scholarly journals Experiences with Weed Discs and Other Nonchemical Alternatives for Container Weed Control

2003 ◽  
Vol 13 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Calvin Chong
Keyword(s):  
Weed Control ◽  
Water Use ◽  
Unit Cost ◽  
Peat Moss ◽  
The Past ◽  
Weed Growth ◽  
Corrugated Cardboard ◽  
Hand Weeding ◽  
New Generation ◽  
Small Holes

The first weed disc (Weed Guard) was introduced to Ontario in the early 1980s. They were made of semirigid plastic similar to 45-rpm records. Small holes allow water to penetrate but weeds germinating on the substrate often grow through them. In the 1990s, we obtained 85% reduction of container weeds using discs made from geotextile fabric (Mori Guard) or foam (similar to polyfoam used for container winter protection). The foam disc tended to curl upward at the edges, become easily windblown, and tended to partially expose the surface of the container mix. During the past 15 years, we have annually reused the same fabric discs (now unavailable due to high unit cost), and have tested various other weed discs, including several new-generation types and also the Mori Weed Bag. The new-generation discs are fabricated from materials such as fabric (Tex-R Geodisc), pressed peat moss (Biodisc), corrugated cardboard (Corrudisc), and plastic (Enviro LID). Both Tex-R Geodisc and Enviro LID were as effective or better in controlling weeds than weekly hand-weeding, herbicides, or the Mori Guard fabric disc. The Mori Weed Bag, a patented black polyethylene sleeve with prepunched holes fitted around the container like a florist's plant prepared for market, is used effectively and almost exclusively by one Ontario nursery. We also tested two types of insulated blanket covers, which when placed around the ball of above-ground container-grown trees, prevented weed growth during the summer and also protected the root ball against cold during the winter. We introduced the garbage bag sleeve, the ultimate no-weed method for pot-in-pot tree culture, which also reduces water use and frequency of irrigation. Due to factors such as under-performance, insufficient demand, and/or high costs, only certain discs are currently manufactured: Weed Guard, Tex-R Geodisc, Biodisc, and Enviro LID. The Mori Weed Bag is available but not the insulated blankets.

scholarly journals Effect of Weed Management Practices on Weed Growth and Yield of Greengram (Vigna radiata (L.) Wilczek) in Southern Rajasthan

2020 ◽  
pp. 12-19
Author(s):  
Arvind Verma ◽  
Roshan Choudhary
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Green Gram ◽  
Growth And Yield ◽  
Leaf Stage ◽  
Net Returns ◽  
Weed Growth ◽  
Hand Weeding ◽  
The Impact

A Field experiment was conducted at Agronomy instructional Farm, Rajasthan College of Agriculture, MPUAT, Udaipur (Rajasthan) during 2016-17 to find out the impact of new generation herbicides in green gram.  The results revealed that all growth and yield characters of blackgram were significantly affected by distinct weed control practices. A similar trend was also observed in weed parameters. Higher seed yield (13.8 qha-1) and higher weed control efficiency (88.97%) were recorded under application of acifluorfen sodium + clodinafop propargyl (370 g a.i. ha-1) at 3-4 leaf stage and which comparable with pre-emergence application of pyroxasulfone +pendimethalin (TM) 127.5+1000 g a.i/ha, imazethapyr+ quizalofop (TM) use at 70 + 60 g a.i/ha at 3-4 leaf stage, imazethapyr 70 g a.i/ha 3-4 leaf stage, imazethapyr + imazamox (RM) use at 70 g a.i/ha at 3-4 leaf stage, pendimethalin fb quizalofop 1000 + 60 at pre-emergence & 3- 4 leaf stage, imazethapyr + pendimethalin (RM) 1000 g a.i/ha as pre-emergence, propaquizfop 75 g a.i/ha at 3-4 leaf stage, weedy check and two hand weeding twice at 20 & 40 DAS. They also recorded improvement in yields and net returns by 65.22% over weedy check. These herbicide ready-mixes may be a promising weed management strategy for the green gram grown in the Southern Rajasthan.

scholarly journals Weed control efficacy of combined application of grass pea and mustard crop residues in T. aman rice

2021 ◽  
Vol 6 (2) ◽  
pp. 134-141
Author(s):  
Showrav Ashraf ◽  
Uttam Kumer Sarker ◽  
Suriaya Perveen ◽  
Mohammad Shahidul Islam ◽  
Shah Golam Azam ◽  
...  
Keyword(s):  
Weed Control ◽  
Crop Residues ◽  
Grass Pea ◽  
Allelopathic Potential ◽  
Straw Yield ◽  
Combined Application ◽  
Weed Growth ◽  
Combined Use ◽  
Mustard Crop ◽  
Hand Weeding

