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Breeding crops for controlled environment production

Controlled environment agriculture growers have been trying to fit a square peg into a round hole by growing field crops in indoor environments. This is changing as research tries to match plant genetics with the production environment.

During this year’s International Congress on Controlled Environment Agriculture (ICCEA) in Panama City, Panama, University of Florida horticulture professor and keynote speaker Kevin Folta discussed the overlooked reality that food crop varieties have not been bred for indoor controlled environment production.

“One of the limitations of controlled environment agriculture (CEA) is that the conditions do not match the genetics,” Folta said. “Plants being grown in CEA environments were actually developed for field production. There are a lot of opportunities that go unrealized by growing plants in a controlled environment. It’s like asking Chihuahuas to pull a dog sled. Plants that were bred for one application are expected to perform under very different applications. The genetics don’t match.”

Research has begun to develop the next generation of plants with the potential to develop different products using the same set of genetics by changing the environment.

Creating the next generation of plants

Folta said research has begun to develop the next generation of plants with the potential to develop different products using the same set of genetics by changing the environment.

“By flipping a switch and varying the light spectrum we could change green leaves to purple or have the plants accumulate specific flavors or textures or nutraceutical compounds,” he said. “That is all very realistic. This is like being able to shine a different light spectrum on a Chihuahua and turning it into an Alaskan malamute or a dachshund. A plant’s body, its composition, its chemicals, its secondary metabolites could be altered by changing the light environment. We need plants that are ready to do that. We need to identify or create those genetics.

“We are exposing plants to different light spectra and evaluating how the plants behave and perform. Then we will work with plant breeders to develop the next varieties.”

Varying the light spectrum has the potential to change leaf colors and textures and to have plants accumulate specific flavors or nutraceutical compounds.
Photos courtesy of Kevin Folta, University of Florida

Need for more industry involvement

Folta said the companies that are developing and manufacturing the lights for CEA production should become more involved with the development of plants grown in these environments.

“The lighting companies should be working with the university researchers and plant breeders,” he said. “The lighting companies should be financing the development of proprietary varieties. Unfortunately that hasn’t been an area of interest for the lighting companies. They want to make and sell lights. They forget the seed. The seed is a much more complicated machine.

“The lighting companies should be able to say to the growers here are the grow lights we are offering and here are the seeds that grow best under them. That opens up recurring revenue for the lighting companies. It behooves the lighting companies to focus on identifying plants that perform best with their products. It’s like saying that a Ford engine does best with a Motorcraft oil filter. It’s manufacturer’s optimized matching parts.”

Folta said plants are the most complicated part of matching the genetics with the environment and the part that people worry least about.

“It doesn’t matter whether the breeding company or the lighting company takes the initiative to develop the genetics,” he said. “This is going to happen whether it’s private plant breeders, universities or technology companies. This is another niche to create new genetics. You’ll see people filling this void.”

Researchers are learning that green, far red and UV light have important roles to play in controlled environment agriculture plant production.

Limiting, changing the production environment

Even technology companies like Panasonic, Toshiba and Fujitsu are finding opportunities in controlled environment agriculture.

“These types of companies will develop the genetics or will find the genetics that work well in CEA environments,” Folta said. “For now the field genetics will continue to be put in artificial conditions and the indoor environment will be reshaped to accommodate the plants. What should be done is finding or developing plants for these energy-efficient, artificial conditions that are sufficient to support growth. Research needs to be done to determine how to maximize output or yields with fewer photons of light or colors of light. Research is going to focus on economic viability. I expect the pharmaceutical companies will get involved in this research.

“My interests are much more about food and how we create the next generation of profitable growers and higher nutrient crops that are more readily available for consumers. That’s what gets me fired up.”

While matching the genetics to fit the environment is important, Folta said researchers also need to be looking at limiting the environment.

