POOR wine grape prices could lead to Sunraysia growers leaving fruit to rot on the vines this harvest.

Growers expect contract prices to barely meet the cost of production and spot market prices could be even lower.

All prices are down more than $100 a tonne on 2008.

Chardonnay is expected to be about $300, semillon $400, cabernet sauvignon and shiraz $500 and merlot $450.

Murray Valley Winegrowers chief executive Mike Stone said it was too early to say if many growers would leave fruit on the vine.

"It has happened before and it will happen again, particularly if the spot price is $150 to $200," Mr Stone said.

"That's $50 to $200 a tonne below the cost of production."

Mr Stone said the low prices could not be blamed wholly on oversupply.

He said in the Murray Valley most varieties were "broadly in balance".

Sunraysia grower Bill McClumpha said chardonnay cost about $500 a tonne to grow and red varieties $700 to $800.

Water costs could add another $50 to $200 a tonne, Mr McClumpha said.

Wine Grape Growers Australia executive director Mark Mckenzie said the prices announced by the major companies were below the cost of production for chardonnay and marginal for other varieties.

"My message for growers is if they cannot meet their cash costs, including freight, then they need to consider whether to harvest," Mr Mckenzie said.

"I expect there will be a bit of chardonnay left on the vines although reds are holding up quite well."

Mr Mckenzie said the companies were probably looking to balance the higher cost of the grapes they bought last year.

"They think they paid too much last year," he said.

He said the country's harvest was tracking towards last year's figure of 1.83 million tonnes.

Mr Mckenzie said a drop in demand was partly due to the effect of the high Australian dollar early this year.

He said the three month slide by the dollar should help to boost exports.

"I genuinely expect to see some improvement in our exports," Mr Mckenzie said.

"But consumer sentiment in the US is at an all-time low. People are watching their pennies, so I would not expect to see a huge bounce."

Mr Mckenzie said the Wine and Brandy Corporation's export approval record in November showed a small increase.

"We have bounced off the bottom and we're heading up for exports," he said.