Weed management: fact or fable?

1981 ◽  
Vol 295 (1076) ◽  
pp. 185-197 ◽  
Keyword(s):  
Weed Control ◽  
Growth Regulators ◽  
Weed Management ◽  
Crop Production ◽  
Management Practices ◽  
Production Systems ◽  
Cropping System ◽  
Ground Cover ◽  
Management Approach ◽  
Leguminous Crops

Weed management is a new term for the age-old practice of employing all available means, in a planned way, to keep weed populations under control. It seeks to distinguish the systematic approach to weed control, based on scientific knowledge and rational strategies, from the pragmatic destruction of weeds. The remarkable efficiency of herbicides has in recent years emphasized the latter and allowed revolutionary methods of crop production to be practised. These have, however, led to serious new weed problems which in turn require more intensive herbicide use. The need for a weed management approach is increasingly recognized. New opportunities for this are provided by the availability of numerous herbicides and plant growth regulators and a growing understanding of the biology, ecology and population dynamics of weeds in relation to crop production systems. Examples discussed include: systematic control of grass weeds in intensive cereals in Britain, weed control in rice and in soybeans, the control of aquatic weeds by biological and chemical methods and an experimental zero-tillage cropping system for the humid tropics based on herbicides, growth regulators and ground-cover leguminous crops. In such management systems, interference of weed behaviour by exogenous growth regulators is likely to be of increasing significance. Constraints on the adoption of weed management practices include lack of support for weed science as a discipline, limited appeal to the agrochemical industry and inadequate extension services in many countries.

scholarly journals Reducing the Risks of Herbicide Resistance: Best Management Practices and Recommendations

Weed Science ◽  
2012 ◽  
Vol 60 (SP1) ◽  
pp. 31-62 ◽  
Author(s):  
Jason K. Norsworthy ◽  
Sarah M. Ward ◽  
David R. Shaw ◽  
Rick S. Llewellyn ◽  
Robert L. Nichols ◽  
...  
Keyword(s):  
Weed Control ◽  
Herbicide Resistance ◽  
Best Management Practices ◽  
Weed Management ◽  
Crop Production ◽  
Management Practices ◽  
Production Systems ◽  
Herbicide Resistant ◽  
Economic Thresholds ◽  
Soil Seedbank

Herbicides are the foundation of weed control in commercial crop-production systems. However, herbicide-resistant (HR) weed populations are evolving rapidly as a natural response to selection pressure imposed by modern agricultural management activities. Mitigating the evolution of herbicide resistance depends on reducing selection through diversification of weed control techniques, minimizing the spread of resistance genes and genotypes via pollen or propagule dispersal, and eliminating additions of weed seed to the soil seedbank. Effective deployment of such a multifaceted approach will require shifting from the current concept of basing weed management on single-year economic thresholds.

Russian Thistle (Salsola iberica) and Kochia (Kochia scoparia) Control in Dryland Corn (Zea mays)

1990 ◽  
Vol 4 (3) ◽  
pp. 631-634 ◽  
Author(s):  
R. E. Blackshaw
Keyword(s):  
Zea Mays ◽  
Weed Control ◽  
Crop Production ◽  
Production Systems ◽  
Cropping System ◽  
Field Studies ◽  
Kochia Scoparia ◽  
Field Corn ◽  
Salsola Iberica

Field studies were conducted in 1987, 1988, and 1989 at Lethbridge, Alberta to determine suitable herbicides for the control of Russian thistle and kochia in field corn grown in a dryland cropping system. Soil-applied atrazine or cyanazine provided inconsistent control of these weeds under dryland conditions. Combining inter-row tillage or 2,4-D applied postemergence with soil-applied atrazine improved the consistency of weed control over years. Postemergence atrazine and dicamba plus 2,4-D controlled Russian thistle and kochia in all years. Corn yields reflected the level of weed control attained with each treatment. The suitability of the various treatments for weed control in corn grown under dryland crop production systems is discussed.

scholarly journals A critical review of integrated grass weed management in Ireland

2018 ◽  
Vol 57 (1) ◽  
pp. 15-28 ◽  
Author(s):  
R. Byrne ◽  
J. Spink ◽  
R. Freckleton ◽  
P. Neve ◽  
S. Barth
Keyword(s):  
Weed Control ◽  
Herbicide Resistance ◽  
Weed Management ◽  
Crop Production ◽  
Management Approach ◽  
Arable Crops ◽  
Irish Context ◽  
Sowing Dates ◽  
Cultivation Techniques ◽  
Grass Weed

