Ping Yu: Hello everyone, welcome to the Blooms and Beyond podcast, a podcast that uncovers plant history, culture, and management through the lens of science.

Ping Yu: I'm your host, Ping.

Ping Yu: How's everyone doing today?

Ping Yu: I'm doing great because I'm about to talk about one of my favorite plants, peonies.

Ping Yu: This plant is so unique.

Ping Yu: It basically covers all the beautiful characteristics a plant can possibly have.

Ping Yu: People who live in the southern U.S. like me may not be able to see them very often because the environment here in the Southeast is not good enough for them to grow.

Ping Yu: Joining me today is Dr. Emily Zhou.

Ping Yu: We are going to talk about this wonderful woman and some of the fantastic, phenomenal research that she has done over her PhD process.

Ping Yu: Without further ado, here is my conversation with Dr. Emily Zhou. I hope you enjoy it.

Ping Yu: Welcome, Dr. Emily Zhou, to the podcast. Before we jump into the topic today, I'd like you to start with a self-introduction. Can you tell us a little bit about who you are and what you do?

Emily Zhou: Hello, everybody. First of all, I am an assistant professor from University of Central Missouri, and this is my second year to be back to academia. Before this, I was in the industry at one of the largest indoor vertical farms, Bowery Farming, on the East Coast. Their headquarters was in Manhattan, New York City.

Ping Yu: So if you guys know that I talked about this in the previous episode, I have encountered many people from different backgrounds who end up going into horticulture, and Dr. Emily Zhou is actually one of them.

Ping Yu: Can you tell us a little bit about your background and how you ended up getting into horticulture?

Emily Zhou: That's great because my experience is quite unique. It's different from other people.

Emily Zhou: My Bachelor of Science was in engineering and I was an HVAC engineer— heating, ventilation, and air conditioning.

Emily Zhou: I love plants. I grew up...

Emily Zhou: on a farm in central China, the main center of agriculture.

Emily Zhou: So I grew up with all types of plants.

Emily Zhou: By nature, I know them and it's always my favorite.

Emily Zhou: But when you are young, life leads you in some other ways.

Emily Zhou: You try to see different opportunities.

Emily Zhou: So I went to engineering.

Emily Zhou: I worked in the industry for around 10 years in China, in European companies.

Emily Zhou: Eventually, I came to the United States in 2002.

Emily Zhou: So 23 years ago, as an engineer, I was traveling a lot when you are young, when you are single, but later on, I wanted to go to grad school.

Emily Zhou: So in the choice of grad school, you need to ask yourself what you love

Emily Zhou: and what is your passion.

Emily Zhou: I was in Virginia at that time.

Emily Zhou: I was very close to Virginia Tech.

Emily Zhou: Then I learned that they have a horticulture program.

Emily Zhou: Just by chance, I asked them if it's possible that I can go into horticulture to learn everything from the beginning.

Emily Zhou: Fortunately, the department had an opening at that time and my master's advisor had a project about seed germination.

Emily Zhou: So it led me, I started my master's and I took a lot of courses, both undergraduate and graduate, to fill the gap. After I got my master's, I think my passion is in traditional ornamental horticulture.

Emily Zhou: My PhD, leading to the herbaceous peony.

Emily Zhou: So it is an interesting experience and I learned a lot of plant science, but I am still an engineer.

Emily Zhou: So later on, at the end of my PhD, we started doing hydroponic research.

Emily Zhou: I was thinking like every step— and I am throwing away my experience and knowledge—and switching to horticulture in my master's, like I threw away all my 10 years of HVAC engineering experience.

Ping Yu: Not really. That's not the case because basically your trajectory in horticulture is very unique and very different from other people. Because you have a very strong engineering background, you have the heart for plants all the way, and then you kind of started from scratch moving to the U.S. and started with your master's degree at Virginia Tech and then started learning all those things about plants. But you ended up combining your knowledge and skill set from both engineering and horticulture for controlled environment agriculture, which was a hot topic probably five years ago.

