French wine growers use satellites as harvest guide

For centuries French wine growers have looked to the skies and prayed for the rain not to spoil their vineyards before grape harvest time. Now, a rising number a seeking help from the heavens for other reasons, in the form of satellite technology.

With grape-picking time fast approaching, dozens of wine domains in France-from the best known Bordeaux chateau to humbler vintners in the Languedoc-Roussillon region-are awaiting information from satellites on when and how to harvest their grapes. The information they will receive would, some say, take 20 to 30 years to build up from observation on the ground.

Satellite-borne cameras have been circling vineyards taking multi-spectral images from more than 500 miles above the Earth at the rate of 1,000 plots every eight seconds. These can detect the surface area and variation of leaf canopy across vineyards. This is a vital statistic to pinpoint the vigour of particular vines, the water level of soil, bunch and grape weight, and the presence of certain minerals.

The Spot-5 and Formosat-2 satellites began mapping this data at the period of veraison, a grape-growing term to describe the moment the berries begin to ripen, swell and change colour.

Wine growers provide data on their fields and a few details about their vines and grape variety. Then, when the time is right, the satellites take pictures. These allow the growers to determine when grapes are mature for harvesting. They also show variations in grape quality within plots, meaning growers can separate out lower-grade bunches for vin de table and keep the best for higher-end grands crus. (August,2011-Daily Telegraph, London – Henry Samuel in Paris).