scholarly journals Weeds Hosting the Soybean Cyst Nematode (Heterodera glycines Ichinohe): Management Implications in Agroecological Systems

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 146
Author(s):  
Leonardo F. Rocha ◽  
Karla L. Gage ◽  
Mirian F. Pimentel ◽  
Jason P. Bond ◽  
Ahmad M. Fakhoury
Keyword(s):  
Weed Management ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Integrated Management ◽  
Cropping System ◽  
Cyst Nematode ◽  
Weed Species ◽  
Initial Inoculum ◽  
Herbicide Resistant ◽  
Sites Of Action

The soybean cyst nematode (SCN; Heterodera glycines Ichinohe) is a major soybean-yield-limiting soil-borne pathogen, especially in the Midwestern US. Weed management is recommended for SCN integrated management, since some weed species have been reported to be hosts for SCN. The increase in the occurrence of resistance to herbicides complicates weed management and may further direct ecological–evolutionary (eco–evo) feedbacks in plant–pathogen complexes, including interactions between host plants and SCN. In this review, we summarize weed species reported to be hosts of SCN in the US and outline potential weed–SCN management interactions. Plants from 23 families have been reported to host SCN, with Fabaceae including most host species. Out of 116 weeds hosts, 14 species have known herbicide-resistant biotypes to 8 herbicide sites of action. Factors influencing the ability of weeds to host SCN are environmental and edaphic conditions, SCN initial inoculum, weed population levels, and variations in susceptibility of weed biotypes to SCN within a population. The association of SCN on weeds with relatively little fitness cost incurred by the latter may decrease the competitive ability of the crop and increase weed reproduction when SCN is present, feeding back into the probability of selecting for herbicide-resistant weed biotypes. Therefore, proper management of weed hosts of SCN should be a focus of integrated pest management (IPM) strategies to prevent further eco–evo feedbacks in the cropping system.

scholarly journals A decade of herbicide-resistant crops in Canada

2006 ◽  
Vol 86 (4) ◽  
pp. 1243-1264 ◽  
Author(s):  
H. J. Beckie ◽  
K. N. Harker ◽  
L. M. Hall ◽  
S. I. Warwick ◽  
A. Légère ◽  
...  
Keyword(s):  
Gene Flow ◽  
Weed Management ◽  
Selection Pressure ◽  
Cropping System ◽  
Fundamental Principle ◽  
Transgenic Crop ◽  
Economic Returns ◽  
Weed Species ◽  
Eastern Canada ◽  
Herbicide Resistant

This review examines some agronomic, economic, and environmental impacts of herbicide-resistant (HR) canola, soybean, corn, and wheat in Canada after 10 yr of growing HR cultivars. The rapid adoption of HR canola and soybean suggests a net economic benefit to farmers. HR crops often have improved weed management, greater yields or economic returns, and similar or reduced environmental impact compared with their non-HR crop counterparts. There are no marked changes in volunteer weed problems associated with these crops, except in zero-tillage systems when glyphosate is used alone to control canola volunteers. Although gene flow from glyphosate-HR canola to wild populations of bird’s rape (Brassica rapa L.) in eastern Canada has been measured, enrichment of hybrid plants in such populations should only occur when and where herbicide selection pressure is applied. Weed shifts as a consequence of HR canola have been documented, but a reduction in weed species diversity has not been demonstrated. However, reliance on HR crops in rotations using the same mode-of-action herbicide and/or multiple in-crop herbicide applications over time can result in intense selection pressure for weed resistance and consequently, greater herbicide use in the future to control HR weed biotypes. History has repeatedly shown that cropping system diversity is the pillar of sustainable agriculture; stewardship of HR crops must adhere to this fundamental principle. Key words: Canola, Brassica napus, corn, Zea mays, soybean, Glycine max, wheat, Triticum aestivum, gene flow, herbicide resistance, transgenic crop, volunteer crop

Survey of Broadleaf Winter Weeds in Indiana Production Fields Infested with Soybean Cyst Nematode (Heterodera Glycines)

2006 ◽  
Vol 20 (4) ◽  
pp. 1066-1075 ◽  
Author(s):  
J. Earl Creech ◽  
William G. Johnson
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Diversity Indices ◽  
Average Density ◽  
Cyst Nematode ◽  
Population Increase ◽  
Weed Species ◽  
The North ◽  
Weed Hosts ◽  
Wild Garlic

Fifty-five soybean cyst nematode (SCN)–infested production fields across Indiana were surveyed in March 2004 to assess broadleaf winter weed prevalence. The most frequently occurring weeds were common chickweed (87%), speedwell (83%), buttercup (58%), and henbit (53%). Henbit and wild garlic were present at the highest average densities, both occurring at greater than 50 plants/m2. Based on relative abundance indices, common chickweed and henbit were the most prevalent winter weeds in this survey. As a composite, winter weed hosts of SCN were found in 93% of fields and occurred at an average density of 151 plants/m2. No correlation existed between weed density and SCN egg counts. Frequency, uniformity, density, and diversity indices for individual weed species were generally higher in the southern region of Indiana than in the north. Thus, the region of highest risk for SCN reproduction and population increase on winter weeds in Indiana appears to be in the southern part of the state.

