Latest / The Illinois Nutrient Loss Reduction Podcast / Episode 15 | Pests and Pathogens, Oh My!
Transcript
- Episode 15 | Pests and Pathogens, Oh My! 00:00:05:12 - 00:00:33:15 Todd Gleason This is the Illinois Nutrient Loss Reduction podcast, episode 14 Pests and Pathogens, Oh, my! I'm University of Illinois Extension’s Todd Gleason. Nick Seiter is an entomologist at the University of Illinois, and he's been thinking a lot about the pests that might thrive in those high residue, no till systems. I asked him what the differences might be between wet and dry years, and what pests the producers might be facing. 00:00:33:17 - 00:00:55:24 Nick Seiter One that we've been looking a lot at recently is the Dectes stem borer in soybean. That's an insect that, while tillage doesn't control it on a field specific basis, when you have a lot of no till in an area and a lot of soybean residue in an area, it allows more of them to survive the winters. And so that can favor those populations over a wide area. 00:00:55:26 - 00:00:57:24 Todd Gleason What are the symptoms and the losses? 00:00:57:25 - 00:01:15:00 Nick Seiter So this is an insect. It's a longhorned beetle. The adult comes in lays it takes on the soybean petiole and that larva gets out and actually bores its way up and down the soybean stem. It eats the pith on the inside of the stem. If you split that open, it looks terrible. 00:01:15:02 - 00:01:24:29 Nick Seiter But where the damage actually comes in is at the end of the season, that larva will burrow down to the base of the stem. It'll girdle the stem. And allows that plant to lodge over. 00:01:25:04 - 00:01:30:19 Todd Gleason In these high residue areas, can the insect populations vary from wet to dry year? 00:01:30:19 - 00:01:36:18 Nick Seiter They can, and there are several that are going to be dropped back, especially when you have saturated soils. 00:01:36:25 - 00:01:55:05 Nick Seiter If you get saturated soils in an area that will actually knock corn rootworm pressure back some, one thing that can be favored by wet years will be slugs, particularly when you have a long, wet, warm spring. So that's something that we'll be looking for. If the temperatures start to warm up here a little bit. 00:01:55:08 - 00:01:58:12 Todd Gleason Are there beneficial insects that come along with no till systems? 00:01:58:13 - 00:02:19:03 Nick Seiter Well, we've actually got a project that we're starting up to sample some of these cover crop systems and look at that. See what beneficials are out there, see what pests are out there and, see how we can adapt our pest management recommendations accordingly. One beneficial insect we see a lot in conservation tillage and in cover crop areas would be ground beetles. 00:02:19:05 - 00:02:26:19 Nick Seiter We see those populations start to pick up a little bit. And those are a predator that feed on a wide variety of different insect pests. 00:02:26:22 - 00:02:31:00 Todd Gleason Do you have any scouting or pest management practices you recommend to producers? 00:02:31:00 - 00:02:42:25 Nick Seiter We're trying to figure a lot of that out right now, but the best thing I can recommend is just to be vigilant, to scout early in the season, you know, early in the season, we're looking mostly at examining plants, looking for damage. 00:02:42:27 - 00:02:46:14 Nick Seiter Looking especially for things like black cut worm and true armyworm. 00:02:46:15 - 00:03:08:06 Todd Gleason Nick Seiter is an entomologist here on the University of Illinois campus. His colleague is Nathan Kleczewski. Both work with UAV extension and Nathan is a plant pathologist. I asked him if there were any particular diseases or pathogens that producers should be paying particular attention to in conservation systems that include no till and cover crops. 00:03:08:10 - 00:03:30:20 Nathan Kleczewski Yeah. So when we think about a lot of the diseases that that impact our crops, especially, let's just talk about corn and soybean, wheat as well, obviously. But a lot of these diseases, such as gray leaf spot, northern corn leaf blight in corn, frog eye leaf spot in soybeans, some of those stem canker as well that we see in soybeans. 