An interview with Dr. Jed Colquhoun about his research on the Bambara groundnut. The Bambara groundnut is a new crop to the United States but commonly grown in its native Africa as a subsistence crop. Jed shares his successes and challenges during his early work breeding this legume for Wisconsin.
Dr. Jed Colquhoun is a Professor in the Department of Horticulture and IPM Program Director at the University of Wisconsin-Madison.
JASON FISCHBACH 0:00
This is a podcast about new crops. You’re gonna love it. Join us on The Cutting Edge, a podcast in search of new crops for Wisconsin.
Jed Colquhoun 0:10
I think we’re very early on the discovery phase to be able to know what the potential is like for the ground met. I’d like what I see so far. But I also remind myself that I’m looking at it through an agronomic lens. There’s also the market and consumer demand end of it and what those products might look like on the shelf.
Jordan Schuler 0:49
Welcome to another episode of the cutting edge podcast in search of new crops for Wisconsin. My name is Jordan Schuler, and I’m the regional crop educator with UW Madison division of extension. Co-hosting with me today is Steffen Mirsky, the Emerging Crops Outreach Specialist. Today’s episode we will be discussing the Bambara groundnut. Our guest today is Dr. Jed Colquhoun, Professor in the Department of Horticulture and Integrated Pest Panagement Program Director here at UW-Madison. Dr. Colquhoun’s research and outreach focus is commercial specialty crop production. So I’m going to let Jed introduce himself and give a little background on his past and current projects.
Jed Colquhoun 1:29
Thanks very much for having me today. As was mentioned, I’m a professor in the Department of Horticulture where I specialize in Applied Research and Outreach and commercial fruit and vegetable production, including some emerging crops that we deal with in the states such as the baneberry, groundnut and hops meant and several others. I’m also the integrated pest management or IPM, Program Director for UW Madison where we develop reasonable and feasible pest management tools that can be used in a way that protects human health and the environment in which we’re farming.
Jordan Schuler 2:09
Well, thank you, Jed for being here today. Could you maybe provide listeners some background on what the Bambara Groundnut is?
Jed Colquhoun 2:17
The Bambara groundnut is a crop that’s native to Sub Saharan Africa, primarily West Africa, originated in the Bambara district near Timbuktu in the southern region of the Sahara Desert. It’s a very interesting crap. It’s one of the most important grain crops where it’s grown natively on Western Africa. But there it’s considered a subsistence crop. It’s not grown to be marketed beyond the farm, but sustains the families on the farms in which it grows. It has not expanded broadly from that region, but is considered by many food security organizations to be one of the underutilized crops in the world. And the crops for which there could be much expansion at this point. There has been a little bit of commercial production in Southern African regions, as well as in Southeast Asia, but very limited in North America. Our interest in it really is several fold. Number one, it’s a high protein crop that has much market interest among plant based proteins, of course, number two, it’s very drought tolerance. It can grow in almost any conditions in my experience, as long as we have some heat, and it’s a nitrogen fixing legume. So it offers an opportunity for us to protect water quality by reducing fertilizer use. And with all those goals in mind a few years ago, we secured some seed from a grower in Pennsylvania, and started trying to grow it here in the state of Wisconsin.
Steffen Mirsky 4:03
Jed, can you talk a little bit about your research and what some of your main objectives are, at this point?
