The WI Soybean Marketing Board (WSMB) sponsors free nematode testing to help producers
stay ahead of the most important nematode pest of soybean, the soybean cyst
nematode (SCN). Eggs of SCN persist in the soil between soybean crops so a
sample can be submitted any time that is convenient. The soil test report
indicates the number of eggs in the sample and is useful for selecting the
right variety for the next soybean crop. Retests of fields planted with
SCN-resistant varieties over multiple years shows how the nematode population
is responding to variety resistance and provides an early warning should the
nematode population adapt to host genetics.
In the spring of 2012, the WSMB expanded the nematode testing program to include other pest nematodes in addition to SCN. These nematodes are less damaging to soybean than SCN but can cause enough yield loss to warrant treatment. As is the case for SCN, there are no rescue treatments for nematodes so the primary purpose of this year’s soil test is to plan for next year’s crop. Soil samples collected in corn for nematode analysis have predictive value for explaining yield if they are collected before the corn V6 growth stage. Sampling early in the season will provide information about the risk potential for the current corn crop AND the next soybean crop.
The assays used to recover nematode pests other than SCN in soil require that the nematodes are alive. So, it is important to keep the samples moist and at least room temperature cool. Collecting a sample that includes multiple cores ensures that there will be plenty of root pieces to assay. It is not necessary to include live plants in the sample. The soil test report will indicate which pest nematodes are present and at what quantities and their damage potential to soybean and corn based on the numbers recovered.
Free soil sample test kits are available now and can be requested from Jillene Fisch at (freescntest@mailplus.wisc.edu) or at 608-262-1390.
For more information on SCN testing and management practices
to help reduce the losses from this pest, please contact: Shawn Conley:
spconley@wisc.edu; 608-262-7975 or visit www.coolbean.info.
Remember the first step in fixing a nematode problem is to know if you have one! The WSMB sponsored nematode testing program provides you that opportunity.