Ping Yu: And so I think it's not to the point that when you were saying you threw away all your experience, all your knowledge, and all your skills. But every mountain you have climbed, every step that you have put into the journey, ended up paying off or you have the reward in the end. Because now look at you—you have all that knowledge and years of experience dealing with both engineering and plants, and it makes you a perfect candidate, a perfect fit for your current position. I really like your story about how you ended up going from pure engineering to ornamentals.

Emily Zhou: Yeah, I can say that. Because a lot of—and when I was a graduate TA, so I am using my experience, but during my grad school time, a lot of people asked me, "Why do you do that? I wouldn't do this," because it's totally—like I spend a lot more time to fill up the plant science background. And also the master's and PhD—we know ornamental plants such as peonies, we do asexual propagation. So the seed background I learned from my master's, I also threw it away. But like you said, eventually you never know. You just learn the things, you never know when one day you can use them.

Emily Zhou: And eventually when coming to controlled environment agriculture, everything came together.

Emily Zhou: So engineering, plant science, seeds, and we use all the HVAC in controlled environments

Emily Zhou: to grow, so everything got together.

Ping Yu: You just know.

Ping Yu: I normally say all those experiences and knowledge and skills that you have gained throughout your years are like growing a plant.

Ping Yu: And every year, every experience adds...

Ping Yu: branches to the plant and makes it bigger and makes it prettier. So like I said, every step counts. So talking about plants, I know that you always kind of loved plants all the way. Can you tell us what is your favorite plant?

Emily Zhou: Oh yeah. I consider myself a plant scientist, but sometimes even my boss said I have a mindset of an engineer, because engineers have different thinking ways than plant scientists.

Emily Zhou: And yes, I have both of them.

Emily Zhou: They are speaking two different languages, but I know both of them.

Emily Zhou: Talking about my favorite plants, I can't target just one.

Emily Zhou: Normally, I don't discriminate any plants.

Emily Zhou: They are all beautiful.

Emily Zhou: Each of them has its unique beauty.

Emily Zhou: But if you ask me, I have to say it is peony because I gained my Doctor of Philosophy out of that.

Emily Zhou: During the time of research, I did four years.

Emily Zhou: With your research in one year, you need to wait another year.

Emily Zhou: Because it's so hard, so you need to think about every possibility.

Emily Zhou: They are growing during the winter time, especially the holiday time.

Emily Zhou: From November till the next year.

Emily Zhou: And you cannot leave for one day.

Emily Zhou: You need to take data.

Emily Zhou: You need to take care of them.

Emily Zhou: You need to do every step.

Emily Zhou: I took so long a time and so much effort on this.

Emily Zhou: And it's rewarding.

Emily Zhou: It is such a beautiful plant.

Emily Zhou: And I think a lot of people might have heard about horticultural therapy.

Emily Zhou: So plants have added a lot of value to your mental and spiritual wellbeing.

Emily Zhou: It is beautiful.

Emily Zhou: When you see a plant from a little piece of crown getting out and then getting the most beautiful flower, that's rewarding.

Emily Zhou: And it has so many types.

Emily Zhou: Like Ping said, it has ornamental value.

Emily Zhou: And it has beautiful flowers.

Emily Zhou: And it has a strong stem of green.

Emily Zhou: And you can use it for cut flower.

Emily Zhou: And they use it for weddings.

Ping Yu: Your reason of...

Ping Yu: like peony being your favorite plant is because it helped you earn your PhD degree.

Ping Yu: It's interesting and funny and rewarding because a lot of times when I ask people, "What's your favorite plant?"

Ping Yu: They'll give me various reasons with, "Oh, this plant is great."

Ping Yu: "This plant is resistant and then it's easy."

Ping Yu: "It's low maintenance for me."

Ping Yu: "This plant reminds me of home," or anything else.

Ping Yu: In between, but no one has told me, "Because this plant gave me my PhD degree." This is very funny. But like you said, your PhD or your dissertation was based on the peony plant.

Ping Yu: And you briefly mentioned that the use of peony in the U.S. is predominantly as cut flowers. I have lived in the United States the whole time.

