I have seen soybean yields on some farms staying stagnant. Some of this is due to weather and management, but some may be due to an invisible robber, Soybean Cyst Nematode (SCN).

Yield losses from SCN can be as high as 25-30% without showing any visual symptoms.  Your 45 bu/ac soybeans could be 56 bu/ac soybeans in the absence of SCN. Combine that with other pathogens that may increase with SCN infection, such as Sudden Death Syndrome, and your yield loss can be upwards of 40%.

SCN damages a soybean plant by taking food, stunting roots, disrupting vascular tissue and nitrogen fixing nodules, as well as causing wounds which allow pathogens to enter the plant. In many cases, there are no above ground symptoms even though the crop may suffer significant yield loss. SCN is a manageable problem if you know you have it; luckily, there are some new tools to help manage SCN.

ILeVO® is a new systemic chemical seed treatment from Bayer CropScience for Sudden Death Syndrome that also shows some activity on nematodes. It disrupts nematode respiration in the seed zone, killing SCN and other nematodes.

VOTiVO® is a bacteria applied to the seed which creates a living barrier that stops SCN from finding the roots. These bacteria compete for space and food with SCN. When used together, ILeVO® + Poncho®/VOTiVO® give 3 modes of action. Maizex will be testing this treatment this summer; stay tuned for results.

ClarivaTM pn is a seed treatment from Syngenta for SCN control containing Pasteuria nishizawae-Pn1 (a naturally occurring soil microorganism). It works by releasing spores into the soil which form a protective layer around the soybean roots. These spores infect then kill SCN. Spores are released back to the soil when the infected nematodes decompose to provide season long protection.

Early detection is imperative to helping control and manage SCN on your farm. Soybean Cyst Nematodes can be found in all soil types, not just sandy soils. Sandy soils tend to show more symptoms due to stress.

Soybean Cyst Nematodes can move through their entire life cycle (egg to juvenile to adult) in only 24 days, allowing several generations of SCN to occur in a single growing season.  After hatching, juvenile worms penetrate soybean roots to feed on the vascular tissue. The females begin to swell, break through the root tissue and expose their lemon shaped body. This is what is visible when you are scouting for SCN on soybean roots. The SCN males exit the roots after feeding and mate with females. Each female produces 50-100 eggs outside the body and also fills with 200+ eggs internally. When females die, their body hardens into a protective cyst filled with eggs which can survive for up to 10 years in the soil.

To Do List

Talk to your Maizex Rep about SCN sampling. There are opportunities for us to help you get your fields tested for SCN.
Use IPM on your farm so SCN doesn’t creep up on you (rotation to non-host crops, scouting for early detection, using SCN-resistant soybeans, weed control).
Talk to your Maizex Rep about choosing the right soybean variety for your farm. Rotate resistant varieties each year to manage SCN populations.

New tools, innovation and monitoring SCN levels in your field can help keep Soybean Cyst Nematode numbers down to manageable levels.  

Laura Johnston, CCA-ON, Maizex Seeds Territory Manager, West Elgin County
Twitter: @lmjohnston8 

 

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