Managing soilborne diseases with biofumigation

In this episode, Natalie interviewed Meg McGrath, a plant pathologist from Cornell, and Jim Jasinski, IPM coordinator at Ohio State University, about using biofumigation to manage soilborne diseases. We discuss how it works and tips for growers who want to try it on their farms.

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Ben Phillips (00:14):
Welcome to The Vegetable Beet. My name is Ben Phillips, and I work with Michigan State University Extension.
Natalie Hoidal (00:20):
And my name is Natalie Hoidal. I work with the University of Minnesota Extension.
Ben Phillips (00:24):
We've been doing this podcast over the last few years, and we're changing the format a little bit for this season. We're going to do some prerecorded interviews in a three act style where Natalie and I will introduce an episode by talking about why we decided to do it. It might not be us doing it, but we will introduce it. Then we'll have the second part, which is the actual interview performed by us or other people. And then the third part will be a wrap up. What did we learn? Where can we go from there? How are we doing this, Natalie?
Natalie Hoidal (00:52):
So, this podcast is brought to you by the Great Lakes Vegetable Producers Network. It was kick started by the North Central Integrated Pest Management Center. And our license for Transistor is held by the University of Minnesota Extension.
Ben Phillips (01:04):
And you can listen to this episode and all the rest at glveg.net/listen. Enjoy the show.
Natalie Hoidal (01:23):
So, this is a unique episode in that it was actually recorded in 2020 for a different project. And then when COVID happened, that project fell off the radar as other things took priority. So, this episode is about biofumigation and specifically in the context of using biofumigation as a tool for managing phytophthora and some other soilborne diseases. And so back in 2020, we were starting to see phytophthora for the first time in Minnesota. And so, I reached out to two colleagues who have some experience with biofumigation, Jim Jasinski at Ohio State and Meg McGrath at Cornell. And I wanted to learn how biofumigation works and when growers should think about using it, but also just some of the practical aspects of what do you need to do to be successful in this practice. What are just some tips and tricks that they've learned from doing it?
Natalie Hoidal (02:19):
So, hopefully we get both of those perspectives, the research based perspective and the more hands on perspective in these interviews. So since they were recorded in 2020, I checked back in with them in 2022 and just asked, "Is this content still relevant? Has anything changed?" And for the most part, they said, "Yep, everything is still the same." But they added a couple of tidbits of insight that they have learned in the last couple of years through their trials. So, we'll insert a little conversation that we had at the end, just learning that updated information. So with that, I hope you enjoy. Here's Jim.
Jim Jasinski (02:59):
So, I started as the IPM Coordinator back in 2013 and my major role there is just to be a project manager. We've got four or five major areas within the IPM program, we fund field crops, specialty crops, bed bugs, pollinator health, clinic stuff. But I've been working in Pumpkins since about 1999. And that's really a lot of fun. There's a lot of things going on in pumpkins, a lot of work we've done in the previous years, we've done cover crops and variety trials and disease trials, insect trials. And most recently we started getting into and reading about biofumigation, which is interesting to think about trying to rid the soil of all kinds of pests, insects, or diseases using more natural needs and not chemicals like methyl bromide, which are outlawed now or metam sodium, which are not really great to be around. So, we're just new into this, have done it for one year and I have some results and are going to do some more this year, actually.
Meg McGrath (04:06):
Yeah. So, I'm Margaret McGrath, I go by Meg. I work for Cornell University, I'm located on Long Island at the Long Island Horticultural Research and Extension Center, part of Cornell University. We've had presence on Long Island doing research and extension activities for great many years because it is one of the more important counties for agriculture in New York. Surprises a lot of people, they think of a Long Island as being a place that tourists want to be. And they certainly do, but we've got a lot of agriculture. So, I've been here since July of 1989. I do a lot of applied research on disease issues in vegetables for growers and a lot of extension. And I got into working on phytophthora when it started to become a big issue on Long Island.
Natalie Hoidal (04:55):
And when was that more or less?
Meg McGrath (04:57):
Oh, that was in the nineties, 1990s.
