The Sweet and the Not-so-Sweet of the U.S. Strawberry Industry - A Discussion with Dr. Gerald Holmes

In the first part of this two-part series on strawberries, Sam and Lara interview Dr. Gerald Holmes, director of the Strawberry Center at California Polytechnic State University in San Luis Obispo. He discusses the challenges that growers face, the costs of producing and harvesting strawberries, the factors that influence the flavor of the berries, and the future of the industry.

To learn more about the Strawberry Center at California Polytechnic State University in San Luis Obispo go to https://strawberry.calpoly.edu/.

For the HortTechnology article "The Status and Future of the Strawberry Industry in the United States" go to https://doi.org/10.21273/HORTTECH04135-18.

Learn more about the American Society for Horticultural Science (ASHS) at https://ashs.org/.
HortTechnology, HortScience and the Journal of the American Society for Horticultural Science are all open-access and peer-reviewed journals, published by the American Society of Horticultural Science (ASHS). Find them at journals.ashs.org.

Consider becoming an ASHS member at https://ashs.org/page/Becomeamember!

You can also find the official webpage for Plants, People, Science at ashs.org/plantspeoplesciencepodcast, and we encourage you to send us feedback or suggestions at https://ashs.org/webinarpodcastsuggestion.

Podcast transcripts are available at https://plantspeoplescience.buzzsprout.com.

On LinkedIn find Sam Humphrey at linkedin.com/in/samson-humphrey. Curt Rom is at https://www.linkedin.com/in/curt-rom-611085134/. Lena Wilson is at https://www.linkedin.com/in/lena-wilson-2531a5141/.

Thank you for listening!

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Transcript

Lara Brindisi: 0:10

Welcome to Plants, People, Science, a podcast by the American Society for Horticultural Science where we talk about all things horticulture. In today's episode we learn about the challenges and future of large-scale strawberry production in California. But first, Sam, how's it going?

Sam Humphreys: 0:27

Hey, Lara, it's good to see you. It's going a little bit rough. So I actually am excited for this strawberry episode because I do strawberry research. Right now I am between Rep 1 and Rep 2 of my Big Masters experiment, and so I have to rearrange my treatments. I have to, like, take down my light fixtures and put them back up in a different way to prepare for Rep 2. And so it's just been a lot of taking down the work that I did and redoing it.

Lara Brindisi: 1:03

But I mean Is that all for randomization?

Sam Humphreys: 1:07

Yes, it is To make sure within my growth chambers that there isn't a huge environmental effect on the plants. But I'm also very excited because in about a week and a half I'm going to leave to Laramie, wyoming, because I'm going to spend five days as an intern at Plenty, which is a vertical farming company.

Lara Brindisi: 1:38

Yeah, that's a big one. Congratulations, that's so exciting.

Sam Humphreys: 1:41

Thank you. I'm really excited because they're doing strawberry work. They're trying to see if they can grow strawberries vertically. They've done a lot of tests too. I'm really looking forward to seeing it behind the scenes.

Lara Brindisi: 1:55

Yeah, it's smart that a lot of the companies are starting to expand beyond the specialty leafy greens and to other horticultural crops.

Sam Humphreys: 2:03

Yeah, I wonder where it's going to go. I mean, you did your PhD research, including some African indigenous vegetables, right? I wonder what the future holds for that.

Lara Brindisi: 2:15

Yeah, I mean. So. Most of my PhD thesis and work was on basil, but I did some dabbling in African indigenous vegetables, as you mentioned, and then some vertically farmed leafy greens. Actually, I just had a paper come out related to some of the chemistry on vertically farmed greens, which is really fun to see that out there. Yeah, so it'll be cool to see where that world goes, Though you're much more involved in it than I am at the moment.

Sam Humphreys: 2:40

Well, congratulations. I'm not involved enough. I didn't see that paper come out. I've got to take a look, so you've got some exciting news to share as well. Lara, what's going on?

Lara Brindisi: 2:50

with you. Yeah, a few things. I mean this weekend is, of course, the ASHS conference, and so I'll be leading four different sessions. One is an oral talk for some of my work on my thesis, Another is a poster from the internship that I did in Taiwan, and then two are actually kind of unique sessions, one being the Fields of Devotion film we're doing an exclusive screening, and the other is a session for this podcast. So I'm really looking forward to this event. I'll be pretty active, and it'll be fun to see people that I haven't seen in a while too, of course, oh, that's so exciting For the Fields of Devotion.

Sam Humphreys: 3:32

is that something that people can only see at the conference, or is that something people can see elsewhere too?

Lara Brindisi: 3:38

Yeah, so as of yet it's limited to these exclusive screenings. In the future it will be available on more popular sites, so it'll be mainly used as an educational resource, and there'll be more information on that to come once I'm allowed to share it.

