Soybean farmers alert - nematode threat grows in Nebraska

By Scout Nelson

The silent destroyer, the soybean cyst nematode (SCN), might be lurking in your soybean fields. Even if you haven't recorded a yield loss, it's possible this tiny roundworm has invaded parts of your lands. Since its discovery in Nebraska in 1986, SCN's reach has expanded to 59 counties as of October 2023.

Recognized as North America's top soybean yield-limiting pest, it costs U.S. farmers a staggering $1.5 billion annually. Its cunning lies in causing up to a 30% yield loss without any noticeable signs above the ground.

How does SCN travel?

Soil movement on farm tools often introduces it. And it doesn’t spread uniformly. That's why it's crucial to watch for unexpected low yields during harvest.

The gold standard to confirm SCN's presence is soil sampling. And there's no better time than now, October – named the soybean cyst nematode action month. This is when SCN concentrations in the soil peak post-harvest.

Here's a golden opportunity: The Nebraska Soybean Board is currently offering free SCN sample analysis. Collect your free-soil sample bags online or from the local extension office.

How to sample: Use a 1-inch probe or spade and gather 15 to 20 soil cores, zigzagging across the field, around 6-8 inches deep. Mix the samples, then send at least 2 cups for testing. Remember, areas like field entryways, low spots, borders, or those showing early defoliation are high-risk SCN zones.

Where to send: UNL Plant & Pest Diagnostic Clinic, Lincoln, NE. Don't forget to label your samples with key details like your name, field ID, and crop history.

Once you identify an SCN-infested field, there are strategies to fight back. Rotate between resistant soybean varieties. Turn to non-host crops like corn, wheat, or alfalfa.

Consider nematode-protectant seed treatments but only alongside resistant soybean types. Lastly, don't ease on monitoring. Regular testing, every 2-3 years, will keep you ahead in the battle against SCN.

Even if you're not seeing SCN's impact, it might be eating away your yield. Regular soil tests are the best defense. If you've forgotten the last test date, now's the time. Collect your free test bags today!