Time to Check for SCN

The SCN Coalition and Valent have joined forces to encourage soybean farmers to check for SCN females attached to roots during the growing season. Iowa State University nematologist Greg Tylka explains why it’s important to check roots.

“The soybean cyst nematode is an extremely damaging pest. Yield loss estimates almost seem unbelievable in that they are $1.5 billion in yield loss annually for North America. North American soybean production is mainly United States and Canada. Those yield loss estimates have been around and updated annually for a couple years, and they’ve always bounced around $1.5 billion, and some of us have wondered if that was accurate or not, because they were people’s estimates. There was a paper published from Penn State University in 2020, which did a mathematical analysis of actual yield data, and their conclusion was $1.5 billion annually. It really validated that horrific yield loss number that’s attributed to soybean cyst nematode each year.” 

Soybean fields infested with SCN may look healthy above ground, but adult SCN females can be detected on the roots as soon as six weeks after soybeans have emerged. Tylka explains how to check roots.

“Many of the fields that are suffering yield loss due to SCN don’t look sick. And so, it’s really a campaign we have to embark on to convince farmers and agronomists to advise those farmers to get out and dig roots and look for the presence of the SCN females on the roots. And you need to do that in perfectly healthy looking soybean fields. And when I give talks in-person, I’m constantly saying carry a shovel, and as you walk through any soybean field for any reason whatsoever, get in the habit of bending over, digging some roots, shaking the soil from the roots and looking for the little white SCN females on the roots. You can see them with your naked eye and at the most you’re going to need a hand lens. And it’s a first step towards managing this terrible pest.” 

Tylka says the weather can also impact the SCN life cycle. Warmer weather seen in recent years and again this year can lead to higher SCN population densities.

“If soybean cyst nematode weren’t bad enough on its own, we’ve observed over decades of consistent observations that SCN females or SCN reproduction is much greater in hot, dry soils. We don’t understand the mechanism of it, but it’s over decades been a consistent observation. And then we’ve actually analyzed about 15 years of data and saw a significant statistical relationship between soil moisture and soil temperature and higher SCN reproduction. I’m always ringing the bell of caution as we end a hot, dry year to farmers, that really might have suffered more yield loss to SCN this year than ever before. And there’s the need to check fields and start actively managing SCN.” 

The SCN Coalition and Valent are encouraging soybean farmers to dig roots and share their findings on social media.

Learn more at TheSCNCoalition.com.