Jed Colquhoun 4:11
Sure, with Jordan’s assistance, our first goal really was to figure out if we could produce the crop in Wisconsin. And we did so in the mindset of a changing climate. And also with the idea that we were looking for crops that could mitigate some of the impacts of agriculture, such as a contamination in groundwater by fertilizers, and potentially some pesticides. And so in the very early stages, and I would say we’re, we’re still in the early stages. The focus is really whether we can grow the crop and our climate that’s much different than Sub Saharan Africa. But with some pieces in common such as coarse textured low organic matter, sandy soils, like we have In the central part of our state, and just seeing if we could get a crop off of the early plantings, as since then our research has taken some progression in two different ways. Number one, we’ve been selecting from the four varieties that we started with, or landraces. These are unimproved varieties really unnamed and unimproved. So over the past four years, we’ve been selecting the winners and traditional mass plant breeding techniques and replanting those in subsequent years. And then that we’re not only selecting those that produce the best ground, and that’s in our production region, but we’re also bulking the seed to be able to be planted at a broader scale. That led us to the next piece, which is to start to refine just a little bit our production techniques. When we began, we started the ground nuts in the greenhouse and then transplanted them in the field. This past season, realizing the amount of energy and time that that took, we transition to planning the ground up from seed as it would have been done in its made of production. And that actually showed us that we could produce more ground nuts when seeding compared to transplanting, which was a bit of a surprise, and allowed us this season in 2022, to be able to plant it three different sites. So we get a better idea of how it grows in different sites and again, gives us a little security in bulking our seed populations. So right now we’re refining the varieties and the very early stage and also figuring out how to best grow it in our production and noting any pests and other problems that may arise.
Steffen Mirsky 6:52
Can you talk about some of the improvements that you’ve seen in the in the few years that you’ve been doing this work?
Jed Colquhoun 6:58
Yeah, so it’s been very interesting. Our variety names are, are just the ones that we put out there in happenstance, we have really old, old, new and new, really new as our four years of different varieties. And when we look back at the really old seed in the beginning, we would get maybe six to 10 groundnuts per plant. And by selecting those that had marked up production in the past three production seasons, this year in the fourth year of improving this really old variety, where to the stage of having maybe 20 to 30 nuts per plant. The groundnut is extremely interesting in the sense that these largely unimproved varieties have a vast range of phenotypic appearance or the appearance of the nut itself. That can range from a very uniform, clear or creamy white ground nuts to on the same plant ground. That’s the cover the whole range from solid black ground nets to speckled and modeled prettier, aesthetically pleasing array of colors on the ground net. So we’ve been selecting for diversity of production in the end product, knowing that there could be multiple markets. So really an increase in production and an increase in quality, the appearance, the number of nuts set per pod. And then the actual size of the nuts. One of these varieties that we started out with had very small amounts like the size of a pea, the varieties that we have now. They’re larger than a pea mat.
Steffen Mirsky 8:48
You mentioned you were doing this work at three different locations around the state. Can you just list what those locations are?
Jed Colquhoun 8:55
Sure, we’ve actually done work in several different locations. We started out in the early stages, covering the diversity as much as we could and statewide production. So we had Arlington and very deep silt loam soil that’s very forgiving. The central sands post textured low organic matter soils that can be droughty without irrigation, and don’t hold much soil moisture nutrition and the northeastern corner of the state in Langlade County with a very short growing season on silt loam soils. And what we found in those early stages is that the ground up prefers the soils like it’s grown in in Africa, which makes good sense. So these coarse textured lower organic matter soils that warm up quickly in the spring can be drought in the summer, but the ground net seems to tolerate if not thrive in that and we have the ability to control moisture through irrigation We’ve not used any fertilizer in any of our production. Again, it’s a nitrogen fixing legume. So it modulates and captures nitrogen. And so our focus in the past couple of years has been in that central sands region where it seems to thrive. This year, we had our small area of production in the Hancock area at a research station. And then we had to private growers plant seed on their farms, just to give us a little more diversity in production.
Jordan Schuler 10:32
So I know previously, plants were transplanted. But you found that seeding worked better? Do you have a seeding rate or maybe an established date that you typically have found works best for establishing the crop
Jed Colquhoun 10:48
Based on the limited amount that’s reported in the literature, we started there and seeded the crop about 30 days after the last anticipated frost. So in the central sands region, on a sandy soil, that actually warms up quite quickly, because it’s not full of soil moisture that allowed us to plant in about the first week or two June. There is some frost risk at that stage, of course, but we’ve avoided that to this point. And then in terms of the actual seeding rate, a lot of that still needs to be determined. But the plant seems to do well when planted close together. So in a row, we’re now seeding them about eight inches apart, I think we could go down to six inches, and still get a good ground net set. And our between row spacing really would be dictated by the cultivation equipment that a grower might be using the distance between the cultivated rows with their equipment, I think it would be interesting, because it does become a very competitive canopy to plant the rows very close together. So within a plant to grow a bench in row spacing, and maybe one foot between seated rows would be sufficient to get good production but also become more competitive with weeds.
