A method for building spatial model of annual weed seed dispersal from experimental data and its application to simulating Bromus sterilis population dispersal

2008 ◽  
Vol 210 (4) ◽  
pp. 446-452 ◽  
Author(s):  
Jihuai Wang ◽  
Svend Christensen ◽  
Preben Klarskov Hansen
Keyword(s):  
Experimental Data ◽  
Seed Dispersal ◽  
Spatial Model ◽  
Weed Seed ◽  
Population Dispersal

scholarly journals Potential for endozoochorous seed dispersal by sheep and goats: Risk of weed seed transport via animal faeces

Weed Research ◽  
2020 ◽  
Author(s):  
Mostafa Oveisi ◽  
Ahmad Ojaghi ◽  
Hamid Rahimian Mashhadi ◽  
Heinz Müller‐Schärer ◽  
Kamran Reza Yazdi ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Weed Seed ◽  
Sheep And Goats

scholarly journals Weed seed survival in experimental mini-silos of corn and alfalfa

2016 ◽  
Vol 96 (3) ◽  
pp. 448-454 ◽  
Author(s):  
Marie-Josée Simard ◽  
Camille Lambert-Beaudet
Keyword(s):  
Seed Dispersal ◽  
Seed Coat ◽  
Storage Time ◽  
Weed Seed ◽  
Weed Species ◽  
Water Imbibition ◽  
Nylon Mesh ◽  
Silage Fermentation ◽  
Weed Seeds ◽  
Mesh Bags

Weed seeds present in harvested silage have to survive silage fermentation and rumen digestion before they are dispersed as a contaminant of manure. Therefore, producing crops that are ensiled could lower the seed dispersal of weed escapes. This study is aimed at evaluating the viability of seven weed species after storage in experimental mini-silos filled with corn or alfalfa. Nylon mesh bags, each containing one hundred seeds of a weed species, were inserted at random locations in mini-silos filled with silage corn or alfalfa and stored for one, three or six months. The experiment included five mini-silos per storage time as well as untreated seeds. Water imbibition by intact seeds was also evaluated to determine if it could be related with survival in silage. After three and six months of storage few seeds were viable in any treatment (<0.1% of all seeds tested). Differences between weed species and silage type were observable after one month of storage and could not be related to seed coat permeability as measured by water imbibition. Ensiling for three to six months, or more, could be used to kill harvested weed seeds. Further evaluations in commercial farm silos could be done to support results.

Competitiveness of windmill grass (Chloris truncata) and feathertop Rhodes grass (Chloris virgata) in mungbean (Vigna radiata)

2020 ◽  
Vol 71 (10) ◽  
pp. 916
Author(s):  
Sudheesh Manalil ◽  
Ahmadreza Mobli ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Seed Dispersal ◽  
Weed Management ◽  
Vigna Radiata ◽  
Northern Region ◽  
Weed Seed ◽  
Weed Species ◽  
Rhodes Grass ◽  
Weed Plants ◽  
Crop Harvest ◽  
Chloris Virgata

Windmill grass (Chloris truncata R.Br.) and feathertop Rhodes grass (Chloris virgata Sw.) are two weeds of the northern region of Australia that are rapidly expanding in range, being favoured by conservation agricultural systems and prevailing weed management using a narrow pool of herbicides. Information on competitiveness and seed-production dynamics of these weeds is lacking for mungbean (Vigna radiata (L.) Wilczek), a major summer crop in the region. Field studies were conducted to evaluate the effect of different densities of these weed species on crop yield of mungbean in the 2016–17 (2016) and 2017–18 (2017) seasons. Windmill grass reduced mungbean yields by 56% with 39 weed plants m–2 in 2016 and 55% with 47 weed plants m–2 in 2017. Windmill grass produced a maximum of 98708 seeds m–2 in 2016 and 118613 seeds m–2 in 2017, and there was 15–21% seed dispersal at crop harvest. Competition from feathertop Rhodes grass resulted in yield losses of 73% with 49 weed plants m–2 and 65% with 45 weed plants m–2. Feathertop Rhodes grass produced a maximum of 229514 seeds m–2 in 2016 and 367190 seeds m–2 in 2017, and seed dispersal at crop harvest was only 3–7%. Competition from both weed species resulted in a significant reduction in number of pods per m2, grains per pod and 1000-grain weight of mungbean. These results show that windmill grass and feathertop Rhodes are highly competitive against mungbean, and their timely management is crucial for minimising yield loss. Although both weeds produced a substantial number of seeds, seed dispersal at crop harvest was low, especially for feathertop Rhodes grass. The high weed-seed retention relative to maturity of mungbean may help in managing these problematic weeds through various means including weed-seed capturing and destruction