Sam Humphreys: 3:59

That's amazing. I hope you have a fantastic time at ASHS. How many years will this have been for you attending?

Lara Brindisi: 4:05

Oh, this is my third conference. Yeah, and unfortunately I don't think I'll be able to go the next couple of years because I'm going to be sadly and happily switching out of a horticultural crop. I recently accepted a job position at Cornell working on maize or corn, so I will be moving into the agronomy world. I don't know for how long, maybe it'll I'll come back to horticultural crops, but for now that's what I'll be doing.

Sam Humphreys: 4:36

I shouldn't say this because this is a horticulture podcast, but agronomists are wonderful. You'll fit right in, I'm sure.

Lara Brindisi: 4:43

Okay, that's good to hear. Yeah, I mean, I've met such really wonderful people in one of my trips up there, so I think it'll be a really great position, though I do have to say, because I'll be accepting this position, which will be very time consuming I will have to step down as a podcast host.

Sam Humphreys: 5:03

We're going to miss you so much, Lara. I can't even say just a lot of the behind the scenes stuff. We don't talk on this podcast about what it takes to make these episodes and the ideas that have to go into developing what these episodes are going to look like. But so much of the podcast has been shaped by you and your perspective and your wonderful questions, so truly I can't say how much will miss you.

Lara Brindisi: 5:35

Aw, thanks, sam. That's so sweet of you to say, and this might not be the last. I could always make another guest appearance in the future, or maybe come back when my schedule opens up, if it ever opens up, and so this is not the last of me, oh don't worry, you'll just see on your Google calendar, you'll see that I've just invited you randomly to certain meetings and we'll jump in and I'll just be interviewing you.

Sam Humphreys: 5:59

It'll happen someday.

Lara Brindisi: 6:00

Yeah, perfect, I mean, that'd be great to come back on this show. I'm open to an interview. But yeah, I mean, I guess that's a bit of our lengthy introduction for today's episode. Shall we get into it.

Sam Humphreys: 6:15

Let's do it so. In today's episode, we introduce Dr Gerald Holmes, who is currently the director of the Strawberry Center at California Polytechnic State University in San Luis Obispo. Before this role, he worked as a product development manager at Valent USA and served as an associate professor and extension vegetable pathologist at North Carolina State University. He earned his PhD in plant pathology from the University of California Riverside and a bachelor's in agronomy and crop science from the California State Polytechnic University in Pomona. All right, Lara, let's get started. Good afternoon, Dr Holmes. Before we get into the content of the episode, could you explain some of the unique aspects of strawberry production?

Dr. Gerald Holmes: 7:08

Yeah, first and foremost, everybody knows California grows a lot of strawberries, but most of them don't know that we grow somewhere between 85 and 90% of all the strawberries that are grown in this country, and so that's usually a number that surprises people. And we do it on just about 40,000 acres, so on a per acre basis it has a very high value. As far as the strawberry production itself, it has a very unique look to it, right, the rows are laid out differently, the beds are laid out differently. If you get on Google Earth, you can tell a strawberry field even without seeing any part of the plant, just by the way the fields are laid out.

Lara Brindisi: 7:59

And most of the production happens in California right.

Dr. Gerald Holmes: 8:03

Yeah, all of it is. Well, those 90% of the strawberries produced in this country are produced in California and all of that is produced along our central coast, real close to the Pacific Ocean, and the unique thing about that is that we have basically a desert climate in California and you have this cold Pacific Ocean that is blowing cool air onto the landmass and that keeps that first mile or so of coastline very, very moderate in climate. In the winter it stays warmer and in the summer it stays cooler, so temperatures are really ideal for strawberries In that environment.

Lara Brindisi: 8:50

Okay, so you have the. California has the perfect climate. I mean, have you always been able to grow strawberries there all year round, or is that a newer thing?

Dr. Gerald Holmes: 9:01

It has always been. To some degree there's an ability to do it because it never freezes or very rarely freezes, especially very close to the coast. Closer you get to the coast, the less possibility or potential there is for a freeze. But really the advent of day neutrality in strawberries is what made the season much longer, so that's a relatively recent advent. Some of the breeders at UC Davis, roy Springhurst, introduced the genes for that trait came from wild strawberries in the Wassatch Mountains and he in in progress those traits into strawberries and that really revolutionized the California industry, made it a much, changed it from a springtime crop to a crop that was around virtually all year. But there's still. You know, in the winter months there's a lot less production than there are than there is in the summer or the spring, but it never goes to zero.

Sam Humphreys: 10:05

So California sounds like the best place to go grow strawberries, but they're a finicky crop, right. What sort of challenges do you see?

