Loss could run to $1 million

BY JOHN EDENS IN ALEXANDRA

Vines worth millions of dollars in the primary grape-growing region of Central Otago were damaged after a chemical was sprayed over crops last month.

A hormone-based agricultural spray – commonly used to kill gorse and broom – drifted and damaged vines and leaves in at least 18 vineyards in the Cromwell basin off the Wanaka-Luggate road.

Central Otago Winegrowers' Association executive committee member and viticulturist James Dicey said abnormal, misshapen leaves were first noticed last month.

But it was this week the growers realised just how many vines involved, he said.

A 30ha block and another 10ha plot of young vines were the worst hit, while at least 16 other mature vineyards suffered damage to the occasional leaf or vine.

Young vines were particularly susceptible to hormone-based sprays, and any damaged crops would be delayed for a season or longer, he said.

The two young blocks would produce about $660,000 of grapes, or 1500 cases of wine, in turn worth $6.5 million.

The delay could translate to a net loss of about $1 million, Mr Dicey said.

Concerned viticulturists discovered the damage extended over 95ha but growers were unable to track down the source of the spray.

It appeared to have drifted some distance from the northeast around Tarras, he said.

Mature vines could weather the minimal damage so grapes and wines would not be contaminated in any way, he said.

"Had a more significant spray drift occurred the vines could have lost their crop for the current season and taken two or three years to recover," he said.

Landowners needed to be aware of how to spray and should limit application to the winter months, when grapevines were dormant and without leaves, he said.

Central Otago Winegrowers' Association president Nick Mills said the incident served as a wake up call to landowners to use hormone-based sprays sensibly and safely.

New Zealand Wine Growers' policy manager Dr John Barker said spray drifting was a perennial worry for viticulturists.

Herbicides sprayed from helicopters or light aircraft could drift for miles and it was difficult to prove the source, he said.

- © Fairfax NZ News