S5: Episode 1: Lorenzo Rossi - Inspiring Aggie Horticulturalists

Dr. Lorenzo Rossi joined Texas A&M University in January 2025 as an Assistant Professor of Horticultural Plant Physiology, with 60% research, 30% teaching, and 10% service appointment. Before joining Texas A&M, he served as an Assistant and then Associate Professor at a University of Florida off-campus research center, where he began in 2018 and earned tenure in 2024. Motivated by a desire to work more closely with undergraduate students and collaborate across disciplines in a main campus environment, Dr. Rossi made the intentional decision to transition to Texas A&M and continue building innovative programs in horticultural sciences. Dr. Rossi’s research explores how crops respond to environmental stresses such as drought, salinity, heat, and pollutants, integrating soil and root health to identify mechanisms of tolerance. His work focuses on fruit tree crops, especially citrus, peaches, pecans, olives, and grapes, and recently on selected vegetables. At Texas A&M, Dr. Rossi teaches HORT 201 Horticultural Science and Practices and HORT 202 Horticultural Science and Practices Laboratory, which together enroll nearly 900 students per year, as well as HORT 618 Root and Rhizosphere Biology for graduate students. He has authored over 60 peer-reviewed publications, mentored numerous students, secured nearly $5 million in research funding, and received multiple national awards recognizing excellence in teaching, leadership, and research.

Website: https://hortphys.tamu.edu/

Program description:
Our program studies how plants interact with the environment and how these interactions influence yield, stress tolerance, and fruit quality across Texas’ unique growing regions.

We focus on key physiological topics such as:
          Rootstock-scion interactions
          Plant water use and efficiency
          Carbohydrate storage and translocation
           Plant responses to abiotic stress, including drought, heat, environmental pollutants, and poor soil conditions

While fruit tree crops are a major focus, we also work with various small fruits and vegetables that are important to growers in Texas. Our goal is to bridge fundamental plant physiology with applied solutions, working closely with growers, Extension professionals, and industry stakeholders to ensure our research leads to practical outcomes. Through this work, we aim to support the success of Texas fruit growers, contribute to sustainable production systems, and train the next generation of scientists. We are always open to collaborations with researchers across disciplines and institutions who share our commitment to advancing fruit crop science.

Transcript

SPEAKER_00 0:10

Audi, welcome to Horticulture Innovators, the podcast series where we will explore impactful innovations in horticulture. I'm Amit Dingra, your host. I'm a professor and head of the Department of Horticultural Sciences at Texas Ana University. In each episode, we'll explore the inspiring stories of the pioneers who are contributing to sustainability, wellness, and food security through their amazing work in horticulture. Howdy! Welcome to Horticulture Innovators. Today we have with us Dr. Lorenzo Rossi, who's an assistant professor of horticultural crop physiology in the Department of Horticultural Sciences. Welcome, Lorenzo. Thank you for having me, Dr. Dingra. Hey, uh, I know you've been here for uh almost a year now. Yes. Any Aaron changes. All right. A few more months. A few more months. And uh, you know, plant physiology, crop physiology is uh one of the oldest sciences. We've been trying to understand how plants really work, and I think for people's understanding human physiologies, it's almost like you know, trying to figure out how things connect, how they work, how they're interrelated as well. So, what got you interested into crop physiology?

SPEAKER_01 1:24

Well, that's a good question. So as a kid, I grew up in Italy, and as a kid, um, all my friends wanted to play soccer. That was the thing to do, you know, it's Italy. So um, but I didn't. I never really liked sports. I like going and watch sport, but I was not really an athletic person per se. And so I remember my mom was pushing me, so it was like, well, you need to do something, you need a hobby. So the next try was piano. She was trying to teach me piano. That was another big failure. Um, didn't work out. Even the teacher, like, ma'am, you're wasting time and money here. And then and then my mom will keep saying, So, what do you want to do? And and I told her, I want to be outside, I want to grow things. And as a kid, I was in elementary school, uh, I think it was third or fourth grade. I will have my garden. I will grow tomatoes, uh lettuce, a little bit of cucumbers. And I remember I will plant the irrigation, I will dig like kind of ditches and everything to have the water going. And and that's kind of how it started. And a lot a lot of people made fun of me. All my friends were they think I was a little bit off, but it worked out in the end.

SPEAKER_00 2:43

Well, you were ahead of their time. I mean, they they need to eat that food that you were already producing. That's amazing, actually. So was it was this field called horticulture there, or what was it called?

SPEAKER_01 2:54

I was going with agriculture. That was the idea in Italy. We have orthofloriculture.

SPEAKER_02 3:02

No.

SPEAKER_01 3:03

Um, but it's the department is orthoflora fruit. So it goes veget vegetables, fruits, and floral. Oh, okay. Um, but as a kid, no, I was it was just agriculture, yeah.

SPEAKER_00 3:17

And so what happened after that? How did you find yourself getting into higher education? Or what happened during college time?

SPEAKER_01 3:23

Um, so in Italy, at the end of uh when you are done with middle school, yeah, you have to pick an high school. And they're different types of high school. Um I decided to go to a technical high school with a kind of track for agriculture. Okay, okay. Um, and that's where I learned more about olives, more about grapes, more about different types of crops. And and after that, it was kind of natural to kind of continue in that path. So I enrolled with the University of Pisa, and the the Bachelor of Science was agricultural sciences. Okay. And since I graduated with Height Mars for gra for in high school, I was able to kind of get um uh into an honors program with Italy. So I was doing my work at the University of Pisa, plus I was doing additional work at the at a small um, it's called Scuola Santana, which will give me a full board. So I will get free food, free rooming, free everything, free lodging uh at college, but I will have to take additional classes. And actually that what because of that track, I was able to do a period abroad in North Carolina at North Carana State.

SPEAKER_00 4:41

Oh, wow. So that was during your undergrad?

SPEAKER_01 4:43

I started during my undergrad the first time. I really, really enjoyed that, and then I wanted and then I came back during my PhD.

