Assessment of crop and weed management strategies prior to introduction of auxin-resistant crops in Brazil

Abstract A stakeholder survey was conducted from April through June of 2018 to understand stakeholders’ perceptions and challenges about cropping systems and weed management in Brazil. The dominant crops managed by survey respondents were soybean (73%) and corn (66%). Approximately 75% of survey respondents have grown or managed annual cropping systems with two to three crops per year cultivated in succession. Eighteen percent of respondents manage only irrigated cropping systems, and over 60% of respondents adopt no-till as a standard practice. According to respondents, the top five troublesome weed species in Brazilian cropping systems are horseweed (asthmaweed, Canadian horseweed, and tall fleabane), sourgrass, morningglory, goosegrass, and dayflower (Asiatic dayflower and Benghal dayflower). Among the nine species documented to have evolved resistance to glyphosate in Brazil, horseweed and sourgrass were reported as the most concerning weeds. Other than glyphosate, 31% and 78% of respondents, respectively, manage weeds resistant to acetyl-CoA carboxylase (ACCase) inhibitors and/or acetolactate synthase (ALS) inhibitors. Besides herbicides, 45% of respondents use mechanical, and 75% use cultural (e.g., no-till, crop rotation/succession) weed control strategies. Sixty-one percent of survey respondents adopt cover crops to some extent to suppress weeds and improve soil chemical and physical properties. Nearly 60% of survey respondents intend to adopt the crops that are resistant to dicamba or 2,4-D when available. Results may help practitioners, academics, industry, and policy makers to better understand the bad and the good of current cropping systems and weed management practices adopted in Brazil, and to adjust research, education, technologies priorities, and needs moving forward.

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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 ◽

10.1614/ws-09-006.1 ◽

2009 ◽

Vol 57 (4) ◽

pp. 417-426 ◽

Cited By ~ 40

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.

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No-till Vegetable Production—Its Time is Now

HortTechnology ◽

10.21273/horttech.9.3.373 ◽

1999 ◽

Vol 9 (3) ◽

pp. 373-379 ◽

Cited By ~ 20

Author(s):

Ronald D. Morse

Keyword(s):

Cover Crops ◽

Weed Management ◽

Production Systems ◽

Control Strategies ◽

Soil Surface ◽

Integrated Weed Management ◽

Vegetable Production ◽

Vegetable Crops ◽

No Till ◽

Minimum Disturbance

Advantages of no-till (NT) production systems are acknowledged throughout the world. During the 1990s, production of NT vegetable crops has increased for both direct seeded and transplanted crops. Increased interest in reduced-tillage systems among research workers and vegetable growers is attributed to: 1) development and commercialization of NT transplanters and seeders, 2) advancements in the technology and practice of producing and managing high-residue cover crop mulches, and 3) improvements and acceptance of integrated weed management techniques. Results from research experiments and grower's fields over the years has shown that success with NT transplanted crops is highly dependent on achieving key production objectives, including: 1) production of dense, uniformly distributed cover crops; 2) skillful management of cover crops before transplanting, leaving a heavy, uniformly distributed killed mulch cover over the soil surface; 3) establishment of transplants into cover crops with minimum disturbance of surface residues and surface soil; and 4) adoption of year-round weed control strategies.

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Weed Management Strategies in Chickpea (Cicer arietinum): A Review

Agricultural Reviews ◽

10.18805/ag.r-1996 ◽

2020 ◽

Author(s):

Akashdeep Singh ◽

S. S. Rana ◽

Anju Bala

Keyword(s):

Weed Control ◽

Cicer Arietinum ◽

Weed Management ◽

Management Practices ◽

Management Strategies ◽

Detailed Knowledge ◽

Basic Requirement ◽

Weed Species ◽

The World ◽

Hand Weeding

Chickpea (Cicer arietinum) is one of the most important pulse crops but it’s productivity in India is quite low. There are various reasons for low productivity. Weed control is the basic requirement and the major component of crop management. Weeds on an average reduce the crop yield by 40-87 per cent. Deciding time to control weeds requires detailed knowledge of the weed populations in the field. Different management practices like altering spacing, competitive cultivars, etc. can help in enhancing the productivity. With the world entering the precision-farming era, more emphasis is being put on the use of post-emergence herbicides. Application of two or more herbicide at the same time or as a double knockdown and integrating with hand-weeding provides desirable control of different weed species besides reducing the hazard of chemical weed control.