Natalie Hoidal (05:00):
Okay. So, you've been dealing with phytophthora for a long time?
Meg McGrath (05:03):
I have, and also trying to manage it in my own research plots. I do a lot more research on powdery mildew in, particularly pumpkins. Pumpkin is a big crop on Long Island and that's the crop that's been hit the most by phytophthora here. We get a lot of people want to come out and pick pumpkins in the Fall. So, we need to have our pumpkins stay good through into early October, mid October.
Natalie Hoidal (05:31):
So, let's back up a little bit and just define biofumigation. So, do you want to just explain the concept of biofumigation if you know anything about the history of biofumigation?
Jim Jasinski (05:43):
Yeah. So again, I'm just starting out with this, but I've read quite a bit about it. And so, fumigation is obviously we're thinking about gases that diffuse out through various areas and they have a sterilizing effect. Biofumigation is the same concept, except it's not always a gas that we're after. Sometimes it's an exudate or something that happens in the soil interaction. So it's not necessarily a gas, but it's using the various plant parts that are ground up, and then there's a chemical reaction that happens in the soil. And that reaction is basically a kind of a sterilant reaction, like it would be for a traditional fumigant.
Natalie Hoidal (06:30):
So in this case, we're talking about brassicas, basically brassica cover crops, usually a mustard and they form a compound called glucosinolate?
Jim Jasinski (06:42):
Yeah, well, so the way it really happens is you're right, we're talking about the mustards in general, the brassicas. But in the brassica family, there's also other plants, even arugulas that have this property for biofumigation. And the way I understand it is, I have two and a half years of chemistry, but I try to forget all that years ago, but what I have relearned, so the plant itself manufactures the compound glucosinolate, and then it peaks during flowering. And then what want to do is take that product and then incorporate into the soil. There's a reaction that happens in the soil, add a little bit of water and an enzyme called myrosinase. And that breaks the glucosinolate down into what's called isothiocyanate. And that's really the product that does sterilizing activity in the soil.
Jim Jasinski (07:40):
And so, when you do the bio fumigation with mustards, that particular isothiocyanate is the allele version and then that product is very similar to metam sodium, which has a methyl, isothiocyanate. So, that's how the chemistry works. That's how the biofumigant final product, this allele isothiocyanate is very similar to the traditional fumigant, metam sodium, which is a methyl isothiocyanate. So chemically, they're very close to related. That's the bottom line. And that's what we think does some of the heavy lifting in this process.
Natalie Hoidal (08:21):
So, one of the reasons that I wanted to talk to you about this, I guess I read about it online, I've even seen videos of it. And I think it's a little bit intimidating the process of it, it seems really complicated, it's this idea that's out there, but before we make recommendations about it, I was just really curious to talk to someone who had done it about how difficult the process was, things that you learned, maybe how you would do it differently. So I guess, could you just walk through the process of when do you plant the cover crop? How are you terminating it? What does that window of tilling it into the soil look like? And maybe what have you learned along the way as you've done that process?
Jim Jasinski (09:08):
So, I think it's a bunch of easy steps all stacked together, which makes it seem hard. But, it's just like planting and managing a cover crop in front of your cash crop. That's really what it's like. So in Ohio, the way that I think of it is, we want to try to plant that early in the spring, but not so early that it gets frozen or frosted off. So, we have that balance, that window for us is between April 1st, maybe April 30th, that's the window, when it looks like we can plant it, we go ahead and plant it. Then mother nature does its thing, it grows. The one thing about... I'll just back up a second and say, most cover crops farmers just throw the seed out, it sprouts, and then they do with it what they want.
Jim Jasinski (10:01):
But this particular cover crop, you really want to maximize the biomass. So, it's really important that you invest in fertilizer, the nitrogen and ammonium sulfate to let this stuff grow up as big as it can grow, because the more biomass you have, the more of that compound, the glucosinolate is produced, the more of that biofumigant effect you're going to see in the soil. So, it does matter if you fertilizer or not. So, that's just a point on front. So anyhow, depending upon the biofumigant mustard you choose, there's specific goal, there's Caliente 199, there's Caliente Rojo, there's a whole bunch of them that are bred for biofumigation. And if you are going to do it for biofumigation, you're going to want to make sure you are growing a variety that was designed for biofumigation because not all mustards are equal.