SPEAKER_00 4:50

So was that was that like a study abroad program?

SPEAKER_01 4:52

It was a study abroad, it was six months.

SPEAKER_00 4:54

Six months, okay. You know, at AM we do a lot of study abroad programs, and I know that uh some of our colleagues are taking study abroad groups to Italy and the Netherlands pretty soon, where horticulture is rather big. That's fascinating. So um walk us through what happens next. So you you did your undergrad, and then how did you get into your PhD, where and what did you do?

SPEAKER_01 5:16

Um I really like what I was doing. My undergrad, I had to do a capstone, and I decided to work on um apples and peaches and antioxidant compounds in different how the environment influenced the antioxidant compounds in apples and peaches. And we found that I don't know, the canopy, uh the more pruning, less pruning, the type the rootstocks, the cultivars, there are a lot of that into the amount of antioxidant. And I really like that my professor suggested me to continue for a master, which I did, and and my master was still on apples and peaches, but more on the carbon sink. So, and and and the idea that you can use uh canopy material that when you prune to put it back in the soil and to kind of have uh your idea of closed loop. Yeah. Um we didn't call it closed loop back then, it was more source. Sure. And and that was my master.

SPEAKER_00 6:20

You know, two things you just said. You were working on plant and health already during what what year was that? 2006, seven. So almost 20 years ago.

SPEAKER_01 6:32

Almost 20 years ago. I started during my bachelor. I graduated in 2008, so with my bachelor. Yeah.

SPEAKER_00 6:40

Isn't it fascinating? Sometimes we do things in our earlier years, and now you're in a position. We'll talk about that, because one of our mission sort of goals for the department is wellness, where we talk about interacting with plants for mental well-being and and obviously consuming healthy fruits and vegetables and nuts to keep ourselves healthy physically. So it's kind of interesting, it's come full circle, right? I mean, it's it's I think a common theme amongst faculty over here in our department that there was some level of working with plants for either feeding people or you know, for me it was how do you solve malnutrition as well. So that's fascinating that you just mentioned that, and I had no idea you were going to say that, actually. So that's fascinating. And then so uh you finished your master's there.

SPEAKER_01 7:24

Finished my master. I was debating if I should go for a PhD. I had an offer from um private company in Italy, uh, really close to my hometown, and I was considering it because it was a good offer, and he was more like about uh quality of their it's it's a transformation that they will do gems and and marmalades from situations. Um so it was more like a quality or increased production. Um, but I really like academia. I wanted to be an high school teacher as a kid. Oh and so I was like, if I go to the private sector, if I go to the industry, I will never go back to academia. But if I go to academia, I can always go back to the industry, or I can have so that what guided me through the PhD. Um I did a rotation the first year. The idea was I started with grapes, um, but I was not really um the idea was organic grapes and copper accumulation into the into the uh berries, but it was not really what um I didn't click with the advisor. And so then I switched with olives and salinity, drought, and that's where I started doing all my um root biology and plant physiology, and that kind of defined me as a plant physiologist.

SPEAKER_00 8:45

You also mentioned previously about carbon sink. You know, I think there's a lot of buzz around carbon markets, carbon credits. I know that's not what you're talking about. Can you elaborate what carbon sink means for the general audience?

SPEAKER_01 9:00

Well, the idea is that um carbon is available into the soil, right? And and plants are uptaking it, and kind of there is a sort of depletion of that because carbon is not something that you kind of put it back with fertilizer. Fertilizer are mostly nitrogen, phosphorus, and potassium. So carbon is actually the major component of organic matter. And the idea of depleting the organic matter means that uh you are kind of altering the the soil functioning and you're just relying as heavily on uh synthetic fertilizers. So if we can kind of bring back, or if we can kind of increase, replenish the carbon sink in the soil, which means that we will have more organic matter. And organic matter is the base for all the nutrients uptakes, microbes interaction, uh, root growth and development, and every water uptake. So that's the idea of the carbon sink. Yeah.

SPEAKER_00 10:00

And and the original carbon comes from the process of photosynthesis, which which plants capture, and that's how they build. So when you're talking canopy, it was not the nice canopy to give you shade. It's primarily for the plant uh leaf area index, which were how many leaves are present per square uh area so that you can get uh how much carbon you can capture from the environment. So that's that's what I was just talking about. So you finished your math, your PhD then in in what what did you study in that olives? Did you make them better or bigger or healthier?

SPEAKER_01 10:33

So the the project has two uh uh well three different objectives. Um the first one was drought and salinity, and we were working on on a 25 year old orchard in southern Italy, so I will travel there. And and my idea was to understand the anatomy involved with with uh different when we when you're under drought. So we cut down the trees and we measure all the vessels in the different ears, and we found that when there is a drought, the vessel, um your vascular system, they will grow smaller. And if you think about this, it's if you're trying to drink from a cup with the big straw, and you only have a little little less of water there, you're not gonna get all the water. But the plants adapt and create smaller vessels, and so your physic, your capillarity, your tension, and so they they try to uptake all the water they can.

SPEAKER_00 11:30

Well, they also develop embolisms, right? Yes. They develop embolism as a bubble in the vessel, and that's that can actually kill that whole uh sort of cell. But that's fascinating how plants are so uh flexible in in developing mechanisms to take out. Plasticity. Plasticity, yeah. I I I want to avoid the use word plasticity because we are going to talk about plastics later on, but just it's flexibility, but plasticity is the word. So that's fascinating that um you know uh you you were able to work with olives. I I'm sure uh how many types of olives grow in Italy?

SPEAKER_01 12:04

A lot. Um and some of the varieties are older, coming from the Romans or or even older. So we're talking about 2,000, 3,000-year-old uh varieties.

SPEAKER_00 12:14

Do we find any in in the US?