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

Crop and Pasture Science ◽

10.1071/cp11201 ◽

2011 ◽

Vol 62 (11) ◽

pp. 1002 ◽

Cited By ~ 22

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.

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Herbicide Rate Effects on Weed and Root Maggot Dynamics in Canola

Weed Science ◽

10.1614/ws-07-172.1 ◽

2008 ◽

Vol 56 (3) ◽

pp. 477-483 ◽

Cited By ~ 4

Author(s):

Jim S. Broatch ◽

Lloyd M. Dosdall ◽

John T. O'Donovan ◽

K Neil Harker ◽

George W. Clayton

Keyword(s):

Weed Management ◽

Management Practices ◽

Management Strategies ◽

Dry Weight ◽

Field Studies ◽

Crop Damage ◽

Weed Species ◽

Alternate Host ◽

Insect Management ◽

Root Maggot

Weed management strategies can influence insect infestations in field crops, yet no attempts have been made previously to manipulate weed populations in canola for integrated weed and insect management. Field studies were conducted during 2003 to 2005 at Lacombe and Beaverlodge, Alberta, Canada to manipulate weed and root maggot, Delia spp. (Diptera: Anthomyiidae), interactions in canola. Densities of monocot weeds were varied by altering herbicide applications, with rates ranging from 0 to 100% of the rate recommended. Weed populations declined, and yields were variable with increased herbicide rates. Root maggot damage decreased with increases in monocot weed dry weight for both canola species at both study sites. Results support the hypothesis that heterogenous environments, arising from mixed populations of monocot weeds with canola, minimize opportunities for females of Delia spp. to complete the behavioral sequence required for oviposition, leading to reduced infestation levels in weedy systems. However, effects of dicot weeds on root maggot infestations varied between sites as a result of site-related differences in weed species complexes. When wild mustard was common, crop damage increased, because this weed can serve as an alternate host for root maggots. The study emphasizes the importance of adopting crop management practices that are compatible for both weed and root maggot control.

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Effect of roller-crimper technology on weed management in organic zucchini production in a Mediterranean climate zone

Renewable Agriculture and Food Systems ◽

10.1017/s1742170515000046 ◽

2015 ◽

Vol 31 (2) ◽

pp. 111-121 ◽

Cited By ~ 11

Author(s):

Corrado Ciaccia ◽

Stefano Canali ◽

Gabriele Campanelli ◽

Elena Testani ◽

Francesco Montemurro ◽

...

Keyword(s):

Weed Control ◽

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Cropping Systems ◽

Central Italy ◽

Competitive Balance ◽

Weed Species ◽

Wide Range ◽

Cropping Seasons

AbstractIntegrating cover crops into vegetable cropping systems can provide a wide range of ecological services, of which weed management is a key component. Cover crop effects on weed control, however, are dependent on termination methods and weed species present in specific cropping seasons. A 2-year weed management experiment with two cultivars of organic zucchini (Cucurbita pepo L.) in central Italy was carried out to compare the effect of a barley (Hordeum distichum L.) cover crop terminated with a modified roller-crimper (RC) to incorporated barley as green manure (GM) and a tilled control left fallow (FA) in the off-season. The effects of cover-crop management on crop competitiveness, yields and weed populations were evaluated by direct measurement, visual estimation and competition index methods. Results showed a significant reduction in weed biomass (>80%) and weed abundance with the RC compared to the GM and FA treatments. Moreover, the RC barley mulch maintained weed control in zucchini plots even under high weed pressure, as determined by the agronomic tolerance to competition (ATC) value of 67% in the RC treatment compared to 40 and 34% in the FA and GM treatments, respectively, averaged over both years of the experiment. The competitive balance (Cb), which quantified the ability of the zucchini crop to compete with weed populations, was also greater (+0.37) in the RC treatment compared to FA (−0.87) and GM (−0.69) treatments over the same period. Zucchini crop biomass was greatest in the RC treatment in 2011. Zucchini fruit yields varied from an average over both years of 1.4 Mg ha−1 in the RC treatment to 0.7 Mg ha−1 in the GM treatment, but yields in the FA treatment, 1.2 Mg ha−1, did not differ from the RC treatment. No differences in yield between ‘Dietary’ and ‘Every’ zucchini, or any significant interactions between cultivar and cover management related to fruit biomass, were observed. Our findings suggested the viability of the modified RC in creating a barley cover-crop mulch to effectively manage weeds and enhance yields in transplanted zucchini.