Among different methods of weed control, allelopathy could lead to reduced labor costs and increased efficiency, without any adverse effects on the environment. In this regard, an experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to evaluate the allelopathic potential of grass pea and mustard crop residues on weed suppression and crop performance of transplanted aman rice. The experiment consisted of three cultivars of T. aman rice viz., Binadhan-7, BRRI dhan49 and BR11 and five different level of crop residues such as no use of crop residues, grass pea crop residues @ 2.5 t ha-1, mustard crop residues @ 2.5 t ha-1, combined use of grass pea and mustard crop residues @ 1 t ha-1 of each and hand weeding. All crop residues applied in the experiment suppressed weed growth and inhibition at satisfactory level. The experiment was laid out in a randomized complete block design with three replications. Weed population, weed dry weight and percent inhibition of weed were not significantly influenced by the interaction effect of crop residues (grass pea and mustard) and cultivars. BR11 produced the highest grain and straw yield among the treatment combination. The highest numbers of tillers hill-1, numbers of grains panicle-1, 1000-grain weight, grain yield, straw yield were observed in hand weeding, followed by combined application of grass pea and mustard crop residues @ 1 t ha-1 of each treatment. The highest grain and straw yield (4.81 t ha-1 and 7.65 t ha-1) was observed in hand weeding along with variety BR11 and the second highest (4.19 t ha-1 and 7.36 t ha-1) was obtained from combined use of grass pea and mustard crop residues @ 1 t ha-1 of each. The results of this study indicate that hand weeding followed by combined application of grass pea and mustard crop residues @ 1 t ha-1 of each showed potential activity to suppress weed growth.

scholarly journals Effects of Preemergence Herbicides on Weed Control and Yield and Vase Life of Leatherleaf Fern

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 820D-820
Author(s):  
Robert H. Stamps
Keyword(s):  
Weed Control ◽  
Vase Life ◽  
Weed Biomass ◽  
Weed Growth ◽  
Herbicide Treatments ◽  
Postharvest Longevity ◽  
Hand Weeding ◽  
Rumohra Adiantiformis ◽  
Preemergence Herbicides ◽  
Establishment Phase

Six preemergence herbicides were applied twice a year at 1x and 2x rates for 2 years to leatherleaf fern [Rumohra adiantiformis (Forst.) Ching] starting from the time of rhizome planting. Predominant weeds present were Cardimine hirsuta, Erechrites hieracifolia, Oxalis stricta, and Phyllanthus tenellus. All herbicides, except pendimethalin and oxadiazon at the 1x rates, reduced weed biomass by 60% to 99% compared to the unweeded control during the fern bed establishment phase (year 1). During that period, hand-weeding times were reduced (51% to 95%) by prodiamine and dithiopyr at both rates, and oxadiazon and pendimethalin at 2x rates. During year 2, herbicides were of greatly reduced benefit due to reduced weed growth caused by the increasingly competitive fern. After 2 years, only 2x dithiopyr-treated plots had reduced yields compared to the hand-weeded controls. Herbicide treatments had no detrimental effects on frond postharvest longevity. In fact, fronds harvested from the 1x isoxaben-treated plots exhibited increased vase life compared to the controls.

Preceding (Rice-Okra) Crops Herbicide Residual Effects on Weed, Growth, Yield and Economics of Succeeding Blackgram Under Different Ecosystem

2020 ◽  
Author(s):  
N. Bommayasamy ◽  
C. R. Chinnamuthu
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Growth Yield ◽  
Residual Effect ◽  
Dry Weight ◽  
Residual Effects ◽  
Weed Growth ◽  
Weed Control Efficiency ◽  
Island Ecosystem ◽  
Hand Weeding

Field experiments were carried out during summer seasons of 2017 and 2018 to study the effect of preceding (Rice-Okra) crops herbicide residue on weed, growth, yield and economics of succeeding blackgram. Residual effect of butachlor at 1.25 kg/ha on 3 days after transplanting (DAT) fb hand weeding (HW) on 40 DAT imposed in the first season rice crop and followed by hand weeding (HW) twice at 20 and 40 days after sowing (DAS) (T6) in okra and blackgram significantly influenced the reduction of weed dry weight accumulation by 8.75 and 7.44 times in mainland and island ecosystem, respectively at 20 DAS. The same treatment recorded the highest weed control efficiency (WCE) of 88.6, 86.5 and 86.2, 80.7 % observed at 20 and 40 DAS under mainland and island ecosystem, respectively. Among, the weed control treatments, residual effect of butachlor at 1.25 kg/ha on 3 DAT fb HW on 40 DAT to rice and HW twice at 20 and 40 DAS (T6) to okra and blackgram has recorded 64.8 and 65.0% higher seed yield of blackgram under main and island ecosystem, respectively.