“At the same time that we are looking at the breeding and genetics, we are also looking at how we can deliver shorter pulses of light that still maintain the same output,” he said. “We have cut energy application by 50-80 percent and grown comparable products. The viability of these systems has come from people who have focused on the diminishing return of light efficiency. What they need to work on is the plant efficiency. That is something that is extremely viable.”

Folta said all of the research he has been focused on is with small format, high value crops, including lettuces, sprouts and microgreens.

“Our university does not have the facilities to conduct the necessary experiments,” he said. “But we are partnering with others to do that. We will have good access to larger spaces in the upcoming months. It’s less likely that this type of production would be done with crops that take more space like melons. We are looking at plants where the vegetative portions of the plants are eaten. If you consider a head of lettuce, every photon that is invested results in the plant structure. With a crop like tomatoes, 80-90 percent of the biomass is being thrown away or composted.

Kevin Folta at the University of Florida is interested in how to create the next generation of profitable growers and higher nutrient crops that are more readily available to consumers.

“Growing the plants in shorter production times, shorter supply chains, better postharvest quality because of shorter supply chains, possibly lower costs, a lower carbon footprint and access to local markets, these are the issues I want to address. I see this being done with lettuces, microgreens and herbs such as cilantro and basil. Not so much with corn or melons where a huge amount of energy is invested in a relative small return in terms of calories. These types of crops do better using the sun.”

Folta said 15 years ago people thought the idea of light recipes and changing the spectrum was a crazy and senseless idea.

“Researchers and light manufacturers thought mixtures of red and blue light were all that was needed to grow plants in controlled environments, so there wasn’t any concern about doing anything different,” he said. “Now people understand that green, far red and UV light have important roles and that light quality should change throughout the day. With that in mind, it gives us some flexibility when it comes to changing the production environment, which is a really good thing.”

 


For more: Kevin Folta, University of Florida, Horticultural Sciences Department, Gainesville, FL 32611; kfolta@ufl.edu; http://www.hos.ufl.edu/faculty/kmfolta.

David Kuack is a freelance technical writer in Fort Worth, Texas; dkuack@gmail.com.

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Using LEDs to manipulate plant growth, characteristics

With the ability to deliver specific light wavelengths
with LED lights, growers, retailers and consumers could eventually manipulate
the scent, color, flavor, postharvest life and other characteristics of
ornamental and edible crops.

By David Kuack

Both ornamental and edible plant growers are using
supplemental lighting. Some use light to control photoperiod. Others use
supplemental light to hasten plant development by increasing the rate of
photosynthesis.

What if you could use light to increase the flavor,
aroma, color intensity, insect and disease resistance and postharvest life of
edible crops? What if you could use light to increase the fragrance, color
intensity, insect and disease resistance, flower timing and postharvest life of
ornamental flowering plants? Sound like science fiction? Read on.

Talking to plants

Kevin Folta, interim chair and associate professor of the
Horticultural Sciences Department at the University of Florida, said the
fundamental idea of using light to manipulate plants is an old one.

“We’ve known for a long time that light can affect
photosynthesis, but we are now starting to understand how light can regulate specific
plant responses,” Folta said. “It’s no big surprise that light could manipulate
something like flavors or any other aspect of plant metabolism.”

Working with other scientists at the university’s
Institute for Plant Innovation, Folta said
initial research indicates red, far red and blue light are the three major
wavelengths that affect volatile accumulation in plants. The researchers have
studied the impact of light wavelengths on strawberries, blueberries, tomatoes
and petunias.

“Volatiles are the chemicals that contribute to the aroma
and flavor that are released,” Folta said. “Volatiles are the chemicals that
are emitted that allow you to smell and taste a piece of fruit. These are the
compounds that are really important in providing flavor to fruit and
vegetables.”

University of Florida associate professor Kevin Folta and other
scientists at the university’s Institute for Plant Innovation are
studying the impact specific light wavelengths can have on
plant characteristics.
Photo by Tyler Jones, UF/IFAS Photography  

 Folta said similar changes could be made to flowering
plants by manipulating the light wavelengths that the plants are exposed to.

