Growing perfect grapes
Is France ready? One winery has taken the plunge, using real-time sap flow measurements to more accurately manage the irrigation of its vines.
In 2002, when the Cazes family bought two neighbouring properties in the south of France, they opted for a complete restructuring. They replaced 35 of the 60 hectares of vineyard with syrah grapes. “The goal was to improve the quality of the product,” explains Fabrice Darmaillacq, the winery’s technical director. He quickly realised that the parcel was subject to large meteorological variations and that judicious management of water would be essential for the health of the vines and, ultimately, the quality of the wine. He also knew it wasn’t just a matter of increasing the amount of irrigation in accordance with temperature or sun exposure because everything depended on the wind. Paradoxically, more irrigation is needed in cloudy conditions when the Tramontana winds are blowing than on hot days when the wind comes off the sea.
To better manage the vines, Darmaillacq decided to use a technology invented by a French-American company, Fruition Science, that was making waves in the Napa Valley. “Evaluating how thirsty a plant is isn’t easy,” says one of the company’s co-founders Sébastien Payen. “The plant’s appearance can be a misleading indication of its actual water deficit.” That’s how the small company came to the idea of measuring the sap flow inside the plant and then adapting the amount of water, almost down to the drop. Darmaillacq had two sap-flow sensors installed on each of the winery’s parcels. The sensor is attached to the vine, and a resistor on it heats the vine, making it possible to measure the speed at which the sap is flowing and the amount of water being used by the plant. The data are recorded in a solar-powered box and collected either by hand or via a SIM card that sends them on to the winery’s computer system.
The advantage of this technology is that it does not just measure soil humidity but also takes into account atmospheric conditions, notably the desiccating effect of the wind. Measurements are taken every 15 minutes, and software provided by Fruition Science analyses the data in real time, creating water deficit curves that Darmaillacq can consult on his tablet. “I can check the data everywhere, which makes it possible for me to continually adapt irrigation according to need,” he says. The system becomes more effective the longer it’s used; each year’s data provides information on the best irrigation methods,
for example by simulating heavy rainfall once every two weeks or by irrigating with smaller amounts on a daily basis. The software also incorporates meteorological data such as temperature, precipitation, and fruit-sugar analyses. This allows the vintner to build up a multi-year database that can be used to manage each parcel with precision, with the ultimate goal of maintaining the health of the vines and the quality of their grapes over long periods of time.
At €3,000 a sensor, the cost is sizeable. But Darmaillacq considers the money well spent. “The investment is compensated by the significant reduction in water consumption and the improvement in yield and in the quality of the wine,” he says.
It’s not easy for a technology developed by North American winemakers to gain a foothold in France. “California wineries are often owned by Silicon Valley types, who are very open to technological innovation,” says Payen. “It’s not as common in France, but we’re getting there.” He adds that the company now has as many employees in France as it does in the U.S. – proof that, with a little convincing, French winemakers can take the leap.
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