Steffen Mirsky 12:20
In terms of planting equipment that you would use, could you use a lot of the same equipment that say like soybean growers use?
Jed Colquhoun 12:28
The ground and that seed is about the size, if not maybe a little larger than soybean seed, the ground net itself one dried is extremely hard. So seed cracking, I don’t think would be an issue in commercial equipment. To this point, we’ve been using push planters with large seed plates to be able to do that. But I don’t see any significant hurdles, given the hard, durable seed and being able to use commercial equipment, like what you would use to plant soybeans.
Steffen Mirsky 13:02
Can you just talk about what some of the challenges are that you faced so far in breeding with them?
Jed Colquhoun 13:09
Sure, it’s been extremely interesting, because when you’re the first to plant something, you have no idea what to anticipate. And so we had no idea in the beginning where it might thrive, it appears to central sands is just the perfect type of soil and climate for growing ground nuts. But in the beginning, there’s really no documentation to go from. So I we didn’t know what to anticipate. This past season was interesting in that we identified the first pest we’ve ever found on the ground net. And that was the corn wire worm. And we’re growing in the field that actually had to have some corn seeded and we took the corn out to plant the ground in that seedling corn just to make space to put our ground in that plot. And it appears that that area had some wire worm left in it and there was corn nearby. Of course, I can’t say that it was a prolific pest we found maybe two wire worms and their entire planting. But again, that’s what you have with an early stage crop like this. We have no idea what the pests may turn out to be if you were to grow it at a larger scale, where it is grown natively. It doesn’t have a lot of pests. There are some viruses that can affect it. We’ve not identified any of those yet. The other challenge would be our opportunity maybe is whether it would benefit from having a little starter nitrogen in the beginning of the season to form more competitive foliage. The resources from the foliage would then feed the nut production when the pegs are set and that nuts are produced. But we haven’t gotten far enough along to be able to determine that we do know Interestingly that there is a penalty to applying too much nitrogen, they will not modulate and fix her own nitrogen and they stay vegetative. So they don’t produce the flowers that send the pegs into the soil that form the ground that’s just like a peanut plant. So that’s interesting and an opportunity to reduce the need for nitrogen because there’s actually a direct production penalty to overusing it.
Jordan Schuler 15:29
So, you mentioned the competitiveness with weeds. What has been your method for weed control?
Jed Colquhoun 15:38
So far, it’s been a lot of hand weeding and hoeing in our small plots. We haven’t gotten any farther than that to determine whether any sort of synthetic herbicides might be useful. We did this year observed in areas where we were hauling and pushing soil around the ground, not plant as it was setting the pegs and ground in that plant will flower, that flower will dip on what they call a peg down into the soil. And at that soil level, and just below the soil surface is where the ground that’s formed. When we were hoeing. This year, inadvertently, we’d often push a little soil over the plants in that process. And interestingly, we found that they produce more like lightly hilling a potato plant by covering some of these pegs that would send out secondary pegs into that soil that enhanced production. So with that in mind, I think this crop could grow be grown without weed competition with a simple mechanical weeding, that also accomplishes the secondary benefit of putting a little soil over the pegs as they’re farmed. We noticed that the pegs that did not make it down into the soil remained green, and did not produce a ground net. So light cultivation would give us weed control followed up with some hand weeding likely and accomplishes the task that you would get similar to hilling a potato plant.
Steffen Mirsky 17:09
I’m curious, because this is this crop is a legume, have you thought about or worked on any intercropping experiments or trials?
