Plant Disease Clinic Update
Well, good afternoon. This is Dave Nicolai with the University of Minnesota Integrated Pest Management Program and this is the fourth in installment of the IPM series of podcasts and this is a special opportunity because today we are producing a second podcast and our co producer and co host Annie Clyde is here and I'll let Annie introduce herself and she also will talk about how this is going to be utilized through another mechanism and channel in terms of podcasting.
Annie Klodd:Hi, I'm Annie Clyde and I'm educator in fruit and vegetable production here at the university. And I co host the fruit and vegetable IPM podcast called What's Killing My Kale. So we're going to be posting this episode there too. This is kind of a joint effort between us.
Dave Nicolai:We have a special guest today that we would like to introduce to the audience and that is the administrator for the Plant Disease Clinic at the University of Minnesota. And Brett, would you like to introduce yourself and give a little background about your own personal background and education and how you came to be in this position? And tell us a little bit in general who the Plant Disease Clinic serves in terms of clientele.
Brett Arenz:Sure, thanks Dave. It's great to be here today. My name is Brett Arons. I am a teaching assistant professor in the Department of Plant Pathology, and I'm also the director of the Plant Disease Clinic at the University of Minnesota. So I've been in this position since 2014.
Brett Arenz:I'm actually from Bemidji, Minnesota from my childhood and I got my master's and PhD degrees at the University of Minnesota in the Department of Plant Pathology. So I've been here for quite some time at this point. My appointment is actually split sort of fiftyfifty and 50% of my appointment is teaching in the department. So I teach a range of graduate and undergraduate classes and the other 50% is as the director of the plant disease clinic. It tends to work out pretty well because the clinic is a bit busier during the summer months, during the growing season when I'm not teaching as much.
Brett Arenz:And then when the growing season is winding down in October, November, that's when I start teaching more. That timing tends to work out pretty well. But of course the clinic is open year round. We're always open for sample submission, whether there are samples being brought in by mail or by delivered in person, basically. We handle about roughly two thousand two thousand five hundred samples per year.
Brett Arenz:Last year, they represent over 170 different plant species as hosts. So we see quite a different range of different types of samples. We receive samples from the general public, from farmers, from professional horticulturalists, from government agencies such as the DNR, from the Forest Service, from anyone basically imaginable. So we receive a really wide range of samples and we're open typically Tuesday through Friday from 08:30 to 04:30.
Annie Klodd:Now I work with a wide range of fruit and vegetable growers. I work with home gardeners up to large growers of grapes, apples and vegetables. And so I'm curious to hear how many fruit and vegetable growers are you getting samples from every year or are you getting more of the, row crop samples?
Brett Arenz:We get a range. We do receive quite a few apple samples and to some extent that's from growers, from people with orchards, but also we receive quite a bit of crab apples as well, just people who have ornamental crab apples and apples in their yards. And in some cases it's not because they're primarily looking to produce fruit, it's simply because there's a lot of sort of pests and pathogens that cause sort of aesthetic problems on those types of trees.
Annie Klodd:Yeah, I think it would be useful to talk about why we're here today. I'm really excited to talk to you because I feel like I get a lot of pictures sent to me during the growing season about wilted leaves, discolored leaves, blemishes on fruit, and sometimes it might be a disease issue, sometimes an insect issue, and sometimes it's just really hard to tell what's going on with the plant. And I think the plant disease clinic is a great opportunity for growers to understand more efficiently what's going on with their plants so that they can do something about it. I'm excited to talk to you today about you know, how growers could benefit from the clinic and how to send in samples. When should a person send in a sample versus just sending a photo to their extension agent?
Brett Arenz:Well, photos can be a good place to start. In some cases there are diseases that you can potentially diagnose with a photo. What I've found is that it can be quite difficult though in most cases to get a 100% confirmation just based on a photo. Simply because there's a range of different pests and pathogens that can cause fairly similar symptoms. We do oftentimes recommend that people send in physical samples, but if they want to send a picture in beforehand, that can be helpful.
Brett Arenz:And we can actually, in some cases, instruct people what types of tissue to collect and to send in. For example, there are some root pathogens that cause foliar symptoms. And if someone just saw that, they might think that it was just a problem with the leaf and only send us leaf tissue. And of course we wouldn't be able to diagnose it based on that. So that kind of helps us prevent potential problems in the future.
Brett Arenz:But in some cases we just ask people to send more material. But if you want to save yourself some postage, maybe send us a picture first.
