Influence of Two Herbicides on Soybean Cyst Nematode (Heterodera glycines) Reproduction on Henbit (Lamium amplexicaule) Roots

Soybean cyst nematode (SCN) is the most yield-limiting pathogen of soybean in the United States. Henbit is a prevalent winter annual weed species in no-till fields and is reported to be an alternative host of SCN. A greenhouse study was conducted to evaluate how the development of SCN on henbit roots was affected by herbicide mode of action and time of herbicide application. Henbit plants were grown in watertight pots placed in a water bath bench that kept soil temperature constant (27 ± 1 C) during the study. Ten d after transplanting, pots were inoculated with approximately 1,000 SCN eggs. At 7, 14, or 21 d after inoculation (DAI), henbit plants were sprayed with recommended dose of either glyphosate (870 g ae ha−1) or 2,4-D (1,070 g ae ha−1). The experiment was arranged in a randomized complete block design with five replications per treatment, and two experimental runs separated in time. At 28 DAI, the total number of SCN cysts and eggs, and plant shoot and root dry weight per pot were determined. Henbit root and shoot biomass increased as the time of herbicide application was delayed. Glyphosate reduced root biomass more than 2,4-D, but no differences in shoot biomass were detected. The number of SCN cysts per henbit plant and eggs per cyst increased as the herbicide application was delayed from 7 to 21 DAI. Glyphosate reduced the number of cysts found on henbit roots more than 2,4-D, especially at earlier application times. On plants treated with glyphosate, SCN-females produced only half the number of eggs of SCN-females on henbit plants treated with 2,4-D, regardless of time of application. These results indicate that early control of henbit plants, especially with glyphosate, can reduce SCN reproduction potential in SCN infested fields.

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Evaluation of Weed Species from the Northern Great Plains as Hosts of Soybean Cyst Nematode

Plant Health Progress ◽

10.1094/php-rs-14-0024 ◽

2015 ◽

Vol 16 (1) ◽

pp. 23-28 ◽

Cited By ~ 4

Author(s):

Susilo H. Poromarto ◽

Greta G. Gramig ◽

Berlin D. Nelson ◽

Shalu Jain

Keyword(s):

Great Plains ◽

Soybean Cyst Nematode ◽

The United States ◽

Cyst Nematode ◽

Host Suitability ◽

Northern Great Plains ◽

Weed Species ◽

Weed Hosts ◽

Survival And Reproduction ◽

Plant Families

Weeds can be alternate hosts of soybean cyst nematode (SCN), a major pathogen of soybean in the United States. Weed species from the northern soybean production area of North Dakota-northern Minnesota have not been evaluated for host suitability. Fifty-one weed species with multiple collections from different locations, representing 13 families were evaluated as hosts of SCN. Weeds were inoculated with SCN HG type 0 and a female index (FI) was calculated by comparing reproduction to that on Barnes, a susceptible soybean cultivar. Thirty-three weed species had not previously been tested. For 20 weed species, no reproduction on roots was observed on any collection. For 31 weed species, SCN females developed on roots of one or more collection, but only two weeds, henbit and field pennycress, allowed substantial reproduction with average FI's of 30.5 to 38, respectively; the other 29 species had average FI's of less than 10 and thus were defined as poor hosts. Twenty-six of the weed species from 11 plant families were newly identified hosts of SCN. Collections of species varied in host suitability. Although most weeds were non-hosts or poor hosts, the number of weeds that supported limited SCN reproduction indicates that weed hosts could influence SCN survival and reproduction in the upper Great Plains. Few weed species, however, are major hosts of SCN in this region. Accepted 10 December 2014. Published 28 January 2015.