Jed Colquhoun 17:20
That’s a great question. In native African production, and often is interseeded or grown as an intercrop with sorghum or maize. So I think it could be very likely done the same here in our system. The challenge really would be if we were looking to mechanize harvest and anyway, that would be terribly difficult. Say with a sweet corn interseeded with a groundnut, sweet corn being four or five feet tall and mechanically harvested, with equipment that would be driving over the groundnuts. The groundnut plant itself is low and compact to the soil, maybe six to eight inches tall. So mechanically harvesting sweet corn would likely be possible, but it would likely damage and make it impossible to harvest the ground and with any sort of mechanization.
Steffen Mirsky 18:14
Can you talk about what what the mechanization of harvesting this groundnut would look like?
Jed Colquhoun 18:21
Sure, so what would be anticipated in terms of mechanized harvest would be similar to what they use in a peanut crop, basically a lifter and a short chain digger that picks up the plant and the ground nuts would fall through the chain onto a belt. So similar to what would be done in peanuts would be very possible in the groundnut.
Steffen Mirsky 18:44
So after harvest, in terms of processing the ground nut, what kinds of things have to be done before we can actually, you know, you actually sell the nut.
Jed Colquhoun 18:56
The groundnut first needs to be dried after harvest, which allows for the separation of the actual nut inside the pod each pod contains one or two nuts. In our primitive production, we typically get one nut per pod. This year in our lightly improved varieties, we were getting a lot more of two nuts per pod, similar to what you would find with a peanut. So that pod needs to be dried so it cracks easily freeing the nut from inside. In that process, the nut becomes extremely hard. It would be a tooth breaker if you were to try to eat them after the pod is dried. And that’s been one of the limitations of expanding from a subsistence crop to a marketed crop and native production areas. The pod or, excuse me, the nut itself being so hard needs to be boiled for quite a long time to make it soft enough to be roasted or crushed or dehulled for the intended processing market. So that depending on how hard the nut is, it appears that it takes somewhere between a half an hour to two hours of boiling to get it to be quite soft and edible at that point. And some of the subsistence production regions, they just eat them fresh, they don’t allow that not to become that hard. But after it’s taken from the pod itself, it’s boiled. And then it can go a number of different directions. It can be roasted, and eaten as a snack nut similar to a peanut as a sweeter flavor with less oil than a peanut, typically about 20% protein. But that can range from 15 to 25% protein. And it’s a source of complex carbohydrates. With all that nutritional aspect in mind, it can be milled after being boiled to form a high protein flour. And there’s a lot of interest in that market to increase the ability to use it as a plant-based protein. Interestingly, there are projects underway in different parts of the world to also crush it for Bambara nut milk, a high protein milk that would be competitive with products like almond milk. So multiple uses beyond that, but it all starts with the need to boil it to soften the product and possibly dehull it to mill it for flour.
Steffen Mirsky 21:33
Just to go back and revisit the the cracking of the actual pod, is there equipment already that can do that?
Jed Colquhoun 21:41
I don’t know the answer to that. Right now the equipment is right here. In forefinger. Once the pods are dry, I shouldn’t say that once the pods are dry, and our primitive small scale production right now they’re sitting on paper, brown paper, craft paper on a greenhouse bench drying. And then after that, we simply smack them with our hand and they pop right out of the pod, the groundnut frees itself at that stage. And then you can just pour it over a screen that retains the pods and the nets fall through. It couldn’t get any simpler at this point. So getting it out of the pod, I don’t think would be a mechanical barrier. It’s more than need to be able to boil it for a long time and and beyond subsistence production have the field to be able to create the heat to boil it.
Jordan Schuler 22:35
Do you have to go through the boiling process? If you’re going to use it for seed?
Jed Colquhoun 22:41
Oh, great question. No, to use it as seed, we simply dry it, break it from the pods and then store it in a cool, dry environment.
Steffen Mirsky 22:51
I’m curious about some of the culinary qualities that you talked about. How much have you experimented in the kitchen with these nuts and what are your impressions.