Dr. Gerald Holmes: 10:15

Yeah, they. So they're very susceptible to soil borne pathogens and we've we battle those quite extensively. Anywhere strawberries are grown, soil borne root pathogens are really important, and so fumigation has been a keystone of production for decades. It was soil borne, I'm sorry, pre-plant soil fumigation started being practiced in the late fifties and, and it's still practiced, but we recently phased out methyl bromide in 2016 was the last year that any methyl bromide was used in fruit production fields, but we still are using other soil fumigants to control soil borne soil borne diseases. So bromide was very, very effective.

Dr. Gerald Holmes: 11:10

So losing that has created some challenges, and we're seeing a rebound in some of the soil borne pathogens and new pathogens, but many other and some new yeah, some new pathogens Macrophomena crown and root rot showed up in about 2008, and then fusarium wilt showed up around that same time, and then verticillium wilt is kind of rebounded, and phytophthora has always been a problem. So those, those diseases we're going to see more of those, I think, and we'll probably see some more root, not nematode, which is something we haven't seen at all. Really, it's been a kind of a non problem for us, but we'll probably see that come back as well.

Lara Brindisi: 11:55

Okay, and then just to clarify, when you're talking about fumigating strawberry fields, what does that actually look like? Just in case anyone in the audience doesn't know what that means.

Dr. Gerald Holmes: 12:04

Yeah, it's a really interesting process that took a long time to develop. How do you get something that volatilizes under normal atmospheric pressure underneath the soil and trap it there so it stays there? So they have these specialized rigs that put the material down about 18 inches below the soil surface and at the same time they're injecting the material into the soil, they're tarping it, so they're covering it with a plastic tarp, and it's really an impressive machinery to watch that happen. So then then it stays there for a few weeks and then and then they remove the plastic and then plant the crop right after that. So many people erroneously think that when a crop is fumigated that they're somehow being exposed to the fumigant. But the fumigation occurs before the crop is even planted. So the fumigant is gone by the time the crop is planted, and then it's many months after it's planted that they're actually harvesting the fruit. So the fruit are never really exposed to a fumigant.

Lara Brindisi: 13:18

Yeah, oh, okay, yeah, that's. That's good to know. I think this type of practice is really happening for almost all of strawberry production.

Dr. Gerald Holmes: 13:27

Yes, but not every year, not every field. So it's expensive, so they don't do it every year, but it is done, especially where you have soil-worn diseases that are important, and it may be every three years or every four years. In some cases it might be every year, but that would be less common.

Sam Humphreys: 13:48

Yeah, it was so impressive the first time I saw it. You drive past imagine you're like driving past this field and it looks like a lake of plastic that's just like reflecting the sunlight and goes potentially for acres. It's really impressive to see. But yeah, you mentioned the cost there. What are the other main costs of strawberry production?

Dr. Gerald Holmes: 14:13

Yeah, strawberries are really expensive to grow. People are always amazed to learn that it costs about $100,000 to grow one acre of strawberries in California, and a big part of that is labor. About 60% of the cost that goes into a growing strawberries is spent on labor. It takes hand labor to plant and then it takes hand labor to harvest, and every strawberry is picked by hand and put into a clam shell. They're field packed and that harvest occurs twice a week. So it's very, very frequent.

Dr. Gerald Holmes: 14:53

Compared to almost any other crop which is maybe a one-time harvest, or two or three times it depends on the crop, obviously but I think strawberries are really the most intensive because during the entire harvest season they're being harvested twice a week. That's a lot of people going through the field twice a week. That's a lot of labor. Every one of those clam shells that you see in the grocery store was hand-picked by somebody and hand-packed, and that was only touched once and then it went onto a pallet and then shipped somewhere in the world. So pretty impressive, but lots of labor, and labor is expensive.

Lara Brindisi: 15:36

Yeah, that sounds like a pretty crazy process and you're saying seasonally, but this is really all year round, as you were saying before. So are there problems that are more severe now that their strawberries are grown around most of the season?

Dr. Gerald Holmes: 15:51

Yeah, so the longer something's in the field, the more time that they have to be exposed to, say, soil-borne pathogens, for example. So that's important. So the length of the season right. If you have a short-season crop, you basically avoid a lot of diseases in pests because they just don't have enough time to multiply and so you can get in and get out before things really get a chance to accumulate.

Dr. Gerald Holmes: 16:25

With strawberries we start in October with planting, we'll start harvesting in, say, february and then that harvest, depending on where it's planted in California, it may go all the way through December, and that gives soil-borne pathogens a long time to work on the roots. So something that if you were only going to have five months or three months, you'd never see that problem. But when you've got a crop that's in there eight, nine months, you're more likely to see it. So you're trying to protect something over a long, long period of time, and this is what many people in the agriculture industry that are in the business of developing products that are crop protectants they don't understand that you're trying to protect something especially for the soil-borne pathogens. You're trying to protect a crop from a pathogen for almost a whole year and you're trying to do that in soil and that's very, very tough.