Ping Yu: I don't see a whole lot of peony in the South, at least in the Southeast U.S., but I wish, I really wish I could see them more because back when I was in China, I saw them more often.

Ping Yu: And they are gorgeous. They have those big flower heads when they bloom. They are just gorgeous because it's native to China.

Ping Yu: Can you tell us a little bit about the history of the plant and moving from...

Ping Yu: China all the way to the U.S. and to Europe?

Emily Zhou: Okay, and that's my favorite part.

Emily Zhou: Because both the tree peony and herbaceous peony, they are native to China.

Emily Zhou: And still now in northern China, you can see some wild-growing peony in the north.

Emily Zhou: They have a big range.

Emily Zhou: They can grow from Zone 2 and 3. Even they can grow in Zone 8, some cultivars.

Emily Zhou: Yes, China has more than three to four thousand years of history growing that, and you can find that in ancient poetry.

Emily Zhou: And it's a flower of love. It's also a medicinal plant. Some of the varieties, they are using the underground crown, or they call it the peony root, for herbal medicine. They have strictly white root peony and also the red root peony. It had a culture and growing—even the peak time was during the Tang and Song dynasties. So it was cultivated in the capital, central China, around the Yellow River, and it's everywhere in the gardens.

Emily Zhou: Nowadays, if you go to Luoyang, it was the 1,300-year-history capital in China.

Emily Zhou: They still have a peony garden. So it's mixed up with tree peonies and herbaceous peonies because herbaceous peonies can extend the flowering time. So altogether it can bloom from late March—my research did that— and until some of the native species, they bloom even in July. So depending on different varieties, you can see all types of flowers. The cultivation went to Japan, and in the end of the 1800s, they introduced it to Europe. And European people brought this to America. And Americans—we learned that in the early 19th century. And suddenly, because of the environment and a lot of climates fit for growing this plant.

Emily Zhou: This plant is also very hardy and they can grow in different climates.

Ping Yu: You mentioned that peony does have different cultivars and varieties, and in China, because it has a very long history of cultivation of this plant.

Ping Yu: So it does involve a lot of different varieties and cultivars.

Ping Yu: Like you said, how many cultivars are there in China?

Emily Zhou: For what we know already, the American Peony Society—and it's not only for the United States, also including Canada and Mexico, majorly Canada—the registered cultivars are already more than—oh my god.

Emily Zhou: So that's only herbaceous peony.

Emily Zhou: And we also have tree peony, and also have the Itoh, and it is a hybrid between tree peony and herbaceous peony.

Emily Zhou: So a lot of different cultivars with different colors, different forms, and the majority of them have double flowers, a big head, and more colors than the tree peonies. I have seen people in the South growing peonies, just not as

Ping Yu: much as I wish it can be, like everywhere. I think it also has something to do with the price. Because one, those that are available that are easily adapted to the southern environment are not that many. And two, those are pretty—I think I can say it's a pretty pricey plant. It's a high-end plant. As I think you mentioned, for wedding purposes, one cut of peony can be worth over six dollars. The limited cultivars available for people to choose from and the higher price of the plant itself, those two reasons maybe cause the reality where we don't see them very often in the South in general.

Emily Zhou: I have seen like one of the yellow color peony cultivars.

Emily Zhou: It's a small plant in a one-gallon pot.

Emily Zhou: It was the year 2017 and it cost $120.

Emily Zhou: Yeah, also the extension.

Emily Zhou: So like the growers, a lot of growers, they don't know.

Emily Zhou: And I went to some conferences like Cultivate.

Emily Zhou: And some of the growers, they came to me, they said like, "They grow, but they don't flower."

Ping Yu: There are specific plants in my heart.

Ping Yu: Every time I think about them, they always give me an instant feeling of homesickness

Ping Yu: type of thing, because of the culture that you have been exposed to when you grow up. And peony is one of them because I think it's a top 10 most famous plant or flower in China and it represents prosperity and it has a long history of cultivation. In the U.S., it symbolizes freedom, horizon, and the pioneering spirit of the American West. Like you said, it also means true love and is used in weddings. So with all that culture and meaning behind the plant, it just gives you extra pleasure of the plant. So I think that's— sometimes I say it's plant power.

