New Zealand wine growers are facing a huge drop in their Sauvignon Blanc crops because of poor weather.

The Grape Growers Association now believes that yields in the Marlborough grape fields, the traditional growing area for SB in New Zealand, will be down 30% to 50% on last year.

The smaller wineries are forecast to be hardest hit which may force them to look at co-operation ventures with the larger growers. The Association has also warned that some may be forced to sell up.

But no-one seems immune from the damage. Even Montana says its yield will be down 15% in its large SB crop.

The blame lies with a wet and cool summer. The low SB crop yields will inevitably have a knock-on effect on domestic sales and exports although growers are hoping the low yields will improve quality and let them push up prices.

"It's been very good in other areas but we are not looking at good yields for the Marlborough Sauvignon Blancs," Grape Growers president Willy Crosse told from his tractor in the South Island.

"But other varieties have seen good average yields and it's still early but wine makers are getting excited about the quality."

Montana, one of the major Australasian wine exporters, says it will boost production of all varieties by 9% this year. This is largely due to a substantial increase in growing area. "We are not that great," says spokesman Zirk van den Berg. "We are up on last year by 9% so anything short of a disaster means things should go reasonably well this year.

"We are looking at producing more high quality wine varieties although that is an on-going change. Making better wines makes us more money. Our exposure in Marlborough has not been as bad as some others possibly because we are larger and our management is better."

Montana believes that its export position should not be hit by the poor SB crop because a number of the other New World growers have also been struggling with various natural disasters which will reduce their sales.

David Robertson, Asia-Pacific correspondent