The Effect of Rotation and In-Crop Weed Management on the Germinable Weed Seedbank after 10 Years

Weed Science ◽  
2011 ◽  
Vol 59 (4) ◽  
pp. 553-561 ◽  
Author(s):  
Robert H. Gulden ◽  
Derek W. Lewis ◽  
Jane C. Froese ◽  
Rene C. Van Acker ◽  
Gary B. Martens ◽  
...  
Keyword(s):  
Crop Rotation ◽  
Weed Management ◽  
Management Practices ◽  
Production Systems ◽  
Yield Response ◽  
Environmental Damage ◽  
Long Term Effects ◽  
Community Size ◽  
Herbicide Resistant ◽  
Alternate Control

Agricultural production systems that reduce the use of in-crop herbicides could greatly reduce risks of environmental damage and the development of herbicide-resistant weeds. Few studies have investigated the long-term effects of in-crop herbicide omissions on weed seedbank community size and structure. A crop-rotation study was sampled 10 yr after a strictly annual rotation and an annual/perennial rotation were exposed to different in-crop herbicide omission treatments. In-crop herbicides were applied either in all annual crops (control), omitted from oats only, or omitted from both flax and oats. Seedbank densities were greatest when in-crop herbicides were omitted from flax and oats, and this treatment also reduced crop yield. Shannon-Wiener diversity differed among crops in the annual crop rotation and among herbicide omission treatments in the perennial rotation. Herbicide omissions changed the weed-community structure in flax and in wheat and canola crops in the annual rotation enough to warrant alternate control methods in some treatments. The magnitude of the effects on the seedbank parameters depended largely on the competitive ability of the crop in which herbicides were omitted. No yield response to omitting herbicides in oats indicated that standard weed management practices have reduced weed populations below yield-loss thresholds.

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.

Influence of Weed Management Practices and Crop Rotation on Glyphosate-Resistant Horseweed (Conyza canadensis) Population Dynamics and Crop Yield-Years III and IV

Weed Science ◽  
2009 ◽  
Vol 57 (4) ◽  
pp. 417-426 ◽  
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 ◽  
Crop Yields ◽  
Management Systems ◽  
No Till

Horseweed is an increasingly common and problematic weed in no-till soybean production in the eastern cornbelt due to the frequent occurrence of biotypes resistant to glyphosate. The objective of this study was to determine the influence of crop rotation, winter wheat cover crops (WWCC), residual non-glyphosate herbicides, and preplant application timing on the population dynamics of glyphosate-resistant (GR) horseweed and crop yield. A field study was conducted from 2003 to 2007 in a no-till field located at a site that contained a moderate infestation of GR horseweed (approximately 1 plant m−2). The experiment was a split-plot design with crop rotation (soybean–corn or soybean–soybean) as main plots and management systems as subplots. Management systems were evaluated by quantifying in-field horseweed plant density, seedbank density, and crop yield. Horseweed densities were collected at the time of postemergence applications, 1 mo after postemergence (MAP) applications, and at the time of crop harvest or 4 MAP. Viable seedbank densities were also evaluated from soil samples collected in the fall following seed rain. Soybean–corn crop rotation reduced in-field and seedbank horseweed densities vs. continuous soybean in the third and fourth yr of this experiment. 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 in-field horseweed densities and protecting crop yields since the growth habit of horseweed in this region is primarily as a summer annual. Management systems also influenced the GR and glyphosate-susceptible (GS) biotype population structure after 4 yr of management. The most dramatic shift was from the initial GR : GS ratio of 3 : 1 to a ratio of 1 : 6 after 4 yr of residual preplant herbicide use followed by non-glyphosate postemergence herbicides.

Weed Problems in Uruguayan Agriculture: Evolution and Current Situation

2021 ◽  
Vol 32 (5) ◽  
pp. 203-207
Author(s):  
M. Alejandro Garcia ◽  
Lucia V. Meneses ◽  
Tiago Edu Kaspary
Keyword(s):  
Weed Management ◽  
Agricultural Production ◽  
Production Systems ◽  
Integrated Weed Management ◽  
Zero Tillage ◽  
Weed Species ◽  
Management Tools ◽  
Herbicide Resistant ◽  
Species Frequencies ◽  
Agricultural Production Systems

Uruguayan agriculture has undergone dramatic changes in the last 50 years driven by the adoption of new agricultural production systems that incorporate zero tillage and herbicide resistant crops. This has resulted in a shift in weed species frequencies and the dispersion of introduced herbicide resistant weed populations. Finally, integrated weed management tools are being developed by research and extension services to manage herbicide-resistant (HR) weeds better and to reduce environmental impact of herbicides.

scholarly journals Influence of Cover Crop, Tillage, and Crop Rotation Management on Soil Nutrients

Agriculture ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 225 ◽  
Author(s):  
Samuel I. Haruna ◽  
Nsalambi V. Nkongolo
Keyword(s):  
Crop Rotation ◽  
Soil Nutrients ◽  
Cover Crop ◽  
Crop Production ◽  
Production Systems ◽  
Soil Nutrient ◽  
Conventional Tillage ◽  
N Availability ◽  
P Availability ◽  
Long Term Effects