SPEAKER_01 12:16

Some of them, but most of the Italian varieties don't do well here because they're not really made for um intensive systems, they're all for traditional like training system, which require a lot of work. Um so the more kind of cultivated varieties here in the country are mostly coming from Spain, Arbequina, Arbosana, some from Greece, uh Koroneki, and we have one mission that was developed in California.

SPEAKER_00 12:46

Oh, okay. And and so there's there's different olives for oil production and different for stable. Oh, okay, just like grapes are different for okay. That's fascinating. So then where did your journey take you? And the reason I'm discussing this journey piece is because oftentimes a lot of students think that their path will be linear. We've kind of adhered to this concept somewhere uh that if you go through school, you go through college, you get your degrees, and then you will end up somewhere. The path is never linear in most of I mean so I just that's what I'm asking you.

SPEAKER_01 13:19

It was not linear at all. Um in college at the beginning, I wanted to be an entomologist. Oh, okay. So I was in a truck to become an entomology major. Um, didn't work out, so I went with fruit science. Um during my PhD, um it it's you know, PhDs are kind of intensive programs, so I have my struggles and everything, um, with the idea that I will stay in Italy. I never thought about uh leaving Italy. I did for a little bit, but my idea was always to come back. And during the PhD my last year, um I wanted to go molecular, so I did anatomy as I told you. We were doing a lot of physiology, but there were no kind of molecular components, like gene expressions or everything to go a little bit more mechanistics and understand. And my advisor suggested me, well, you need to go to a different institution if to want to go their route. Um, and that's what um that's what I did. I applied for several um colleges, and I ended up uh North Carolina State again because I know the professor and that was an easy path. And um and there I did uh gene expression of I think it was 15 genes related to salinity and olives, and I learned a little bit about everything related to DNA extraction, RNA, and but seems like your first passion is physiology.

SPEAKER_00 14:54

Yes. And and uh just to help us understand, what what do you measure, what do you study, and how how do you study physiology of a plant? Or what aspects can you really invest in?

SPEAKER_01 15:05

You know, I'm interested in everything that kind of put uh an interaction between plants and the environment. And lately we're adding soil, so soil, plant, environment interaction. So we're seeing this um increase uh on on extreme climate event, um, a lot of different types of weather during summer, winter, and how cultivated crops are responding and how can science help in not only understanding what's going on, but also um making sure we have the tools to breed for species. And that's why my work is heavily connected with other colleagues here in the department. I I don't think nobody is an island. Um we work together on several topics.

SPEAKER_00 15:58

Well, when you talk about plant and environment, I think it's very I mean, in in in the grape world that's the terror war, which is the you know, your immediate environment, but that includes diseases, that includes non-disease and vi environmental factors as well. That's fascinating. And and don't you think we've uh we've as because there used to be this effort of like, oh, there's drought that happens once in a while, or or extreme heat happens once in a while, or you had those hot regions and USDA had these different zones of production. But now all of that is getting jumbled up because we can have a winter event in the middle of high summer and vice versa. So I mean I I I think physiology becomes even more relevant today to really guide how do we breed crops, how do we develop new uh varieties of like olives or grapes or pecans or uh fruits and vegetables to really survive those environments.

SPEAKER_01 16:59

That's one topic. And if you think about Texas, I mean the the state is big. We have a lot of different climate and microclimate, different types of soils, different type of crops. So for a physiologist, this is like a candy shop. Everywhere I go, I find something that I can work on.

SPEAKER_00 17:17

Well, according to USDA, eleven different growing regions are here, and then 1300 soil types. Yeah. So that's fascinating. It's it's a candy shop, but also it gives us a unique advantage in the world to grow anything we want. Yes.

SPEAKER_01 17:30

I mean, people think of Texas just as hot, but if you start going up in high plains, um but then you have drought too, and you have the desert horticulture, you have uh temperate horticulture, subtropical horticulture.

SPEAKER_00 17:45

Now it's fascinating. You get this is the world's uh best lab to grow any kind of crops actually. So after that, after you were done your PhD and you came to North Carolina, what what was next for you?

SPEAKER_01 17:56

Um I um I stayed there almost a year and a half. Yeah. I did I finished up my dissertation there, and again, the idea was to go back. I was never really thinking about staying, and I I told my professor, I'm ready to come back, I want to graduate. Um and and my advisor in North Carolina, an NC State, suggested me, well, why don't you stay for a post though? I will keep you. I was I don't know, I want to go back. But at the same time, my advisor in Italy was telling me, no, you should stay. There is not much here at the moment, and it's a good opportunity. So I stayed there. I started a postdoc there. I stayed there for one year, and then um that postdoc ended, it was one-year contract. I wanted to do something different, um, and there was an opportunity here at Tech CNN to work on pollutants, which I found was something new and interesting. What year was that? Uh 2015. Oh wow, what pollutants we uh we were working with cerium oxide nanoparticles and everything that was related to nanoparticles and nanofertilizers.

SPEAKER_02 19:07

Yeah.

SPEAKER_01 19:07

And so I ended up uh working in the civil and environmental engineering department here. Oh wow, okay um, and I realized that they didn't know anything about physiology, so and they didn't even know how to grow plants, of course, but they were really good on the engineering part. And my idea was well, I I will not be able to be successful if I don't partner up with someone in orthoticulture, and that's where I found Dr. Leo Lombardini. Okay, and we started a long collaboration, and so I will be in this department some days of the week and in civil engineering some other days. And Dr. Lombardini was nice, he let me use some of the greenhouse. We did some research together with the coffee, and he also has a Lycor, yeah, so I was able to use it.

SPEAKER_00 19:58

So Lycor is a measurement device that captures what what does it capture?

SPEAKER_01 20:03

It capture uh stomatal gas exchange. So the amount of uh vapor and water, mostly oxygen and and water that goes out and in and out from the leaves during the photosynthesis also capture um the health of the leaves in terms of photosynthesis, how much uh kind of uh uh CO2 oxygen is going in and out from the leaves.