Jed Colquhoun 23:01
So I have experimented some but it’s been very conservative because we’re trying to bulk our seed and it doesn’t bulk well in my stomach, of course. So we’re trying not to eat all of next year’s crop at this stage of production. But of course, as a self proclaimed foodie, I’ve tried it. And I’ve boiled it and then roasted it simply in a pan in the oven. It can be fried also. But we’ve tried roasting, it tastes great, just with a little salt and pepper. I have also tried wasabi groundnuts and they’re quite good. So I do think there are several uses that could be explored. And I’ve talked to my colleagues and the Department of Horticulture who work with local chefs to develop new food products. And that’s in mutual interest to be able to see what they might be able to make out of it that’s very creative. So I think as much potential largely based on its protein content, in terms of the taste itself, I would say that it’s much like a peanut but maybe just a little bit sweeter and taste when roasted.
Jordan Schuler 24:16
So are there any other uses for the plant, like minus the nut.
Jed Colquhoun 24:22
So in some regions, they’ve explored using it, the top so the plants vegetation is animal feed, and it appears to have a nutritional profile that would be good for animal feed. Also, that’s not my area of expertise, but certainly wouldn’t be one worth exploring as a secondary market for the other portion of the plant that we’re not consuming. Beyond that though a lot of the uses have been as a snack food as I mentioned, boiled and then roasted or fried. As a high protein flour product and multi ingredient products or the In one of these milk type products in Africa, they also boil it, and then basically blend it into a gelatinous appearing product that they use as a breakfast food mixed with other oils like coconut oil and spices. It’s been used as a breakfast food for hundreds of years.
Steffen Mirsky 25:27
So I’m curious just what your near term research plans are with this crop. Next year, what do you, what do you have planned?
Jed Colquhoun 25:38
We’re continuing down the two paths that we’re on now first, working with plant breeders to intentionally select for the desirable traits. Those would be a diverse, nut portfolio under the ground of what we’re getting from each plant is something that’s aesthetically and culinary, appetizing and pleasing. But also, looking at the production part of that, how can we optimize production, so get the most deal that have the least land, water and nutrients. And we’ll continue down that path. We’ll continue down the path of general production research, the seeding versus transplanting bed configurations? Is a starter fertilizer useful to get it going? What amount of irrigation optimizes production, and generally observing the conditions in which it produces the most. So what were the climatic conditions like? And are there any pest management barriers that we would need to address like if we were to find more wireworms and such, and that production research, again, will be combined with this early plant breeding selection. So right now we want to see how consistent are our lines carry from year to year. And soon we’ll be planting them in the greenhouse noting the appearance of the nut that we’re planting, and then documenting the nuts that we get out of our greenhouse production over the winter. To see if there’s a consistency if we plant a speckled groundnut, for example, do we get consistent, speckled groundnuts of the same size and quality out of the other end, that’ll give us a sense of how far along these plants are in improvement of the varieties. While we’re also bulking more seed to be produced in the field next year. One of the potential hurdles to the groundnut is that it really enjoys heat. And Wisconsin, while we consider our summers to be warm, they’re not as hot as the native production area, not as arid for sure. And I think we are probably relying very heavily on a warm fall to this point to get good ground net production. So it’ll be interesting to observe what it would do if we had an earlier for us than what we’ve had in the past few years. Or if we don’t have these warm September months, I think the crop is made in September, like growing sweet potatoes in Wisconsin. And so we also want to observe what it does in different climatic conditions. I would say in general, our research focuses on three goals, improving the groundnut varieties that we’re planting so that they’re consistent. evaluating whether groundnut would be a resilient crop and our climatic production areas and developing the tools and practices to optimize production.
Steffen Mirsky 28:50
And are you doing any of this work in collaboration with other universities or growers around the country or is Wisconsin kind of taking the lead on this?