00:03:30:23 - 00:03:52:04 Nathan Kleczewski And then also in wheat would be the leaf blotch complexes. So the Septoria, Stagonospora, tan spot, that group. All of those are going to be organisms that are over wintering on, on residue, from, from the previous crop. And the more residue that you have in those situations, for example, you're doing corn on corn on corn. 00:03:52:04 - 00:04:16:12 Nathan Kleczewski No. Till all that corn residue that's going to basically bulk up the initial inoculum load within that field. And so the more residue you have, the more potential for those diseases your you're going to see throughout the course of, of the growing season. Cover crops are a little tricky because they're so diverse. There's a lot of options that people have with cover crops. 00:04:16:15 - 00:04:53:02 Nathan Kleczewski Some cover crops, for example, legumes, things like that. They can actually host some of the diseases that might be found on soybeans, for example, some of the grassy, grassy cover crops can be host for some of the diseases we might find on wheat, viruses, for example, that might be transmitted by aphids. And so with those cover crops, we can see them kind of acting as green bridges that can allow some of these organisms to survive and even reproduce over and over the the growing season. 00:04:53:02 - 00:04:59:19 Nathan Kleczewski And then when you do plant in your corn or your wheat, you know, you can have problems or even nearby fields, you can have issues. 00:04:59:25 - 00:05:07:13 Todd Gleason Is there the opposite effect for some pathogens as well? Are cover crops are good at controlling or helping to control. 00:05:07:13 - 00:05:13:29 Nathan Kleczewski Sure, yeah. And and that's very good question because we we have a lot of interest in cover crops. 00:05:13:29 - 00:05:39:25 Nathan Kleczewski But what we know in terms of what they do for pathogens and pests is fairly limited. Some some cover crops actually have been shown to be able to reduce, for example, pathogenic nematodes, soybean cyst nematodes, some other nematodes, and reduce populations that way. They they are also some cover crops, for example some of the brassicas where you can actually grow them and then they can be used as a green mulch. 00:05:39:25 - 00:05:54:17 Nathan Kleczewski And so when those are chopped and incorporated into the soil and a little bit of water thrown on top, they actually will produce chemicals that can, can fumigate the soil. And actually, it can do a really good job of reducing some of the soil born pests and pathogens. 00:05:54:18 - 00:05:57:11 Todd Gleason Tell me a little bit about your tar spot research. 00:05:57:11 - 00:06:01:28 Nathan Kleczewski So right now this year, we're getting ready to set up a few different, field trials. 00:06:01:28 - 00:06:31:22 Nathan Kleczewski We're going to be assessing the impacts of, different fungicides and fungicide timings in terms of their their efficacy on the spot. We're going to be screening different germ lines or germplasm of corn, and not just in Illinois but throughout the region, to try to identify regions of resistance and maybe, perhaps, develop some markers. And that's some work that we're collaborating on with some of our colleagues, Dr. Tiffany Jamann in our department. 00:06:31:22 - 00:07:03:12 Nathan Kleczewski She's the one that's that's really our focal person doing that work. And then currently right now we're we're actually looking at overwintering of the pathogen. So we're collecting trying to collect as many residue samples as we can assessing spore viability. Also seeing if we can, get that pathogen to to take from the residue in the greenhouse. And actually, we had some good results, yesterday, where we are able to actually replicate symptoms, and see tar spot in the greenhouse from samples that had overwintered in, in DeKalb. 00:07:03:12 - 00:07:16:08 Nathan Kleczewski So we are confirming kind of what we had presumed and that that's the that the pathogen over winters here. And once it's established, we now can at least survive one year. But, you know. 00:07:16:08 - 00:07:26:24 Todd Gleason Tell me a little bit about wet springs and whether that be topsoil or subsoil moisture or the difference between the two and what pathogens corn and soybeans producers should be watching out for. 00:07:26:27 - 00:07:49:29 Nathan Kleczewski With soybeans, the ones that I'm particularly concerned about. And and again, this kind of goes towards people trying to plant earlier and earlier every year. You realize when you plant earlier you're you're increasing the likelihood of encountering these, these cool wet soils. And what that is going to do is it's going to favor, some of these diseases. 