Natalie Hoidal (10:52):
Yeah. Are there seeds available in standard outlets?
Jim Jasinski (10:58):
Oh, yeah.
Natalie Hoidal (10:58):
Like, High Mowing, Johnnys
Jim Jasinski (10:58):
Yeah. Of the four or five or six major seed distributors, I'm not going to name any, unless you get money for this, but I could, you can find it, it's in usually the cover crop section of the guide. And it'll talk about, mustards are for biofumigation. The rates are anywhere from five to 10 pounds, an acre, the prices anywhere from six to $10 a pound, just depends. But there's really no special magic. You can broadcast it, you can drill it. I can't remember off top of my head, but I think it's about a half inch deep, it's small seeded like alfalfa, so you don't want to bury it so deep that it can't come up, but that's all. You can read about the planter requirements. And I think you'd be very successful. It comes up between 50 and 60 days, it maxes out.
Jim Jasinski (11:50):
So when we're at maximum flowering, peak flowering, that's the time that those glucosinolate levels are highest in the plant. That's the time that you want to do your different actions to get all of that compound into the soil where it's really going to do its work. So once you're at that stage, you're going to want to mow it, bush hog it or flail mow is actually preferred. Then you're going to want to take a rototiller and you want till that green biomass, you just chop into the soil profile, maybe three, four or five inches deep, you can get that all in this and mixed up, come back with a packer and then pack that soil down, something like that.
Jim Jasinski (12:35):
And if you're able to spray water on top of it to help increase that seal and kind of keep those gases in, then that's something that you also want to do. So, there's really four operations that happen all within the span of 15, 20 minutes. So, it's almost like you have to have all three or four of those pieces of equipment lined up with three or four tractors lined up, ready to go. Because if you delay between those steps, then that's time that all of that potential gas is just getting into the atmosphere and you're losing that biofumigant effect. So, it's really about the timing of that, is really probably the most important piece of it.
Natalie Hoidal (13:15):
So, I would say one of the barriers to that is the fact that many people don't have three tractors. If this worked really, really well, and you had a really specific disease problem that this could address, maybe it would be worth investing in extra machinery, but how well does it actually work?
Jim Jasinski (13:39):
Yeah. Well, to your first point, I realize that not everyone has three or four tractors laying around like we have at the research station. So, I would think that growers know each other, they've got neighbors, right?
Natalie Hoidal (13:51):
Yeah.
Jim Jasinski (13:52):
And if you really wanted to give it a go, I think you would just maybe ask your neighbor on the left, your neighbor on the right and say, "Hey, can I borrow your tractor for a couple hours on this day to do this operation?" And hopefully they'll say, "Yes." And so, you can probably borrow a tractor for a couple hours to do the operation. So, I understand that the equipment can be a barrier, but I think, you can probably beg and borrow and get some equipment to give it a whirl, to see if it works for you.
Natalie Hoidal (14:22):
Yeah. That's a good point. And it's a short enough time period that hopefully people can make it work.
Jim Jasinski (14:26):
Right. You just borrowing for an afternoon, like, "Hey, I'll bring you over a six pack if I can borrow the tractor for a couple hours." So, I wouldn't let the tractor and the equipment necessarily be the barrier. But you definitely want to have that thought out before you buy the seed and then throw it in the ground. Because once the seed's in the ground, then the clock is ticking.
Natalie Hoidal (14:50):
So, typically when people terminate a cover crop, we tell them to wait a couple of weeks before they plant, just to let that organic matter break down, so you're not getting competition for nitrogen. Is that pretty much the same with this type of biofumigant? Or do you need to wait a little bit longer since you're trying to get that fumigation effect?
