Published on 02/21/07

Monitor reveals how plants feel, what they need

By Sharon Omahen
University of Georgia

With the help of a controlled-atmosphere facility and sensory equipment, scientists at the University of Georgia are learning how agricultural crops will react to future climate change.

The facility is the Georgia Envirotron on the UGA campus in Griffin, Ga. Using a series of enclosed growth chambers there, researchers can study how stresses affect plants. The chambers allow them to control temperature, humidity, carbon dioxide and light. And they subject plants to air pollutants and other atmospheric gases.

The sensory equipment is a device called a Phytosynthesis and Transpiration Monitor. The PTM sensors attach to plants. And with the help of computer software, they show what the plants need.

How do the plants feel?

"The PTM sensors close and open on the plant's leaves every 30 minutes," said Gerrit Hoogenboom, an agricultural engineer with the UGA College of Agricultural and Environmental Sciences. "The data from the sensors is transmitted to a computer and processed. We then know how well a plant responds to different environmental conditions and if it's under stress."

Hoogenboom and visiting Israeli scientist Jiftah Ben-Asher are using the Envirotron and PTM to study global warming's effect on corn.

"Until now, most of what we know has come through computer modeling," he said. "Using this method, we can directly measure how global warming will affect agricultural crops. We know what has happened in the past. But we don't know what's going to happen in the year 2070 and how it can ultimately impact agriculture."

Focusing on corn

Hoogenboom and Ben–Asher are recording how corn plants react to changes in temperature, humidity, carbon dioxide and other major variables that can affect crops.

"We chose corn because it's a relatively important economic crop for Georgia, the Southeast and the entire United States," he said, "and because of its potential as a bioenergy crop. It's also a fast-growing crop with a short cycle, which is excellent for research purposes."

Using "artificial dew," the research team is evaluating how plants react to early morning irrigation schedules, too. And they're measuring the rate of water flow in the plant stems, soil water content and transpiration. All are potential indicators of the response of crops to climate change.

"Farmers can then adapt their management schedules based on these findings," Hoogenboom said. "Understanding how a crop will react to temperature changes will help farmers know when to plant to compensate."

Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.