“For ornamentals we could affect aromas, colors and
flower timing by changing the light environment—the specific wavelengths,” he
said. “It would be possible to synchronize an entire greenhouse of plants to
flower at the same time just by flipping a switch. By understanding the light
spectrum and how a plant sees it, it could allow us to manipulate how a plant
grows.

“It’s almost like we can talk to the plants. It’s a
language that is essentially a vocabulary of light wavelengths and that we can
use to influence how a plant grows.”

Focused on LEDs

Folta said all of the research being done involves the
use of LED lights.

“LEDs allow us to deliver very precise amounts of
specific wavelengths,” he said. “LEDs allow us to mix the light conditions
precisely. We can pick and choose the light we want to use.”

Folta said one of the ways different light wavelengths
could be used is to customize what the final fruit, vegetable or flower would
look, taste and smell like.

“For example, maybe we could put the plants under blue
light for a few days and then switch to far red and then red. We know that such
sequential treatments allow us to bump up the pigments, then the nutrients and
then the flavors,” he said. “This treatment could change the way we grow, ship
and sell crops, as well as how consumers store them at home.

“All plant traits are a combination of genetics and the
environment. The genetics are already in place to make a quality fruit,
vegetable or flower, so the LEDs allow us to manipulate what’s already there.
We can tweak the environment with the LEDs to alter plant characteristics.
Maybe an LED light would be placed in a box of roses. When a consumer opens the
box there would be this incredible aroma released.”

Folta said the research has tremendous potential for both
edible and ornamental crops.

“This research would probably have happened a longtime
ago, but LED lights were prohibitively expensive,” he said. “Now that the cost
of LEDs and narrow band width lighting is becoming more affordable, we realistically
see LED arrays being used in greenhouses to manipulate the way plants grow.”

Endless potential

Although the initial research has focused on changing the
taste of fruit and vegetables, Folta said the use of light could easily be
expanded to manipulate other plant characteristics.

Kevin Folta said growers may eventually be able to synchronize
an entire greenhouse of plants to flower at the same time just
by flipping a switch for LED lights.
Photo by Tyler Jones, UF/IFAS Photography

“There is an increasing body of research literature that
indicates some of the compounds emitted by plants and their fruit deter insects
or deter fungal growth,” he said. “It may be possible that we could affect
insect and disease resistance. For example, by using LED lights we could change
the metabolic profile of the plant so that poinsettias would be more resistant
to whitefly. This might be done by stopping production of plant compounds that
attract whiteflies, or producing compounds that scare them away or even better
than that may attract a predator of the whitefly.

“What we are doing is manipulating the plant metabolism
or changing it in ways that we don’t necessarily understand 100 percent yet,
but we know we can do it.”

An example of one of the results of the research he
doesn’t completely understand has occurred with strawberry plants.

“In the lab we have exposed strawberry plants to LED
lights and they don’t get spider mites,” he said. “We don’t know if there is
something that the LEDs are doing to change the development of the spider mite.
Or the light maybe doing something to the plant that causes it to produce a
chemical the spider mites don’t like so they choose to go to a different plant.
This is something that we still need to test.”

Folta said most of the previous research that involved
the same type of plant process manipulation involved inserting a gene, spraying
a chemical or other types of treatments that were labor intensive and required
other inputs.

“Now we are looking at basically flipping a switch to
turn on a low energy device,” he said. “Adding value at a low cost would be a
great thing for the horticulture industry.”

For more: Kevin
Folta, University of Florida, Horticultural Sciences Department, (352) 273-4812
office; kfolta@ufl.edu; http://www.hos.ufl.edu/faculty/kmfolta.

David Kuack is a freelance technical writer in Fort
Worth, Texas; dkuack@gmail.com.

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