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Influence of Intraspecific Henbit (Lamium amplexicaule) and Purple Deadnettle (Lamium purpureum) Competition on Soybean Cyst Nematode Reproduction

Weed Science ◽

10.1614/ws-07-051.1 ◽

2007 ◽

Vol 55 (6) ◽

pp. 665-670 ◽

Cited By ~ 7

Author(s):

J. Earl Creech ◽

Jamal Faghihi ◽

Virginia R. Ferris ◽

Andreas Westphal ◽

William G. Johnson

Keyword(s):

Root Biomass ◽

Soybean Cyst Nematode ◽

Egg Production ◽

Plant Density ◽

Biomass Accumulation ◽

Dry Weight ◽

Cyst Nematode ◽

Nematode Reproduction ◽

Greenhouse Study ◽

Number Of Stems

A greenhouse study was conducted to determine the effect of henbit and purple deadnettle density on weed biomass accumulation and soybean cyst nematode (SCN) reproduction. SCN did not impact shoot or root dry weight of purple deadnettle, henbit, or soybean. Foliar and root biomass of henbit and purple deadnettle were comparable but the biomass per stem was higher for purple deadnettle. Shoot and root biomass per pot of henbit and purple deadnettle at corresponding plant densities were statistically similar and were generally higher with increasing plant density. Henbit produced a greater number of stems than purple deadnettle and the least number of stems for both species existed at low densities. Purple deadnettle allowed for more SCN reproduction than did henbit. Weed densities also influenced SCN cyst and egg production but the results were species dependent. The highest SCN reproduction per pot was supported at low to moderate densities of purple deadnettle but at moderate to high densities of henbit. These results suggest that purple deadnettle should be more aggressively managed than henbit in management programs for SCN, but that henbit, especially at high densities, can support SCN reproduction at levels near those of purple deadnettle.

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Determination of weed hosts of soybean cyst nematode in South Dakota

Weed Technology ◽

10.1017/wet.2019.122 ◽

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.

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

Agronomy ◽

10.3390/agronomy11010146 ◽

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.

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Classification methods and identification of reniform nematode resistance in known soybean cyst nematode resistant soybean genotypes

Plant Disease ◽

10.1094/pdis-01-21-0051-re ◽

2021 ◽

Author(s):

Mariola Usovsky ◽

Robert Robbins ◽

Juliet Fultz Wilkes ◽

Devany Crippen ◽

Vijay Shankar ◽

...

Keyword(s):

Soybean Cyst Nematode ◽

Germplasm Collection ◽

Nematode Species ◽

The United States ◽

Cyst Nematode ◽

Classification Methods ◽

Reniform Nematode ◽

Plant Introductions ◽

Scn Resistance ◽

Moderately Resistant

Plant parasitic nematodes are a major yield-limiting factor of soybean in the United States and Canada. It has been indicated that soybean cyst nematode (SCN, Heterodera glycines Ichinohe) and reniform nematode (RN, Rotylenchulus reniformis Linford and Oliveira) resistance could be genetically related. For many years fragmentary data has shown this relationship. This report evaluates RN reproduction on 418 plant introductions (PIs) selected from the USDA Soybean Germplasm Collection with reported SCN resistance. The germplasm was divided into two tests of 214 PIs reported as resistant, and 204 PIs moderately resistant to SCN. The defining and reporting of RN resistance changed several times in the last 30 years, causing inconsistencies in RN resistance classification among multiple experiments. Comparison of four RN resistance classification methods was performed: (1) ≤10% as compared to the susceptible check, (2) using normalized reproduction index (RI) values, and transformed data (3) log10 (x) and (4) log10 (x+1), in an optimal univariate k-means clustering analysis. The method of transformed data log10 (x) was selected as the most accurate for classification of RN resistance. Among 418 PIs with reported SCN resistance, the log10 (x) method grouped 59 PIs (15%) as resistant, and 130 PIs (31%) as moderately resistant to RN. Genotyping of a subset of the most resistant PIs to both nematode species revealed their strong correlation with rhg1-a allele. This research identified genotypes with resistance to two nematode species and potential new sources of RN resistance that could be valuable to breeders in developing resistant cultivars.

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Characterization of Virulence Phenotypes of Soybean Cyst Nematode (Heterodera glycines) Populations in North Dakota

Phytopathology ◽

10.1094/phyto-01-21-0031-r ◽

2021 ◽

Author(s):

Intiaz Amin Chowdhury ◽

Guiping Yan ◽

Addison Plaisance ◽

sam markell

Keyword(s):