Ping Yu: It's not just the plant, it's everything about the plant.

Emily Zhou: Yeah, it's a famous flower in China, and tree peony is the national flower in China.

Emily Zhou: And in history, people call that the queen of the flowers.

Emily Zhou: But it also needs a lot of skill to grow it better.

Emily Zhou: That also explains why

Emily Zhou: it's expensive.

Ping Yu: Peony is one type of bulb, just like daffodils, tulips.

Ping Yu: They normally need vernalization, which means they need a certain period of cold to be able to break dormancy so that they can bloom.

Ping Yu: I think that's one of the key research areas that you have studied during your PhD, right?

Ping Yu: Can you tell us a little bit about how different lengths of the cold period influence the plant growth and plant flowering?

Emily Zhou: As Ping said, the herbaceous peony is one type of geophyte.

Emily Zhou: So it's similar with the tulips, daffodils—they are bulbs, and some of them like crocus, they are corms, and some of them, they are rhizomes.

Emily Zhou: The peony is an underground

Emily Zhou: stem tissue which has a core and the propagation part, called the crown. So it has buds, and those buds normally grow up during the summer after flowering. It normally flowers in the springtime. Some of them early spring, late spring, depending on the cultivar.

Emily Zhou: So after flowering, they start to develop the photosynthesis, they store energy, they start to develop the underground crown.

Emily Zhou: So during the fall time, like September, October, most of the underground buds are already set.

Emily Zhou: It is critical why this plant is precious if it's not favorable.

Emily Zhou: If you don't have good care or the environment is not favorable to the plants and you lose the foliage after flowering or you cut it too early, the buds are not developed enough.

Emily Zhou: Part of my research is studying the buds during the dormancy period, which is the chilling period or the vernalization period.

Emily Zhou: So during that time, it looks like it's dormant, but the underground buds, they are developing.

Emily Zhou: So after the late fall, the aboveground shoots and leaves are starting to decline, but all the energy is stored in the underground shoot.

Emily Zhou: So they develop the buds.

Emily Zhou: And it is just like tulips— if you don't have enough

Emily Zhou: cold, a lot of the cold-hardy types, they won't flower.

Emily Zhou: So they will grow the shoots, but no flower.

Emily Zhou: Most of the growers grow these plants.

Emily Zhou: They dig them out in November, before Thanksgiving.

Emily Zhou: They leave them either outside

Emily Zhou: or they can put them in a cooler or a cold room.

Emily Zhou: So a big portion of my PhD study is about artificial chilling and comparing with natural chilling. But natural chilling just depends on the weather that year.

Emily Zhou: But we have different models to calculate the chilling units.

Emily Zhou: Either put them in a greenhouse, forcing them to flower early for Valentine's Day.

Ping Yu: Wow, so you kind of mentioned that you compared the natural chilling period depending on the location where the state that you're in versus the forcing treatment, which is just putting them into a growth chamber or cooling chamber to force them to go through the vernalization period.

Ping Yu: But you mentioned you were able to force the peony to start flowering during Valentine's Day.

Ping Yu: In your research, what is the treatment? How long was the chilling or the cold period that you put them into?

Emily Zhou: Yeah, and I would like to say that before using anything, just pure chilling.

Emily Zhou: And if you don't have a cold winter, you can put it in a cold room, which is a temperature of 40 degrees Fahrenheit.

Emily Zhou: I did study about different periods.

Emily Zhou: But I used two cultivars. Sarah Bernhardt is a big pink flower, has a very big double flower head.

Emily Zhou: That's the number one cut flower used worldwide, and it occupies 50% of the peony cut flower market, even worldwide. In Europe, the Netherlands is the biggest flower producer, especially for bulbs, tulips, same thing.

Emily Zhou: So they are also producing a lot.

Emily Zhou: My research was starting that, and I put them to constant chilling— three weeks, 21 days.

Emily Zhou: And it should be enough.

Emily Zhou: After that, you can take it out.