Jim Jasinski (15:13):
After you do the incorporation, you're supposed to wait 10 or 14 days, let that reaction in the soil calm down before you either direct seed or you transplant. Because, the idea is that it's a fumigant and you plant in there, then it's going to have a detrimental effect on the plant. I can vouch for that in a way, especially the direct seeding part. The plants will grow, but they're a little stunted and they don't produce as much fruit as those that are transplanted. So, that waiting period of, I think it's 10 to 14 days.
Natalie Hoidal (15:49):
Was that when you direct seeded prior to waiting enough time or was that even after the 10 to 14 days, the direct seeded crops didn't do as well?
Jim Jasinski (15:57):
So, we had just worked the soil and it was either that day or I think it was the next day, we direct seeded and transplanted just to see what the effect would be. I'd read that plants are going to die or whatever, but what I observed was the plants were fairly normal looking. Maybe the seeded ones, they were a little behind because they're two weeks behind in development anyway, for a transplant. But the fruit was very different. These fruit came off the transplanted, big pile of orange. These fruit came off the direct seeded, smaller green.
Natalie Hoidal (16:33):
Interesting.
Jim Jasinski (16:33):
Yeah. And it wasn't just two strips, I had done a strip where I had direct seeded here and direct seeded there, transplanted here and transplanted there. And then I've got two pictures that show, these are the transplants here and over here and you can see there's definitely something to it.
Natalie Hoidal (16:49):
So, basically just to recap, make sure you're fertilizing your cover crops, be ready, have all your equipment in place, and then after you have terminated your cover crop, make sure you wait a good 10 to 14 days before seeding and transplanting, but especially direct seeding?
Jim Jasinski (17:09):
Yeah, I would say that's all perfect, in the way it works in Ohio is, I would prefer to be transplanting at that time because now we're talking about probably the end of June and you're going to pick up about two weeks if you're transplanting, if you're direct seeding, now you're another two weeks out from that even. So, that's why I would lean more toward the transplanting because we're getting late in the growing cycle. We haven't had a year recently where it's been warmer in the Fall or it's been cooler in the Fall, excuse me. But if it does, and those plants haven't matured, those fruit, the window might not be there. So, that's the only reason to go for transplant versus direct seed.
Natalie Hoidal (17:50):
So, at the time that I talked to Jim about his work with biofumigation, he was pretty new to it. And so, while he did a great job of explaining the process, he recommended that I follow up with Meg McGrath, who you were briefly introduced to at the beginning of the episode, to learn more about the work that she's been doing with biofumigation and how well it's working in her trials with phytophthora in New York. So, here's Meg.
Natalie Hoidal (18:15):
So, you have been doing work with bio fumigation. Was that work inspired by phytophthora specifically, or was that a little bit more broad?
Meg McGrath (18:28):
I specifically started looking at it for managing phytophthora.
Natalie Hoidal (18:32):
Okay. And was that just because other things weren't working and so this was a novel, new thing to try, or is there something specific about phytophthora that makes it potentially more susceptible to biofumigation?
Meg McGrath (18:47):
Recognizing that phytophthora as a soilborne pathogen is more difficult to manage, soilborne pathogens, period, are more difficult to manage. Growers have a long growing season that they need to manage it for pumpkins and also winter squashes. And recognizing that, because it is such an explosive disease that it can really get going, that it's not going to take just a fungicide program to manage it, you really need an integrated program. So, I actually started looking at other kinds of management practices, alternatives to, you know, things to add to an integrated management program, before fumigation, I've looked at adding compost to the soil to try to encourage good organisms to help compete or attack phytophthora in the soil. I've looked at reduced tillage. And then I heard some talks from people who are starting to look at biofumigation for other diseases and heard that phytophthora and pythium are particularly sensitive to biofumigation and decided that it was something worth giving it a try.
Natalie Hoidal (20:02):
Okay. So, what was that process? What kinds of trials have you done with biofumigation?