North Dakota ◽

Soybean Cyst Nematode ◽

Heterodera Glycines ◽

The United States ◽

Cyst Nematode ◽

Sources Of Resistance ◽

Resistance Sources ◽

First Time ◽

Primary Strategy

Soybean cyst nematode (SCN; Heterodera glycines) continues to be the greatest threat to soybean production in the United States. Since host resistance is the primary strategy used to control SCN, knowledge of SCN virulence phenotypes (HG types) is necessary for choosing sources of resistance for SCN management. To characterize SCN virulence phenotypes in North Dakota (ND), a total of 419 soybean fields across 22 counties were sampled during 2015, 2016, and 2017. SCN was detected in 42% of the fields sampled and population densities in these samples ranged from 30 to 92,800 eggs and juveniles per 100 cm3 of soil. The SCN populations from some of the infested fields were virulence phenotyped with seven soybean indicator lines and a susceptible check (Barnes) using the HG type tests. Overall, 73 SCN field populations were successfully virulence phenotyped. The HG types detected in ND were HG type 0 (frequency rate: 36%), 7 (27%), 2.5.7 (19%), 5.7 (11%), 1.2.5.7 (4%), and 2.7 (2%). However, prior to this study only HG type 0 was detected in ND. The designation of each of the HG types detected was then validated in this study by repeating the HG type tests for thirty-three arbitrarily selected samples. This research for the first time reports several new HG types detected in ND and confirms that the virulence of SCN populations is shifting and overcoming resistance, highlighting the necessity of utilization of different resistance sources, rotation of resistance sources, and identification of novel resistance sources for SCN management in ND.

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Relating initial paraquat injury to final efficacy in selected weed species influenced by environmental conditions

Weed Technology ◽

10.1017/wet.2020.109 ◽

2020 ◽

pp. 1-10

Author(s):

Nick T. Harre ◽

Garth W. Duncan ◽

Julie M. Young ◽

Bryan G. Young

Keyword(s):

Environmental Factors ◽

Negative Relationship ◽

Injury Rate ◽

Time Of Day ◽

Palmer Amaranth ◽

Shoot Biomass ◽

Lag Phase ◽

Progression Rate ◽

Weed Species ◽

Time Of Application

Abstract Weed control of paraquat can be erratic and may be attributable to differing species sensitivity and/or environmental factors for which minor guidance is available on commercial labels. Therefore, the objectives of this research were to quantify selectivity of paraquat across select weed species and the influence of environmental factors. Experiments were performed under controlled conditions in the greenhouse and growth chamber. Compared with purple deadnettle (dose necessary to reduce shoot biomass by 50% = 39 g ai ha−1), waterhemp, Palmer amaranth, giant ragweed, and horseweed were 4.9, 3.3, 1.9, and 1.3 times more sensitive to paraquat, respectively. The injury progression rate over 3 d after treatment (DAT) was a more accurate predictor of final efficacy at 14 DAT than the lag phase until symptoms first appeared. For example, at the 17.5 g ha−1 dose, the injury rate of waterhemp and Palmer amaranth was, on average, 3.6 times greater than that of horseweed and purple deadnettle. The influence of various environmental factors on paraquat efficacy was weed specific. Applications made at sunrise improved control of purple deadnettle over applications at solar noon or sunset. Lower light intensities (200 or 600 μmol m−2 s−1) surrounding the time of application improved control of waterhemp and horseweed more than 1,000 μmol m−2 s−1. Day/night temperatures of 27/16 C improved horseweed and purple deadnettle control compared with day/night temperatures of 18/13 C. Though control was positively associated with injury rates in the application time of day and temperature experiments, a negative relationship was observed for waterhemp in the light-intensity experiment. Thus, although there are conditions that enhance paraquat efficacy, the specific target species must also be considered. These results advocate paraquat dose recommendations, currently based on weed height, be expanded to address sensitivity differences among weeds. Moreover, these findings contrast with paraquat labels stating temperatures of 13 C or lower do not reduce paraquat efficacy.