Emily Zhou: Normally you need to put it in a greenhouse or protection because when they start to emerge, the tender shoots cannot survive if there's frost, snow, or cold temperature.

Emily Zhou: If you start in your greenhouse under normal greenhouse conditions, forcing them, like we normally do, they start to pot up. And some parts of the northern states, they already have late frost and the temperature will be below 40.

Emily Zhou: So you can start putting them in mid- to late November.

Emily Zhou: And you can put them in December, three weeks in 40 degrees Fahrenheit.

Emily Zhou: You can take them out to force them, and it normally flowers in two months.

Ping Yu: So for instance, for growers in the north, if they choose not to use forcing during the chilling period, they can still do that and they can still hit the market just because they have the environment there, and they don't have to spend extra time and effort putting them into a chilling period so that they can still hit the market.

Ping Yu: Valentine's market and vase blooming. But for people who live in the South, if they want to hit the market, they have to go through the chilling period and forcing so that they can hit the market.

Emily Zhou: Absolutely.

Emily Zhou: I did research also on natural chilling.

Emily Zhou: And take them back to the greenhouse just forcing them to grow flowers and grow the plants. So when you have temperature favorable, they start to emerge and then grow and get flower shoots. And yes, the northern states, you don't need to worry about that.

Emily Zhou: I think if it is in hardiness Zone 6 and below, the chilling should be satisfied.

Emily Zhou: Zone 7 is almost the line.

Emily Zhou: So most of the peonies can grow— the chilling, the natural chilling should be okay— and to get that in Zone 7.

Ping Yu: I think one of the things that almost all growers want is to shorten the production cycle of any given plant because the faster you can grow plants, the more plants that you can grow, the more money you can gain.

Ping Yu: So, can you tell us a little bit about what you have learned from your research so that people can have a better understanding of how they can use that to grow peony better

Ping Yu: and faster?

Emily Zhou: Oh, yes.

Emily Zhou: Yes, absolutely.

Emily Zhou: My research was done in Virginia, and I was working together with a large nursery production, Battlefield Farms, and it's in the center of Virginia.

Emily Zhou: They have, like...

Emily Zhou: thousands of peonies and they start to get the crowns in mid-November every year.

Emily Zhou: And normally they're using crowns that are small and have three to five buds that you can pot up in a one-gallon pot.

Emily Zhou: So the traditional process is after potting them up, they leave them outside. And the first year they grow through the natural chilling. After the winter, the first springtime, containerized peony should have like three-plus flowering shoots.

Emily Zhou: That means the shoots with the flowers, they are on the market in flowering time, normally May, and some cultivars may be late April.

Emily Zhou: Normally the production cycle is 18 months, one and a half years.

Emily Zhou: My research is majorly for the containerized nursery and then they sell the peony in the pot.

Emily Zhou: Majorly targeting the home garden.

Emily Zhou: Some years the chilling units

Emily Zhou: are not enough. You need to wait— and it's reaching the ideal units, then you can take it to the greenhouse to force them. In order to get Valentine's Day blooming, I did—I compared the controlled chilling in a cold room and also the natural chilling. Another way, if people don't have a lot of space and don't have that big chilling place, is using a plant growth regulator, the gibberellic acid, the GA3.

Emily Zhou: It can replace some of the chilling and it can make your peony flower.

Emily Zhou: I have an extension publication from Virginia Tech, and later on you can find out we use gibberellic acid, GA3, and the ideal concentration is 100 parts per million.

Emily Zhou: Normally my suggestion— I did several research trials—either you do it before chilling or after chilling. And the good suggestion is, after you finish the chilling, either natural or you put it first in a constant cold room, one week. After you take it to the greenhouse for forcing, you apply the drench of gibberellic acid.

Emily Zhou: And it can satisfy some of the chilling.

Emily Zhou: You can shorten the growing cycle.

Emily Zhou: That's a big benefit for growers.

Emily Zhou: Imagine you have 10,000 peonies, you need to occupy a lot of space and care.

Emily Zhou: So you need to water them, fertilize them, you need to take care of them, you need to cut them back after one season.