00:07:49:29 - 00:08:09:08 Nathan Kleczewski And so if you're going into a field where you had issues with Pithium in the past or SDS in the past, and you're and you're planting early, you're really setting yourself up for some potential issues down the road. So with SDS, what we have to keep in mind is that as an organism that really likes it, sure, it likes it wet, right? 00:08:09:08 - 00:08:32:21 Nathan Kleczewski But it it actually grows better when it's cool, when it's under these kind of cool conditions. That's at that same time point, if you think about it, that soybean plant isn't going to be growing as rapidly. So it's kind of, you know, germinating slowly, not growing as quickly. And that gives gives that, SDS pathogen more opportunities to infect the plant cause stand loss, infect the roots. 00:08:32:21 - 00:09:09:29 Nathan Kleczewski And then later on in the season, you can see those foliar symptoms as well. With pithium, it's kind of a similar story. Wet soils, we know that pithium have kind of a different species. It's basically a complex of different species, and each species has kind of a different temperature optima. So as long as it's wet, you can always get pithium, but when it's cool, you're, you're under those conditions again where that seedling isn't growing rapidly and those pithium that can be aggressive under those cool conditions are able to really rapidly degrade and decay that root system, that plant can't, grow out of it, basically. 00:09:09:29 - 00:09:16:18 Nathan Kleczewski So that's that's why I get pretty concerned about those two diseases, especially in, in soybeans. 00:09:16:23 - 00:09:17:27 Todd Gleason Corn and wet springs. 00:09:18:03 - 00:09:33:26 Nathan Kleczewski Corn. Yeah. The, the big issues we're going to have with with corn very similar to, to soybeans. So you're going to have potentially some pithium issues in our corn can cause stand loss. And unlike soybean, corn can't really compensate for those stand losses as well. 00:09:33:26 - 00:09:58:18 Nathan Kleczewski So you really do have to be, looking out for, for pithy. In that case, we also do have some other organisms, some Fusarium complexes that that can get in there, in these wet conditions and can also cause root rots and some seedling blights. And you do see that from, from time to time. But in general, it's going to be the pithiums, it's going to be the saturated areas of the field. 00:09:58:20 - 00:10:21:11 Nathan Kleczewski And anything you can do in the off season to improve the drainage of any problematic areas is going to be a good investment. If you've got low lying areas with compaction, you've been holding off on putting on tile, and you got hammered last year with our rains with some seedling issues or root rot. Think think about investing in some tile, improving that drainage, if you can. 00:10:21:11 - 00:10:45:01 Todd Gleason Nathan Kleczewski is a plant pathologist at the University of Illinois. We've been talking with Nathan and his colleague Nick Seiter, an entomologist, about the impact of plant diseases and insect pests, in particular in no till and cover crop systems. Joe Rothermel is a farmer in Broadlands, Illinois, and has been putting all of this into place. I asked him a bit about his operation. 00:10:45:04 - 00:10:48:16 Joe Rothermel The management system. 00:10:48:19 - 00:11:17:12 Joe Rothermel Well, it changes quite a bit. Currently, we are trying to increase the diversity of the farm a little bit by getting wheat back into the rotation and also, trying to grow some, cover crops, in the off season. So trying to increase diversity a little bit that way. Currently use, reduced tillage, which means, no till beans or strip till or no till corn. 00:11:17:15 - 00:11:43:10 Joe Rothermel As far as, other management areas, most of the nitrogen, actually, all the nitrogen for the corn is put on in season. And, as far as our other fertilizer management, try and place all the phosphorus, banded under the soil surface 80, 85% of it’s done that way. So that's that's how we manage the farm currently. 00:11:43:17 - 00:11:47:27 Todd Gleason How does all this work into the nutrient loss reduction strategy? 00:11:47:29 - 00:12:16:29 Joe Rothermel Well, by not putting any nitrogen on on the fall, hopefully we don't lose as much. And, by deep banding the phosphorus, we reduce the risk of losing it with erosion, where, you know, sometimes attaches to the soil, runs off with erosion. And so and also, the cover crops hopefully will catch anything that's left in the fall, especially on the corn fields where there's cereal rye growing. 