SPEAKER_00 20:29

And a big shout out to Dr. Lambertini, now he's now the department head at uh University of Georgia, Department of Horticultural Sciences there. Uh he used to be here, uh we we miss him here, but uh you know. Um so you you were doing that postdoc, so you were at Texas AM at that time. And then what came next?

SPEAKER_01 20:48

It was a postdoc, so as I as all the good things come to an end. Um I applied, I was start I start applying for jobs, yeah. And um because of this research I was doing on roots and and and drought and salinity, um one of the things that uh kind of defined my my research was I was not just doing anatomy, but I was starting I was trying to understand how root kind of change their anatomy and plasticity when they are in contact with salinity, with heavy metals, with pollutants. And we found that they developed barriers at the well, there are several layers in the roots, and I don't want to go into all the details about anatomy, but they kind of put a layer of walks, a walksy coating on the roots, yeah. On the on inside the it's called the endodermis. Yeah. So they developed this layer, and if you use a dye, a fluorescent dye that react with the subarine, which is the element, the walks, you can visualize them under the microscope, and you can see that if you have pollutant salinity, this is There earlier.

SPEAKER_00 22:04

You know, it's fascinating that you brought up the roots thing, because I think if you look at the studies, or at least maybe I was blind to it, but a lot of the work was focusing on above ground and because we can't see the roots. So they were both invisible naturally, but also scientifically, because we would not consider the root system sometimes.

SPEAKER_01 22:26

And it was hard to sty I mean, in order to study the roots, you will have to dig the plant or you have to excavate and it was distractive. Um and uh in the past 20 years, I think we have been developing uh novel tools to study roots. We have mini rhizotron now, these transparent tubes that go into the soil.

SPEAKER_00 22:45

So tell us about it. So it's called a rhizotron. Yes. And and what does it do? So you you use you have a column like a plastic column?

SPEAKER_01 22:52

It's a plastic tube.

SPEAKER_00 22:53

Yes.

SPEAKER_01 22:54

Uh plexiglass.

SPEAKER_00 22:55

Plexiglass tube, okay.

SPEAKER_01 22:56

Um it goes into the ground. We usually put 45 degrees so you can capture more of the root system.

SPEAKER_00 23:03

So do you just put one tube or you put it?

SPEAKER_01 23:06

It depends on what you're trying to get. Okay. We always suggest two or three tubes per plant. Per plant. Okay. So it's more representative.

SPEAKER_02 23:13

Yeah.

SPEAKER_01 23:14

And then there is a special camera. Oh. Um, it's a it's a root scanner, and you insert the camera and it takes a 360 degrees picture.

SPEAKER_00 23:25

So how does the camera move around the tube? Is there like a like a space between?

SPEAKER_01 23:29

Yeah, there is there is a little bit of space, so the camera is able to rotate inside the tubes, and you can take picture at different uh level depth. Yeah.

SPEAKER_00 23:37

That's fascinating. But how do you distinguish the roots from the soil?

SPEAKER_01 23:41

So there is a software that we use, so a little bit of um artificial intelligence there. Okay. And that can recognize by the color different the roots and the soil. And then if you take pictures every month, let's say, you can reconstruct root growth and development over time, considering that you're taking the same picture in the same spot.

SPEAKER_00 24:05

But also, I think you're although you're still constricting root growth because root can go anywhere in nature, right? There's nothing. But this is the best approximation, perhaps.

SPEAKER_01 24:14

Is the best approximation non-destructive in the field for what we have at the moment?

SPEAKER_00 24:20

Well, you're studying a very hard system, which is hard to track, but very important. Obviously, everything happens at the root system as well, or not everything, but half of it happens at the root system, half happens above ground. So so you were looking for jobs, studying this part, and where did you start your career?

SPEAKER_01 24:38

There was a root biology position at the University of Florida. Uh-huh. And I didn't consider myself a root biologist. I was always talking of myself as a crop physiologist, as a plant physiologist, horticultural crop physiologist. Yeah. Fruit physiologist for a short time. Um, so but I applied um and I did the interview, and the position was with the University of Florida at the research center on the East Coast. Okay. Um it's a beautiful area. It's on the East Coast. There is a lot of nice uh restaurants and and the the the center was also really nice. Uh they were dealing with a big problem, which is citrus greening.

SPEAKER_00 25:26

Yeah, yeah.

SPEAKER_01 25:27

And so the idea was to increase root and soil health. So there is no cure for the disease, but if we hire someone that can help us, like managing the health of the soil and the roots, maybe we can get three or four more years. Before replanting.

SPEAKER_00 25:46

Before replanting. Are people replanting there?

SPEAKER_01 25:49

They are, some of them, but the production dropped 98% in the past. 98%.

SPEAKER_00 25:56

By some numbers, that used to be a $12 billion industry. Uh maybe more.

SPEAKER_01 26:02

It's now I think it's four, yeah.

SPEAKER_00 26:03

It's probably dropped quite a bit. I mean so t talk a little bit about citrus greening. How does that disease uh manifest itself and where what's the function of the roots in there? So it's uh it's a bacterial disease.

SPEAKER_01 26:16

Okay. Um if any anybody is familiar with uh Pierce disease. Yeah. In grapes. In grapes. Xylella. Um xylella or olives too.

SPEAKER_00 26:26

Olives has that too.

SPEAKER_01 26:27

Yeah. Sweet cherries, I think they have something similar. We can get in pears as well. Um so it's a bacterial disease that it needs a vector. So if you think about malaria, it's the same with the mosquito that will transmit malaria to humans. Yeah. Um, in that case, the the vector is a is a small fly that is called psiliate. And when the psili and the bacteria kind of get in contact, the bacteria will stay inside the psiliate body. Inside its gut. It's gut, yeah. And so every time the psili goes and feed on the tree, it will transmit this bacteria inside the phloem. It's a phloem limit that is not xylem like the xylem.

SPEAKER_00 27:13

Oh, okay, okay.

