System lets grape growers rest easy

Pioneering winemaker Daniel Le Brun has developed a frost-fighting system, using electric cables, that means sleep-depriving frost fans and helicopters could become a thing of the past.

"This is definitely the way of the future," said Mr Le Brun, 64, who brought his methode champenoise winemaking skills to Marlborough in the 1970s.

"It has never been used in Marlborough before and is clean, green and, most importantly, quiet. It will be socially and environmentally acceptable to everyone."

Mr Le Brun has trialled his hot-cable system on a one-hectare test block on his No 1 Family Estate vineyard and is poised to convert the rest of his 32 hectares should the need arise.

The hot-cable system uses electric cables fastened to existing fruiting wires in the rows to heat up canes which then warm the sap and circulate to all areas of the vine, protecting precious tender, green shoots.

The system has been proven to work down to 6C and below.

"People are astonished, it is so simple," he said.

"They ask why has no one thought of it before?"

At $50,000 a hectare, the set-up cost is high, but Mr Le Brun said that once it was installed, the running costs were low compared to other systems.

The system uses a solar-panelled switchboard connected to a generator which kicks in automatically with instant heat generation whenever sensors dip below the temperature setting.

Mr Le Brun first saw the system, which is near noiseless apart from the hum of a generator, in France 10 years ago and was astonished to see how effective it was.

"On a frosty morning we visited a vineyard in southern Champagne. On one side the vines were brilliant white, covered in frost, and on the other were bright green leaves glistening with dew in the sunlight. I could hardly believe it."

At the time, Mr Le Brun was unable to import the cable into New Zealand and has only recently been successful with a new Danish manufacturer. He has now teamed up in a joint venture with John Mackey of Blenheim's Cresswell Electrical to offer the technology to other vineyard owners.

The system, which uses similar technology to underfloor house heating, has been successfully used on trial grape blocks in Otago, Canterbury and Martinborough.

The only drawback, said Mr Le Brun, was that pruners had to be extra-careful with their loppers not to cut the cables.

- NZPA