The author examines several life stories to help readers begin to envision childlessness within a new paradigm of meaning. This chapter encourages readers to consider new metaphors for how they think about childlessness. It ends with considerations about the deep and necessary connections between the childless and the childful within the quest for human flourishing.


1996 ◽  
Vol 76 (3) ◽  
pp. 537-544 ◽  
Author(s):  
F. C. Stevenson ◽  
A. T. Wright

Seeding rate and row spacing are management practices that affect flax seed yield. Two experiments were conducted from 1988 to 1990 to determine the influence of flax seeding rates (300, 600, and 900 seeds m−2) and row spacings (9, 18, and 27 cm). One was a flax-weed interference study (three sites) and the other was a weed-free study (13 sites). In the presence of weeds, increasing seeding rate from 300 to 900 seeds m−2 improved flax seed yield by 180 kg ha−1, and reduced broadleaf weed yields by 300 kg ha−1 and grassy weed yields by 180 kg ha−1. In weed-free conditions, seed yield was not affected by seeding rate. Row spacing did not affect flax yield and had minor effects on weed yields when weeds were not controlled. When weeds were controlled, seed yield in the 9-cm row spacing was 9% (15% in the flax-weed interference study) greater than in the two wider row spacings. Seeding rate and row spacing independently influenced flax yield, and their effect was consistent among sites with weeds present, but was not consistent when weeds were controlled. Our results showed that flax seeding rate was an important component of integrated weed management. Key words: Flax, seeding rate, row spacing, weed interference


Antiquity ◽  
1947 ◽  
Vol 21 (83) ◽  
pp. 116-121
Author(s):  
M. E. L. Mallowan

IT is a pity that Hume, who carried the Cartesian system of philosophy to its logical conclusion, lived too early to contemplate the discoveries of the past century in Egypt and Babylonia, for he would readily have understood and assimilated the ancient processes of thought which arose at the dawn of history in Western Asia--‘ And no truth appears to me more evident ’, he said, ‘ than that beasts are endowed with thought and reason as well as man ’. The arguments are developed in section XVI of ‘ The Understanding ’, where there are many delightful passages of special relevance to the ancient concepts about life. Again, he said that a bird, that ‘chooses with such care and nicety the place and materials of the nest, and sits upon her eggs for a due time, and in a suitable season, with all the precaution that a chymist is capable of in the most delicate projection, furnishes us with a lively instance of animal sagacity’. Locke, on the other hand, in his discussion of animal rationale, had refused to be drawn so far. ‘ And if Balaam’s ass had, all his life, discussed as rationally as he did once with his master, I doubt yet whether any one would have thought him worthy the name ‘man’, or allowed him to be of the same species with himself ’. Of these two statements Hume’s approximates more closely to the earliest Asiatic view of life, and it is on these lines that Messrs. Frankfort, Wilson, and Jacobsen have approached their problem, which, briefly put is-how did the early thinkers of the Near East come to say what they did about creation, the state, and man ? Professor and Mrs Frankfort define the earliest mode of thought as an ‘ I-thou ’ relation-ship, by which they mean that the primitive Asiatic conceived of all creation in a reciprocal nexus wherein the material world was percipient as well as perceived, and Professor Wilson elaborates the same theme by saying that for the Egyptians the world was consubstantial, and that their view of life might be defined as monophysite. Pro-fessor Jacobsen’s contribution illustrates to what extent the Mesopotamian view of life conformed with this outlook, for example how salt and grain were conceived of as animate beings in a close relationship with man, responsible and responsive to him. Other ideas peculiar to the Mesopotamian mind are no less clearly stressed, and herein lies the fascination of the book, that we have a comparative examination of the Egyptian, Mesopotamian and Israelite approach to life, for Hebrew theology was cast out of a similar matrix. In a concluding chapter by the Frankforts, we see the dawn of a new intellectual era. The Greek physical philosophers, regardless of the data of experience, carried the old basic concepts of the Egyptians and Mesopotamians from a concrete to an abstract frame and worked them to a reductio ad absurdurn, much as Hume did for the concepts of Cartesian philosophy. Their prescience gave birth to science. Nor should we forget that Thales of Miletus prophesied an eclipse, thereby following in the wake of the Babylonian astronomers, who had made similar observations and recorded them centuries earlier.


Weed Science ◽  
2018 ◽  
Vol 66 (6) ◽  
pp. 729-737 ◽  
Author(s):  
Thomas R. Butts ◽  
Bruno C. Vieira ◽  
Débora O. Latorre ◽  
Rodrigo Werle ◽  
Greg R. Kruger

