Improving Grape Quality with Precision Agriculture

October 5, 2004

COLUMBUS, Ohio -- Precision agriculture is mainly equated with production of field crops, but the technology is finding its place among other agricultural industries.


Ohio State University agricultural engineers are conducting research on the feasibility of using precision agriculture on Ohio grapes — a commodity where both quality and quantity are important to the viability of juice and wine production.

"Research in other places, like California and Australia, has shown that field variability (soil type, compaction, drainage, for example) has a big impact on grape quality. Growers don't know how much they are losing, but precision agriculture can help quantify that," said Reza Ehsani, an Ohio State Extension agricultural engineer working on the project. "Other areas have seen success in using precision agriculture to improve quality for more premium wine production. It would stand to reason that growers in Ohio have the same problems and could see the same successes by using the technology."

Ehsani, along with graduate student Dharmendra Saraswat, are conducting research at Troutman Vineyards in Wooster, Ohio, using aerial imagery, GPS (Global Positioning System), EC (electrical conductivity) sensor and GIS (geographic information system) to measure and visualize variability throughout the fields.

"The goal is to find the factors that can cause variability and measure how those factors can impact grape quality," said Saraswat, pointing out that precision agriculture research in other places has shown an eight-fold variability within a single field. "We are looking for effective tools and methods of collecting information that a grower can use to make better management decisions. It's all about saving growers money while increasing a crop's productivity."

The researchers are taking aerial images of the vineyard during two stages of the grape's development: veraison, the point when the fruit begins to accumulate sugar, and near harvest.

"The reason these two stages are important is because they have the maximum correlation with what is going on in the ground." said Saraswat. "The idea is to extract several vegetative indices from aerial imagery and see which ones correlate with yield and quality."

Researchers are also exploring the possibility of using aerial imagery for making management decisions, such as where pruning or leaf removal are required. If one or both are done improperly, grape quality can be impacted.

"Pruning decisions usually help achieve a balance between fruit production and adequate, but not excessive, shoot growth," said Saraswat. "In regards to leaf removal, you want the grapes exposed to the appropriate amount of sunlight in order to accumulate sugars properly. The extent of vine growth obtained from aerial imagery is expected to guide in this regard."

Ehsani said that other precision agriculture equipment, such as a network of wireless weather monitoring units, could be used to monitor the weather and aid in better controlling for frost — an event that can damage grapes and impact yields.

"The inputs in grape production are huge," said Ehsani. "If we can help growers reduce those inputs by even 1 percent with better management through precision agriculture, that's a significant savings."


Candace Pollock
Dharmendra Saraswat, Reza Ehsani