00:12:16:29 - 00:12:20:08 Joe Rothermel So hopefully we're we're addressing it well. 00:12:20:10 - 00:12:23:07 Todd Gleason How do you manage for pests and diseases? 00:12:23:07 - 00:12:46:10 Joe Rothermel Well, we really haven't had a lot of issues with pests or disease. We, use fungicides, as required, to manage some disease pressure in corn and also in beans. As far as the cover crops go, we terminate before we plant, especially for corns to eliminate that green bridge between covers and corn. 00:12:46:13 - 00:13:13:13 Joe Rothermel So hopefully we won't have any problems with cut worms. Really haven't seen any pest problems growing beans after cereal rye. So haven't really had a lot of issues with pests or pathogens. Do you have any suggestions for producers thinking about switching to reduced tiller cover crops in terms of pest management? Well, I would do just that. I would, I would if I had a cover crop growing in front of corn and over winter I would kill it, terminate it. 00:13:13:16 - 00:13:34:04 Joe Rothermel So it's brown before you plant corn. That would be my best advice. In front of beans, which usually cereal rye, I really haven't had any issues once we get some rodents out there. But, again, you know, to be safe, you would terminate when it was small. Just make sure you got the beans planted before it went down. 00:13:34:06 - 00:13:41:18 Todd Gleason Have you picked up any economic gains because of, the production practices that you're using? I mean, have you saved money? 00:13:41:23 - 00:14:00:20 Joe Rothermel Yeah. Yeah. Well, mainly from reduced tillage. We just make less passes across the field. That's the easiest one to identify. So, with covers, we have had, instances where we have not sprayed a post because the, cover crop held or suppressed the weeds pretty well. 00:14:00:21 - 00:14:22:17 Joe Rothermel I won't get them all, but if you, you know, drill 70 or 80 pounds of cereal rye, it really suppresses weeds. So, there's hope for that in the future. And also, something we need to learn more about. I think we, hopefully, if we can make some of these nutrients in the soil more available. Hopefully that will support our fertility program. 00:14:22:17 - 00:14:24:05 Joe Rothermel But we got a lot to learn in that area. 00:14:24:07 - 00:14:38:26 Todd Gleason So that's how one farmer is deploying no till and cover crops on his farm. However, it's part of a larger push across the state and the nation, says Jennifer Woodyard, who is a watershed outreach associate for University of Illinois Extension. 00:14:38:26 - 00:14:43:26 Jennifer Woodyard Yeah. So when we think about the nutrient loss reduction strategy here in Illinois, we have goals. 00:14:43:26 - 00:15:07:29 Jennifer Woodyard By the year of 2025, we are trying to reduce nitrate nitrogen losses by 15% and total phosphorus losses by 25%. And so cover crops are one of those best management practices that producers can utilize that can help reduce both nitrogen and total phosphorus losses. So it's really exciting to have this new research that Nick mentioned, working on characterizing the pests. 00:15:08:01 - 00:15:30:23 Jennifer Woodyard Pests within cover crops and no till just because we're still trying to optimize that system, for growers. And we have gained a lot of ground in the past recent years just trying to make the system work better for producers. But to continue having new research being developed is just really exciting. And I also want to talk about two new resources that we have available for growers who are interested in trying cover crops. 00:15:30:26 - 00:15:56:04 Jennifer Woodyard So University of Illinois Extension partnered with the Midwest Cover Crops Council to make two new fact sheets. And so these are cover crop recipes for growers who are interested in trying cover crops and haven't yet before. So we have one recipe for post corn going to soybean. And that's to adopt cereal rye into that system. And then we also have a post soybean going to corn recipe which is to adopt oats radish. 00:15:56:04 - 00:16:14:11 Jennifer Woodyard And so these again are just for beginners who are interested in trying cover crops. And it gives a step by step process of, you know, seeding rates termination dates, things like that. So you can find these resources on the Midwest Cover crop councils website, which is mccc.msu.edu. 00:16:14:13 - 00:16:21:00 Todd Gleason Jennifer Woodyard is a watershed outreach associate. You've been listening to the Illinois Nutrient Loss Reduction podcast. 00:16:21:02 - 00:16:23:29 Todd Gleason I'm Illinois Extension's Todd Gleason.