scholarly journals Shifting the Paradigm: An Ecological Systems Approach to Weed Management

Agriculture ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 179 ◽  
Author(s):  
Karla L. Gage ◽  
Lauren M. Schwartz-Lazaro
Keyword(s):  
Weed Control ◽  
Cover Crops ◽  
Weed Management ◽  
Systems Approach ◽  
Rapid Evolution ◽  
Ecological Systems ◽  
Integrated Weed Management ◽  
Biological Weed Control ◽  
Weed Ecology ◽  
Selection Pressures

Weeds have been historically, and are still today, the primary and most economically important pest in agriculture. Several selection pressures associated with weed management, such as an overreliance on herbicides, have promoted the rapid evolution of herbicide-resistant weeds. Integrated Weed Management (IWM) is promoted as an ecological systems approach, through the combination of biological, chemical, cultural, ecological, and mechanical control methods. The concept of a systems approach is defined as managing weeds by combining practice and knowledge with the goals of increasing yield and minimizing economic loss, minimizing risks to human health and the environment, and reducing energy requirements and off-target impacts. The reliance on herbicides in modern cropping systems has shifted the management focus from requiring intimate knowledge of biology, ecology, and ecological systems to herbicide chemistry, mixes, and rotations, application technology, and herbicide-tolerant crop traits. Here, an ecological systems approach is considered, examining new trends and technologies in relation to IWM and weed ecology. Prevention of spread, seedbank management, crop rotations, tillage, cover crops, competitive cultivars, biological weed control, and future solutions in concept-only are presented, and knowledge gaps are identified where research advancements may be possible. An ecological systems approach will provide improved stewardship of new herbicide technologies and reduce herbicide resistance evolution through diversification of selection pressures. Agroecological interactions should be studied in light of new, developing weed control technologies. The science of weed management needs to refocus on the foundations of weed biology and ecology to enable an ecological systems approach and promote agricultural sustainability.

scholarly journals Sustainable Weed Management for Conservation Agriculture: Options for Smallholder Farmers

Agriculture ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 118 ◽  
Author(s):  
Brian Sims ◽  
Sandra Corsi ◽  
Gualbert Gbehounou ◽  
Josef Kienzle ◽  
Makiko Taguchi ◽  
...  
Keyword(s):  
Weed Control ◽  
Cover Crops ◽  
Weed Management ◽  
Agricultural Production ◽  
Crop Production ◽  
Smallholder Farmers ◽  
Conservation Agriculture ◽  
Soil Tillage ◽  
Integrated Weed Management ◽  
Resource Base

Land degradation and soil fertility deterioration are two of the main causes of agricultural production stagnation and decline in many parts of the world. The model of crop production based on mechanical soil tillage and exposed soils is typically accompanied by negative effects on the natural resource base of the farming environment, which can be so serious that they jeopardize agricultural productive potential in the future. This form of agriculture is destructive to soil health and accelerates the loss of soil by increasing its mineralization and erosion rates. Conservation agriculture, a system avoiding or minimizing soil mechanical disturbance (no-tillage) combined with soil cover and crop diversification, is considered a sustainable agro-ecological approach to resource-conserving agricultural production. A major objective of tillage is supposed to be weed control, and it does not require very specific knowledge because soil inversion controls (at least temporarily) most weeds mechanically (i.e., by way of burying them). However, repeated ploughing only changes the weed population, but does not control weeds in the long term. The same applies to the mechanical uprooting of weeds. While in the short term some tillage operations can control weeds on farms, tillage systems can increase and propagate weeds off-farm. The absence of tillage, under conservation agriculture, requires other measures of weed control. One of the ways in which this is realized is through herbicide application. However, environmental concerns, herbicide resistance and access to appropriate agro-chemicals on the part of resource-poor farmers, highlight the need for alternative weed control strategies that are effective and accessible for smallholders adopting conservation agriculture. Farmers in semi-arid regions contend with the additional challenge of low biomass production and, often, competition with livestock enterprises, which limit the potential weed-suppressing benefits of mulch and living cover crops. This paper reviews the applicability and efficacy of various mechanical, biological and integrated weed management strategies for the effective and sustainable management of weeds in smallholder conservation agriculture systems, including the role of appropriate equipment and prerequisites for smallholders within a sustainable intensification scenario.