Meg McGrath (20:09):
Well, I started right back actually, in 2008 I did an observational planning after I'd started hearing about biofumigation and we just went out and did a strip with mustard and had a section next to it where we didn't grow mustard. And it was just a phenomenal difference came through and planted zucchini squash where the mustard was in the section right next to it. Had some favorable weather and phytophthora was widespread in the strip of zucchini that was not where mustard was. And we were seeing no symptoms initially in the strip where there'd been mustard.
Meg McGrath (20:48):
It was a phenomenal difference. Also, seeing fewer weeds, suggesting that the biofumigation had an impact on weed seeds, which other people had also noticed. So then the next two years, we did a replicated trial looking at it with acorn squash. I did that work with our cooperative extension agent who works here on vegetable crops. We did that trial together and saw some good results, continued doing work since then. And it is now my standard practice before the major field that I'm going to do, my powder mildew research in, here at the facility I'm located at on Long Island.
Natalie Hoidal (21:31):
Interesting. So, actually one of the questions I was going to ask was, do you consider this a last resort or is it something that you would see as a regular part of a balanced management program? And it sounds like the latter is definitely the case for you.
Meg McGrath (21:45):
Absolutely. I think this is a disease you've got to have an integrated management program. You've got to be using whatever practices work within your farming situation. Biofumigation might not fit in well or might not fit in every year. We also have done work in more recent years, looking at alternating on a farm using biofumigation one year and reduced tillage another year.
Natalie Hoidal (22:10):
Are there particular conditions that might make biofumigation more effective on one farm versus another?
Meg McGrath (22:22):
The quality of the mustard planting, so getting it in with some fertilizer, some people plant cover crops and don't treat them like a crop. But if you're going to get the maximum out of a cover crop, which is mustard biofumigation crop is you want to treat it like a crop. You want to make sure it's properly seeded. So yes, you can broadcast the seed, but you're going to have a much better stand if you drill the seed, making sure it's fumigated. If you get a dry spring, giving it water, you want to have a maximum amount of plant tissue there when it comes time to incorporate it.
Natalie Hoidal (23:03):
Okay. So, when Jim who is also in this episode, presented some of his material with the Great Lakes Vegetable Working Group Crew, there was this really robust discussion about how sealing is a part of the process. So you go through when you chop it and you immediately are supposed to seal it. And there was this discussion of, maybe it's actually not that process that's so important, maybe it's not even the glucosinolate production, that's so important, but there are these other side benefits of just adding a lot of organic matter. I'm curious, just to hear your perspective on how important is it to do every single part of the process correctly at that critical point of chopping and working it in versus the overall just benefit of having the mustard there at all?
Meg McGrath (24:02):
Well, there is actually can be a downside to adding just a lot of organic matter. And that's that a lot of organisms will really take off with just organic matter beneficials, but also for instance, pythium very much likes it. So, if we were seeing no biofumigation and just adding a lot of organic matter, I think we'd start seeing a lot of issues with pythium root rot. So, that partly tells me that there's a lot happening with the biofumigation. When grower who's been doing an awful lot of work with biofumigation, Dale Geese, who's out in Washington, he's been a really good source of information for me. He's been in contact with people in Italy who have been really working on developing these mustard varieties that are high in a particular glucosinolate that's so good. They've done a lot of work measuring the volatility that's coming out, how biocidal they are.
Meg McGrath (25:06):
He's also been in contact with a lot of other growers who have looked at using mustard biofumigation for different pathogens, also seeing results with nematodes, wire worms, weeds, which as I mentioned earlier. So there's certainly has been some... I think there's strong evidence that it is the biocidal activity that's happening that's really doing it. Realize that mustard has a special type of glucosinolate that's particularly effective, a particularly volatile, particularly biocidal. Sealing the surface of the soil so that you don't lose the volatility. And that can simply be done. What we do is, we run a cultipacker behind our rototiller, which is incorporating it, so it's not a second step. It's all done in that one step of incorporating the mustard that we've already chopped up and then sealing the surface.
Natalie Hoidal (26:06):
Okay. And I think I read in one of your publications that you don't necessarily irrigate it in, you just do it on a morning where sometime during that day you're anticipating rain?