Dave Nicolai:Certainly we have in our audience here crop consultants, ag professionals, farmers as well that might be tuning in and listening. And I also think sometimes as you do Annie, that the clinic is sometimes underutilized as a source of information. And certainly, I know you might have companies that actually send in samples from time to time, but we have the regular integrated pest management questions that come up on soybeans and in corn. And particularly we anticipate in soybeans everything from Phytophthora identification or the presence of that Rhizoctonia, other types of things that were evident in soybeans this last year, some of the early seedling diseases like Pythium, but certainly right now and I've got a couple pictures on my phone, Brett, even pictures of foliar symptoms in soybeans. And there's a lot of questions and diagnosis that a lot of our extension educators.
Dave Nicolai:So it's really helpful in that regard. In that situation, I know that Annie and I were talking a little bit before we started about sample preparation and sending samples into the clinic for identification. And I know it's helpful to get as much information on a form in terms of background information, is it not? And I believe you have forms for that. And then maybe you want to talk a little bit about actually sending in soft tissue samples or hard samples.
Dave Nicolai:Can you talk a little
Brett Arenz:bit about information that's necessary for a good diagnosis? Sure. We have a website, pdc.umn.edu and there is some information there on sample submission or even some pictures showing how to package samples, as well as the sample submission form you mentioned. And it actually is very important to be thorough in the sample submission form. There's a section there, of course, with the submitter information, address, and how they want their report.
Brett Arenz:There's also a section on a thorough description of the problem and what the timing of the problem was, if there's other species that are affected, if things have been sprayed in the area. And all this information really helps us give as accurate a diagnosis as we can. And what's kind of interesting, something I've noticed in the last five years, it's and kind of the opposite of what you'd expect, we actually, in a lot of cases, receive more information from homeowners about their samples than we will from professional growers.
Annie Klodd:Why do you think that is?
Brett Arenz:That's a great question. I'm not sure. Sometimes we just get a box with a business card thrown in it with the plant. Not sure if it's just because they're busy or they assume we know exactly what's going to happen. But yeah, that's just kind of something I've noticed in the last few years.
Brett Arenz:But yeah, maybe this is a message to the professional growers and farmers out there. Please be thorough with the information you put on the submission form. It really does help us have an accurate diagnosis.
Annie Klodd:Can you say what some of the examples are of the type of information you would like included with the sample?
Brett Arenz:One thing that's important to realize, especially if you're mailing a sample in, is when we actually get the sample, and it might take two or three days in the mail, hopefully not longer, is it might not look exactly like what you thought it was going to look like when you put it in the Sometimes things get banged up quite a bit, they dry out, they start to wilt. And so it's not really clear what the initial problem was in some cases that basically made you want to send the sample in. So that can be just one thing that's really important. What was the major problem that you're seeing? And also when did you start to see it?
Brett Arenz:Okay, the timing of when things start to take place are really an important clue as to whether this is a disease issue or potentially an abiotic issue. As far as packaging samples go, again, we have some information on our website about that. It's really important that we have a good sample to work with and there are some good things to think about there. It's very difficult to diagnose a sample that's completely dead because at that point you get other microorganisms that start to colonize the sample and it can be hard to tell what caused the initial problem. So having tissue that has the symptomatic problem on it, but also still has some green healthy tissue is really important because oftentimes we look at those transition areas between the green tissue and between the, potentially diseased tissue to actually look for the active pathogen.
Brett Arenz:As as sending a good sample so that doesn't dry up, we oftentimes recommend people wrap the roots in plastic or maybe put the roots in a plastic bag and tie it off. And then just simply wrap the above ground part of the plant in maybe some newspaper so it doesn't get banged up when it's in the box. That really will prevent the plant from drying out too much because the roots will be, sort of contained in plastic. But it's not gonna be as if it's totally contained in plastic, which for some types of plants really will degrade very quickly if they're in the mail for too long during hot weather.
Dave Nicolai:So Brett, sending things to you on a Friday afternoon would not be a good idea, I take it.
Brett Arenz:Yeah, it can be bad if they're going to be sitting in the post office for too long. You know, and it really depends on what type of sample you're talking about. If you're talking about a spruce sample or a pine sample, well, that kind of tissue actually can last quite a while. It's not really going to dry out too much, But other things, particularly things like soybean, actually can break down fairly quickly. So that's gonna depend to a certain extent on what you're dealing with.
Brett Arenz:But we do recommend people mail them so that they're not gonna be sitting in the post office on the weekend.
Dave Nicolai:Well those sound like good guidelines I think Brett when we talk about soybeans in terms of the timing of the week and wrapping the roots and so forth. And we'll have a lot of soybean samples I think coming in as well as other agronomic crops here too. We can get alfalfa at this time of the year. There might be corn leaves later on as well as perhaps other corn problems. But those are good guidelines for that.
Dave Nicolai:Annie, I think you mentioned to me a couple of key horticulture diseases and concerns that you have right now. Think was one in grapes, I believe.