Emily Zhou: In 18 months' time, it can shorten to five to six months' time.

Ping Yu: Basically, if you are using GA3 for drenching to grow peonies, of course you have to do it right.

Ping Yu: And if you do it right, you can actually reduce the production cycle of peonies from 18 months to five, six months.

Emily Zhou: That's crazy.

Emily Zhou: For the Valentine's Day supply, like you do that, till that time is three to four months.

Ping Yu: Wow.

Emily Zhou: Yeah, but you need a cold room and you need a greenhouse.

Ping Yu: For all those growers who want to use GA3 for peony, the plant has to go through either the natural chilling period or the forced chilling period.

Ping Yu: It's just that using GA3 can actually add on benefits of reducing the production cycle on top of everything you do.

Emily Zhou: If you're using the right cultivar to satisfy the standard marketing, you can sell them with three flowering shoots.

Emily Zhou: And that can reduce at least a year of production.

Ping Yu: Wow.

Ping Yu: So that's great.

Ping Yu: That's great.

Ping Yu: That's great for any peony growers who want to cut down the production cycle.

Ping Yu: They need to think about using that just so they can save tons of effort, space, and money in general.

Emily Zhou: Also, I calculated the cost.

Emily Zhou: It is very low cost.

Emily Zhou: For each pot, the cost is just less than 10 cents.

Emily Zhou: So it is very easy and everybody can do that.

Emily Zhou: And if you get the right concentration, you can do one day and a thousand pots.

Ping Yu: I think for anyone who has seen peony and who deals with peony, we know peony generally have big flower heads, which is why people love it.

Ping Yu: But it can also cause problems for growers who grow them, because if they grow too big, they're pretty fragile.

Ping Yu: When you are dealing with a very big plant in a container, it can cause a lot of problems, especially when you are moving them around or when you apply inputs in there.

Ping Yu: So I think one of the things that people are trying to do or have done in practice is to use PGR, the plant growth regulators, especially retardants, to make it shorter, make it more compact.

Ping Yu: So that it will become easier for growers to handle when they grow the peony plant.

Ping Yu: I guess there are so many different retardants that are available for people to choose from, but with your experience, the two retardants that you have used—or three.

Ping Yu: What is the best...

Ping Yu: What was the most effective in terms of making the plant more compact and have more flower heads?

Emily Zhou: Oh, that's a great question. Yes.

Emily Zhou: Especially for the containerized grower.

Emily Zhou: And it is a problem.

Emily Zhou: This plant is beautiful, but normally it has too-heavy heads.

Emily Zhou: And they can grow quite tall.

Emily Zhou: The heavy head can droop, especially in the landscape.

Emily Zhou: If there is wind or rain during flowering time, they are dropping to the ground.

Emily Zhou: For the nursery grower/producer, it is also the shipping and handling— it's a big problem.

Emily Zhou: If they are too big, they can fall down and then they crack the stem, especially the flowering stem.

Emily Zhou: Expensive plants, you cannot sell them.

Emily Zhou: One of my research areas is using plant growth regulators, we call them plant retardants.

Emily Zhou: The major function of plant retardants is to make the plant more compact, shorter, with more stems, and stronger.

Emily Zhou: Another advantage of that is your plant, the leaves, get greener and look more full.

Emily Zhou: And the flower should get also stronger.

Emily Zhou: It's not easy to fall down. If you use staking, that's more money and more time.

Emily Zhou: And consuming, especially the growers, they don't want to do that.

Emily Zhou: My research, I used together the chilling and the GA3.

Emily Zhou: But I used two types of growth retardants.

Emily Zhou: One is uniconazole and another is paclobutrazol.

Emily Zhou: Overall, uniconazole is more significant. Paclobutrazol is less effective for herbaceous peonies, at least.

Emily Zhou: So my suggestion is to use uniconazole and gibberellic acid together.

Emily Zhou: The application method—if you want to have a compact plant, with more flower heads, you can use uniconazole at 15 parts per million concentration. For each one-gallon container, just 12 ounces per pot.

Emily Zhou: The application is almost at the same time, after you satisfy the chilling and moving them either to the greenhouse, forcing them to flower early.