Jed Colquhoun 29:00
As far as I know, I think we’re the largest groundnut producer in the country. So now we are not doing it in collaboration with really anybody outside of a few farmers in Wisconsin and my colleagues on the emerging crops team, and including the plant breeders. And I’m not aware of any substantial research being done with it in other parts of the country. It has been lightly explored, probably in the same range as what we’ve done in Wisconsin and states like North Carolina and Florida. But I think we’re all at about that same stage of the early introduction and discovery. Cool.
Jordan Schuler 29:45
So other than Wisconsin, do you have any predictions or thoughts on what other states might be able to work with the ground net?
Unknown Speaker 29:54
I think that the groundnut could be a good fit for several production systems, particularly those that have warm, long growing seasons, course-textured, lower organic matter soils, like maybe what you would find in parts of Florida, Texas, California and the southwestern United States, on general. And I think I could make a good rotational fit in areas where agriculture is being constrained by a lack of water, and particular, it really seems to thrive and very droughty conditions and is an extremely resilient crop and my early experience with it. So I think it would make a nice agronomic fit in those regions, but also have a benefit in improving the resiliency of agriculture, in systems that are threatened by aspects like reduce water availability.
Steffen Mirsky 30:58
So if you had to look into the future, into the crystal ball, how much potential do you see in Wisconsin for the groundnut? Like how many how many years away are we from having, you know, registered varieties and being able to start a commercial industry? Or is that even in the future for the ground net? In your opinion?
Jed Colquhoun 31:21
That’s a great question. I think we’re very early on the discovery phase, to be able to know what the potential is like for the ground net. I’d like what I see so far. But I also remind myself that I’m looking at it through an agronomic lens, there’s also the market and consumer demand end of it, and what those products might look like on the shelf in terms of competing with other plant based proteins. So from an agronomic perspective, I think there is a fair amount of potential for it to be a very nice rotational crop. In our diversified production systems here in Wisconsin, we have the experience to do so we have processing infrastructure to be able to be creative, and are growers like trying something new. So I think there’s a good potential across a broad spectrum of production in Wisconsin. And from there, we would need to see what the market demands in terms of the volume of production.
Jordan Schuler 32:28
Are there any systems already in place in terms of processing that could potentially be adapted for this crop?
Jed Colquhoun 32:36
I think there are systems to be able to process it in milling to form flour type products, we do not have an industry similar to ground net industries where they boil and roast or fry nuts, as far as I know, you know, so, for example, we don’t have peanut producers in Wisconsin, for which we could adapt to the groundnut. So that would be a little bigger stretch. But again, if the demand is there, Wisconsin has a long experience of having very diversified processing crops. So I don’t think that would be a significant hurdle. To be able to adapt to that, if there’s the demand, the pull side would have to dictate whether financially, it was something worth investing in. But at some point, somebody planted the first potato here, and the first soybean and this first sweet potato. And we’ve shown that we’re we’re resilient and adaptable. So that’s kind of the fun part is to be at this very early stage to see if that has that potential to be able to blossom into something like the crops that we’re known for growing today. That will say probably what I’ve learned about exploring new crops is maybe more valuable about the actual substance I’ve learned about the ground nut. And that’s been very interesting to put something in the ground for the first time as you know, Jordan and not knowing what’s going to come up to identifying the first pests to evolving the crop in the very early stages from labor intense transplanting and the energy rich greenhouse, to figuring out that you could just put the seed in the ground and walk away for a few weeks was quite a jump. So those jumps are really interesting and eye opening to be able to have that type of experience on a very early agronomic end is exciting.
Steffen Mirsky 34:46
Well, thank you so much, Jed for joining us. This was really interesting. I think Jordan and I both learned a lot about the groundnut and good luck with the research. This has been another episode of The Cutting Edge, a podcast in search of new crops for Wisconsin. Thank you all for listening. And thanks again to Jed for joining us today.
JASON FISCHBACH 35:18
Brought to you by the University of Wisconsin Madison Division of Extension.
Transcribed by https://otter.ai