Annie Klodd:Yes. So it was recently brought more to our attention that there is a potential trunk disease going around in grapevines throughout the Midwest. It's a very common trunk disease. But so far we have not sent any samples in to confirm that the symptoms that we're seeing are due to this disease in grapevines. So I'm starting to encourage growers to cut woody tissue off of their cordons of their grapevines and send their samples in.
Annie Klodd:And so for something like this, I think a grapevine sample, especially with something like a trunk disease and woody tissue is going to be a lot different from sending in a soybean sample. Is that right?
Brett Arenz:Yeah, with woody plants, it can be difficult, especially if it's a woody plant you want to keep alive. It can be difficult to collect material while not hurting the plant, particularly when it comes to important branches, of course, stem sections and root sections. I would say with grape and specifically the disease you're concerned with, what we would do to diagnose it is we would look for the presence of the fungus directly on the sample. And I would just reinforce the idea of sending in a sample that is not completely dead, but also has some living tissue, because it's really important to look at that transition between the living and dead tissue. So finding where that canker appears to be starting and cutting off that section to send in.
Brett Arenz:We would really concentrate on that margin of where the disease front appears to be.
Annie Klodd:Okay, that's good to know. It seems to be there are a couple of different situations here when people could send in samples. The first is if they see something and they have no idea what could be causing the problem. And then there might be other situations where somebody suspects a certain issue. Is that kind of accurate?
Annie Klodd:I mean, can somebody send in a sample if they don't have any idea what's wrong with the plant?
Brett Arenz:They certainly can. In that case, it really is helpful to get a detailed description of what they're concerned about, but it's not uncommon for us to find that in a sample that someone suspects has a disease issue, we actually don't find a pathogen and the cause of the health problem appears to be something else, whether it's a herbicide drift or a nutrient issue or some sort of environmental stress or a wounding or winter desiccation, dehydration. There's really a range of different things that can cause plants to look as if they are diseased.
Annie Klodd:Yeah, recently this week I was out at a vegetable farm and I symptoms that looked like bacterial spot on strawberry leaves and it actually, talking to the farmer about their environment, I learned it was actually from blowing sand and from hail damage.
Dave Nicolai:Certainly we've had a wet year in terms of that and that brings up to mind is when we don't have things positively identified as either caused by a bacteria or fungi or a virus, but it's environmental. I imagine you try to take note of that, Brett. And also perhaps do you ever offer management suggestions back to the people that are supplying them, whether it is a plant disease or whether it might be environmental? Do you do your best in some of those areas?
Brett Arenz:Oh, definitely. We do specialize in the diagnosis of disease in the plant disease clinic. One of the first things we do when we get a plant in is we look for pathogens that can cause the symptoms that the submitter is concerned about. When we don't find those pathogens, that's when we start to consider more of an abiotic kind of cause to the symptoms. And in some cases, the people provide a lot of good information with the plants and sometimes even pictures that they've also sent into our email.
Brett Arenz:We're able to be, in some cases, confident on what that abiotic issue might be. In other cases, we actually will call the client and talk about the history of the plant in the area to see if we can narrow down what might have happened.
Annie Klodd:If you get a sample and it's not actually a disease issue, it ends up being an insect issue, will you go ahead and diagnose that insect?
Brett Arenz:We will, if we can identify it to a reasonable extent. And we often actually will get insect issues such as insects that people can't see without magnification. For example, there's a wide range of mites that can cause a lot of damage to plants, whether they're spider mites or area fit mites. And the symptoms in the plant really can be very reminiscent of other diseases and growers just can't see the mites without magnification. So that's a kind of a very common type of sample for us.
Brett Arenz:Other types of insects, if we can ID them based on their appearance and the damage they're causing, we certainly will. I should also point out that we frequently consult with other faculty at the University of Minnesota. Of course, other faculty in the plant pathology department, in agronomy, soil water climate, forestry, and especially entomology. So even if we don't necessarily know what something is, we'll probably seek out someone at the university who does.
Dave Nicolai:Brett, can you give the audience just maybe a frame of reference? How long does it typically take? And I'll just use an example of some of our soybean leaf diseases, whether it's a brown spot or a bacterial spot or other types of diseases. In terms of isolation time from the time it's sent in, clinic receives a sample, what kind of a turnaround time can people reasonably expect oftentimes with what I would call it, you know, full year or above ground?
Brett Arenz:Yeah, that's a good question. It really depends on what kind of test we need to do to diagnose something. In some cases with a lot of these fungal diseases, they might actually be producing spores on the plant tissue when they are brought in. And in that case, it doesn't take too long to actually identify it. So you might get a response in maybe two or three days if it's not too busy.
Brett Arenz:In other cases, for example, with diagnosing oak wilt, the procedure is actually to sample from the discolored wood underneath the bark and then actually grow it out in culture. And that can take actually up to two weeks to when the fungus is actually producing spores that we can identify. Oak wilt, we oftentimes tell people that it might take actually up to two weeks get a diagnosis for that. So it really depends on what we have to do for that.