SPEAKER_01 27:14

So every time the the and if you think about Florida, we're talking about a mostly subtropical state, yeah, which no real winter besides some part in the north. So the psyllid is active 365 days over the year. Yeah. And it feeding constantly. It's not just one time. We're talking about every day constant population of psylli feeding.

SPEAKER_00 27:39

Yeah, so it's non-stop. Non-stop assault. Yeah. So you you talked about phloem, so just for everybody's knowledge, phloem is where food is transported to the roots. To the roots from the leaves uh or to the growing regions, and xylem is where you have the water and the the sort of you know, that's how water reaches the various parts of the plant. So that's from the roots. Water and nutrients. Yeah, other nutrients as well. So if there is any obstruction in xylem, for example, in case of Pierce disease in grapes, plants will die.

SPEAKER_01 28:11

And in this case, at the floor, and so you will see that it's called citrus green because there is no transport of all the sugars and other uh products that from the leaves needs to reach other parts of the tree. And so you'll see that the tree is gonna look greenish, it's gonna look yellow. You start producing a lot of starches to defend himself from the disease, but in five years it he will be eventually be dead. So there's no cure for that yet? There is no cure, it's not culturable in the lab yet because it's a phloem-limited bacterium. Yeah. And you know, if you cannot culture it, it's really, really hard to that's why we call it Candidatus Liberibater Asiaticus. The candidate.

SPEAKER_02 29:00

Oh, okay.

SPEAKER_01 29:01

There is uh Liberibater Americanus, Liberibater uh Africanus. We we we assume that is the Asiaticus.

SPEAKER_00 29:09

Oh, okay. Wow.

SPEAKER_01 29:10

But we cannot do the postulate to confirm.

SPEAKER_00 29:13

You know, as part of land grant systems, we try to support our farmers, but sometimes nature can beat you. And I think this is an example. I mean, there have been other diseases in in in uh history, like the potato blight.

SPEAKER_01 29:26

Um American chestnut blight.

SPEAKER_00 29:28

Chestnut blight. I mean, sometimes there are no cures. For chestnut blight, now they have a GMO version to a counter, but nothing has worked so far in citrus screening.

SPEAKER_01 29:38

There is a little bit of crisper cuss going on. Um gene editing. Gene editing. We're working, they are working, um, well, still working on citrus, of course. Um, toward more acceptability of GMO and juice and well, you know, Texas also produces a lot of citrus, although different types, right?

SPEAKER_00 29:57

Mostly grapefruit. So I I know that citrus is a nationally important food fruit crop, so that's very important. Are people trying to grow olives in Florida? They are.

SPEAKER_01 30:08

I was actually part of a state project on evaluating the feasibility of growing olives in Florida. We found a couple of spots that may be uh suitable.

SPEAKER_00 30:20

As we are trying to grow them in Texas as well. But the freeze gets them every time.

SPEAKER_01 30:24

And that was the same with Florida. I mean, if if you find the right spot in terms of temperature, because most of the state doesn't have enough um uh cold uh chilling hours, but uh the northern part it does reach the amount of coal that is needed, but also it gets extremely cold. Yeah.

SPEAKER_00 30:42

What I find so cool about plants, and it's there's a little play of words here, it's so cool that they can measure how much cold they have accumulated or how much heat degrees they have. I I don't think people walking around picking fruit realize that if there was not enough cold or heat degree days, or so you have to be below certain temperature or in a range at low temperature or at a higher to really make this system work. And it's all tuned with solar cycles. I mean, uh and and the days. It's just fascinating how plants have attuned themselves to their environments. And now with this extreme weather conditions coming in, it it is really going back to that whole thing.

SPEAKER_01 31:25

Sometimes just one degree will mess up the entire flowering schedule or cycle.

SPEAKER_00 31:30

Or if it's too hot at the pollination. Pollination, you know, or too cold, it does the flowers free. So it's a very fragile system. The food system is very fragile in that sense.

SPEAKER_01 31:41

And it's a system that has evolved over a million of years of domesticated plants.

SPEAKER_00 31:46

It's fascinating. So this is what you were doing in Florida. What came next?

SPEAKER_01 31:51

Well, I was um I was looking for something that, you know, I always looking for something that gave me more energy or kind of put me to the next step. I think I was getting to comfortable promo. I like to get out of my comfort zone.

SPEAKER_02 32:06

Yeah.

SPEAKER_01 32:07

And and I saw this opportunity for an horticulture carrophysiologist. It was around um the holiday break in 2024, I think. That position opened, and I had a lot of conversation with myself about whether I apply or not, because I was about to get tenure there.

SPEAKER_02 32:28

Yeah.

SPEAKER_01 32:29

I already submitted all my documents. So I was I was kind of my research was going well. Um, I had good funding, but I was missing the teaching component. I was missing the interaction with uh a more like uh kind of academia community because I was at the research station, I was not on the main campus. And so these positions open up, opened up, and I I did apply. I was like, well, I'm gonna try. If it works, it works it. Now I already have a job.

SPEAKER_02 33:02

Yeah.

SPEAKER_01 33:03

And it worked, so I moved here in um, well, actually it was December 2023 when I December 23, yeah. Not 24. During 24, we did the interview process, and then I moved here in 2025.

SPEAKER_00 33:21

Well, you know, that was a strategic move for the department to really uh bolster our mission around sustainability, wellness, food security. And part of it was we we really wanted to make sure we've had planned like excellent exceptional plant physiologists in the department, horticulture crop physiologists, or people who work on secondary metabolism also, or plant breeding. And we really wanted to really bring in an um you know early career scientists in that field in these three areas to kind of continue supporting our industry, uh training undergraduates or graduate students and educate, you know, having the latest in classrooms as we are now moving towards robotics and mechanization and AI, we're trying to bring in those colleagues as well in the near future as well. So now we we were very excited that you're here. And so while you've joined here, what has become your emphasis? I I know that despite the fact that we move from our hometowns to universities or we move from universities, the arc of what we study or what systems we work with doesn't go away because we we learn from these systems, and I also believe these plants choose us rather than us choosing them sometimes.

