Plant researchers turned on by LED technology

While holiday lights have taken a shine to light-emitting diodes as replacements for incandescent bulbs, University of Florida researchers are celebrating LED technology for another application: bettergrowing crops.

In addition to staying cool to the touch, lasting longer and using up to 90 percent less energy, LEDs can also be designed to emit specific frequencies of light that promote plant growth.

"Everyone knows about greenhouses or home growers that use these special fluorescent white lights or filtered light to help plants grow," says Kevin Folta, a horticulture researcher at the UF Institute of Food and Agricultural Sciences. "Light is the language plants listen to when deciding how to grow… and we're learning how to speak these various ways to make plants do what we want them to do, when we want them to do it."

In a paper published in a special December issue of the journal HortScience, Mr. Folta and undergraduate researcher Kayla Shea Childers report on progress made using combinations of LEDs to direct plant growth. They report using specific light frequencies to restrict flowering in the early life of strawberry plants, causing the plants to divert their resources to growing more runners and leaves.

Growers could employ such techniques to encourage stronger plants that produce more fruit. Farmers might even want to employ colored mulches and reflective panels to supplement the effect.

"We still have a lot to learn before we can start using these techniques on a large scale, but it is certainly looking more and more attractive," Mr. Folta says. "Overall consumer demand for LEDs is beginning to make the technology really inexpensive, so it's not inconceivable to picture acres of crops spurred on by LEDs," he adds.

Similar studies are taking place around the planet on crops such as rice, peas, tomatoes and maize.

One of the most prominent uses of the technology, however, could someday be off-planet. Future astronauts could use the same technology used to light Christmas trees to grow their own trees and plants in space.

"As we start to explore space for longer periods of time, we're not going to be able to just take food with us. We'll have to grow it," Mr. Folta said. "Crops have evolved to need the specific kind of light they get on Earth — not on, say, Mars," he adds. "We'll have to give it to them to ensure that desirable plant products are there in space when we need them."