The nation's 2010 grape harvest has just started in the North Island and grapegrowers say they expect it to be the same size or just slightly smaller than the 2009 vintage.
"Based on data received from 59 medium and large wineries, our expectation is for producers to harvest between 265,000 and 285,000 tonnes of grapes this year" said Philip Gregan New Zealand Winegrowers' chief executive officer.
That would be marginally smaller than the 2009 and 2008 vintages - both of which had harvests of 285,000 tonnes.
Wineries covered by the survey accounted for 88 percent of the 2009 grape harvest, but this year the vintage will be produced from around 33,000 hectares of grapes, up 2000ha from last year.
The prospect of a slightly reduced vintage, despite a further increase in the area of producing vines, showed a focus on quality, he said.
"Producers will continue to focus on the key element in New Zealand wines' export success of the past two decades - producing world class grapes and wines".
Mr Gregan was positive about the outlook for the vintage. "Although in some regions the harvest seems to be running a week or two later than last year, the prospects for the vintage are looking good. The key for a successful harvest will be the weather over the next two months."
Winegrowers chairman Stuart Smith last month predicted that for the first time yield caps, not price, will be the major talking point in negotiations between wineries and growers in Marlborough this season.
Six of the largest wineries in New Zealand from Montana to Nobilos all buy fruit from Marlborough's 568 wine growers.
Mr Smith said the major feature this year would be a yield cap per hectare, with growers tied down to a specific tonnage.
One Marlborough winegrower, who did not wish to be named, said wineries were offering about $1200 per tonne with a yield cap of 12 tonnes per hectare, which he suggested was close to break-even point for many grape-growers.
Contract growers have reported wild variations with prices offered as low as $600 a tonne to $1600 for sauvignon blanc, with restrictions as low as 9.6 tonnes per hectare.
Industry commentators have been saying since the first bumper harvest in 2008 that dumping excess bulk wine on the international market risks devaluing the country's reputation as a top-quality wine producer.
The industry managed to hold the 2009 grape harvest to the 2008 level of 285,000 tonnes, but has said it would prefer the lower end of the current season's range, around 265,000 tonnes.
In 2009 bulk wine exports quadrupled from about 5 per cent of total export volumes to almost 20 per cent. This gave rise to opportunistic brands with a short life that were usually owned by retailers with no stake in the New Zealand industry, according to Mr Smith said.
Common methods for reducing the harvest were pruning vines to put them to "sleep" for the season and viticulturally managing blocks to produce fewer, higher-quality grapes.