SPEAKER_01 34:32

Um so I brought some of my research topics with me. Um we have a project with the Texas Water Research Institute, uh Research Institute, and we're uh identified uh plastics and uh PIFAS, which are called forever chemicals, um in woody crops. Uh we're working on pecans and grapes. Um I'm still working on my um the idea of soil health. Um I have some collaboration about the use of biochar for different types of soils. Um we're about to start a collaboration with uh Texan and Kingsville to kind of also continue my citrus research. Yeah, yeah. And I also expanded like like these are all fruit free crops. Um I'm expanding a little bit into vegetables and herbs.

SPEAKER_00 35:26

Yeah. So that's fascinating. That's going to be a great support for our industry on one side. On the other side, I think this is new material for our undergraduate students to be exposed to in classrooms because you teach as well. I'll come to that in a second. And then also the graduate students who will train. Because part of what we do in academia is pass on the baton. And I I think that's needed in farming as well, because our farming generation is aging, and we need to have the next generation come in. So that's our responsibility to train experts in that area. So talking about research, so you're doing this uh PFAS work or forever chemicals. So what do they do to the sort of ecosystem, first of all?

SPEAKER_01 36:08

Um, so those are long-chain um kind of residues that will stay in the environment and they're they're small, they're na we're talking about nano.

SPEAKER_02 36:20

Yeah.

SPEAKER_01 36:21

And and they're coming from different sources, plastics or or uh everyday kind of trash, uh and they will find their way to the groundwater, and then they it's not just uh one time, it's the accumulation over time. And and there's there was a study that has a different type of groundwater in the state, and they found high level of different types. And these can be uptaken by the plants when you do irrigation, and they will find their way into uh fruits, but also interact with the physiology of the plant itself because it's something that can alter photosynthesis or nutrients uptake.

SPEAKER_00 37:05

So it's not only impacting the accumul or the accumulation piece or which we will consume, of course, it affects us. Do we know all the negative aspects of consuming this over a period of time?

SPEAKER_01 37:16

It's something new. So I don't think sometimes you need an entire generation to understand the effect. Yeah.

SPEAKER_00 37:22

So but can we just say like wave of one and get a get done with these BFACs? Because how hard is it?

SPEAKER_01 37:30

Well, there are there are strategies that we are studying. Biochar is one of them. Use of um again, and I I think it will go back to soil health eventually, taking care of your soil.

SPEAKER_00 37:43

Yeah. And we haven't really found any microbes that can break these down yet.

SPEAKER_01 37:46

I don't think so, or at least I'm not aware of it.

SPEAKER_00 37:49

Yeah, yeah. That's fascinating that you're working on that. So uh while you're doing this work, what are you focusing on? The above part of the plant or the lower part of the plant?

SPEAKER_01 37:58

Um we're well everything at the moment. We are studying the plant as a whole.

SPEAKER_02 38:02

Yeah, yeah.

SPEAKER_01 38:03

I learned that a long time ago that and you already and you say the same that roots are actually part of the plant. Yeah, yeah. So I think as a crop physiology, you have to study the entire crop, not just the above ground.

SPEAKER_00 38:16

So um, how do you study the root system in trees, like in a pecan? What would you do? I mean, you can't dig up the tree because these are like massive trees.

SPEAKER_01 38:24

Yeah. The idea of the mini rhizotron is one of them. So having these tubes. Tubes, okay. Uh root density, that is just sampling um on a on a monthly or or or every season, the amount of roots that you have. Um, we can collect a small portion of root. We have a root scanner in the lab and and we can check for root diameter.

SPEAKER_00 38:45

Um, this is uh like an image analysis software. What about the I I heard heard that just like we can uh use radar.

SPEAKER_01 38:54

Ground penetrating radars.

SPEAKER_00 38:55

Ground penetrating radars. What are those called?

SPEAKER_01 38:57

Um those are ground uh GPR, ground penetrating radar. Um the technology works, but it's it needs some fine-tuning still. Yeah, it it will give you more qualitative data than quantitative, so it will tell you where most of the roots are and it will give you a a a heat map with different spots. But it won't kind of tell you the exact yeah.

SPEAKER_00 39:24

I had heard I had read somewhere that because soil has a lot of organic matter and roots are obviously organic, the carbon containing, it's very hard to distinguish between them sometimes, or there are a lot of false positives. Yeah. But that's an area of really technological development, you know.

SPEAKER_01 39:40

That one and I think the other area that it we have here on campus, that's the plant phenotyping facility. Yeah. I was lucky enough to um have a student in my lab that actually works there. Yeah. And and we are working on grapes, different varieties, and salinity. And again, we are doing above and below ground phenotyping, and they have a system, it's uh is an MRI magnetic resonance imaging.

SPEAKER_00 40:09

Oh, but MRI was for medical reasons.

SPEAKER_01 40:12

We we yeah, that's uh that's a low field, yeah. Um that with the one we are using for plants, uh, and they will give you a 3D reconstruction of the root system.

SPEAKER_00 40:24

That's non-destructive, and that's non-destructive. But I think you still have to grow the plants in a pot.

SPEAKER_01 40:28

In a pot. So it's not really made for the field.

SPEAKER_02 40:32

Yeah, yeah.

unknown 40:34

Wow.

SPEAKER_01 40:35

But still, yeah, it's something that I think we should be really proud of. There are a lot of phenotyping facility, but most of the in the country, but most of them don't combine above and below in the same space.