Meg McGrath (26:17):
Yes. Just because we don't have a irrigation system that we can cover the whole field at one point in time, we don't have a big gun kind of a system. So, it means we're going to have to move irrigation pipe across the field in order to get it all watered in. Having good moisture in the soil is important. That is also what's helping to get it started, the fumigation process.
Natalie Hoidal (26:43):
Okay. That's encouraging. I think a lot of farmers are in a similar situation where they don't have irrigation systems across their whole fields. And so, I was wondering if there's this perfect amount of time that has to be done in 20 minutes, or if you have a little more flexibility?
Meg McGrath (27:00):
Well, you want to chop that mustard and get it promptly into the ground because you're going to have some release of that volatile... The isothiocyanate is, you're going to get that natural gas released and lost, if you don't get it incorporated and sealed into the soil. And that's the reason you hear that it's better done on a cooler day, which is often the day where you're expecting rain to come in. It tends to be a cooler day, of course, than a hot sunny day.
Natalie Hoidal (27:39):
Just because that breakdown process is...
Meg McGrath (27:41):
Yeah. Slows it down a little bit. So you're not going to lose the isothiocyanate to keep most of it in the soil, so it can do its thing.
Natalie Hoidal (27:53):
So, one question I had about the isothiocyanate is, it is a similar product to metam sodium. It's chemically similar to metam sodium, which is used for fumigation in potatoes. And there are significant safety concerns with metam sodium. Are there things that growers should be thinking about, whether it's just personal protector equipment stuff, when they're chopping and doing this biofumigation process?
Meg McGrath (28:29):
Well, if they've eaten any Oriental mustard, they've actually eaten the glucosinolate. We've been eating Oriental mustard for thousands of years without any issues. The particular glucosinolate that's in the biofumigation mustard is sinigrin. During incorporation, if a lot of volatility is coming off, a person who's running a tractor, if they're not in a CAD tractor, they might experience a runny nose, might feel it clearing their sinuses a little bit, like wasabi can do. I've never noticed this when I've been around it, but that could happen.
Natalie Hoidal (29:10):
Okay.
Meg McGrath (29:11):
Realize you are talking a different chemical. Yes, it's a related chemical, but it is a different chemical.
Natalie Hoidal (29:17):
Yeah, that makes sense. So, I know we have been talking about fumigation very specifically, but I wonder if, to wrap up, you could talk a little bit more comprehensively about how biofumigation fits into your broader management plan and the other strategies that you are including in the management of phytophthora in addition to biofumigation?
Meg McGrath (29:43):
We think of phytophthora, people often talk about rotation as being a part and part of managing phytophthora blight. And the phytophthora capsici, the pathogen, it survives in soil for such a long time that I don't look at rotation as being important part of the program. I've sometimes seen it show up in the fields that have been rotated. So too often in our research facility, I'm amazed to see it pop up in a field where we've rotated out of cucurbits, so we're now back into cucurbits for an experiment, before I see it in my block where I study phytophthora every year.
Natalie Hoidal (30:23):
Okay.
Meg McGrath (30:24):
Yeah. So you get some of those odd things and I have a grower friend who grows... He's got a, you pick pumpkin field and his other ag business is a greenhouse, you can't rotate those. So, he has pumpkins every year for 20 plus years now in the same field. He uses mustard every year, he does a lot of other things to try to manage soil moisture and has got a good strong fungicide program. And he has not had serious problems with phytophthora most years. If we get a really rainy bad year, he might lose more than he'd like to see, but he's been doing pretty well.
Natalie Hoidal (31:06):
Okay. And at the beginning you mentioned you have some trials where you're rotating every other year with biofumigation and then like a no till, I wonder if there's-
Meg McGrath (31:19):
Growers have been doing that, I've not done that myself.
Natalie Hoidal (31:21):
Okay.
Meg McGrath (31:22):
But we've definitely seen some good results with reduced tillage.
Natalie Hoidal (31:28):
Okay. So, in terms of broader cultural practices for phytophthora, would you say reduced tillage ranks among the top of those recommendations?
