scholarly journals Response of Heterodera glycines and Soybean Cultivar to Tillage and Row Spacing

Plant Disease ◽  
2001 ◽  
Vol 85 (3) ◽  
pp. 311-316 ◽  
Author(s):  
S. Y. Chen ◽  
W. C. Stienstra ◽  
W. E. Lueschen ◽  
T. R. Hoverstad
Keyword(s):  
Population Density ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Resistant Cultivar ◽  
Row Spacing ◽  
Initial Population ◽  
Susceptible Cultivar ◽  
Nematode Density ◽  
Nematode Reproduction ◽  
Resistant Cultivars

Heterodera glycines, commonly known as the soybean cyst nematode (SCN), has become a major factor in soybean production in the Midwest United States. The influence of five tillage treatments and two treatments of row spacing on SCN population dynamics and yield of SCN-resistant and -susceptible soybean cultivars was investigated in a corn-soybean rotation system in southern Minnesota from 1993 to 1996. No effects of tillage and row spacing were observed on nematode population density. As expected, the susceptible cultivar Sturdy consistently supported higher nematode densities than did the resistant cultivar Bell in 1993 to 1995 and Freeborn in 1996. Nematode reproduction varied among years. Predicted nematode density at equilibrium was 3,800, 13,000, 12,000, and 27,000 eggs per 100 cm3 of soil in plots with the susceptible cultivar and 480, 240, 430, and 700 eggs per 100 cm3 of soil in plots with the resistant cultivars in 1993, 1994, 1995, and 1996, respectively. The effects of tillage and row spacing on soybean yield were inconsistent. The resistant cultivars yielded 653, 195, and 435 kg/ha more (P < 0.05) than the susceptible cultivar in 1994, 1995, and 1996, respectively, but no yield difference between susceptible and resistant cultivars was observed in 1993. Planting resistant cv. Bell increased the yield of the following susceptible cv. Sturdy compared with continual planting of the susceptible cultivar. A sequence with continued resistant cultivar or cultivars, however, produced a higher overall yield and lower nematode density at the end of the 4-year rotation cycle than any sequence in which the susceptible cultivar was included. Yield of resistant and susceptible cultivars was negatively related to the SCN initial population density.

scholarly journals Population Dynamics of Phialophora gregata in Stem Residue of a Resistant and a Susceptible Soybean Cultivar

Plant Disease ◽  
2006 ◽  
Vol 90 (6) ◽  
pp. 759-764 ◽  
Author(s):  
A. E. Impullitti ◽  
C. R. Grau
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Soil Surface ◽  
Resistant Cultivar ◽  
Soybean Cultivar ◽  
Second Phase ◽  
Susceptible Cultivar ◽  
Resistant Cultivars ◽  
Phialophora Gregata ◽  
Genotype A

Previous studies on the saprophytic survival of Phialophora gregata were conducted with soybean residue derived from a susceptible cultivar and did not address genotypes of P. gregata. This current study monitored the saprophytic population density of P. gregata in stem residue derived from a susceptible and a resistant soybean cultivar placed in the field. A second phase of the study followed the frequencies of genotypes A and B of P. gregata in stem residue derived from a susceptible cultivar. The population density of P. gregata declined 10-fold in stem residue from the initiation of sampling to the end of this 16-month study, regardless of cultivar or whether residue was positioned on the soil surface or buried. The population density of P. gregata was greater in buried residue of the resistant cultivar compared with the susceptible cultivar after 12 to 14 months, but equalized after 16 months. The population density of P. gregata was similar in residue derived from the susceptible and resistant cultivars if positioned on the soil surface. Genotype B was detected more frequently than genotype A of P. gregata at each sampling date regardless of residue placement.

scholarly journals Dynamics of Population Density and Virulence Phenotype of the Soybean Cyst Nematode as Influenced by Resistance Source Sequence and Tillage

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2111-2122
Author(s):  
Senyu Chen
Keyword(s):  
Population Density ◽  
Soybean Cyst Nematode ◽  
Conventional Tillage ◽  
Cyst Nematode ◽  
Susceptible Cultivar ◽  
Sources Of Resistance ◽  
Resistant Cultivars ◽  
No Till ◽  
Negative Effect ◽  
Pi 88788