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Effects of Diseases on Soybean Yields in the United States 1996 to 2007

Plant Health Progress ◽

10.1094/php-2009-0401-01-rs ◽

2009 ◽

Vol 10 (1) ◽

pp. 24 ◽

Cited By ~ 83

Author(s):

Allen Wrather ◽

Steve Koenning

Keyword(s):

Soybean Cyst Nematode ◽

Management Strategies ◽

The United States ◽

Cyst Nematode ◽

Disease Suppression ◽

Stem Rot ◽

Soybean Yield ◽

Funding Agencies ◽

The Usa ◽

Soybean Diseases

Research must focus on management of diseases that cause extensive losses, especially when funds for research are limited. Knowledge of yield suppression caused by various soybean diseases is essential when prioritizing research. The objective of this project was to compile estimates of soybean yield suppression due to diseases in the USA from 1996 to 2007. The goal was to provide information to help funding agencies and scientists prioritize research objectives and budgets. Yield suppression due to individual diseases varied among years. Soybean cyst nematode suppressed USA soybean yield more from 1996 to 2007 than any other disease. Phytophthora root and stem rot ranked second among diseases that most suppressed yield seven of 12 years. Seedling diseases and charcoal rot also suppressed soybean yield during these years. Research and extension efforts must be expanded to provide more preventive and therapeutic disease management strategies for producers to reduce disease suppression of soybean yield. Accepted for publication 25 February 2009. Published 1 April 2009.

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Turfgrass Evaluation Under Artificial Shade in the Greenhouse

HortScience ◽

10.21273/hortsci.32.3.520f ◽

1997 ◽

Vol 32 (3) ◽

pp. 520F-521

Author(s):

Mark R. LeBlanc ◽

James N. McCrimmon

Keyword(s):

Block Design ◽

Dry Weight ◽

Leaf Length ◽

The Sun ◽

Average Decrease ◽

Greenhouse Study ◽

Randomized Block Design ◽

Shade Cloth ◽

Stolon Length ◽

Total Dry Weight

Establishing and maintaining turfgrass in the shade is one of the most challenging problems facing turfgrass managers and home owners. A greenhouse study was initiated to determine the shade tolerance of centipedegrass [Eremochloa ophiuroides (Munro.) Hack.], carpetgrass [Axonopus affinis Chase], and selected St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] cultivars (`Floratam', `FX-10', `Seville', and `TR 6-10'). Plants were grown under artificial shade (85% polypropylene shade cloth) and full sun. Actual percent shade (%shade={PAR under shade/PAR under sun}*100) was determined by measuring photosynthetically active radiation (PAR) under shade cloth and full sun adjacent to the shade structure using a quantum sensor. Pots were arranged in a completely randomized block design with four replications. All turfgrasses, except `TR 6-10', had a significant reduction in total dry weight in the shade compared to those in the sun. `TR 6-10' had the highest root, leaf, and total dry weight in the shade. `FX-10' had the lowest root, leaf, and total dry weight in the shade. Plants grown under the shade treatment compared to those in the sun resulted in an average decrease in stolon number of 13 and in total stolon length of 170 cm. In the shade, `Floratam' and `Seville' had the longest stolon internode lengths, while `Floratam' had the longest in the sun. There were significant differences for leaf length between the shade and sun treatments, except for carpetgrass and `FX-10'. `Floratam' and `FX-10' had differences in leaf width between the sun and shade.

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Application of oxyfluorfen and pendimethalin to control weeds on soybean plantation

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/951/1/012066 ◽

2022 ◽

Vol 951 (1) ◽

pp. 012066

Author(s):

H Hasanuddin ◽

G Erida ◽

S Hafsah ◽

A Marliah ◽

Y Agustiawan ◽

...

Keyword(s):

Weed Control ◽

Crop Yield ◽

Weed Management ◽

Chemical Control ◽

Block Design ◽

Dry Weight ◽

Significant Loss ◽

Weed Species ◽

Weed Population ◽

Different Types

Abstract The appearance of weeds on crops has led to the significant loss of crop yield. Therefore, chemical control with herbicides has been an important tool for rapid and efficient weed management in crops. The objective of this study was to evaluate the effect of herbicides oxyfluorfen and pendimethalin against weeds on soybean plantation. This research employed Randomized Completely Block Design (RCBD) Factorial with 2 factors. The first factor was the type of herbicides: oxyfluorfen and pendimethalin. The second factor was herbicide doses: 0, 500, 1000, 1500 and 2000 g a.i ha-1, applied on soybean at 1 day after planting (DAP). The percentage of weed control, percentage of weed coverage, weed species, weed population, and weed dry weight were observed at 3, 5, 7 and 9 weeks after planting (WAP). The results revealed that different types and doses of herbicide applied has affected the percentage of weed control, percentage of weed coverage weed species and weed dry weight.

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