AbstractGrass weeds affect arable crops throughout the world, inflicting yield penalties, reducing crop quality and taking available nutrients away from the growing crop. Recently in Ireland, the presence of herbicide resistance in grass weeds has been noted. In order to preserve the sustainability of crop production in Ireland, an integrated pest management approach must be implemented. How this applies to control grass weeds was the focus of this review. Here we examined the state of current research into grass weed biology and the nature of herbicide resistance, identifying gaps in research in the Irish context. We identified a number of cultural grass weed control techniques, as being relevant to the Irish mode of crop production. Crop rotation, cultivation techniques, manipulation of sowing dates and increased crop competition were recognised as useful strategies. Combining these strategies to provide effective grass weed control may be key to reduce dependence on herbicides.

scholarly journals Assessing weeds at risk of evolving glyphosate resistance in Australian sub-tropical glyphosate-resistant cotton systems

2011 ◽  
Vol 62 (11) ◽  
pp. 1002 ◽  
Author(s):  
Jeff Werth ◽  
David Thornby ◽  
Steve Walker
Keyword(s):  
High Risk ◽  
Weed Management ◽  
Management Practices ◽  
Cropping Systems ◽  
Cropping System ◽  
Glyphosate Resistance ◽  
Management Approach ◽  
Weed Species ◽  
Summer Fallow ◽  
Very High

Glyphosate resistance will have a major impact on current cropping practices in glyphosate-resistant cotton systems. A framework for a risk assessment for weed species and management practices used in cropping systems with glyphosate-resistant cotton will aid decision making for resistance management. We developed this framework and then assessed the biological characteristics of 65 species and management practices from 50 cotton growers. This enabled us to predict the species most likely to evolve resistance, and the situations in which resistance is most likely to occur. Species with the highest resistance risk were Brachiaria eruciformis, Conyza bonariensis, Urochloa panicoides, Chloris virgata, Sonchus oleraceus and Echinochloa colona. The summer fallow and non-irrigated glyphosate-resistant cotton were the highest risk phases in the cropping system. When weed species and management practices were combined, C. bonariensis in summer fallow and other winter crops were at very high risk. S. oleraceus had very high risk in summer and winter fallow, as did C. virgata and E. colona in summer fallow. This study enables growers to identify potential resistance risks in the species present and management practices used on their farm, which will to facilitate a more targeted weed management approach to prevent development of glyphosate resistance.

scholarly journals Weed Management Strategies to Reduce Herbicide Use in Zero-Till Rice–Wheat Cropping Systems of the Indo-Gangetic Plains

2013 ◽  
Vol 27 (1) ◽  
pp. 241-254 ◽  
Author(s):  
Virender Kumar ◽  
Samar Singh ◽  
Rajender S. Chhokar ◽  
Ram K. Malik ◽  
Daniel C. Brainard ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Crop Residues ◽  
Management Strategies ◽  
Cropping System ◽  
Weed Suppression ◽  
Long Term Effects ◽  
Weed Ecology ◽  
Gangetic Plains

In the rice–wheat (RW) systems of the Indo-Gangetic Plains of South Asia, conservation tillage practices, including zero-tillage (ZT), are being promoted to address emerging problems such as (1) shortages of labor and water, (2) declining factor productivity, (3) deterioration of soil health, and (4) climate change. Despite multiple benefits of ZT, weed control remains a major challenge to adoption, resulting in more dependence on herbicides for weed control. Alternative management strategies are needed to reduce dependence on herbicides and minimize risks associated with their overuse, including evolution of herbicide resistance. The objectives of this review are to (1) highlight and synthesize research efforts in nonchemical weed management in ZT RW systems and (2) identify future weed ecology and management research needs to facilitate successful adoption of these systems. In ZT RW systems, crop residue can play a central role in suppressing weeds through mulch effects on emergence and seed predation. In ZT rice, wheat residue mulch (5 t ha−1) reduced weed density by 22 to 76% and promoted predation of RW weeds, including littleseed canarygrass and barnyardgrass seeds. For ZT wheat, rice residue mulch (6 to 10 t ha−1) in combination with early sowing reduced emergence of littleseed canarygrass by over 80%. Other promising nonchemical approaches that can be useful in suppressing weeds in ZT RW systems include use of certified seeds, weed-competitive cultivars, stale seedbed practices, living mulches (e.g., sesbania coculture), and water and nutrient management practices that shift weed–crop competition in favor of the crop. However, more research on emergence characteristics and mulching effects of different crop residues on key weeds under ZT, cover cropping, and breeding crops for weed suppression will strengthen nonchemical weed management programs. Efforts are needed to integrate multiple tactics and to evaluate long-term effects of nonchemical weed management practices on RW cropping system sustainability.

