 Hello everyone, I'm Sam Markell. I'm an extension plant pathologist at NDSU and I'm going to be talking about soybean cyst nematode today. I'm out here standing at the agronomy seed farm in Castleton in a soybean field. This field looks pretty good, but we know it's had SCN for quite some time. I'm going to talk about what it looks like and now's a good time to take a look at it, talk about why it's important and how to manage it. Right now we've got a soybean field where it's planted in late May, it's early July, and soybean cyst is a parasitic worm and at this point in the season you can usually see the white females show up on the roots if you have SCN. So I would encourage everyone to get out and take a look and that's exactly what we're doing this morning. So I've got a graduate student with me, Brian Hansen out there, he's digging roots and we're going to take a look at this. So what Brian's doing here is he's got a trowel and he's very carefully digging up the entire root mass and if you do that you can lots of time see these white females that will stay on the roots. So Brian's got some up and what he's looking for not the big nodules, the big nodules that are easy to see, that's a normal healthy soybean, but on the on the lateral root slots at times and sometimes maybe on the main roots about 10 times smaller you'll start to see these white SCN females. And what you're looking at here is the female worm filling full of eggs and so from the cycle it will go about three times in a summer. Well you have these eggs hatched, they'll form SCN, they'll attack the roots, they'll form eggs and then they'll reproduce and so go through about three cycles. So early July really is a good time to take a look and we've got quite a few on these roots. When you get close what you're looking at is really cream-colored little lemon-shaped lesions that are lemon-shaped cysts that really you almost need a hand lens, most of us need a hand lens to see them clearly. So Brian found a really good example of an SCN cyst compared to a nodule. So on the left side is a nodule, nice healthy nodule, pretty normal nodule. On the right you can see that small cream colored maybe lemon shaped if you have really good eyes, that's the SCN cyst and so that cyst is probably full of 150 or 200 eggs of the nematode. So the reason SCN is such a problem is because of that cyst structure. That cyst structure is really really tough and it's full of eggs and the way SCN moves across the state and we know it's been moving since 2003 here is with soil. So those cysts will survive when soil moves. So when you see soil moving through the wind, through water, through equipment, anything that moves soil is going to be moving SCN. And the North Dakota Soybean Council has been really progressive in trying to figure out where SCN is in the state and they started a sampling program back in 2013 where growers could take a sample bag with the program, they could do some sampling like Brian's doing at the end of the season and they could send that soil into the lab and they will cover the lab fees. So the producers can do this, they get their data back in the mail, it doesn't cost them anything and NDSU gets enough data so we can create a map. So we don't have any farm information, any names anything like that, but what we do have is egg counts and where they occur. So the maps that you're looking at are the result of work from 2013 until now. And so you've got about 4,000 samples that have been pulled in the last seven years. And on the map you can see that those black circles, those are negatives and the gray boxes are inconclusive, but really any of those colored circles, squares, diamonds, they're real. And when you get up into the yellow and the red those are over 10,000 eggs per 100 cc's and that's a lot that's going to cause damage on even the best resistant soybean varieties. And those eggs per 100 cc's that's actually what you just looked at which was Brian was pulling out of the field. So the next thing we really want to do is we want to figure out who's got it. So you know the southeastern part of the state most most growers if not all growers should be thinking about SCN and a lot will have it. And I would encourage folks to get out in the field and take a look right now even if your field looks healthy, but really the most important time to samples in the fall. And so you want to think about fall sampling sometime before or after harvest. That's when the SCN population is the highest and easiest to detect. But what's really important is how to manage it especially in the southeast. So we know we can manage it. We've got genetic resistance, we've got crop rotation techniques, we've got some seed treatments and putting them all together in a system to use is really what we need to do. And so I'm going to let you listen to a grower from Iowa describing how he manages SCN. Now he got this about 20 years before it showed up in North Dakota and he's done a fantastic job managing it. And it really is the situation that we're in right now. I'm Ron Heck. I'm a farmer from Perry, Iowa. And I raise soybeans and corn in a two year rotation. The first time we tested for SCN we had egg counts as high as 30,000 in half acre grid. We also had some areas where they were lower. But the unexplained yield loss that I was having in those areas where it was 30,000 the beans were not growing very well, not yielding very well like 30 bushels an acre. There isn't anything you can do to get rid of your SCN right away. It's a process. It's going to take six years to do that. You plant a PI 88, 788 resistance variety and then go to corn and then come back with another PI 88, 788 resistance and go back to corn and then come back with a Peking resistance and go back to corn and then on the fourth cycle your yields will be better than you thought possible on the soybeans. With so many PI 88, 788 varieties available the SCN has started to overcome that resistance so it's very important to farmers that they use other means of control including Peking resistance and the new seed treatments that will help with SCN. Their yields will go up. They should not be concerned about the newer Peking varieties. They will make their yields better not worse and prevent a bigger problem in the future. My bean fields are healthy now all over. I don't have iron chelorosis. I don't have the spots where the beans look a little sick and there's a little bear and there's a weed patch. The beans are healthy and growing everywhere in the field and my yields have easily gone up for field averages of more than 10 bushels an acre and in the worst spots where I used to think it was iron chelorosis those are now the best spots in the field and in those spots the yield has gone up 20 or 30 bushels an acre. The last four tests I've taken for SCN egg counts two said undetectable one said a hundred and another one said 300. If you control your SCN population your soybean yield will go up. It's as simple as that and when your yield goes up with healthier soybeans you'll also get better weed control so that'll be another plus. If you don't drive down your SCN populations you're going to keep losing soybean yield and your loss will be a little more each year that you do that. With SCN you lose at least five bushels an acre before you could even see it. By the time you've lost 10 bushels an acre and this is every year if you lose five bushels an acre for three or four cycles you have lost a lot of yield. The only way to really know if you have SCN is to take the test so you can beat the pest. And there's one more thing I want to talk about SCN. We do have genetic resistance but it's it's all from this line PI 88788 95% of the resistant soybean varieties have this and it's been grown widely across the US in the last two decades really. And you can imagine what would happen if you put the same mode of action herbicide on a soybean variety across the US for 20 years right. Things change and the nematode is adapting so one of the things that's really important is to try to figure out what your egg levels are and start moving those management tools around. If you can get a if you can get a PI 8878 variety and rotate it with a Peking based variety you're going to be much better off in the future. Here at NDSU we're doing a couple things to try to help. Obviously we've got a breeding program that we're trying to breed in resistance but also we're looking at evaluating these chemical seed treatments to see if some of these are going to help us in our area. We also have a small evaluation of different resistant varieties to see how well they perform in our area as well and all that data will be available this winter. You have another resource that you can use for SCN it's called the SCN Coalition at thescncoalition.com. It's where this video is produced and I encourage you to take a look at this and to best manage SCN on your farm.