scholarly journals Yield and weed density of Blackgram (Vignamungo (L.) Hepper) as influenced by weed control methods

2017 ◽  
Vol 9 (2) ◽  
pp. 693-697
Author(s):  
S. Sahoo ◽  
G.N. Dhanapal ◽  
Pavankumar Goudar ◽  
M.T. Sanjay ◽  
M.K. Lal
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Control Methods ◽  
Rabi Season ◽  
Weed Population ◽  
Weed Density ◽  
Maximum Reduction ◽  
Weed Growth ◽  
Hand Weeding ◽  
Level Of Significance

The study conducted with pre-emergent herbicides alone and with sequential application of post-emergent herbicides at All India Co-ordinated Research Project (AICRP) on Weed management, Gandhi KrishiVignyan Kendra (GKVK), Bangalore in late rabi season of 2013 revealed the predominance of grasses over broad leaved weeds in blackgram. Interculture @ 20 days after sowing (DAS) and hand weeding @ 40 DAS resulted in higher yield (1182 and 5873 kg ha-1 seed and haulm yield, respectively) and least weed density of 41.33 m-2 during harvest. Uncontrolled weed growth recorded maximum population (70.00 m-2). During initial days pendimethalin 30 EC @ 0.75 kg a.i. ha-1 and alachlor 50 EC @ 1.0 kg a.i. ha-1 recorded significantly least weed population of 29.33 m-2at p< 0.05 level of significance. Uncontrolled weed growth resulted in maximum reduction in yield of 65.64 per cent.

scholarly journals Evaluation of different post-emergence herbicides in chickpea (Cicer arietenum L.)

2020 ◽  
Vol 1 (1) ◽  
pp. 87-91
Author(s):  
Indrajeet Niranjan ◽  
◽  
Shashank Tyagi ◽  
Birendra Kumar ◽  
Amit Pradhan
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Harvest Index ◽  
Dry Weight ◽  
Rabi Season ◽  
Straw Yield ◽  
Net Returns ◽  
Weed Growth ◽  
Hand Weeding ◽  
Quizalofop Ethyl

A field experiment was conducted during rabi season of 2018-2019 at research farm of Bihar Agricultural University, Sabour, Bhagalpur to assess the effect of various post-emergence herbicides in chickpea. The results indicated that among different herbicides, post-emergence application of imazethapyr + imazamox @ 60 g a.i. ha-1 at 20 days after sowing recorded significantly lowest weed density & weed dry weight at 60 days after sowing and highest weed control efficiency at harvest, which was statistically at par with quizalofop-ethyl + imazethapyr @ 60+50 g a.i. ha-1 at 20 days after sowing. As a consequence of effective weed control, quizalofop-ethyl + imazethapyr @ 60+50 g a.i. ha-1 at 20 days after sowing recorded significantly highest grain yield, straw yield and harvest index which was significantly superior over hand weeding twice at 30 and 50 days after sowing. In weedy check, uncontrolled weed growth caused significant reduction in grain yield of chickpea. Net returns and B:C ratio was found maximum with quizalofop-ethyl + imazethapyr @ 60+50 g a.i. ha-1 at 20 days after sowing which was significantly superior over weedy check.

The Contribution of Intermediate-Voltage, High-Resolution Electron Microscopy In Materials Science: An Appraisal

1990 ◽  
Vol 48 (1) ◽  
pp. 478-479
Author(s):  
John L. Hutchison
Keyword(s):  
High Resolution ◽  
Materials Science ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
The Past ◽  
Resolution Electron ◽  
Extreme Sensitivity ◽  
Electron Microscopes ◽  
New Generation ◽  
Small Metal Particles

Over the past five years or so the development of a new generation of high resolution electron microscopes operating routinely in the 300-400 kilovolt range has produced a dramatic increase in resolution, to around 1.6 Å for “structure resolution” and approaching 1.2 Å for information limits. With a large number of such instruments now in operation it is timely to assess their impact in the various areas of materials science where they are now being used. Are they falling short of the early expectations? Generally, the manufacturers’ claims regarding resolution are being met, but one unexpected factor which has emerged is the extreme sensitivity of these instruments to both floor-borne and acoustic vibrations. Successful measures to counteract these disturbances may require the use of special anti-vibration blocks, or even simple oil-filled dampers together with springs, with heavy curtaining around the microscope room to reduce noise levels. In assessing performance levels, optical diffraction analysis is becoming the accepted method, with rotational averaging useful for obtaining a good measure of information limits. It is worth noting here that microscope alignment becomes very critical for the highest resolution.In attempting an appraisal of the contributions of intermediate voltage HREMs to materials science we will outline a few of the areas where they are most widely used. These include semiconductors, oxides, and small metal particles, in addition to metals and minerals.