scholarly journals Growth and Yield Response of Wheat to Tillage, Rice Residue and Weed Management under Rice–Wheat Cropping System

2020 ◽  
Vol 1 (1) ◽  
pp. 43-48
Author(s):  
Bisheshwor Prasad Pandey ◽  
Tanka Prasad Kandel
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Weed Management ◽  
Production Systems ◽  
Cropping System ◽  
Growth And Yield ◽  
Yield Response ◽  
Potential Yield ◽  
Yield Attributes ◽  
Residue Retention

Recent decades have seen many changes in agricultural production systems in Nepal, such as increased mechanization for harvesting of major cereal crops, which leaves a large volume of crop residue in the field, increased herbicide application for weed control, and increased adoption of reduced tillage systems. In this study, we compared the effects of tillage, rice residue and weed managements on yield and yield attributes of wheat cultivated under rice-wheat rotation in the Southern Plain (Terai) region of Nepal. The study was conducted during the wheat growing seasons (November through April) of 2013–2014, 2014–2015 and 2015–2016 in Rupandehi district. The experiment was deployed in a split-split plot design with tillage system as main plot [conventional tillage (CT) and zero tillage (ZT)], residue removal management as a sub-plot [whole residue retained (WR), partial residue retained (PR) and no residue retained (NR)], and weed management as a sub-sub plot [(manual weeding (MW) and chemical weeding (CW)], replicated three times. Analysis of variance was applied to the yield and yield attributes of wheat for fixed and interaction effects. Averaged across the years, the CT system (2.4 t ha–1) had significantly higher yield than ZT (2.2 t ha–1) but the difference was not consistent in all study years. While rice residue retention did not influence grain yield in Year1, WR produced greatest and NR produced lowest yield in Year2 and Year3, indicating potential yield increase in wheat following the whole rice residue retention in the long run. Grain yield did not significantly vary with weed management method, suggesting that manual weed control can be as effective as herbicide in weed management in wheat agroecosystem in the Southern Plains (Terai) region of Nepal.

scholarly journals Crop Diversification for Improved Weed Management: A Review

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 461
Author(s):  
Gourav Sharma ◽  
Swati Shrestha ◽  
Sudip Kunwar ◽  
Te-Ming Tseng
Keyword(s):  
Climate Change ◽  
Weed Management ◽  
Crop Production ◽  
Production Systems ◽  
Cropping System ◽  
Farming Systems ◽  
Crop Diversification ◽  
Herbicide Resistant ◽  
Technology Innovations ◽  
Diversified Farming Systems

Weeds are among the major constraints to any crop production system, reducing productivity and profitability. Herbicides are among the most effective methods to control weeds, and reliance on herbicides for weed control has increased significantly with the advent of herbicide-resistant crops. Unfortunately, over-reliance on herbicides leads to environmental-health issues and herbicide-resistant weeds, causing human health and ecological concerns. Crop diversification can help manage weeds sustainably in major crop production systems. It acts as an organizing principle under which technological innovations and ecological insights can be combined to manage weeds sustainably. Diversified cropping can be defined as the conscious inclusion of functional biodiversity at temporal and/or spatial levels to improve the productivity and stability of ecosystem services. Crop diversification helps to reduce weed density by negatively impacting weed seed germination and weed growth. Additionally, diversified farming systems are more resilient to climate change than monoculture systems and provide better crop yield. However, there are a few challenges to adopting a diversified cropping system, ranging from technology innovations, government policies, farm-level decisions, climate change, and market conditions. In this review, we discuss how crop diversification supports sustainable weed management, the challenges associated with it, and the future of weed management with respect to the diversification concept.