Emily Zhou: It is also safe to apply, easy to apply, and very economical.

Emily Zhou: I did calculate the cost, so it is similar to the GA3.

Ping Yu: So basically with your experience and your research, would you suggest peony growers apply GA3 along with uniconazole?

Ping Yu: And for people who live in the border Zone 7, apply those two chemicals along with a forced chilling period.

Ping Yu: Is that what you would suggest for growers in like a border state?

Emily Zhou: Yes, because if you are in a northern state, you don't need GA3 because you already have enough chilling.

Emily Zhou: And if you do natural chilling, it is already enough, but you just need to apply uniconazole.

Emily Zhou: And then, especially for container growers, you have more compact

Emily Zhou: plants and they have a greener foliage color and it is more marketable.

Emily Zhou: And for the border states like Zone 7, they can do both.

Ping Yu: And I think it's pretty straightforward because GA3 and uniconazole can both be applied as a drench.

Ping Yu: Can they mix those two together so that instead of doing two drenches, they can do one drench all at the same time?

Ping Yu: Because in that case, it can save labor and everything.

Emily Zhou: I haven't done that.

Emily Zhou: I first applied the GA3, the drench, and the uniconazole I do normally a day after.

Emily Zhou: So both of the growth retardants I was using—uniconazole and paclobutrazol— they can stay.

Emily Zhou: Even if you apply that, you water them, they stay in the media, they stay with the pot for a long, long time.

Emily Zhou: I just don't suggest a tank mix together because I don't know.

Emily Zhou: This is also preliminary research I did with four seasons.

Emily Zhou: And I need to do more research in order to get that.

Ping Yu: I think uniconazole can also be applied as a foliar spray and also as a dip or pre-plant bulb dip.

Emily Zhou: Yeah.

Emily Zhou: I don't suggest a pre-plant dip.

Emily Zhou: So this is the crown—you first do that because normally when you get the crowns before you pot up, they have some fungicide treatment.

Emily Zhou: So you don't want to wash it out.

Emily Zhou: The research also shows if you apply it earlier, during the chilling or before chilling, it's not as good as when you apply it after chilling.

Emily Zhou: After chilling.

Emily Zhou: I know the big growers are coming from the Netherlands, and some of the cultivars, they are from the northern states— Oregon, Washington State, and also the Great Lakes area around there, Minnesota, Michigan.

Emily Zhou: They have some growers and they are selling those.

Ping Yu: Okay, so the application time also plays a big role in terms of the effect of the chemical.

Emily Zhou: Yeah, I don't suggest pre-dipping.

Emily Zhou: And I also don't suggest a foliar spray because you don't know what stage— and if you do, you want to affect it as long as possible. Because when the shoots get out, they're already with the flower buds. The flower buds are already there before they emerge. So you want to affect the shoot growth.

Emily Zhou: And when the plants are small, they do not have enough surface area to absorb the foliar spray.

Emily Zhou: And also, there are other difficulties to do that.

Emily Zhou: The plants are not uniform in size.

Emily Zhou: Some are large, some are smaller.

Emily Zhou: So you cannot make sure each plant receives the same amount of plant growth regulator.

Emily Zhou: So the drench is the best way.

Emily Zhou: The drench is easy—each pot will receive the right amount.

Emily Zhou: And it stays with the media, the substrate particles, even with the pots.

Ping Yu: Yeah, it's also easy to do the job.

Ping Yu: Sounds great.

Ping Yu: Can you tell us a little bit about your current projects or interests?

Ping Yu: Are you going to carry along with your peony work in your current job?

Ping Yu: And what is the plan?

Ping Yu: What are your current projects or interests?

Emily Zhou: I can do the peony work, but at the end, I came to controlled environment agriculture.

Emily Zhou: Yeah.

Emily Zhou: Just like my introduction earlier, I am an HVAC engineer.

Emily Zhou: When I started my PhD, there were very few people

Emily Zhou: in the United States doing controlled environment agriculture.