Sam Humphreys: 17:31

Especially when, like you described, people are going out into the fields very frequently to harvest right, that could be moving around pathogens and spreading disease even more right.

Dr. Gerald Holmes: 17:43

Yeah, although most of the pathogens that we're concerned about aren't the kind that are being spread on by workers. They're soil-borne pathogens, but those workers will go from one field to another and they have soil on their shoes, so there's a little bit going on there. But there's also equipment that goes from field to field and there's probably a lot more soil being carried from one place to another that way. Although growers understand this and they do wash their equipment between fields and do their best to minimize the spread of soil from one place to another, above ground pathogens are being wind-borne, and so I think the workers as a method of means of spreading pathogens around is probably minimal.

Lara Brindisi: 18:39

Yeah, does any of this affect the taste of strawberries? I mean, there's the age-old concept of buying in season, right, but can you buy them at any time and they always taste the same in California.

Dr. Gerald Holmes: 18:53

You can buy them at any time. You can go to the store at least stores I go to you can find strawberries at any time of year there. They may not be from California, they may be coming from Mexico and strawberries are shipped all over the world. So you can buy them any time of year and I think that they're. They have the potential to taste great any time, but you're more likely to get great tasting strawberries during the main season If you're buying them from California.

Dr. Gerald Holmes: 19:26

You know strawberries will vary in their flavor a lot just from week to week. That's pretty interesting. If you've ever been in a strawberry field and been able to sample the fruit over and over again from the same place, you realize, oh, they really can taste quite different, especially after rains. It seems like the flavor gets diluted by all the water in the environment and you get a more watery, less flavorful strawberry after rains. The best conditions that I find is when you have cool nights and warm days and so the fruit aren't growing super fast and there's plenty of sunshine for all of that photosynthate to get in, the sugars to accumulate. There's enough time for them and they also tend to have a really great texture when they're that temperature, that cool morning temperature, so. But I've tasted great strawberries any time of year from our fields and I sample them a lot, but they do vary a lot based on weather. I would say mostly.

Lara Brindisi: 20:31

Okay, I have a follow-up question, then. In terms of taste, I know a lot of people complain to me that, you know, crops don't taste as good as they used to, and tomato is the prime example. Do you get asked this a lot about strawberries too? If so, what would be some of the potential causes for why it might not be quote tasting as good as it used to?

Dr. Gerald Holmes: 20:52

Yeah, that's a great question. I got that from my mom, actually, and she would complain that you know what have they done to strawberries. But agriculture and strawberries are part of that system and the system has the same characteristics whatever the crop is. Things are evolving, things are changing, new varieties are being developed, that some taste better than others, and so you know she may have grown up tasting a strawberry that was a totally different variety. It's going to have to be a totally different variety than what we produce now, and when I showed her strawberries that I thought were great, she also thought they were great, and the reason they were great is because I picked them from a plant where they ripened all the way until they were ready to eat, and they did that on the plant.

Dr. Gerald Holmes: 21:50

So that's number. That's probably the second most important thing to consider. And the first most important thing is which variety are we talking about? So you get a variety that has great flavor and you're going to enjoy that. So if you go to roadside stands, they'll tell you what variety they're growing, and they're usually growing something that is very, very tasty. And they do that deliberately, obviously, because people going to a roadside stand expect a little different strawberry. So so I think the two most important features that would determine flavor are variety.

Dr. Gerald Holmes: 22:28

And now now I forgot the other thing I said. What was it? Oh, it's ripened on the plant. Sorry, it letting it ripen all the way.

Dr. Gerald Holmes: 22:39

So you have this thing that you're trying to do, which is very difficult, which is ship a strawberry across the country and you think that some of the strawberries are really perishable, and they refrigerate them and they ship them across the country, and so they have to have some durability to them.

Dr. Gerald Holmes: 22:57

And one way they get that is by picking them just a little bit on the under ripe side, because if you pick them ripe, they're going to be overripe by the time they get to market and they're going to rot, and nobody wants the rot. And so what you're trying to do is ship the most flavorful berry that's been on the fruit plant as long as possible, but it doesn't rot quickly. I mean, they'll all rot eventually. Strawberries, you know, five days is a long time to have them on the shelf, and if you've put them in your refrigerator, everybody knows how quickly they go bad. So you have to eat them right away, and it's amazing that we can grow them on one side of the United States and ship them to the all the way to the other side of the United States, and you can go to a supermarket any day of the week and find strawberries that were picked within days.