scholarly journals Spring-planted cover crops for weed control in soybean

2021 ◽  
pp. 1-8
Author(s):  
Katja Koehler-Cole ◽  
Christopher A. Proctor ◽  
Roger W. Elmore ◽  
David A. Wedin
Keyword(s):  
Weed Control ◽  
Biomass Production ◽  
Cover Crops ◽  
Weed Management ◽  
Block Design ◽  
Weed Suppression ◽  
Crop Species ◽  
Cold Temperatures ◽  
Weed Biomass ◽  
Small Grains

Abstract Replacing tillage with cover crops (CC) for weed management in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems with mechanical weed control has many soil health benefits but in the western Corn Belt, CC establishment after harvest is hampered by cold temperatures, limited labor and few compatible CC species. Spring-planted CC may be an alternative, but information is lacking on suitable CC species. Our objective was to evaluate four spring-planted CC with respect to biomass production and weed suppression, concurrent with CC growth and post-termination. Cover crop species tested were oat (Avena sativa L.), barley (Hordeum vulgare L.), brown mustard [Brassica juncea (L.) Czern.] and yellow mustard (Brassica hirta Moench). They were compared to no-CC treatments that were either tilled pre- and post-planting of soybean (no-CC tilled) or not tilled at all (no-CC weedy). CC were planted in late March to early April, terminated 52–59 days later using an undercutter, and soybean was planted within a week. The experiment had a randomized complete block design with four replications and was repeated for 3 years. Mustards and small grains produced similar amounts of biomass (1.54 Mg ha−1) but mustard biomass production was more consistent (0.85–2.72 Mg ha−1) than that of the small grains (0.35–3.81 Mg ha−1). Relative to the no-CC weedy treatment, mustards suppressed concurrent weed biomass in two out of 3 years, by 31–97%, and small grains suppressed concurrent weed biomass in only 1 year, by 98%. Six weeks after soybean planting, small grains suppressed weed biomass in one out of 3 years, by 79% relative to the no-CC weedy treatment, but mustards did not provide significant weed suppression. The no-CC tilled treatment suppressed weeds each year relative to the no-CC weedy treatment, on average 87%. The ineffective weed control by CC reduced soybean biomass by about 50% six weeks after planting. While spring-planted CC have the potential for pre-plant weed control, they do not provide adequate early season weed suppression for soybean.

scholarly journals Herbicide-resistant crops in resistant weed management : An industrial perspective

2005 ◽  
Vol 75 (4) ◽  
pp. 79-84 ◽  
Author(s):  
D. Shaner
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Wild Species ◽  
Integrated Weed Management ◽  
Herbicide Resistant ◽  
Resistant Varieties ◽  
Selection Of

Some of the first products of biotechnology to reach the marketplace have been herbicide-resistant crops. Industry sees the development of herbicide-resistant varieties as a way to increase the availability of proven herbicides for a broader range of crops. However, the development of herbicide- resistant crops requires special attention to potential environmental questions such as herbicide usage, selection of resistant weed biotypes and spread of resistance from the resistant crop to wild species. Industry is actively addressing these concerns during the process of development. Proper development and use of herbicide-resistant crops in integrated weed management programs will provide farmers with increased flexibility, efficiency, and decreased cost in their weed control practices without increasing the risk of herbicide-resistant weeds. Furthermore, herbicide-resistant crops should prove to be valuable tools in managing herbicide- resistant weeds.

scholarly journals Growth suppression of sandspur grass by cover crops1

2015 ◽  
Vol 45 (3) ◽  
pp. 319-325 ◽  
Author(s):  
Rodrigo Fonseca da Silva ◽  
Leandro Pereira Pacheco ◽  
Leandro dos Santos Soares ◽  
Wéverson Lima Fonseca ◽  
João Batista da Silva Oliveira ◽  
...  
Keyword(s):  
Leaf Area ◽  
Cover Crops ◽  
Weed Management ◽  
Pennisetum Glaucum ◽  
Control Treatment ◽  
Integrated Weed Management ◽  
Fagopyrum Tataricum ◽  
Root Volume ◽  
Crambe Abyssinica ◽  
Dry Biomass

