Sampling for Soybean Cyst Nematode – It’s time!

This year’s early harvest provides the perfect opportunity to take a look at the SCN populations in your fields.  We know that the state is now “polluted” with SCN, fortunately most of those fields are at very low levels – which is where they should be kept.  However, there are some surprising locations where individual fields are getting or have gotten into trouble with very high populations.  So let’s review the loss levels for SCN for the majority of soil types here.

Levels of SCN and concerns

SCN egg Count/100 cc

Cyst count

Population Level

0-40

0

not detected

40-200

1

trace

200-2000

1-4

low

2000-5000

3-20

moderate

5000 & over

15-20

high

 

 

 

 

 

If your SCN report in the past has come back as:

1.       Not detected: this is not surprising.  Remember that SCN sits in pockets and can be quite variable (Figure 1).  Continue to monitor your fields.

2.       Trace:  May begin to measure some yield loss on susceptible varieties, especially on lighter soils.

3.       Low: Plant SCN resistant varieties or rotate to a non-host crop (corn or wheat). 

4.       Moderate:  Rotate to a non-host crop and follow with SCN resistant varieties the following year.  We have planted susceptible varieties in fields with this level of SCN and have recorded 20 to 50% yield loss. 

5.       High:  rotate to a non-host crop for two to three years, then sample SCN to determine if populations have declined to a level where soybeans can be planted again.

SCN is picky about what it feeds and reproduces on but it does like a few weed hosts and cover crops as well as soybean.  If you have SCN in your fields , it is important to also control winter annuals such as purple deadnettle, but also avoid cover crops such as several of the clover’s, cowpea and common & hairy vetch. 

So it is time to sample!  We recommend sampling in the fall – because in most cases this is what the population will be in the spring.  With the warmer weather this year and hopefully no frozen ground should give ample time to collect and process the samples in plenty of time for spring planting. Processing of samples does cost time and money, so here are a few thoughts on how to sample or how to target your sampling to get the best information for your money.  Through funds from the soybean check-off, we have completed several targeted surveys over the past 5 years.  My group tended to target those fields where yields were stuck or below 30 bu/A.  Or when we sampled we hit those pockets in the field where the soybeans tended to be shorter or where they matured earlier and always yielded less that the rest of the field.  We were able to detect SCN in almost all of these situations, so these are the ones that should have the top priority for sampling. 

Updated information on where to send the samples:

OSU C. Wayne Ellett Plant and Pest Diagnostic Clinic

8995 E. Main St. Bldg 23

Reynoldsburg, OH 43068

Phone: 614-292-5006

www.ppdc.osu.edu  - follow this link to download forms to go along with the samples

 

Brookside Laboratory Inc.

200 White Mountain Dr.

New Bremen, OH 45869

417-977-2766

www.blinc.com

 

Spectrum Analytic Inc.

1087 Jamison Rd. NW

Washington Court House, OH  43160

740-335-1562

www.spectrumanalytic.com

For some additional information on Management of SCN – always check Ohio’s SCN fact sheet and several other resources as well:

http://soybeanresearchinfo.com/ - link to the 5th edition of the SCN guide developed through the North Central Soybean Research Program.

Link to recent findings and sampling protocol for SCN: https://www.youtube.com/watch?v=FQgg-UPQdcs&feature=youtu.be

About the C.O.R.N. Newsletter

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.