Emily Zhou: I connected with that at the end, so it led to my postdoc, and I built up an indoor vertical farm and did a lot of hydroponic research.

Emily Zhou: I was doing peony work still, as I started with controlled environment agriculture.

Emily Zhou: Later, after my postdoc time, I did enough academic research and I wanted to go to the real industry.

Emily Zhou: And because in controlled environment agriculture, the highest technology and facilities and equipment were in industry.

Emily Zhou: Because we don't have the equipment, we cannot do research in the universities.

Emily Zhou: So I went to an indoor vertical farming company and became a research and development scientist.

Emily Zhou: I did a lot of research.

Emily Zhou: I know it's a long way still.

Emily Zhou: And for controlled environment agriculture, there's a lot of things we still don't know.

Emily Zhou: That's the reason I went back to academia because the indoor vertical farm industry has been experiencing, if you know, in the past few years, a lot of difficulties— bankruptcies one by one—because

Emily Zhou: we don't know enough. And my idea is going back to academia being a professor. I see a lot of growers, a lot of farmers, a lot of even technicians, they don't know the basic things for controlled environment agriculture. It is industry together with plant science and engineering. Plant scientists and engineers have two different languages.

Emily Zhou: Engineers—they want to have a universal system.

Emily Zhou: You can grow all plants, all plant stages.

Emily Zhou: But for plant scientists, we say it's impossible because each of them requires different conditions.

Emily Zhou: So my job now, I do all types of research.

Emily Zhou: I'm a plant scientist.

Emily Zhou: I'm a horticulturist.

Emily Zhou: So I do ornamentals.

Emily Zhou: I also do vegetables and fruits.

Emily Zhou: And so I do controlled environment agriculture research.

Emily Zhou: But if it's favorable, like I get support, I would like to continue.

Emily Zhou: So the peony work, it is lifelong, as well as controlled environment agriculture.

Emily Zhou: So we all learn something new.

Emily Zhou: So it's science.

Emily Zhou: Yeah.

Ping Yu: So basically with your knowledge and experience in both backgrounds— engineering and horticulture—I guess CEA, controlled environment agriculture, is the best fit for you to shine with all your knowledge and skill. And who knows, you may come up with a brand new idea of

Ping Yu: growing peonies in CEAs and then shorten the production cycle significantly and help growers make tons of money.

Ping Yu: By adapting your technology.

Ping Yu: Who knows?

Ping Yu: No one knows what's gonna happen.

Emily Zhou: Yeah, I just tested a few plant growth regulators.

Emily Zhou: Plant growth regulators are one big group.

Emily Zhou: Some of them, I haven't tried yet.

Ping Yu: So with that in mind, if people want to find out more about your research, where do you recommend they go and look for more?

Emily Zhou: If some of the growers listened to our talk, if they are interested, we can do a collaboration.

Emily Zhou: I have students and I have space. I can do the work.

Emily Zhou: Yeah, if somebody's interested in that, you can find me.

Ping Yu: What would be the best way for people to follow your work?

Emily Zhou: I have LinkedIn and people can find me or go to the University of Central Missouri page.

Emily Zhou: I am in the Department of Agriculture.

Ping Yu: Okay.

Ping Yu: Yeah.

Ping Yu: Sounds great.

Ping Yu: Thank you, Dr. Zhou, for joining us today.

Ping Yu: This is great.

Ping Yu: And I...

Ping Yu: Thank you for taking your time to talk with us today.

Ping Yu: As always, I'll make sure that I put the links and some of the work that you sent me in the show notes so that people can learn more about this topic and any other topic that we feature on this show.

Ping Yu: Again, thank you so much.

Ping Yu: Thank you for listening.

Ping Yu: Till the next time, stay healthy and go plants!

Ping Yu: Thank you. Bye.

Emily Zhou: Pleasure.

Emily Zhou: Thank you.

Ping Yu: Besides the resources that our guest speaker provided us today, AFE also provides additional resources for this topic.

Ping Yu: Just go to DLI Maps and they also have a free DLI poster.

Ping Yu: And again, I will add all the links in the show notes to save you time.

Ping Yu: Go check it out.