ABSTRACTSandspur grass has hindered the integrated weed management in the Brazilian crop systems. This study aimed at evaluating the efficiency of biomass levels of different cover crops on the soil surface to control the sandspur grass. A complete randomized blocks design with four replications, in a 6 x 5 + 1 factorial arrangement, was used. The first factor consisted of six cover crops (Pennisetum glaucum-ADR 7010 and ADR 300 cultivars, Crotalaria ochroleuca, Urochloa ruziziensis, Fagopyrum tataricum and Crambe abyssinica) and the second one consisted of five biomass levels of each species (2 t ha-1, 4 t ha-1, 8 t ha-1, 12 t ha-1 and 16 t ha-1), plus a control treatment without soil cover. The variables analyzed were the total number of emerged plants, germination speed index, leaf area, root volume and shoot and root dry biomass. U. ruziziensis excelled in the suppression of C. echinatus growth by reducing the number of emerged plants, emergence speed index, shoot and root dry biomass, root volume and leaf area.

scholarly journals Non-Chemical Weed Management in Vegetables by Using Cover Crops: A Review

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 257 ◽  
Author(s):  
Husrev Mennan ◽  
Khawar Jabran ◽  
Bernard H. Zandstra ◽  
Firat Pala
Keyword(s):  
Weed Control ◽  
Cover Crops ◽  
Weed Management ◽  
Water Conservation ◽  
Crop Residues ◽  
Production Systems ◽  
Organic Production ◽  
Substantial Part ◽  
Vegetable Production ◽  
Negative Effects

Vegetables are a substantial part of our lives and possess great commercial and nutritional value. Weeds not only decrease vegetable yield but also reduce their quality. Non-chemical weed control is important both for the organic production of vegetables and achieving ecologically sustainable weed management. Estimates have shown that the yield of vegetables may be decreased by 45%–95% in the case of weed–vegetable competition. Non-chemical weed control in vegetables is desired for several reasons. For example, there are greater chances of contamination of vegetables by herbicide residue compared to cereals or pulse crops. Non-chemical weed control in vegetables is also needed due to environmental pollution, the evolution of herbicide resistance in weeds and a strong desire for organic vegetable cultivation. Although there are several ways to control weeds without the use of herbicides, cover crops are an attractive choice because these have a number of additional benefits (such as soil and water conservation) along with the provision of satisfactory and sustainable weed control. Several cover crops are available that may provide excellent weed control in vegetable production systems. Cover crops such as rye, vetch, or Brassicaceae plants can suppress weeds in rotations, including vegetables crops such as tomato, cabbage, or pumpkin. Growers should also consider the negative effects of using cover crops for weed control, such as the negative allelopathic effects of some cover crop residues on the main vegetable crop.

Herbicide Timing and Rate Effects on Weed Management in Three Herbicide-Resistant Canola Systems

2004 ◽  
Vol 18 (4) ◽  
pp. 1006-1012 ◽  
Author(s):  
K. Neil Harker ◽  
George W. Clayton ◽  
John T. O'Donovan ◽  
Robert E. Blackshaw ◽  
F. Craig Stevenson
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Integrated Weed Management ◽  
Weed Biomass ◽  
Herbicide Resistant ◽  
Leaf Stage ◽  
Rate Effects ◽  
Herbicide Timing ◽  
Weed Removal

Herbicide-resistant canola dominates the canola market in Canada. A multiyear field experiment was conducted at three locations to investigate the effect of time of weed removal (two-, four-, or six-leaf canola) and herbicide rate (50 or 100% recommended) in three herbicide-resistant canola systems. Weeds were controlled in glufosinate-resistant canola (GLU) with glufosinate, in glyphosate-resistant canola (GLY) with glyphosate, and in imidazolinone-resistant canola (IMI) with a 50:50 mixture of imazamox and imazethapyr. Canola yields were similar among the three canola cultivar–herbicide systems. Yields were not influenced by 50 vs. 100% herbicide rates. Timing of weed removal had the greatest effect on canola yield, with weed removal at the four-leaf stage giving the highest yields in most cases. Percent dockage was often greater for GLU and IMI than for GLY. In comparison with the other treatments, dockage levels doubled for GLU after application at 50% herbicide rates. The consistency of monocot weed control was usually greater for GLY than for GLU or IMI systems. However, weed biomass data revealed no differences in dicot weed control consistency between IMI and GLY systems. Greater dockage and weed biomass variability after weed removal at the six-leaf stage or after low herbicide rates suggests higher weed seed production, which could constrain the adoption of integrated weed management practices in subsequent years.