scholarly journals Emerging Challenges for Weed Management in Herbicide-Resistant Crops

Agriculture ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 180 ◽  
Author(s):  
Karla L. Gage ◽  
Ronald F. Krausz ◽  
S. Alan Walters
Keyword(s):  
Weed Management ◽  
Selection Pressure ◽  
New Technologies ◽  
Cropping Systems ◽  
Critical Role ◽  
Cropping System ◽  
Herbicide Resistant ◽  
Increased Risk ◽  
Sites Of Action ◽  
Weed Resistance

Since weed management is such a critical component of agronomic crop production systems, herbicides are widely used to provide weed control to ensure that yields are maximized. In the last few years, herbicide-resistant (HR) crops, particularly those that are glyphosate-resistant, and more recently, those with dicamba (3,6-dichloro-2-methoxybenzoic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid) resistance are changing the way many growers manage weeds. However, past reliance on glyphosate and mistakes made in stewardship of the glyphosate-resistant cropping system have directly led to the current weed resistance problems that now occur in many agronomic cropping systems, and new technologies must be well-stewarded. New herbicide-resistant trait technologies in soybean, such as dicamba-, 2,4-D-, and isoxaflutole- ((5-cyclopropyl-4-isoxazolyl)[2-(methylsulfonyl)-4-(trifluoromethyl)phenyl]methanone) resistance, are being combined with glyphosate- and glufosinate-resistance traits to manage herbicide-resistant weed populations. In cropping systems with glyphosate-resistant weed species, these new trait options may provide effective weed management tools, although there may be increased risk of off-target movement and susceptible plant damage with the use of some of these technologies. The use of diverse weed management practices to reduce the selection pressure for herbicide-resistant weed evolution is essential to preserve the utility of new traits. The use of herbicides with differing sites of action (SOAs), ideally in combination as mixtures, but also in rotation as part of a weed management program may slow the evolution of resistance in some cases. Increased selection pressure from the effects of some herbicide mixtures may lead to more cases of metabolic herbicide resistance. The most effective long-term approach for weed resistance management is the use of Integrated Weed Management (IWM) which may build the ecological complexity of the cropping system. Given the challenges in management of herbicide-resistant weeds, IWM will likely play a critical role in enhancing future food security for a growing global population.

Determination of weed hosts of soybean cyst nematode in South Dakota

2019 ◽  
Vol 34 (3) ◽  
pp. 377-382
Author(s):  
Pawan Basnet ◽  
Sharon A. Clay ◽  
Emmanuel Byamukama
Keyword(s):  
South Dakota ◽  
Weed Management ◽  
Soybean Cyst Nematode ◽  
The United States ◽  
Cyst Nematode ◽  
Corn Belt ◽  
Management Approach ◽  
Weed Species ◽  
Weed Hosts

AbstractSoybean cyst nematode (SCN) causes over $1.2 billion in revenue loss annually in the United States and consistently ranks as the most threatening pathogen for soybean. SCN weed hosts have been documented in other states in the eastern Corn Belt, but very little work has been done in the midwestern Corn Belt. To determine alternative SCN weed hosts in South Dakota, 670 whole weed root samples comprising 63 weed species were collected from 48 SCN-positive fields in 13 counties during fall 2016 and spring 2017. Among the 63 weed species, 12 contained SCN juveniles and 7 were confirmed hosts of SCN based on the completion of the SCN life cycle in greenhouse studies. Ranking of female index (FI) for the weed hosts were purple deadnettle (FI = 34.6) > field pennycress (FI = 26.9) > common mallow (FI = 2.04) > shepherd’s purse (FI = 1.89) > white clover (FI = 1.86) > Canada thistle (FI = 1.24) > common cocklebur (FI = 1.10). These results indicate that some weeds can support SCN, and therefore a proactive weed management approach should be employed for fields infested with SCN.

Influence of Winter Annual Weed Management and Crop Rotation on Soybean Cyst Nematode (Heterodera Glycines) and Winter Annual Weeds

Weed Science ◽  
2008 ◽  
Vol 56 (1) ◽  
pp. 103-111 ◽  
Author(s):  
J. Earl Creech ◽  
Andreas Westphal ◽  
Virginia R. Ferris ◽  
Jamal Faghihi ◽  
Tony J. Vyn ◽  
...  
Keyword(s):  
Crop Rotation ◽  
Weed Management ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Winter Annual ◽  
Winter Annual Weeds ◽  
Annual Weeds

scholarly journals Herbicide efficacy on Borreria densiflora control in pre- and post-emergence conditions

2014 ◽  
Vol 32 (4) ◽  
pp. 817-825 ◽  
Author(s):  
B.A.B. Martins ◽  
P.J. Christoffoleti
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Integrated Management ◽  
Block Design ◽  
Dry Weight ◽  
Northeastern Brazil ◽  
Weed Species ◽  
Herbicide Resistant ◽  
Randomized Block Design ◽  
Herbicide Mixtures