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European Perspectives on the Adoption of Nonchemical Weed Management in Reduced-Tillage Systems for Arable Crops

Weed Technology ◽

10.1614/wt-d-12-00066.1 ◽

2013 ◽

Vol 27 (1) ◽

pp. 231-240 ◽

Cited By ~ 70

Author(s):

Bo Melander ◽

Nicolas Munier-Jolain ◽

Raphaël Charles ◽

Judith Wirth ◽

Jürgen Schwarz ◽

...

Keyword(s):

Cover Crops ◽

Weed Management ◽

Crop Residues ◽

Cropping Systems ◽

Management Strategies ◽

Crop Protection ◽

Crop Rotations ◽

Future Research ◽

Reduced Tillage ◽

Tillage Systems

Noninversion tillage with tine- or disc-based cultivations prior to crop establishment is the most common way of reducing tillage for arable cropping systems with small grain cereals, oilseed rape, and maize in Europe. However, new regulations on pesticide use might hinder further expansion of reduced-tillage systems. European agriculture is asked to become less dependent on pesticides and promote crop protection programs based on integrated pest management (IPM) principles. Conventional noninversion tillage systems rely entirely on the availability of glyphosate products, and herbicide consumption is mostly higher compared to plow-based cropping systems. Annual grass weeds and catchweed bedstraw often constitute the principal weed problems in noninversion tillage systems, and crop rotations concurrently have very high proportions of winter cereals. There is a need to redesign cropping systems to allow for more diversification of the crop rotations to combat these weed problems with less herbicide input. Cover crops, stubble management strategies, and tactics that strengthen crop growth relative to weed growth are also seen as important components in future IPM systems, but their impact in noninversion tillage systems needs validation. Direct mechanical weed control methods based on rotating weeding devices such as rotary hoes could become useful in reduced-tillage systems where more crop residues and less workable soils are more prevalent, but further development is needed for effective application. Owing to the frequent use of glyphosate in reduced-tillage systems, perennial weeds are not particularly problematic. However, results from organic cropping systems clearly reveal that desisting from glyphosate use inevitably leads to more problems with perennials, which need to be addressed in future research.

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Effect of Crop Residues on Weed Emergence

Agronomy ◽

10.3390/agronomy11010163 ◽

2021 ◽

Vol 11 (1) ◽

pp. 163

Author(s):

Nebojša Nikolić ◽

Donato Loddo ◽

Roberta Masin

Keyword(s):

Weed Management ◽

Crop Residues ◽

Cropping Systems ◽

Chenopodium Album ◽

Seedling Emergence ◽

Amaranthus Retroflexus ◽

Weed Species ◽

Field Quantity ◽

Crop Fields ◽

No Till

Weed behaviour in crop fields has been extensively studied; nevertheless, limited knowledge is available for particular cropping systems, such as no-till systems. Improving weed management under no-till conditions requires an understanding of the interaction between crop residues and the seedling emergence process. This study aimed to evaluate the influence of maize and wheat residues, applied in three different quantities (1, the field quantity, 0.5, and 1.5-fold amounts of the field quantity), on the emergence of eight weed species: Abutilon theophrasti, Amaranthus retroflexus, Chenopodium album, Digitaria sanguinalis, Echinochloa crus-galli, Setaria pumila, Sonchus oleraceus, and Sorghum halepense. The experiment was conducted over two consecutive years. The results showed that the quantities 1 and 1.5 could suppress seedling emergence by 20 and 44%, respectively, while the quantity 0.5 seems to promote emergence by 22% compared with the control without residues. Weed species showed different responses to crop residues, from C. album showing 56% less emergence to S. halepense showing a 44% higher emergence than the control without residues. Different meteorological conditions in the two-year experiment also exhibited a significant influence on weed species emergence.

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INTEGRAÇÃO DE PRÁTICAS PARA O MANEJO DE PLANTAS DANINHAS NA CULTURA DO MILHO

Scientia Agraria ◽

10.5380/rsa.v12i2.33724 ◽

2011 ◽

Vol 12 (2) ◽

Author(s):

Alvadi Antonio BALBINOT JUNIOR ◽

Gilcimar Adriano VOGT ◽

Michelangelo Muzell TREZZI

Keyword(s):

