Soybean cyst nematode (SCN) is a big problem for soybean growers across the country. It can be a very costly, yield robbing pest that we need to be aware of and watch out for closely. Iowa State University nematologist Greg Tylka joins us to explain what to look for and why it’s important to do a SCN root check. Learn more below the video or at https://www.thescncoalition.com.
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.
“One thing I’ve learned over my career is that while many farmers get their information directly from universities and extension, they also get tremendous amounts of good useful information from industry, and we’re very happy, the Coalition is, to have Valent embarking on this program, convincing farmers and agronomists to dig roots to look for the presence of SCN. That’s the first step towards actively managing SCN. We actually want farmers and agronomists who are doing this to take photographs, especially of roots they find with soybean cyst nematode females. Ttake a photo or a video, and send it out on social media with the hashtag SCNRootCheck, and that will start spreading the word among those that are doing this, and we might see how prevalent SCN is in mid-season, which is a very persuasive thing to see during the growing season.”