Soybean Cyst Nematode Management

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Soybean Cyst Nematode Management

• Senyu Chen
• University of Minnesota

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Generalized Recommendations for SCN Management
Non-host
gt 10,000 eggs/100 cc soil
No egg
detected
Non-
Non-
Susceptible
host
host
soybean
lt 10,000 eggs/100 cc soil
Resistant
soybean
Non-host
Non-host
(1st source)
lt 200 (-500) eggs/100 cc soil
Resistant
Susceptible
soybean
Non-host
soybean
(2nd source)
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• Soil Sampling
• Detecting/diagnosing
• Take soil from areas where are most likely
  infested by the nematode
• Field entrance
• Low areas
• Flooded areas
• Where wind-blown soil settles
• Spots with stunting and chlorotic soybeans and
  low soybean yield
• In rows during soybean growing season

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• Soil Sampling
• Deciding on management strategies
• Take a sample representing average egg number in
  an area of 10 acres
• 20 soil cores, 6-8 depth
• A zigzag pattern
• Prior to planting susceptible soybean or
• Fall after harvesting corn or other non-host crop

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Generalized Recommendations for SCN Management
Non-host
gt 10,000 eggs/100 cc soil
No egg
detected
Non-
Non-
Susceptible
host
host
soybean
lt 10,000 eggs/100 cc soil
Resistant
soybean
Non-host
Non-host
(1st source)
lt 200 (-500) eggs/100 cc soil
Resistant
Susceptible
soybean
Non-host
soybean
(2nd source)
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Parker, Waseca, 2002
163 eggs/100 cc soil
13,950 eggs/100 cc soil
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Yield of top ten resistant varieties and top ten
susceptible varieties in SCN-infested and
non-infested fields in 1999-2002
Infested
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Lamberton, 1997
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35,000 eggs/100 cc soil 24 bu/a
3,000 eggs/100 cc soil 38 bu/a
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S - SCN S - Phytophthora S - Iron
S - SCN S - Phytophthora T - Iron
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S - SCN S - Phytophthora S - Iron
R - SCN S - Phytophthora T - Iron
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R - SCN R - Phytophthora T - Iron
S - SCN S - Phytophthora S - Iron
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Effects of genes resistant to SCN and
Phytophthora, and tolerant to iron-deficiency on
soybean chlorosis - Waseca, 2002
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Waseca, 2002
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Population density changes in sequences of R-C
rotation, R and C monoculture during 1996 - 2002
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Soybean yield in 1999-2002
R Freeborn, S Sturdy. LSD0.05 4.8
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• Summary
• SCN is a major factor limiting soybean yield
• When SCN is detected in a field, a long-term
  management program should be practiced
• Use of resistant varieties and rotation with
  non-host crops are the most effective means
• Different sources of resistance should be
  included in the rotation
• lt 200 (500) eggs/100 cc soil, susceptible cv.
  should be used
• gt 10,000 eggs/100 cc soil, no soybean should be
  grown