Lara Brindisi: 23:53

So that same strawberry that I might be buying in New Jersey that came from California. If I picked that same strawberry a few days later on the actual plant, it would taste a lot better.

Dr. Gerald Holmes: 24:07

Yes, the sugars are accumulating rapidly. So, and then a variety. Don't forget the variety piece. It's super important, and you know, people are sometimes making they are always making trades. The growers have to consider yield as part of the package when they decide what to grow, and the breeders are trying to produce varieties that yield really well but also taste great and will be shipped across the country, and that's a hard thing to do. Get all three of those things in one package. And then I'm not even mentioning disease resistance and pest resistance, and you know texture and aroma and so forth. There's a lot of things to consider and so there's no perfect package, but I think we get better at it over time and we keep producing better and better varieties. So I think the varieties we're producing right now in California taste great. Monterey is probably our number one variety, and it's a great tasting variety.

Sam Humphreys: 25:13

Yeah, I'm really excited too about the new flavors they're trying to develop, some of these breeders and how you know, maybe it'll have more of like a cotton candy profile or more of a, you know, tark flavor profile too. Are you seeing a lot of that in California as well?

Dr. Gerald Holmes: 25:34

Yeah, the flavor profiles differ dramatically and it's fun to taste them. We have an experiment that we've been doing for the last six years in a row where we evaluate anywhere from 90 to 50 to 90 different genotypes. So we get to taste all of those and they're amazing and they do very dramatically in their flavor and they're very subtle and you ask people to tell you which one they like the best and they'll all come up with a slightly different answer. But there are some trends that you see. People really love Albion. That's one of my favorites and there's always brand new things coming. Some of them taste really fruity, almost like a pineapple, and others have kind of a kiwi type of flavor to them. Some are just super sugary, sweet, without much acid, and then others have a lot of acid, a little bit of a tang to them, and I like that.

Dr. Gerald Holmes: 26:31

I think that's what Albion has to it. I like that. Gives it some depth to the flavor, not just sweet. If you're going to dip strawberries in chocolate, you don't really want to compete with the chocolate, so the tart is very helpful. So anyway, it depends on what you're doing with the strawberries and I think most people that I've shared Albion with are just amazed.

Dr. Gerald Holmes: 26:56

I remember the first year. So Albion was the number one variety in California about 15 years ago and it's since fallen out of favor because it doesn't yield as well as the newer varieties. But if I share that variety with anybody they are amazed at its flavor. And the first year that we started our center here at Cal Poly we grew Albion and we were able to sell that on campus and to a local grocery store and many people thought that we were the most amazing research center because we had basically solved the problem, because they'd never tasted better strawberries and I, as much as I appreciated the compliment, I had to inform them that it was all about the variety and that that variety was actually about 15 years old.

Sam Humphreys: 27:50

At your center. You also do disease research right. You do a lot of different things.

Dr. Gerald Holmes: 27:56

Yeah, we have the Strawberry Center. Let me just tell you a little bit about that. We started in 2014. It's a partnership between the California Strawberry Commission and Cal Poly, san Luis Obispo. The long name is the California Polytechnic State University, but it's affectionately known as Cal Poly and the partnership between. So the Strawberry Commission is the organization that represents all the growers, processors and shippers of strawberries in California, and they wanted to partner with Cal Poly because many of the people who work in the ag world here in California are graduates of Cal Poly. We have a large college of agriculture over 4,000 students, nine departments and so many people were very familiar. And then our location is right in the middle of Strawberry Country. We're about equidistant between the two northern and southern districts Watsonville, salinas, and then, south of us, oxnard, and then we're about 30 miles north of Santa Maria. So we're very, very centrally located to the industry.

Dr. Gerald Holmes: 29:08

And we started just in pathology. That was my background as a pathologist and there were two pathologists. We got started and we were doing nothing but pathology research. We started a diagnostic clinic. We started doing research on soil-borne pathogens and we found that the fields here were infested with verticillium. So we started screening genotypes for resistance to verticillium. That emphasis on pathology quickly grew to include automation. Because of the importance of labor in this industry, we started an automation program and hired Dr John Lin, an engineer out of Maryland who was actually working on an automated decapping machine for the processing industry. He joined the Strawberry Commission but works at Cal Poly on automation projects, and they have a really thriving program now, and then, shortly after that, we added entomology. So our three areas of focus are pathology, entomology and automation, and we have probably anywhere from six to 10 projects ongoing in each of those areas at all times.

Lara Brindisi: 30:25

On the topic of automation, I've been seeing some provocative news articles suggesting that robotic harvesting is going to solve all of these issues regarding labor shortage and cost of harvesting, et cetera. Do you think this type of automation is on the horizon?