Weed Control ◽

Cover Crops ◽

Weed Management ◽

Management Practices ◽

Plant Density ◽

Control Strategies ◽

Dry Mass ◽

Corn Yield ◽

Weed Infestation ◽

Narrow Row

As práticas de manejo do solo e de culturas podem afetar diretamente a infestação de plantas daninhas na cultura do milho. O objetivo desse trabalho foi avaliar o efeito da integração de práticas culturais e químicas na infestação de plantas daninhas e na produtividade da cultura do milho. Foi conduzido um experimento em Papanduva, SC, em delineamento experimental de blocos ao acaso, com três repetições e parcelas subdivididas. Nas parcelas foram avaliados dois sistemas de manejo cultural de plantas daninhas: S1 (cultivo de consórcio de espécies para cobertura do solo no inverno, uso de sementes de milho com elevada massa e espaçamento entre fileiras de 0,45 m) e S2 (pousio no inverno, uso de sementes de milho com baixa massa e espaçamento entre fileiras de 0,90 m). Nas subparcelas foram avaliadas quatro estratégias de controle de plantas daninhas no milho (sem controle, atrazine, atrazine+mesotrione e capina). Avaliaram-se a quantidade de palha no momento da semeadura do milho, a velocidade de decomposição da palha, a densidade e a massa seca da parte aérea de plantas daninhas e o desempenho da cultura de milho. O uso de práticas culturais para o manejo de plantas daninhas promoveu redução da infestação dessas plantas na cultura de milho, além de aumentar a produtividade da cultura. A aplicação de atrazine + mesotrione proporcionou melhor controle de plantas daninhas e maior produtividade de grãos em relação à aplicação isolada de atrazine. ABSTRACT Soil and crop management can affect the weed population in corn. The experiment was carried out to evaluate the effect of cultural and chemical management practices on weed infestation and corn yield. The experiment was carried out in Papanduva, SC, Brazil. The experimental design was a randomized complete blocks with three replications in a split-plot arrangement. In plots were evaluated two cultural weed management systems: S1 (multicropping of winter cover crops, corn seeds with high weight and narrow row of 0.45 m) and S2 (winter fallow, corn seeds with low weight and narrow row of 0.90 m). In subplots were evaluated four weed control strategies (no-control, atrazine, atrazine + mesotrione and weeding). The parameters evaluated were the straw quantity, residue decomposition, weed plant density and shoot dry mass and corn performance. The use of cultural weed management practices reduced the weed infestation on corn and improved the crop yield. The association of atrazine + mesotrione herbicides showed more efficient weed control than atrazine.

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Weed community structure and soybean yields in a long-term organic cropping systems experiment

Weed Science ◽

10.1017/wsc.2019.44 ◽

2019 ◽

Vol 67 (6) ◽

pp. 673-681 ◽

Cited By ~ 1

Author(s):

Margaret G. Ball ◽

Brian A. Caldwell ◽

Antonio DiTommaso ◽

Laurie E. Drinkwater ◽

Charles L. Mohler ◽

...

Keyword(s):

Community Structure ◽

Weed Management ◽

Management Practices ◽

Cropping Systems ◽

Nutrient Inputs ◽

Weed Species ◽

Soybean Yield ◽

Weed Density ◽

Weed Species Richness

AbstractWeed management is a major challenge in organic crop production, and organic farms generally harbor larger weed populations and more diverse communities compared with conventional farms. However, little research has been conducted on the effects of different organic management practices on weed communities and crop yields. In 2014 and 2015, we measured weed community structure and soybean [Glycine max (L.) Merr.] yield in a long-term experiment that compared four organic cropping systems that differed in nutrient inputs, tillage, and weed management intensity: (1) high fertility (HF), (2) low fertility (LF), (3) enhanced weed management (EWM), and (4) reduced tillage (RT). In addition, we created weed-free subplots within each system to assess the impact of weeds on soybean yield. Weed density was greater in the LF and RT systems compared with the EWM system, but weed biomass did not differ among systems. Weed species richness was greater in the RT system compared with the EWM system, and weed community composition differed between RT and other systems. Our results show that differences in weed community structure were primarily related to differences in tillage intensity, rather than nutrient inputs. Soybean yield was lower in the EWM system compared with the HF and RT systems. When averaged across all four cropping systems and both years, soybean yield in weed-free subplots was 10% greater than soybean yield in the ambient weed subplots that received standard management practices for the systems in which they were located. Although weed competition limited soybean yield across all systems, the EWM system, which had the lowest weed density, also had the lowest soybean yield. Future research should aim to overcome such trade-offs between weed control and yield potential, while conserving weed species richness and the ecosystem services associated with increased weed diversity.

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