Banded Herbicide Applications and Cultivation in a Modified No-till Corn (Zea mays) System

1992 ◽  
Vol 6 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Allan G. Eadie ◽  
Clarence J. Swanton ◽  
James E. Shaw ◽  
Glen W. Anderson
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Soil Conservation ◽  
Crop Production ◽  
Field Experiments ◽  
Production Systems ◽  
Corn Production ◽  
No Till ◽  
Annual Weeds ◽  
Corn Grain

The acceptance of no-till crop production systems has been limited due to expected problems with weed management. Field experiments were established at two locations in Ontario in 1988 and one location in 1989. Band or broadcast applications of preemergence (PRE) combinations of high or low label rates of atrazine with or without metolachlor or inter-row cultivation, were evaluated for their effectiveness in controlling annual weeds in no-till corn. At each location, different herbicide and cultivation combinations were required to achieve adequate weed control. Corn grain yield was equivalent regardless of whether herbicides were applied as a band or broadcast treatment at all three sites. At two of the three sites, one cultivation combined with herbicides applied as a band was adequate to maintain weed control and corn grain yields. Selective application of herbicides in bands represented an approximate 60% reduction in total herbicide applied into the environment. The integration of a shallow post-plant inter-row cultivation combined with the soil conservation attributes of no-till, would enhance the sustainability of a modified no-till corn production system.

scholarly journals Weed management practices in natural ecosystems: a critical overview

Koedoe ◽  
2000 ◽  
Vol 43 (1) ◽  
Author(s):  
C.F. Reinhardt
Keyword(s):  
Biological Control ◽  
Weed Management ◽  
Crop Production ◽  
Management Practices ◽  
Production Systems ◽  
Management Practice ◽  
Management Tool ◽  
Natural Ecosystems ◽  
Basic Biology ◽  
Herbicide Use

Increasing public pressure against the use of pesticides and other agricultural inputs has placed increased emphasis on the development of ecologically based pest management. One distinct reaction of the Weed Science discipline has been the swing away from herbicide research to increased research on the basic biology and ecology of weeds in hopes of reduced reliance on "technological crutches" such as herbicides and other practices that are potentially harmful to the environment. Biological control is the long-standing alternative to the use of herbicides and interest in the former practice has been boosted by the realization that the use of herbicides may lead to the development of herbicide resistance in weed populations, and that herbicide residues occur in surface and groundwater. Supporters of herbicide use would point out that biological control is generally not effective in crop production systems, and is basically slow-acting. Debates between protagonists for the exclusive use of one or the other weed management practice tend to obscure the benefits that integration of different techniques are likely to have. For natural ecosystems it is proposed that integration of the more subtle practice of biological control with the use of herbicides, which relatively quickly overwhelm a biological system with mortality, is likely to be the most effective weed management tool. Different weed management practices that could be considered in natural ecosystems are discussed in terms of three key performance rating criteria, viz. activity, selec- tivity and persistence In this concise review, general discussion is focussed on the fundamentals of weed management practices, with the view to promote concept-based approaches that are critical for the development of effective weed management strate- gies.

scholarly journals Crop Diversification for Improved Weed Management: A Review

2021 ◽  
Author(s):  
Gourav Sharma ◽  
Swati Shrestha ◽  
Kunwar Sudip ◽  
Te Ming Tseng
Keyword(s):  
Climate Change ◽  
Weed Management ◽  
Crop Production ◽  
Production Systems ◽  
Cropping System ◽  
Farming Systems ◽  
Crop Diversification ◽  
Herbicide Resistant ◽  
Technology Innovations ◽  
Diversified Farming Systems

Weeds are among the major constraints to any crop production system, reducing productivity and profitability. Herbicides are among the most effective methods to control weeds, and reliance on herbicides for weed control has increased significantly with the advent of herbicide-resistant crops. Unfortunately, over-reliance on herbicides leads to environmental-health issues and herbicide-resistant weeds, causing human-health and ecological concerns. Crop diversification can help manage weeds sustainably in major crop production systems. It acts as an organizing principle under which technological innovations and ecological insights can be combined to manage weeds sustainably. Diversified cropping can be defined as the conscious inclusion of functional biodiversity at temporal and/or spatial levels to improve the productivity and stability of ecosystem services. Crop diversification helps to reduce weed density by negatively impacting weed seed germination and weed growth. Additionally, diversified farming systems are more resilient to climate change than monoculture systems and provide better crop yield. However, there are a few challenges to adopting a diversified cropping system, which ranges from technology innovations, government policies, farm-level decisions, climate change, and market conditions. In this review, we discuss how crop diversification supports sustainable weed management, the challenges associated with it, and the future of weed management with respect to the diversification concept.

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