Dr. Gerald Holmes: 30:42

You know, it's normal for people to be really optimistic about it, because automation has done a lot of great things. We've seen in agriculture just tremendous advances and I've had a lot of fun watching the automation improve over the years that I've been involved in strawberries since 2014. It's been really impressive. There's more than a dozen companies in this space trying to perfect it. They're working on an end effector or a hand that mimics the human hand that can be very delicate in finding and picking the strawberry. Cameras and artificial intelligence that sees the strawberries and can identify the ripe ones, but no camera, no matter how technologically advanced, can see it when it's hidden, and no camera can find out what the color of the strawberry on the underside is. It's very, very difficult, so it's a very challenging thing to do. We have really made a lot of advances.

Dr. Gerald Holmes: 31:49

There are strawberry robotic harvesters out there today in California harvesting fruit, packing it and selling it, but the caveat is they're not doing it yet at a level that would justify its commercial, widespread use. It's not fast enough yet. It's not finding enough of the fruit. It's finding too many fruit that it shouldn't find. It's not finding enough of the fruit that it should find, and so it works best on early season crop, when the plants are small and the fruit are large and they're more visible.

Dr. Gerald Holmes: 32:30

That may be the place, and even if we can develop robots for that portion of the season, it's still a tremendous advance, and so we keep working on it. We're not there yet, but I don't know if we'll ever get there. I'm not going to predict the future on that one and it's really interesting to see just these engineers are amazing what they are coming up with and things that you wouldn't think they're capable of doing, like picking a strawberry, as delicate as that is, without bruising it. I think how could a robot do that? But it's amazing what they've been able to do.

Sam Humphreys: 33:06

Yeah, something I really have admired about you is how optimistic you are, and my research is in strawberry and so I'm familiar with a lot of the challenges and it seems like there are a lot of reasons to not be optimistic about the costs and the challenges of strawberry production, but how excited you are about the future is very validating. So what, yeah, what are you excited about right now In strawberry research or in strawberry production?

Dr. Gerald Holmes: 33:39

Well, automation is one of those things and it doesn't have to be robotic harvesting. It could be some other part of the process of farming strawberries that we're able to do and do better with machines. Our group just developed a hole punch which punches or burns holes in the plastic using an implement drawn behind a tractor, and it's able to do the work of ten people. That's a really, really impressive. If we can develop runner cutters, that's going to save time and energy. We developed another hole hole punch that just makes the hole that is already punched with a kind of a slicing mechanism. It makes it a little bit wider so that during stand establishment more water gets in. So that's helping. It's not necessarily it does reduce some labor, but it's also helping water ingress and stand establishment. So that's a tremendous advance. And I see a lot of exciting things happening in breeding and I'm really excited about breeding for disease resistance. I think we've been able to see that in places where we thought there wasn't as much optimism about controlling soil-borne pathogens and the diseases they cause through genetics, I think we're finding that there's a lot more that we can do than we thought previously, and so there's been a lot of advances made with macrophomena fusarium wilt. They just identified the genes responsible for that resistance. That's really exciting. So there's a lot of things to be optimistic about.

Dr. Gerald Holmes: 35:18

I think our industry as a whole. We have very innovative farmers and they're really cutting-edge thinkers and they are not slow to adopt to new technologies. They're always looking for new ways of doing things and they're not waiting for the university to show them either. In some ways they need our help, but in other ways they just go out and do it and then we find out later that they've developed this really new, interesting practice that's solving problems.

Dr. Gerald Holmes: 35:47

For example, in macrophomena. That's a very opportunistic pathogen, meaning that it gets in and attacks plants that are compromised in some way, and the compromise usually occurs in terms of drought, stress and heat. And another thing that probably contributes to it is salt stress. So if you have salt stress and you have drought stress and you have high temperatures and those things tend to go together, you get a lot more macrophomena. And we're starting to tease out what are the individual contributors to that and we're finding that if you relieve the physiological stresses on the plant, that it'll do much better against that disease, to the tune of 50 to 70% reduction in disease, so that's really impressive. If we got that with a chemical, we'd be really that chemical would be making millions of dollars.

Lara Brindisi: 36:48

Wow, yeah, that's so cool. I mean, a lot of our topics besides, I guess, variety choice have been also on conventional agriculture for strawberries. But what are your thoughts on organic farming? Do you think it's actually better, like a lot of people believe out there?