AbstractWaterhemp [Amaranthus tuberculatus(Moq.) J. D. Sauer] is a troublesome weed occurring in cropping systems throughout the U.S. Midwest with an ability to rapidly evolve herbicide resistance that could be associated with competitive disadvantages. Little research has investigated the competitiveness of differentA. tuberculatuspopulations under similar environmental conditions. The objectives of this study were to evaluate: (1) the interspecific competitiveness of three herbicide-resistantA. tuberculatuspopulations (2,4-D and atrazine resistant [2A-R], glyphosate and protoporphyrinogen oxidase [PPO]-inhibitor resistant [GP-R], and 2,4-D, atrazine, glyphosate, and PPO-inhibitor susceptible [2AGP-S]) with soybean [Glycine max(L.) Merr.]; and (2) the density-dependent response of eachA. tuberculatuspopulation within a constant soybean population in a greenhouse environment.Amaranthus tuberculatuscompetitiveness with soybean was evaluated across five target weed densities of 0, 2, 4, 8, and 16 plants pot−1(equivalent to 0, 20, 40, 80, and 160 plants m−2) with 3 soybean plants pot−1(equivalent to 300,000 plants ha−1). At the R1 soybean harvest time, no difference in soybean biomass was observed acrossA. tuberculatuspopulations. AtA. tuberculatusdensities <8 plants pot−1, the 2AGP-S population had the greatest biomass and stem diameter per plant. At the R7 harvest time, the 2AGP-S population caused the greatest loss in soybean biomass and number of pods compared with the other populations at densities of <16 plants pot−1. The 2AGP-S population had greater early-season biomass accumulation and stem diameter compared with the otherA. tuberculatuspopulations, which resulted in greater late-season reduction in soybean biomass and number of pods. This research indicates there may be evidence of interspecific competitive fitness cost associated with the evolution of 2,4-D, atrazine, glyphosate, and PPO-inhibitor resistance inA. tuberculatus. Focus should be placed on effectively using cultural weed management practices to enhance crop competitiveness, especially early in the season, to increase suppression of herbicide-resistantA. tuberculatus.


Water Policy ◽  
2014 ◽  
Vol 17 (1) ◽  
pp. 46-60 ◽  
Author(s):  
Casey Furlong ◽  
Lachlan Guthrie ◽  
Saman De Silva ◽  
Robert Considine

The idea that water management should take an integrated approach has become the global paradigm over the past two decades. This new paradigm has come to be known by many different names. This paper explores the use, history and meaning of these competing terms, and discusses the possible implications of this term-proliferation. The literature indicates that a minimum of 26 distinct terms have been used. The use of different terms appears to have underwritten a belief that each term identifies a distinctly different field of study. After analysing sample definitions and subject areas for the eight most frequently used terms, it has been determined that some terms do have fundamental differences and others are essentially the same. This unnecessary term-proliferation contributes to a ‘knowledge silo’ effect, impeding knowledge-sharing and research advancement within the water management field. It is recommended that both academia and industry start actively considering term-proliferation when searching and publishing literature.


2006 ◽  
Vol 3 (3) ◽  
pp. 495-521 ◽  
Author(s):  
JAMES T. KLOPPENBERG

In December of 1850, exhausted by his role in French politics and recuperating from tuberculosis, Alexis de Tocqueville retreated to the Amalfi coast to think, write, and recover. To his best friend Louis de Kergolay, Tocqueville wrote about completing his memoir on the 1848 revolution and his plans to undertake a comprehensive account of French history that would explain the turmoil of the past century. The appeal was powerful, he explained to Kergolay, but “the difficulties are immense. The one that most troubles my mind comes from the mixture of history properly so called with historical philosophy. I still do not see how to mix these two things,” he conceded, “and yet, they must be mixed, for one could say that the first is the canvas and the second the color, and that it is necessary to have both at the same time in order to do the picture.” Tocqueville feared “that the one is harmful to the other, and that I lack the infinite art that would be necessary in order to choose properly the facts that must, so to speak, support the ideas.


2014 ◽  
Vol 8 (1) ◽  
pp. 21-57
Author(s):  
Gregory S. Alexander

Abstract Under the human flourishing theory of property, owners have obligations, positive as well as negative, that they owe to members of the various communities to which they belong. But are the members of those communities limited to living persons, or do they include non-living persons as well, i.e., future persons and the dead? This Article argues that owners owe two sorts of obligation to non-living members of our generational communities, one general, the other specific. The general obligation is to provide future generations with the basic material background conditions that are necessary for them to be able to carry out what I call life-transcending projects that their forebears have transmitted to them. The specific obligation is project-specific; that is, its purpose is to enable successive generational community members to whom particular life-transcending projects have been forwarded to be carried out in their way. The future generational members to whom the project is transferred must also be given whatever resources or goods are necessary to carry the project forward in its intended way. I argue further that each generational community owes its predecessors the obligation to accept life-transcending projects transmitted to them by their forebears and make reasonable efforts to carry those projects forward into the future. The obligation is based on the past generational community members’ dependency on their successors for the projects to continue into the future, a matter that is constitutive of the project creators’ flourishing. This obligation is defeasible, rather than absolute, however.


Author(s):  
Rupinder Saini ◽  
Sukhbir Singh

Over the last five decades, weed management systems have relied primarily on synthetic herbicides. Due to the concerns over the potential impact of chemicals on human health and the environment, efforts are being made to reduce the heavy reliance on synthetic herbicides. To reduce the use of synthetic herbicides, the use of natural products such as essential oils, plant extracts, allelochemicals, agricultural by-products, and some microbes are gaining attention because of their short environmental half-life and low toxicity. They are a good alternative to synthetic herbicides, especially in organic agriculture, since they focus on environmental protection, and ecological stability. Most of the commercially available natural herbicides are non-selective and require careful application in order to preserve the cash crops. Although many studies in this direction have been undertaken, the use of these natural products is still not common because of their cost the difficulties in their synthesis due to their complex structure, cost effectiveness, poor performance, and rapid degradation. When used singly, these natural herbicides do not perform as well as the chemical herbicides. An integrated approach may provide better results. Using a combination of natural herbicides may be more effective than using just one.&nbsp;&nbsp;


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