Meg McGrath (31:39):
It's definitely up there along with... I think one of the challenges with reduced tillage is weed management. I've seen good results. The other that I've seen with commercial fields is where they're using reduced tillage in rotation. So, using reduced tillage for corn, which is a little bit easier to grow, reduced tillage situation and then coming in the next year with their pumpkin crop, for instance. Water management is a big one. So, what I routinely do now with my pumpkins is, grow them with drip tape. So I'm using drip irrigation, so I'm only wetting the field around the root system of the plant instead of irrigating the whole field. Which also helps with weed management, which is good.
Meg McGrath (32:31):
I have improving soil drainage in any way, so subsoiling between the pumpkin rose before they vine out is another good practice. I do that routinely as well. Not planting low areas, you know where your low areas are and a good fungicide program. The other thing I see growers do for instance, that one grower I mentioned is, he's routinely inspecting his crop. And if he sees a plant going down, or fruit that are affected, he takes them out.
Natalie Hoidal (33:02):
Great. Okay. Sounds great. I think those are actually all of the questions that I have written up ahead of time. Is there anything that I'm missing, anything really important that you want to say about biofumigation that I didn't ask about?
Meg McGrath (33:25):
I think there's a lot of advantages to it. I think beyond what it's doing for phytophthora in the spring, it's, you're going to have a field full of flowers before there are very many other flowers and it will just be alive with bees and beneficials. So, there's a big plus that you're doing biofumigation. You are adding a lot of organic matter to the soil. There's some advantages to that. Another grower here on Long Island who got into biofumigation pretty early and has continued doing it, commented to me how he can just feel the soil works better when he prepares it before planting his pumpkins and winter squashes.
Natalie Hoidal (34:10):
That's great. This has been really helpful.
Meg McGrath (34:12):
Oh, good.
Natalie Hoidal (34:13):
Thank you.
Meg McGrath (34:16):
Yeah. I'm obviously a big believer in it. I've got mustard growing out in my field, getting ready for my pumpkin experiments this summer.
Natalie Hoidal (34:26):
So, that's the end of the interviews from 2020. In late spring of 2022, I checked back in with both Jim and Meg to see how biofumigation was continuing to go for them. Jim had somewhat mixed experiences. He ended up reaching a point of not recommending biofumigation to growers due to the extra expense and time. He was also having good success, managing plectosporium with fungicides. He did say that for growers who are interested in the pollinator benefits and soil health benefits of a mustard cover crop, it could still be worth it, but recommended trying it for a few years on a small scale to see how it works for you. Meg continues to use biofumigation and mention the farmer she works with on Long Island continue to use it too, and feel like it's worth the time and effort.
Natalie Hoidal (35:12):
She wanted to share some cost estimates for her method, which includes two people and two tractors. The first person has a flail mower terminating the crop and the other person follows behind with a disk to incorporate the residues. She said they spend about a hundred dollars per acre for fertilizer, which is a little bit more than a typical cover crop because the goal is to get a lot of biomass. They also spend 50 to $60 per acre on seed, but she mentioned that for a much smaller grower, you might pay a little bit more just because you're not getting the bulk benefit. Meg terminates the mustard in the first or second week of June and plants pumpkins a minimum of seven days later. And she wanted to remind people to make sure to disk the soil before planting, to release any remaining biofumigant. And that also gives you the added benefit of another cultivation pass for weed management.
Ben Phillips (36:07):
That concludes this episode of The Vegetable Beet. If you'd like to check out all of our past episodes, head on over to glveg.net/listen. Sweet. Okay. Thanks Natalie.
Natalie Hoidal (36:21):
Okay.
Ben Phillips (36:22):
I got to run.
Natalie Hoidal (36:22):
[inaudible 00:36:23].
Ben Phillips (36:23):
Okay. See you.
Natalie Hoidal (36:24):
All right. Okay, bye.
Ben Phillips (36:24):
Bye.

This transcript was exported on Aug 26, 2022 - view latest version here.

Biofumigation episode final (Completed 08/24/22)
Transcript by Rev.com
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