Dr. Gerald Holmes: 37:06

Hmm, that's another one that I. It's a conversation that I get frequently with friends. Most of my friends are not in the agricultural world. They're people that have, like most of us, we interact with other people outside of agriculture and they don't know anything about how crops are grown, and they will often ask me about organics and if it's better or worse or the same or more. What I find is that people don't really understand what it is and they falsely attribute flavor or quality that they're experiencing to a label like organic. So you have to again. We talked earlier about flavor. What are the two things that make up mostly we can attribute strawberry flavor to? One is the variety and two is how long it was on the plant. Does any of the either one of those things have anything to do with organic? No, but oftentimes an organic strawberry may be sold at a roadside stand, and so the person will attribute the flavor they're getting to the fact that they're organic rather than the fact that they got picked that day or that they're growing a variety with superior flavor. So that's what I see as a kind of problem with false attribution. So I don't. We grow about. Let's see, california has about 12 to 13% of our acreage is grown organically.

Dr. Gerald Holmes: 38:33

The same strawberry farmers that do conventional farming also do organic farming. They have certain fields, certain locations that they think are better for their organic production. They have to do it in a very different way. Sometimes one of the biggest challenges with organic farming in strawberries is getting enough nitrogen to the plants. So conventional farming can use highly concentrated nitrogen fertilizers. Organic production has to use natural fertilizers that have very much lower concentration of nitrogen, so it's harder to give the plants all the natural fertilizers that they have. So you give the plants all the nitrogen for maximum production, so yields go down. That's one of the reasons why organic costs more is because you don't produce as much fruit from an acre of strawberries with organic production, and one of the reasons why is because of nitrogen fertilization, and so sometimes when you stress the plants for nitrogen, you get a more flavorful strawberry. That is also one of the things that might contribute to it. So it's kind of an interactive fact, right, but I wouldn't say that overall you get a different flavor of strawberry from organic farms versus conventional farms.

Dr. Gerald Holmes: 40:02

So I try to, without saying you shouldn't do that, or you should do that. That's the way to go, or you don't want to poison your children, don't buy your conventional. You know it's a choice. People have their preferences. I just want them to be rational about and realize too.

Dr. Gerald Holmes: 40:22

Something that people don't realize is that organic any organically grown crop is sprayed with pesticides. They're just not the same pesticides that can be used in conventional farms. Sometimes the same products are used in both conventional and organic strawberry production. Sulfur, for example, is something that gets a lot of use, and that's okay in conventional and organic strawberries. Probably about 60% of the practices that are used for strawberry production in conventional fields are also used in organic fields. So people don't realize that. They think that it's like another world. You went into the forest where no human has ever been and you picked these berries in a pristine form. This isn't what happens. They're farming strawberries in a very modern way and they're just having to use different products to protect their investment. Farming is very risky business, so you want to protect that investment and organic farmers want to protect it, just like conventional farmers. They are the same people, so they're going to use whatever they can that they feel is effective from protecting it from pests and diseases.

Lara Brindisi: 41:44

Maybe the discussion isn't so much about organic but large-scale or small-scale producers and what they can manage and what types of practices and how long it's sitting on the plant.

Dr. Gerald Holmes: 41:54

But I guess it's hard to label for all of those little things when they're going to get shipped and, if they're going to get shipped, who their customer is. All those things play into it, yeah.

Sam Humphreys: 42:05

Yeah, there's so much complexity. That's really been. One of the things that struck me about this conversation is the nitrogen, like you mentioned, and the disease resistance and the post-harvest quality and how long it takes to get to the store and then to get to the dinner table. So, in the view of all of this complexity and this huge industry, what would you say are the big takeaways about strawberry production?

Dr. Gerald Holmes: 42:39

I would say, when I look at the big picture, I'm just so impressed with, like you say, the complexity of it and that we make it happen year after year after year, with few hiccups, relatively few. This year we had the torrential rains, we had more rain than we've had in 25, 30 years and we lost about 1200 acres of strawberries just to flooding, damage, rivers that overflowed their banks and rain that destroyed the crop. And we still are managing to pull off a pretty successful year. And actually the thing that that most people don't know at all is that More of a setback for us this year was the temperature, not the rain. We've had a very cool year and it remains cool to this day. We're here and already we're first second week of June and we're still having weather that feels very early springish, and so this has delayed yields pretty dramatically in the state. So volume is way down than it has normally and we're still managing. It will have its impact, but I go into the supermarket and I see this cornucopia of produce from all over the world and I think it's a modern miracle and we've been doing it for a very long time. It's just so impressive that we can have these things at our disposal any day of the week, walk into a store and see that I find that so impressive. And then, when you see what actually goes into it, when you see the fields and you see people working and packing these things and forklifts loading them onto trucks and trucks driving to coolers and then coolers cooling the product and the product getting on another transportation device a truck or a plane or a rail car and they're getting shipped all over the world, and somehow we walk into the grocery store and everything is there and this pristine, colorful, for the most part amazing array of variety and we have access to it at really inexpensive prices, at low I would say amazingly low prices. And I look at that and I just think, wow, how did we do that? That's really, and I know and I really if I look at every one of those, there's things about each one of those commodities I don't know. I've worked on quite a few commodities in my career and so I know enough about enough of the commodities to know what a miracle it is that it occurs. And then, working with farmers, I just really these are great people.

