Scramble to prevent vineyards freezing

Fog hangs over an irrigation pond feeding overhead frost-fighting sprinklers on a vineyard between Cromwell and Wanaka yesterday morning. Photo by Mark Price.
Fog hangs over an irrigation pond feeding overhead frost-fighting sprinklers on a vineyard between Cromwell and Wanaka yesterday morning. Photo by Mark Price.
Another touch of frost through Central Otago and the Waitaki Valley had vineyard managers and workers scrambling again yesterday morning.

Overhead sprinklers and wind machines were brought into use when temperatures dipped around dawn, although helicopters were not required for frost-fighting.

Central Otago Winegrowers Association president James Dicey said there was virtually no frost on the vineyards he manages in the Upper Clutha, between Wanaka and Cromwell.

Temperatures were milder than on Sunday and Tuesday mornings, when frosts damaged new growth on vines.

Mr Dicey was still assessing the damage. He had found in past years frost-damaged vines could still produce crops, although they were of reduced size.

He was less concerned about damage to leaves and growing tips than to grape inflorescences [flower clusters]. Damage would not become apparent until after flowering and fruit-set.

Consultant Timbo Morrison-Deaker said on the 200ha of viticulture land he |manages in the Cromwell basin and Gibbston Valley there were "some pretty good frosts" but the temperature in vineyards did not fall far below zero.

Mr Morrison-Deaker decided not to call in helicopters for vines damaged in earlier frosts.

He was still surveying the damage but it would be "fair to say" there would be a "reasonable" crop loss - "but we won't be able to work that out until post-flowering."

• Correction: Frosts in Central Otago in the last week will affect the quantity of grapes produced this season, not the quality. Central Otago Winegrowers Association president James Dicey was incorrectly quoted yesterday.