SPEAKER_00 40:47

No, that's great. I think uh we've gone from destroying the plant to study things in plant physiology to going into now non-invasive methods where you can measure from the top, but also like in my lab, we study photosynthetic performance, where we can really see how the systems are working inside an intact leaf as well. So technology's come a long way. Hopefully, we can also start looking at roots properly that way as well. So you mentioned that you decided to leave uh the research center because you missed teaching. And I know that uh you have you took on a course when you joined, which had been taught by the previous professor for 47 years. So how does Dr. Lorenzo Rossi come in and fill in the shoes of a professor? Because that was one of the most popular classes for the longest time. In fact, even before I joined myself five years ago to the university, just me walking around in the general public, people said, Oh, Dr. David Reed, do you know him? I said, Well, he's in my department, yes. So that's fascinating. So, how did you approach this and what have you done? What kind of innovations have you brought in?

SPEAKER_01 41:54

Um, so as everything I do, I always try to think a little bit before, and I realized that I have two options. Yeah, um, I could have kept the class the way Dr. Reed had um for 47 years. Yeah. Um, or I could have bringed something new, something that was more about the way I wanted to do it. And I decided to go for the second route. So of course I couldn't change the syllabus, but I could change the way the information is is kind of transmitted. And and that was the idea. Um, so I well the first struggle I had was that um students now need to well they will come to class if they found the class interesting or if they found the class engaging. Um there with the constant information that we get from YouTube, from a lot of other sources, it's it's not easy. And I probably would have done the same. I don't know if I've been going to a class which is just traditional teaching. And so what I did was the idea of combining, of course, a part of more like traditional teaching, but also a component in which we do story time. So for each module, I have a story time on a specific thing, like citrus green is a story time. Um we did a story time on uh dates and how they get to the US, the the entire story of uh Dr. Zwingle going to Morocco and bringing the first offsprings here. And then the other thing was I realized that a lot of students didn't know what horticulture was, or they there is a lot of kind of confusion between horticulture and agronomy, and and I realized that we need Needed to make clear what are horticultural crops, how horticultural crops are in everyday's life, and that's what I try to do at least every week. We do tasting. Tasting of what? Something that they usually don't try a lot. Like we did artichokes, dates, uh figs. We did a different uh citrus uh juices, orange and grapefruit. Which one was the best? From Florida and Texas. They like the Texas the most cool. They're used to the Texas Terror War, right? Olives, different types of olives. And and that will also expose them to the variety of cultivars, of fruits, of everything. Um we do a flower uh display, and they can play with, I don't know, we do we usually do lilies because they're easy, so they can see the hunters, they can see the stamina, they can see the um ovary. And and that kind of keep them engaged. And I mean, they may not come to all the lectures, there are 30 lectures, but at least I would say they come at least to 20 on average.

SPEAKER_00 45:14

That's great.

SPEAKER_01 45:15

And so, and I think the most important thing for a for a professor that is teaching a big class like that, we're talking about 356 in person and 175 online is to have an audience. The idea of teaching to an empty room kind of remove the po not remove, but kind of Dampens the passion. The passion and and then you kind of start you start questioning it yourself.

SPEAKER_00 45:45

So you have is that the second largest class on campus?

SPEAKER_01 45:49

Um, it's one on the I think it's the third. Okay. Um with Dr. Shiner.

SPEAKER_00 45:57

I was gonna say, even the largest class is also from our department. So horticulture is such a big part of people, but as you said, they don't realize So what is horticulture in your mind?

SPEAKER_01 46:07

Well, I always say it's the heart. So there is an artistic component, there is a scientific component, but there is also a business component. It's the heart science and business.

SPEAKER_00 46:19

And technology is coming in there.

SPEAKER_01 46:20

Technology is coming in there now, it's been there, but now it's it's becoming more predominantly.

SPEAKER_00 46:25

I think one of our challenges is labor. And I think mechanization, robotics, uh in in many other crops like apples and pears, cherries, a lot of things have started happening. But other crops like our pecans, I mean, the if you go to the West part of the state, they are using mechanical pruning. Uh they have to, because you can't climb a tree that large. So uh not only West, everywhere else as well. So it's it's fascinating. So um and so in this classroom, so you said 356 students in person, 175 online. Are these all horticulture majors?

SPEAKER_01 47:01

No, that's the other beauty of that class that got me exposed to pretty much every major on campus. This is uh what we call a science core curriculum. So it goes with the Texas uh science curriculum that came down from the legislation. Yeah. And we have to assess particular things, quantitative skills, critical thinking, teamwork. That's why we have projects, that's why I do tasting, that's why I want them to think critically about different issues.

SPEAKER_00 47:30

I notice a lot of posts on Instagram uh of the class and how much students are learning. But I think what is most important you're teaching is where does people's food come from. I think one of the challenges is that if you're not exposed to it, you think the food just appears on the shelf at a grocery store at HEB or Kroger's or whatever you have. And and I think that what you're really educating people from other majors is where food's coming from. And I think that's really critical for our coming generation to understand. And we need to protect that source as well.

SPEAKER_01 48:03

Um I always ask them to write a reflective essay at the end, and this is the time of the semester in which they're turning in those essays. And it's it's fascinating to see how many of them start the essays, say, Well, when I first sign up for this class, I thought this was gonna be another biology class, or this is gonna be another one of those classes that I had to memorize a lot of enzymes, and and but then no, I learned that there are different types of I don't know, peaches.

SPEAKER_00 48:35

Peaches, olive, yeah.

SPEAKER_01 48:36

And and we grow them here in Texas, and I didn't even know that Texas was this important nationwide for horticulture, because everybody thinks about cotton and soybean and peanuts.

SPEAKER_00 48:47

And cattle.

SPEAKER_01 48:48

And cattle. That's right.

SPEAKER_00 48:50

Well, horticulture combined is a $70 billion industry for the state, 70, 80. And you know, between fruits and vegetables, pecans, grapes, uh, you know, ornamentals is the largest industry here. People just forget that that's horticulture. And also, of course, now controlled environment production, which goes everything from uh greenhouses to indoor farming to space. I mean, horticulture is everywhere. That's fascinating. So, in this classroom, you're really changing minds to understand what horticulture is. And and our mission of sustainability obviously starts with profitability for our farmers, but I think the major part is how are we going to sustain this uh sort of economic ecosystem? And that's where our focus on students. So, what you're doing is really critical in educating the next generation who are Texans and anybody from outside who's here at AM to really understand that we need to preserve this system, we need to obviously support our farmers, and then finally, you're also working on the other the third leg stool of sustainability, the soil health and plant health. So the environment. Environment as well. Uh so that's fascinating. So that's one class that you teach. What else do you teach?