Weed seed dispersal via runoff water and eroded soil

2018 ◽  
Vol 265 ◽  
pp. 488-502 ◽  
Author(s):  
Anneke de Rouw ◽  
Olivier Ribolzi ◽  
Mathilde Douillet ◽  
Hatsadong Tjantahosong ◽  
Bounsamay Soulileuth
Keyword(s):  
Seed Dispersal ◽  
Weed Seed ◽  
Runoff Water

scholarly journals Survival of the densest accounts for the expansion of mitochondrial mutations in ageing

2020 ◽  
Author(s):  
Ferdinando Insalata ◽  
Hanne Hoitzing ◽  
Juvid Aryaman ◽  
Nick S. Jones
Keyword(s):  
Experimental Data ◽  
Skeletal Muscle ◽  
Spatial Model ◽  
Copy Number ◽  
Wave Speed ◽  
Travelling Waves ◽  
Muscle Fibres ◽  
Mitochondrial Mutations ◽  
Noise Density ◽  
Skeletal Muscle Fibres

AbstractThe expansion of deleted mitochondrial DNA (mtDNA) molecules has been linked to ageing, particularly in skeletal muscle fibres; its mechanism has remained unclear for three decades. Previous accounts assigned a replicative advantage to the deletions, but there is evidence that cells can, instead, selectively remove defective mtDNA. We present a spatial model that, without a replicative advantage, but instead through a combination of enhanced density for mutants and noise, produces a wave of expanding mutations with wave speed consistent with experimental data, unlike a standard model based on replicative advantage. We provide a formula that predicts that the wave speed drops with copy number, in agreement with experimental data. Crucially, our model yields travelling waves of mutants even if mutants are preferentially eliminated. Justified by this exemplar of how noise, density and spatial structure affect muscle ageing, we introduce the mechanism of stochastic survival of the densest, an alternative to replicative advantage, that may underpin other phenomena, like the evolution of altruism.

The Influence of Weed Seed Dispersion Versus the Effect of Competition on Crop Yield

1992 ◽  
Vol 6 (1) ◽  
pp. 196-204 ◽  
Author(s):  
Bruce D. Maxwell ◽  
Claudio Ghersa
Keyword(s):  
Seed Dispersal ◽  
Crop Yield ◽  
Competitive Ability ◽  
Practical Implication ◽  
Demographic Data ◽  
Relative Importance ◽  
Weed Seed ◽  
Weed Species ◽  
Green Foxtail ◽  
Seed Dispersion

A theoretical model was developed to assess the relative importance of weed competition and seed dispersal in determining long-term crop yield reductions imposed by weeds. Weed seed dispersal by cultivation, natural means, and harvest machines was incorporated into a weed and crop population model. Model simulations were conducted with green foxtail and spring wheat demographic data from the literature. Simulations indicated that seed dispersal from a weed species invading a field may have a more important influence on crop yield than the relative competitive ability of the weed with respect to the crop. However, if a weed species has a uniform or a high frequency random distribution, there is less difference in the relative importance of dispersal versus competitive ability in determining crop yield reductions. Harvest machines may be an important mechanism for dispersing weed seeds that are harvested with the crop. The practical implication is to make harvesters weed seed ‘predators’ rather than dispersal agents and thereby reduce herbicide and mechanical weed control inputs.

Evaluating the potential for weed seed dispersal based on waterfowl consumption and seed viability

2017 ◽  
Vol 73 (12) ◽  
pp. 2592-2603 ◽  
Author(s):  
Jaime A Farmer ◽  
Elisabeth B Webb ◽  
Robert A Pierce ◽  
Kevin W Bradley
Keyword(s):  
Seed Dispersal ◽  
Seed Viability ◽  
Weed Seed

Modelling annual grass weed seed dispersal in winter wheat, when influenced by hedges and directional wind

2019 ◽  
Vol 410 ◽  
pp. 108729 ◽  
Author(s):  
Gayle. J. Somerville ◽  
Bo Melander ◽  
Per Kudsk ◽  
Solvejg K Mathiassen
Keyword(s):  
Seed Dispersal ◽  
Winter Wheat ◽  
Annual Grass ◽  
Weed Seed ◽  
Grass Weed
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