The soybean cyst nematode (SCN), Heterodera glycines, is the most damaging pathogen of soybean. Use of resistant cultivars is an effective strategy to manage SCN, but it also selects for virulent populations over time. A 12-year field experiment was initiated in 2003 to study how tillage and 11 different sequences of four cultivars impact SCN population dynamics and virulence. An SCN-susceptible cultivar and three resistant cultivars (R1, R2, and R3 derived from cultivars PI 88788, Peking, and PI 437654, respectively) were used. Tillage had minimal effect on SCN population density. Compared with no till, conventional tillage resulted in a faster increase of SCN virulence to Peking when the SCN was selected by R2 and virulence to PI 88788 by R3. Among the three SCN-resistant cultivars, R1 supported the greatest population density, R2 supported intermediate population density, and R3 supported the least SCN population density. The SCN populations selected by R1 overcame the resistance in PI 88788 but not in Peking and PI 437654. R2 selected SCN populations that overcame the resistance in Peking but not in PI 88788 and PI 437654. In contrast, R3 selected SCN populations that overcame both PI 88788 and Peking sources of resistance. There was no increase of virulence to PI 437654 in any cultivar sequence. R1 in rotation with R2 or R3 had a negative effect on female index on Peking. Susceptible soybean reduced SCN virulence to Peking, indicating that there was fitness cost of the Peking virulent SCN type. These results suggest that rotation of Peking with PI 88788 is a good strategy for managing the SCN, and susceptible cultivar and no till may reduce SCN virulence selection pressure in some rotations. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Temporal-spatial population density of Heterodera glycines in soybean roots during the early growth stage

Nematology ◽  
2011 ◽  
Vol 13 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Zhenhua Wang ◽  
Haiyan Wu ◽  
Jing Liu ◽  
Xiuxia Li
Keyword(s):  
Population Density ◽  
Soybean Cyst Nematode ◽  
Growth Stage ◽  
Heterodera Glycines ◽  
Soil Depth ◽  
Lateral Roots ◽  
Cyst Nematode ◽  
Soybean Plant ◽  
Nematode Density ◽  
Soybean Roots

AbstractPrevious research found that the population density of Heterodera glycines in soybean fields fluctuated during the growth of soybeans. However, the population density in soybean root was unclear. In this study, the dynamics of soybean cyst nematode (SCN; Heterodera glycines, race 4) in soybean roots were investigated over a period of 2 years. Soybean plant roots were sampled during a period of 7-37 days after seedling emergence, and SCN in taproots and lateral root were counted. The results indicated that the total population density of nematodes increased with the growth of soybean roots, showing a sigmoid curve. A comparison of nematode density between taproots and lateral roots showed a decrease in the numbers of nematodes in taproots and an increase in the numbers in lateral roots with increasing age of the plants. There was an overall decrease in nematode numbers with increasing soil depth. Our results show that most of the nematodes were found in roots from 5-15 cm soil depths (2006, 81.3-91.4%; 2007, 86.6-97.6%) during the soybean seedling growth stage, which may provide some useful information for integrated management of soybean cyst nematode.

Efficacy of the fungi Hirsutella minnesotensis and H. rhossiliensis from liquid culture for control of the soybean cyst nematode Heterodera glycines

Nematology ◽  
2005 ◽  
Vol 7 (1) ◽  
pp. 149-157 ◽  
Author(s):  
Shufen Liu ◽  
Senyu Chen
Keyword(s):  
Heat Treatment ◽  
Population Density ◽  
Soybean Cyst Nematode ◽  
Liquid Culture ◽  
Heterodera Glycines ◽  
Nematode Population ◽  
Solid Culture ◽  
Nematode Population Density ◽  
Biological Control Potential ◽  
Shoot Weight

AbstractHirsutella minnesotensis and H. rhossiliensis are endoparasites of nematodes, and their biological control potential against Heterodera glycines when cultured and applied on corn grits has been reported. In this study, the potential of liquid cultures of the two fungi was evaluated in two glasshouse experiments. Both liquid culture at 0.2, 0.4 and 0.8 g of fresh mycelium/300 cm3 soil (per pot) and solid culture at 1% (corn grits: soil, w/w) reduced nematode egg population densities in both autoclaved and unheated soils as compared with soil-only control or corn-grits control. However, the liquid culture at 0.2–0.8 g of mycelium/pot appeared to be more effective in reducing the nematode population than the solid culture of 1%. Hirsutella rhossiliensis resulted in lower nematode population density than H. minnesotensis only in unheated soil in one experiment. The soil heat treatment generally increased the nematode population density but did not affect percentage reduction of the nematode population density as compared with respective controls, except that reduction by H. rhossiliensis was greater in unheated soil than heat-treated soil in one experiment. Percentage of second-stage juveniles (J2) parasitised by fungi at the end of the experiment (60 days after planting) was generally higher with H. minnesotensis than with H. rhossiliensis. The percentage parasitism was positively correlated with initial fungal inoculation level. The soil heat treatment increased fungal parasitism in one experiment but not in the other. Plant growth was unaffected by treatments except that the soil heat treatment increased plant shoot weight as compared with unheated soil in one experiment.

scholarly journals Influence of Soybean Cropping Sequences on Seed Yield and Female Index of the Soybean Cyst Nematode