SPEAKER_01 50:00

Um that class has a lab component. Oh, okay. Um, so we're talking about 100 students from or two or one, usually take the lab. Yeah. Um, we have five different sections, and the lab is usually run by the TAs. So those are graduate students that we train them with with teaching and research, of course. And that was another thing that I inherited from Dr. Reed. He did an excellent job, of course. Um, so we took what we had and and I kind of tweaked it a little bit. So we are making we did we did we did make some changes. Um so we have 13 labs.

SPEAKER_02 50:45

Wow.

SPEAKER_01 50:46

And in each lab, they the students will set up an experiment, and it needs to be set up in a scientific way. So four or five replicates. Each student is there there are tables, so each student is considered a replica, and they have uh usually we have six tables or six treatments. Wow. And then we do statistics. Uh and so we do drought, salinity, water, that's one. Uh we do different hormones. We do we we now we're doing hydroponics. Which hormones? Steroids? Uh no. Plant hormones.

SPEAKER_00 51:20

Plant hormones, okay. Just want to make sure. Um although plants do make sterols in the other. But yes, yes. Plant hormones, which are different, of course.

SPEAKER_01 51:28

Yeah, so they're those are mostly plant growth regulators. Plant buffer, you know. Um plant growth regulators. Some of them they will make them a little bit. Yeah, that's right, yeah. Um and we in uh now we're doing hydroponics. Oh, cool. Uh we're doing LED lightning system with different light color. And they have to record the data, they will have to uh do statistics, and and for each lab, they will have to submit a lab record on their observations.

SPEAKER_00 51:54

And these are students from different majors as well. That's fascinating. So you're you're kind of giving them those basic skills, life skills, because you know, if you have to make a decision, you know, what is better, what is not, I mean, statistics obviously comes in healthy, uh it's very helpful as well. And I I also heard you teach another honors course. Tell us about that.

SPEAKER_01 52:13

Um that was an opportunity. I as I told you, um I always like to kind of explore new avenues. Um there was an email that came out when I first got here, it was February or March, and they were saying that we are launching a new program. It's an honors academy. Um I know the AM has a long history with the Honors Academy, but um they kind of redeveloped the the academy around the six core values.

SPEAKER_00 52:41

So hold on. A lot of people outside AM have no idea what the six core values are, but they're part of everybody's life. What are those? Please tell us.

SPEAKER_01 52:48

Um so we're talking about respect, excellence, leadership, loyalty, integrity, and selfless service.

SPEAKER_00 52:57

Oh my god, those values are you know they they found the core of our uh being an Aggie.

SPEAKER_01 53:03

Being an Aggie, and um so I did apply and I was selected for one year. So this past spring and sorry, fall and spring. Yeah. And um, so the first one's one or honor one on one, and we we we focus on the first three core values uh respect, excellence, and leadership. And for each of the core values, we read a book, and then after that we will have a class discussion, and the students need to submit uh an uh reflective essay.

SPEAKER_02 53:42

Okay.

SPEAKER_01 53:43

So we did that on 101 and 102. Those are small classes, yeah. Those are one hour per week, uh, one credit seminar classes, 15 students. Yeah, okay. Um but it was great because um in a small class like that, you kind of develop a sort of um relation. Um, and the topic that we're discussed, they were all about nowadays problems, and and you can see how students are passionate about that and try to find solution.

SPEAKER_00 54:22

Yeah, what I find really fascinating that a horticulture professor is teaching about, but I think that also reflects the culture that we should have. You know, it it makes us quintessentially Aggies, and I I think that's kind of our identity in a way. So that's fascinating that you did that.

SPEAKER_01 54:42

I did it. Um it was a great experience. Um I enjoyed working with them. The final presentation were last week and they were all excellent. Yeah.

SPEAKER_00 54:54

No, this is fascinating. So as we as we wrap up the whole thing, uh and and being an innovator, you've been innovating all through, starting from growing your own vegetables when everybody else was doing everything else, to today while you're you're foraying into teaching um honors courses and the or or honors academy courses, uh also trying to develop new methods. What do you think foresee some of the challenges for food production, food or horticulture crop production, or or just food crop production would be in the future? Or today actually.

SPEAKER_01 55:27

Water will be one of the major problems we we're seeing this in Texas every day. We're running out of water for a lot of crops that we are growing. Uh pecans, as you know. Um grapes can be affected too. Um cold and heat stress are becoming another major theme. Um, also because not just the regular heat stress, but the one that is unexpected, or the one that that calls that it was not supposed to be there in June and then actually is there. And so these are the things that I think from a physiology point of view, but also informing the next generation of students, yeah, and also collecting data and traits that can inform a breeding program. Yeah. Um of course, we also have the bigger picture, uh, growing healthier fruits and crops that can increase human health.

SPEAKER_02 56:28

Yeah.

SPEAKER_01 56:28

Um, and that's can be related to physiology as well. Absolutely, absolutely. So and taking care of our soil, uh, inputs, you know how much uh it is becoming a fertilizer, our the the cost is under the roof. So um having a better notion of soil health, regenerative horticulture. Yeah, I think those are the areas areas that's gonna be our tomorrow's.

SPEAKER_00 56:58

Well, it's it's great for our department, our students, and uh that you're here. Uh we look forward to seeing more innovations from you, and uh good luck with everything and uh keep doing your physiology and and inspiring uh the coming generation. Thank you for being here today. Thank you. Thank you. Thank you. We hope you enjoyed this episode of Horticultural Innovators. Subscribe if you want to learn more and spread the good word. Thanks and giga.