The economic value of haying and green manuring in the integrated management of annual ryegrass and wild radish in a Western Australian farming system

2004 ◽  
Vol 44 (12) ◽  
pp. 1195 ◽  
Author(s):  
M. Monjardino ◽  
D. J. Pannell ◽  
S. B. Powles
Keyword(s):  
Weed Control ◽  
Herbicide Resistance ◽  
Weed Management ◽  
Integrated Management ◽  
Farming System ◽  
Integrated Weed Management ◽  
Annual Ryegrass ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Green Manuring

Most cropping farms in Western Australia must deal with the management of herbicide-resistant populations of weeds such as annual ryegrass (Lolium rigidum) and wild radish (Raphanus raphanistrum). Farmers are approaching the problem of herbicide resistance by adopting integrated weed management systems, which allow weed control with a range of different techniques. These systems include non-herbicide methods ranging from delayed seeding and high crop seeding rates to the use of non-cropping phases in the rotation. In this paper, the Multi-species RIM (resistance and integrated management) model was used to investigate the value of including non-cropping phases in the crop rotation. Non-crop options investigated here were haying and green manuring. Despite them providing excellent weed control, it was found that inclusion of these non-cropping phases did not increase returns, except in cases of extreme weed numbers and high levels of herbicide resistance.

scholarly journals Weed Management in Cranberries: A Historical Perspective and a Look to the Future

Agriculture ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 138 ◽  
Author(s):  
Hilary Sandler
Keyword(s):  
Weed Control ◽  
Precision Agriculture ◽  
Weed Management ◽  
Management Practices ◽  
Integrated Weed Management ◽  
Unmanned Aerial Systems ◽  
Early 19Th Century ◽  
Research Areas ◽  
Hand Weeding ◽  
The Impact

Integrated weed management (IWM) has been part of cranberry cultivation since its inception in the early 19th century. Proper site and cultivar selection, good drainage, rapid vine establishment, and hand weeding are as important now for successful weed management as when the industry first started. In 1940, Extension publications listed eight herbicides (e.g., petroleum-based products, inorganic salts and sulfates) for weed control. Currently, 18 herbicides representing 11 different modes of action are registered for use on cranberries. Nonchemical methods, such as hand weeding, sanding, flooding, and proper fertilization, remain integral for managing weed populations; new tactics such as flame cultivation have been added to the toolbox. Priority ratings have been developed to aid in weed management planning. Despite many efforts, biological control of weeds remains elusive on the commercial scale. Evaluation of new herbicides, unmanned aerial systems (UAS), image analysis, and precision agriculture technology; investigation of other management practices for weeds and their natural enemies; utilization of computational decision making and Big Data; and determination of the impact of climate change are research areas whose results will translate into new use recommendations for the weed control of cranberry.

Influence of Weed Management Practices and Crop Rotation on Glyphosate-Resistant Horseweed Population Dynamics and Crop Yield

Weed Science ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 508-516 ◽  
Author(s):  
Vince M. Davis ◽  
Kevin D. Gibson ◽  
Thomas T. Bauman ◽  
Stephen C. Weller ◽  
William G. Johnson
Keyword(s):  
Population Dynamics ◽  
Crop Rotation ◽  
Crop Yield ◽  
Cover Crops ◽  
Weed Management ◽  
Management Practices ◽  
Plant Density ◽  
Management Systems ◽  
Integrated Weed Management ◽  
Rapid Decline

Horseweed is an increasingly problematic weed in soybean because of the frequent occurrence of glyphosate-resistant (GR) biotypes. The objective of this study was to determine the influence of crop rotation, winter wheat cover crops (WWCC), residual nonglyphosate herbicides, and preplant herbicide application timing on the population dynamics of GR horseweed and crop yield. A field study was conducted at a site with a moderate infestation of GR horseweed (approximately 1 plant m−2) with crop rotation (soybean–corn or soybean–soybean) as main plots and management systems as subplots. Management systems were evaluated by quantifying horseweed plant density, seedbank density, and crop yield. Crop rotation did not influence in-field horseweed or seedbank densities at any data census timing. Preplant herbicides applied in the spring were more effective at reducing horseweed plant densities than when applied in the previous fall. Spring-applied, residual herbicide systems were the most effective at reducing season long horseweed densities and protecting crop yield because horseweed in this region behaves primarily as a summer annual weed. Horseweed seedbank densities declined rapidly in the soil by an average of 76% for all systems over the first 10 mo before new seed rain. Despite rapid decline in total seedbank density, seed for GR biotypes remained in the seedbank for at least 2 yr. Therefore, to reduce the presence of GR horseweed biotypes in a local no-till weed flora, integrated weed management (IWM) systems should be developed to reduce total horseweed populations based on the knowledge that seed for GR biotypes are as persistent in the seed bank as glyphosate-sensitive (GS) biotypes.

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