The Ohio State University Partner
SCN is important in Ohio because:
- SCN contributes to soybean yield loss in Ohio every year.
- Low yielding fields may have high SCN numbers with no above ground plant symptoms.
- SCN infestations now occur statewide and can be detected in most fields in the state.
- Some fields with high populations have adapted to the most common source of resistance (PI88788).
SCN Management Recommendations
There are multiple tactics for managing SCN:
- Identify fields with SCN + monitor populations.
- Rotate crops.
- Use resistant varieties wisely.
- Use best cultural practices.
- Manage other diseases (SDS, BSR).
- Prevent introduction.
Soil testing tips:
- Where in the field?
- Low yielding areas (use GPS from yield maps)
- Pockets where soybeans mature early
- Areas with the presence of sudden death syndrome
- Places subject to flooding
- Entrances and borders of fields
- Anywhere pH of soil is alkaline (pH higher than 7)
- The optimal window of time in which to monitor SCN population density is from one week before harvest until the ground freezes.
- However, if the purpose of sampling is diagnostic, to identify the presence of SCN in fields with no previous record of it or to conduct a survey to determine its distribution in a region, then sampling for SCN at any time is suitable.
- How often? Once every year, usually between harvest and freezing.
Where should soil test samples be sent?
C. Wayne Ellett Plant & Pest Diagnostic Clinic
Ohio State University
8995 E. Main St. Bldg. 23
Reynoldsburg, OH 43068-3399
Spectrum Analytic, Inc.
1087 Jamison Rd. NW
Washington Court House, OH 43160
Brookside Laboratories, Inc.
200 White Mountain Dr.
New Bremen, OH 45869
Rotate different resistant varieties:
- Use resistant varieties in rotation with non-host crops.
- Do not plant resistant varieties in fields with very high numbers of SCN (10,000 eggs or greater).
Rotate different sources of resistance:
- Do not use the same variety derived from the same source of resistance two years in a row. Doing so could result in a selection of SCN populations with the ability to reproduce on that source. It is best to switch up the genetics to other high yielding varieties as much as possible.
- Ohio now has sizable populations of SCN that can reproduce on PI 88788. Rotate to varieties that use Peking as a source of resistance to prevent SCN reproduction.
What to know about rotating to non-host crops:
- Rotating with non-host crops like corn, small grains, and alfalfa is the most effective method of controlling SCN.
- Where SCN populations are high, it may take three years or more of non-host crops between soybean crops to reduce SCN populations significantly.
- SCN can increase 10 to 30 fold per year on susceptible soybeans.
- SCN can decrease up to 50% in one year of non-host rotation. Rotate, rotate, rotate!
Nematode-protectant seed treatments:
- We do not recommend any seed treatments at this time to help with SCN.
- More studies are in progress on both short term and long term effects on populations.