Dave Nicolai:If they send in a root sample, whether it's agronomic or a horticulture crop, do you want a certain amount of soil with it or just the root itself or cleaned off typically that's in a bag or not?
Brett Arenz:I would say in general, just the roots are fine. You know, there is of course a different clinic at the university that does soil testing. We don't do that at the plant disease clinic. But with the sort of caveat there, in some cases we do check for soil salinity. For example, strawberry is a very salt sensitive plant and we've seen issues with people over fertilizing strawberries and that's actually causing the damage.
Brett Arenz:And so having a little bit of soil with that strawberry actually lets us do that test. It's fairly quick so that we can check for those salinity levels.
Dave Nicolai:Can you give us a little frame of reference in terms of average costs or there's a nominal fee here obviously to cover costs in terms of diagnosis at the clinic, but it'll be something that people can obviously observe on the internet as well or perhaps by making a phone call.
Brett Arenz:Yeah, so we are a fee for service lab. Most of our sample fees are around $45 That's our basic fee. And for most fungal pathogens, that's probably all it's going be. For some things that we actually have to culture to diagnose, it'll be $59 Oak wilt is a test that involves culturing as well as a DNA test. So it's, $75 For some things that require more advanced techniques, for example, looking at viruses with an electron microscope, which is more time consuming, requires more specific kinds of equipment.
Brett Arenz:The costs can range between $85 and $100
Dave Nicolai:What sort of contact do you have and recommendations? I'm assuming that you might have a phone number at certain times of the week, but also in addition to that, how can they best find a clinic if they want to be online and look things up in terms of information in forms, etc.
Brett Arenz:Again, our website is pdc.umn.edu. If you just Google search University of Minnesota Plant Disease Clinic, I'm fairly sure it will come up first. We do have an email address pdcumn dot edu and our phone number is (612) 625-1275.
Annie Klodd:What would you say to somebody who says 45 that's a lot to send in a sample?
Brett Arenz:Well, I mean, that really depends on how valuable the plant is to them. For a homeowner, if it's a type of plant that they can buy two or three of them for that cost, I can definitely see why they would rather go that route. I guess if it's potentially a disease that might cause problems for them down the road, it spreads around or maybe it affects a plant that they try to plant in the same area, that could be a bad thing. But for some people, for example, with oak wilt, these are very valuable trees in people's yards. They can cost thousands of dollars to remove them.
Brett Arenz:And there actually is a treatment available if it's a white or bur oak, which can prolong the life of the tree and save you some of that high expense. So for those kinds of clients, the price is definitely worth it. And of course for farmers and professional growers, price is often worth the savings that they can get by managing a disease kind of proactively.
Annie Klodd:Yeah, definitely. I agree with that. And I'll use the grapevine example again, I think for people who have acres of grapes and there's a potential trunk disease or something that could have a big impact on their vines, they're very valuable. And to me, 45 is more than worth it to figure out what's going on so they can control.
Dave Nicolai:And your ability to offer, at least some type of management advice, I think will be very helpful in addition to the diagnosis, particularly if it's a, whether it's a perennial crop or an annual crop. But again, services involve agronomic, fruit and vegetable, home garden, certainly trees and windbreaks, whether you live in the country or whether you live in town or a suburb or wherever you might be. So all of those are really valuable services. I know we all get questions about those things and crossover back and forth.
Brett Arenz:Yeah, we do send, I didn't probably mention this before, but when we make a diagnosis, we will send relevant information about recommendations for management. And typically these are what are called fact sheets that are written by various extension personnel around the country. So we really try to find the best information that's available from someone who really specializes in the disease.
Dave Nicolai:That is getting towards the end of our podcast. I want to thank, obviously our guests here on behalf of, Integrated Pest Management as well. And again, your podcast can be found at?
Annie Klodd:Yep, our podcast is for fruit and vegetable IPM. It's called What's Killing My Kale? And it can be found on the UMN Extension Small Farms site as well as FruitEdge.
Dave Nicolai:And the IPM Field Crops podcast can be found at the University of Minnesota sites as well as on iTunes and Stitcher as well.
Annie Klodd:Yep, ours are on iTunes and Kind Stitcher
Dave Nicolai:of a fun deal here, we've never really tried to do a joint podcast because we're still new into this particular aid of communication, but certainly as things and times goes along, it can be helpful to all of the audiences here with Extension at the University of Minnesota. So once again, Brett, thank you for stopping by this afternoon and talking to us a little bit about the Plant Disease Clinic and the services and operations that you have over there. We look forward to visiting with you in the future as the summer goes along and perhaps talk about other issues and so forth that may be of interest to the citizens and growers here in Minnesota.
Brett Arenz:Great, yeah, I'm happy to be here.