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 615-619 ◽  
Author(s):  
Lawrence D. Young
Keyword(s):  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Resistant Cultivar ◽  
Breeding Line ◽  
Sources Of Resistance ◽  
Resistant Cultivars ◽  
Cropping Sequence ◽  
Moderately Resistant ◽  
Different Sources ◽  
Female Index

Several soybean (Glycine max) cropping sequences were planted for 12 years in a field that, at the beginning of the test, was infested with race 14 of the soybean cyst nematode, Heterodera glycines. Continuous soybean cropping sequences included H. glycines-susceptible cultivars Forrest, J82-21, Peking × Centennial breeding line, and moderately resistant cultivars Bedford and J81-116. Forrest treated with aldicarb or pentachloronitrobenzene (PCNB) plus metalaxyl and resistant breeding line JS83-236 followed by resistant cultivars Cordell and Hartwig were additional continuous soybean sequences. Rotations included two sequences each of Bedford with J81-116 or J82-21, and three sequences of Bedford with corn (Zea mays) and susceptible Essex soybean. Rotations of Bedford, corn, and Essex had 12-year mean yields significantly greater than continuous Bedford or Forrest. The female index (FI) of H. glycines on five cultivars and lines was used to bioassay changes in parasitic potential in each cropping sequence. The FI on Bedford bioassay plants increased significantly over time for all field treatments involving Bedford. When J82-21 was the bioassay plant, FI decreased significantly in treatments involving Bedford. There were no significant changes in FI for any treatment when Forrest, J81-16, and Peking were used as bioassays. Rotations of soybean cultivars with different sources of resistance and rotations of resistant and susceptible cultivars with a nonhost crop were not successful practices to manage the nematode's ability to parasitize the resistant cultivar Bedford. However, rotation of resistant and susceptible cultivars with a nonhost crop produced greater mean soybean yields and slowed the shift toward greater parasitism of the resistant cultivar sufficiently to warrant adoption of this practice.

scholarly journals Crop density and seed production of tall fescue (Festuca arundinacea Schreber). 1. Yield and plant development

1999 ◽  
Vol 79 (4) ◽  
pp. 535-541 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch
Keyword(s):  
Population Density ◽  
Seed Production ◽  
Seed Yield ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Plant Density ◽  
Initial Density ◽  
Row Spacing ◽  
Initial Population ◽  
Crop Density

A field study was conducted with tall fescue (Festuca arundinacea Schreber) to determine the effect of the initial population density and spatial arrangement of plants on crop development and seed yield. Individual seedling plants were transplanted at seven densities (1.6, 3.1, 6.3, 12.5, 25, 50, and 100 plants m−2) and three row spacings (20, 40, and 80 cm), and characteristics of seed production were determined for 3 yr (1991–1993). Over the 3 yr, heading commenced at dates differing by 15 d and was delayed, as density increased, by 8, 6, and 2 d, respectively, in the first, second, and third production years. The time of seed maturity differed among years (21 July to 4 August) but was generally unaffected by density or row spacing. In the first production year, seed yield increased with density up to 25 plants m−2 for each row spacing, then remained constant to at least 50 plants m−2 with both 20- or 40-cm rows; it decreased slightly at 100 plants m−2 with 20 cm rows. In the second production year, seed yield was relatively independent of plant density except that it decreased when the initial density was less than 6 plants m−2 with a row spacing of 80 cm, and tended to be greatest with the 40-cm row spacing at 6–25 plants m−2. In the third production year, seed yield was much lower than in the previous 2 yr but the pattern of response to the density and row spacing treatments was similar to that in the second production year. The seed yield of tall fescue can be optimized for at least 3 consecutive years by establishing an initial density of 20–100 plants m−2 in rows spaced 20–60 cm apart. If the maximization of first-year seed yield is a priority, then the initial establishment should be at a density of 25–50 plants m−2 in rows spaced 20–40 cm apart. Key words: Tall fescue, Festuca arundinacea Schreber, population density, plant spacing, seed production

Effects of Cover Crops on Population Reduction of Soybean Cyst Nematode (Heterodera glycines)

Plant Disease ◽  
2020 ◽  
Author(s):  
Krishna Acharya ◽  
Guiping Yan ◽  
Addison Plaisance
Keyword(s):  
Cover Crops ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Foxtail Millet ◽  
Cyst Nematode ◽  
Natural Soil ◽  
Initial Population ◽  
Annual Ryegrass ◽  
Initial Population Density ◽  
Population Reduction