Dr. Gerald Holmes: 45:22

Sometimes farmers and farming get a bad rap. There's like these are the people that are destroying the planet or abusing workers. This is not what's happening. These are people who care about their workers, who care about the planet and the environment and are very, very grounded in reality, because they understand the law of the harvest, and that is that you reap what you sow and so you don't get. They got a really good BS meter farmers. You don't trick them very easily about things. You know there's no shortcuts in farming. You can't plant your crop a month later than normal and expect to harvest at the same time. So you're going to pay the price If you're late on your planting, if you're late on your pest control, if you didn't prepare the field properly, you're probably going to pay the price for doing that. So there are consequences for your actions. That's an important thing to live by, and I find that that's maybe something I really enjoy about working with farmers is those kind of people.

Lara Brindisi: 46:27

Yeah, I totally agree, farmers are the biggest skeptics, and reasonably so, with what they have to deal with. But before we conclude the episode, I do want to ask a bit of a personal question. I know in your background you've hopped around between industry and academia, and I know there's this idea out there that it can be really hard to do so I mean, did you have any challenges between entering industry when being in academia previously, or vice versa?

Dr. Gerald Holmes: 46:57

Yeah, great question One I've thought a lot about, and I think the fact that I have worked in industry and in academia is really what prepared me for what I'm doing now, which is really interesting blend of both of those things, because I have to be steeped in research, I have to be steeped in cooperative extension and I have to be steeped in industry. Those three things are things that I've done. Not too many people do that. They go back and forth.

Dr. Gerald Holmes: 47:33

I had a really nice position at North Carolina State University. I was pretty close to being a full professor when I had an offer from private industry and I decided to leave because I felt like I had done the things that I wanted to do in academia and I felt like the rest of my career was. Although there wasn't anything very negative about it, I felt like I needed a new challenge and so I went into private industry. I had worked with private industry for all of my career but I had never been in private industry. I thought that that looked like an interesting place to be and a place that I could excel in, and I spent six years doing product development for fungicides and I decided that I didn't want to do that the rest of my career. I started looking for other opportunities and I found this one and I thought that its job description fit my background very nicely. It's been a really great thing to do. I've been here nine years now, almost as long as I was a professor at NC State, and I'll probably finish my career here.

Dr. Gerald Holmes: 48:51

It's been really fun to build something. It's different, right, you build a program in an academic institution and this is an academic institution. However, I'm building this new concept and it's been fun to build it. It's been fun to work a lot more with undergraduate students and to work really closely with industry. I'd always worked with industry, like I said, and also, in cooperative extension, worked with a lot of commodity boards, but I'm working with this commodity board much closer than I ever had before. It's brought new insights. I enjoy that mixture and I think the things I've done have prepared me for it. When you look back, you think, oh, it looks very, very normal course of progression, but believe me, every fork in the road was a very, very laborious decision and heart-wrenching. It's not easy to navigate life and your career, but so far it's worked out well for me.

Sam Humphreys: 50:00

Well, I don't know about Lara, but that's very reassuring for me. Thank you, Dr Holmes, and thank you for this interview. This has been fantastic To learn more about the Strawberry Center at Cal Poly. Please visit strawberrycalpolyedu or visit the Strawberry Center on Facebook. To learn more about the strawberry industry, you should check out the related paper titled the Status and Future of the Strawberry Industry in the United States, which is published by Hort Technology, which is one of the open-source peer-reviewed journals published by the American Society for Horticultural Science. Links to these articles will be provided in the show notes.

Lara Brindisi: 50:45

If you'd like more information about the American Society for Horticultural Science in general, you can go to ashsorg Sam. If people want to follow your work, what's the best way?

Sam Humphreys: 50:56

They can find me on LinkedIn at Samson Humphrey Lara. What about you?

Lara Brindisi: 51:01

You can follow me on Instagram, at theplantphd, or on LinkedIn with the tag LaraBrendisi, and I just want to say it's been a blast being a co-host for this podcast. Thank you so much for being a wonderful audience and hopefully you'll hear from me again soon. Ashs podcasts are made possible by member-dos and volunteerism. Please go to ashsorg to learn more. If you are not already a member of ASHS, we invite you to join us. Ashs is a not-for-profit and your donations are tax deductible. This episode was hosted by Sam Humphrey and Lara Berdisi, thanks to our audio engineer, alex Fraser, our research team, lena Wilson and Andrew Pumax, our ASHS support team, sarah Powell and Sally Murphy, and our musician, john Clark.