Cover cropping, tillage and crop rotation management can influence soil nutrient availability and crop yield through changes in soil physical, chemical and biological processes. The objective of this study was to evaluate the influence of three years of cover crop, tillage, and crop rotation on selected soil nutrients. Twenty-four plots each of corn (Zea mays) and soybean (Glycine max) were established on a 4.05 ha field and arranged in a three-factor factorial design. The three factors (treatments) were two methods of tillage (no-tillage (NT) vs. moldboard plow [conventional] tillage (CT)), two types of cover crop (no cover crop (NC) vs. cover crop (CC)) and four typess of rotation (continuous corn, continuous soybean, corn/soybean and soybean/corn). Soil samples were taken each year at four different depths in each plot; 0–10 cm, 10–20 cm, 20–40 cm and 40–60 cm, and analyzed for soil nutrients: calcium (Ca), magnesium (Mg), nitrogen (NO3 and NH4), potassium (K), phosphorus (P), sulfur (S), sodium (Na), iron (Fe), manganese (Mn) and copper (Cu). The results in the first year showed that CT increased NO3-N availability by 40% compared with NT. In the second year, NH4-N was 8% lower under CC compared with NC management. In the third year, P was 12% greater under CC management compared with NC management. Thus, CC can enhance crop production systems by increasing P availability and scavenging excess NH4-N from the soil, but longer-term studies are needed to evaluate long-term effects.

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.

Competitiveness of Herbicide-Resistant Waterhemp (Amaranthus tuberculatus) with Soybean

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
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Cropping Systems ◽  
Biomass Accumulation ◽  
Stem Diameter ◽  
The Other ◽  
Harvest Time ◽  
Herbicide Resistant ◽  
Amaranthus Tuberculatus ◽  
Soybean Plants

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.

scholarly journals Changes in Herbicide Use after Adoption of HR Canola in Western Canada

2011 ◽  
Vol 25 (3) ◽  
pp. 492-500 ◽  
Author(s):  
S. J. Smyth ◽  
M. Gusta ◽  
K. Belcher ◽  
P. W. B. Phillips ◽  
D. Castle
Keyword(s):  
Environmental Impact ◽  
Active Ingredient ◽  
Weed Management ◽  
Management Practices ◽  
Soil Management ◽  
Western Canada ◽  
Herbicide Resistant ◽  
Production Technologies ◽  
Time Required ◽  
Herbicide Use

This article examines the changes in herbicide use in relation to canola production in Western Canada, comparing 1995 and 2006. The commercialization and widespread adoption of herbicide-resistant (HR) canola has changed weed management practices in Western Canada. Before the introduction of HR canola, weeds were controlled by herbicides and tillage as the leading herbicides at that time required tillage to allow for soil incorporation of the herbicide. Much of the tillage associated with HR canola production has been eliminated as 64% of producers are now using zero or minimum tillage as their preferred form of crop and soil management. Additionally, there have been significant changes regarding the use and application of herbicides for weed control in canola. This research shows that when comparing canola production in 1995 and 2006, the environmental impact of herbicides applied to canola decreased 53%, producer exposure to chemicals decreased 56%, and quantity of active ingredient applied decreased 1.3 million kg. The cumulative environmental impact was reduced almost 50% with the use of HR herbicides. If HR canola had not been developed and Canadian canola farmers continued to use previous production technologies, the amount of active ingredient applied to control weeds in 2007 would have been 60% above what was actually applied.

scholarly journals Diverse Approaches to Herbicide-Resistant Weed Management

Weed Science ◽  
2016 ◽  
Vol 64 (SP1) ◽  
pp. 570-584 ◽  
Author(s):  
Micheal D. K. Owen
Keyword(s):  
Weed Management ◽  
Crop Production ◽  
Production Systems ◽  
Cost Effective ◽  
Developed Countries ◽  
Weed Species ◽  
Herbicide Resistant ◽  
Cost Effective Method ◽  
Evolution Of Resistance ◽  
Complexity Cost

Herbicides have been the principal means of weed control in developed countries for approximately 50 yr because they are the most cost-effective method. Such general use of herbicides has resulted in weed resistance to herbicides, which continues to be a growing problem. Within the past decade, the evolution of resistance to the once-dominant herbicide glyphosate has resulted in major concerns about the future ability to control weeds in many crop systems. Moreover, many weed species have evolved resistance to multiple mechanisms of herbicide action. Given the dearth of new herbicides with novel mechanisms of action, it appears inevitable that weed management programs will need to be supplemented by the use of tactics other than herbicides. However, the inclusion of more diversity for weed management also introduces complexity, cost, and time constraints to current crop production systems. This paper describes broadly the considerations, opportunities, and constraints of diverse weed management tactics to address the burgeoning problems with herbicide resistance.

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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