Microplot experiments were conducted to evaluate the effects of cover crops on population reduction of a major soybean pest, soybean cyst nematode (SCN; Heterodera glycines Ichinohe) in 2016 and 2017. Ten crop species, including annual ryegrass (Lolium multiflorum L), Austrian winter pea (Pisum sativum L. subsp. arvense), carinata (Brassica carinata A. Braun), faba bean (Vicia faba Roth), foxtail millet [Setaria italica (L) P. Beauvois], daikon radish (Raphanus sativus L.), red clover (Trifolium pratense L.), sweetclover (Melilotus officinalis L.), turnip (Brassica rapa subsp. rapa L.), and winter rye (Secale cereale L.) were planted along with susceptible soybean [Glycine max (L.) Merr., cv. Barnes] in soil naturally infested with each of two SCN populations (SCN103 and SCN2W) from two North Dakota soybean fields. Crops were grown in large plastic pots for 75 days in an outdoor environment (Microplot). Soil samples were collected from each pot for nematode extraction and SCN eggs were counted to determine the final SCN egg density. The population reduction was determined for each crop, and non-planted natural soil (fallow). All the tested crops and non-planted natural soil had significantly (P < 0.0001) lower final population densities compared to susceptible soybean (Barnes). Also, a significant difference (P < 0.0001) was observed between the SCN population suppressions caused by cover crops versus the fallow treatment. All cover crops except Austrian winter pea, carinata, faba bean, and foxtail millet had consistently lower SCN egg numbers than in fallow in both years of the experiments. The average population reductions of SCN by the cover crops ranged from 44 to 67% in comparison with the initial population density, while the fallow had natural reductions from 4 to 24%. Annual ryegrass and daikon radish reduced SCN egg numbers to a greater extent than the other cover crops, with an average of 65 and 67% reduction of initial population density, respectively from two years. The results suggested that cover crops reduced the SCN populations in external microplot conditions, and their use has great potential for improving SCN management in infested fields.

scholarly journals Soybean Cyst Nematode Reduces Soybean Yield Without Causing Obvious Aboveground Symptoms

Plant Disease ◽  
2003 ◽  
Vol 87 (6) ◽  
pp. 623-628 ◽  
Author(s):  
J. Wang ◽  
T. L. Niblack ◽  
J. A. Tremain ◽  
W. J. Wiebold ◽  
G. L. Tylka ◽  
...  
Keyword(s):  
Seed Development ◽  
Soybean Cyst Nematode ◽  
Field Experiments ◽  
Heterodera Glycines ◽  
Biomass Accumulation ◽  
Cyst Nematode ◽  
Southern Illinois ◽  
Resistant Cultivars ◽  
Wide Range ◽  
Growth Development

Field experiments were conducted at locations in northern and southern Illinois, central Iowa, and central Missouri from 1997 to 1999 to investigate the effects of Heterodera glycines on soybean growth, development, and yield. A wide range of infestation levels was present at all locations. Two locally adapted cultivars, one resistant to H. glycines, were grown at each location. Cultivars were planted in alternating four-row strips with 76 cm between rows. For each cultivar, 20 1-m-long single-row plots were sampled every 2 weeks starting 4 weeks after planting. Infection by H. glycines reduced plant height and leaf and stem weight on the resistant cultivars in the first 12 weeks after planting, and delayed pod and seed development 12 to 14 weeks after planting. Biomass accumulation was not reduced on the susceptible cultivars until 10 weeks after planting; reduction in pod and seed development occurred throughout the reproductive stages. Susceptible cultivars produced significantly lower yields than resistant cultivars, but the yield reductions were not accompanied by visually detectable symptoms.

scholarly journals Soybean Stem Colonization by Genotypes A and B of Cadophora gregata Increases with Increasing Population Densities of Heterodera glycines

Plant Disease ◽  
2006 ◽  
Vol 90 (10) ◽  
pp. 1297-1301 ◽  
Author(s):  
G. M. Tabor ◽  
G. L. Tylka ◽  
C. R. Bronson
Keyword(s):  
Population Density ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Stem Rot ◽  
Population Densities ◽  
Brown Stem Rot ◽  
Phialophora Gregata ◽  
Soybean Genotypes ◽  
Genotype A

Growth chamber experiments were conducted to investigate whether parasitism by increasing population densities of Heterodera glycines, the soybean cyst nematode, increases the incidence and severity of stem colonization by the aggressive genotype A and the mild genotype B of Cadophora gregata (Phialophora gregata), causal agents of brown stem rot of soybeans. Soybean genotypes with three combinations of resistance and susceptibility to H. glycines and genotype A of C. gregata were inoculated with each genotype of C. gregata alone or each genotype with two population densities of H. glycines eggs, 1,500 or 10,000 per 100 cm3 of soil. Stems of two H. glycines-susceptible soybeans were more colonized by both aggressive and mild genotypes of C. gregata in the presence of high than in the presence of low H. glycines population density.

Sign in / Sign up

Export Citation Format

Share Document