New Zealand exporters should be targeting markets such as aspiring middle classes in China where people can afford to buy premium New Zealand produce such as wines, said New Zealand Agriculture Minister David Carter.

"The challenge we have is to make sure the Chinese middle class gets a taste for New Zealand wine, because that middle class is huge," he told Winegrowers NZ's national conference in South Island town of Blenheim on Friday.

"Of China's 1.3 billion people, at least 250 million earn the same per capita income as the average New Zealander, so they can afford our premium products," he said.

Carter told the conference that China was now New Zealand's second-largest trading partner and that the free trade deal meant from the end of next year there would be no Chinese tariffs on New Zealand wine.

"Our exporters will have a significant advantage over international competitors who will continue to pay tariffs between 14 and 20 percent," he said.

Over the next 40 years the world's population was expected to increase from 6 billion to 9 billion people, he said.

"As a producer of premium products, our target will be the upper and middle classes the 50 million people in the future that can afford, and are prepared to pay more, for high quality food and beverage that is backed by integrity and reputation," he said.