The weed Borreria densiflora is a management issue in soybean and sugarcane crops from North and Northeastern Brazil. Knowledge upon chemical control of B. densiflora contributes to the integrated management of this weed species, especially when active ingredient options become reduced due to the selection of herbicide resistant or tolerant weed species. Experiments in pre- and post-emergence of B. densiflora were conducted in greenhouse, in a randomized block design and four replications. In pre-emergence, the dose-response curve methodology was used and 7 herbicides were tested. In post-emergence, 9 herbicides at the recommended rate and 4 herbicide mixtures were tested. For pre and post-emergence conditions, evaluations were conducted at 60 and 21 days after treatment (DAT), respectively, and the variables analyzed were weed control and dry weight (%). The results showed options of pre-emergent herbicides that can be used for controlling B. densiflora, especially in sugarcane, where chemical weed control is mainly based on pre-emergent applications. In the current glyphosate resistance scenario, one should consider the use of pre-emergent herbicides within an integrated management of B. densiflora. For satisfactory post-emergence control, B. densiflora plants should be sprayed at the phenological stage of up to three pairs of leaves. Herbicide mixtures have been and will continue to be an important tool in chemical weed management, broadening the spectrum of weed control, while diversifying herbicide mechanisms of action, which helps to prevent or delay the appearance of herbicide resistance.

AAC Richard Soybean

2022 ◽  
Author(s):  
Kangfu Yu ◽  
Lorna Woodrow ◽  
M. Chun Shi
Keyword(s):  
Glycine Max ◽  
Research And Development ◽  
Soybean Cyst Nematode ◽  
Protein Concentration ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Processing Quality ◽  
Food Grade ◽  
High Protein Concentration ◽  
Glycine Max L

AAC Richard is a food grade soybean [Glycine max (L.) Merr] cultivar with yellow hilum, high protein concentration, and good processing quality for foreign and domestic soymilk, tofu, and miso markets. It has resistance to SCN (soybean cyst nematode) (Heterodera Glycines Ichinohe). AAC Richard was developed at the Agriculture and Agri-Food Canada (AAFC) Harrow Research and Development Centre (Harrow-RDC), Harrow, Ontario and is adapted to areas of southwest Ontario with 3100 or more crop heat units and has a relative maturity of 2.3 (MG 2.3).

scholarly journals Taxonomic Resolution of the Nematophagous Fungal Isolate ARF18 via Genome Sequencing

2017 ◽  
Vol 5 (34) ◽  
Author(s):  
Sandeep Sharma ◽  
Alex Z. Zaccaron ◽  
John B. Ridenour ◽  
Amy Bradshaw ◽  
Terry L. Kirkpatrick ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Novel Species ◽  
Biological Control Agent ◽  
Draft Genome ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Cyst Nematode ◽  
Fungal Isolate ◽  
Taxonomic Resolution

ABSTRACT The taxonomically uncharacterized nematophagous fungus ARF18, which parasitizes cysts, juveniles, and adults of the soybean cyst nematode (Heterodera glycines), was proposed as a nematode biological control agent in 1991. A 46.3-Mb draft genome sequence of this fungus is presented, and a tentative taxonomic identification as a novel species of Brachyphoris is proposed.

scholarly journals The genome of the soybean cyst nematode (Heterodera glycines) reveals complex patterns of duplications involved in the evolution of parasitism genes

2018 ◽  
Author(s):  
Rick Masonbrink ◽  
Tom R. Maier ◽  
Usha Muppiral ◽  
Arun S. Seetharam ◽  
Etienne Lord ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Control Strategies ◽  
Cyst Nematode ◽  
Effective Control ◽  
Evolutionary Mechanisms ◽  
Long Read ◽  
Soybean Plants ◽  
Parasitism Genes ◽  
Nematode Genomes

AbstractHeterodera glycines, commonly referred to as the soybean cyst nematode (SCN), is an obligatory and sedentary plant parasite that causes over a billion-dollar yield loss to soybean production annually. Although there are genetic determinants that render soybean plants resistant to certain nematode genotypes, resistant soybean cultivars are increasingly ineffective because their multi-year usage has selected for virulentH. glycinespopulations. The parasitic success ofH. glycinesrelies on the comprehensive re-engineering of an infection site into a syncytium, as well as the long-term suppression of host defense to ensure syncytial viability. At the forefront of these complex molecular interactions are effectors, the proteins secreted byH. glycinesinto host root tissues. The mechanisms of effector acquisition, diversification, and selection need to be understood before effective control strategies can be developed, but the lack of an annotated genome has been a major roadblock. Here, we use PacBio long-read technology to assemble aH. glycinesgenome of 738 contigs into 123Mb with annotations for 29,769 genes. The genome contains significant numbers of repeats (34%), tandem duplicates (18.7Mb), and horizontal gene transfer events (151 genes). Using previously published effector sequences, the newly generatedH. glycinesgenome, and comparisons to other nematode genomes, we investigate the evolutionary mechanisms responsible for the emergence and diversification of effector genes.

Sign in / Sign up

Export Citation Format

Share Document