Increasing intrinsic water-use efficiency over the past 160 years does not stimulate tree growth in southeastern China

2018 ◽  
Vol 76 (2) ◽  
pp. 115-130 ◽  
Author(s):  
G Guo ◽  
K Fang ◽  
J Li ◽  
HW Linderholm ◽  
D Li ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Tree Growth ◽  
Southeastern China ◽  
The Past ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

Molecular Epidemiology and Biomarkers in Etiologic Cancer Research: The New in Light of the Old

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Gene Expression ◽  
Cancer Research ◽  
Molecular Epidemiology ◽  
Exposure Assessment ◽  
Large Scale ◽  
First Generation ◽  
Cancer Epidemiology ◽  
Policy Changes ◽  
The Past ◽  
New Generation

The purpose of this review is to evaluate progress inmolecular epidemiology over the past 24 years in canceretiology and prevention to draw lessons for futureresearch incorporating the new generation of biomarkers.Molecular epidemiology was introduced inthe study of cancer in the early 1980s, with theexpectation that it would help overcome some majorlimitations of epidemiology and facilitate cancerprevention. The expectation was that biomarkerswould improve exposure assessment, document earlychanges preceding disease, and identify subgroupsin the population with greater susceptibility to cancer,thereby increasing the ability of epidemiologic studiesto identify causes and elucidate mechanisms incarcinogenesis. The first generation of biomarkers hasindeed contributed to our understanding of riskandsusceptibility related largely to genotoxic carcinogens.Consequently, interventions and policy changes havebeen mounted to reduce riskfrom several importantenvironmental carcinogens. Several new and promisingbiomarkers are now becoming available for epidemiologicstudies, thanks to the development of highthroughputtechnologies and theoretical advances inbiology. These include toxicogenomics, alterations ingene methylation and gene expression, proteomics, andmetabonomics, which allow large-scale studies, includingdiscovery-oriented as well as hypothesis-testinginvestigations. However, most of these newer biomarkershave not been adequately validated, and theirrole in the causal paradigm is not clear. There is a needfor their systematic validation using principles andcriteria established over the past several decades inmolecular cancer epidemiology.

Vēsturiskā atmiņa Latvijas teātra jaunās paaudzes mākslinieku darbos: izrādes „Dvēseļu utenis” piemērs

2020 ◽  
pp. 269-275
Author(s):  
Ieva Rodiņa
Keyword(s):  
Historical Memory ◽  
Intergenerational Relationships ◽  
Phenomenological Approach ◽  
Political Theater ◽  
Hermeneutic Phenomenological ◽  
The Past ◽  
The Social ◽  
Humanistic Study ◽  
New Generation ◽  
Flea Market

The aim of the research “Historical Memory in the Works of the New Generation of Latvian Theater Artists: The Example of “The Flea Market of the Souls” is to focus on the current but at the same time little discussed topic in Latvian theater – the change of generations and the social processes connected to it, that are expressed on the level of world views, experiences, intergenerational relationships. Most directly, these changes are reflected in the phenomenon of historical memory. The concept of “postmemory” was defined by German professor Marianne Hirsch in 1992, suggesting that future generations are closely related to the personal and collective cultural traumas of previous generations, which are passing on the past experience through historical memory, thus affecting the present. Grotesque, self-irony, and focusing on socio-political, provocative questions and themes are the connecting point of the generation of young Latvian playwrights born in the late 1980s and early 1990s, including such personalities as Jānis Balodis, Rasa Bugavičute-Pēce, Matīss Gricmanis, Justīne Kļava, etc. However, unlike Matīss Gricmanis or Janis Balodis who represent the aesthetics of political theater, in Justīne Kļava’s works, sociopolitical processes become the background of a generally humanistic study of the relationships between generations. This theme is represented not only in “The Flea Market of the Souls”, but also in other plays, like “Jubilee ‘98” and “Club “Paradise””. The tendency to investigate the traces left by the Soviet heritage allows to define these works as autobiographical researches of the identity of the post-Soviet generation, analyzing life in today's Latvia in terms of historical memory. Using the semiotic, hermeneutic, phenomenological approach, the play “The Flea Market of the Souls” and its production in Dirty Deal Teatro (2017) are analyzed as one of the most vivid works reflecting the phenomenon of historical memory in recent Latvian original drama.

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