Geneva, N.Y. -- An important breakthrough in the measurement and regulation of water stress in grapevines and vineyards is closer to reality with the development of a microsensor that can be embedded in the trunk of a grapevine. For more than 15 years, monitoring and optimizing water relations in the vineyard has been a major research interest of Dr. Alan N. Lakso, a Cornell professor in the Department of Horticultural Sciences at the New York State Agricultural Experiment Station in Geneva, N.Y.

Drought and overwatering are both factors that can reduce wine quality. Until now the chief tool has been to measure and regulate soil moisture. But this method has had major drawbacks, since a grapevine's roots are not uniformly distributed in the soil. Additionally, soil moisture doesn't take into account important fluctuating atmospheric conditions such as temperature or sunlight.

Lakso has long tried to find a way to monitor water status inside the grapevine on an ongoing basis. "To measure for optimum stress," he says, "it is necessary to know exactly what is going on in the vine, not just the soil." He sees the situation as analogous to the difference between a doctor checking a patient's heart once a week and having that person on a heart monitor that provides continuous readings.

The breakthrough came when Lakso learned about the pioneering work of Abraham Stroock, associate professor of chemical engineering at Cornell. Stroock had developed a synthetic tree that mimicked the flow of water in plants through the use of microfluidic tubes. Lakso went to see Stroock, and the two began to design a microsensor that would meet Lakso's goals. Currently they are engineering the components at the Cornell Nanofabrication Facility and hope to have prototypes ready this fall.

The microsensor will be only a few millimeters in size, and it will be embedded in the spring in the trunk of the vine, allowing the vine to grow around it. The number of sensors required in a vineyard to give accurate information about the water relations in the vineyard will depend on the uniformity of the vineyard site and the soil. Variable vineyards will require more sensors.

Once the sensor has been fully developed and tested, plans are already under way to make it commercially available. Infotonics, a firm in Canandaigua, N.Y., that specializes in microelectromechanical systems, is collaborating in planning the eventual commercialization.

Lakso speculates that the microsensor will become part of a wireless network that will ultimately transmit additional data such as humidity and temperature to a central server that would then make the information available to growers via the web.