A sensor to detect when plants are under attack

Athens, GA – What we perceive as a sweet aroma of freshly cut grass is actually the plant equivalent of a distress call, one that the grass releases to signal that the lawn is under attack.

“Plants have a defense mechanism in which they release unique chemicals as means of communicating with other plants,” said University of Georgia researcher Ramaraja Ramasamy. “And the signature is very specific to the type of stress that is experienced by the plants.”

Ramasamy, an assistant professor in the College of Engineering, is currently developing a chemical sensor to detect these odorless, invisible volatiles that foretell plant distress well before they show signs of disease or trauma. The sensor has a variety of potential applications, but he hopes his work will have its greatest impact on farms and food storage facilities. Rather than spray entire fields with expensive chemicals as a preventive measure, Ramasamy hopes that farmers could rely on sensors that identify specific sectors of a field that are under stress. “You can create a network of sensors on a large field, and it can tell the farmer where the infection is,” he said. “Then, he can localize the application of pesticides or herbicides.”

The sensor that promises to make all this possible works much like glucose meters used by those with diabetes or hypoglycemia to test blood sugar levels. A glucose meter is designed to only recognize sugar so it is not confused by the myriad of other chemicals and compounds found within human blood. Similarly, Ramasamy’s sensor is designed to only identify specific molecules associated with plant distress or decay—so that the dust, pollen, pesticides and other elements floating through the atmosphere won’t confuse it.

http://pubs.rsc.org/en/content/articlelanding/2012/an/c2an35350d.