New Zealand blueberry growers have the green light to enter the South Korean market for the first time.

Minister for Trade and Agriculture Todd McClay has unveiled the long-awaited duty free agreement, with the Ministry for Primary Industries (MPI) working behind the scenes to gain biosecurity sign off.

Blueberries New Zealand chief executive Kelvin Bezuidenhout said growers expected positive spin-offs and a good deal of competition from local producers and rival southern hemisphere exporters.

"We know there are good opportunities for our window," Bezuidenhout said.

"There are not sufficient blueberries for them to supply their market all year so it's really up to us to exploit the opportunity we have been given."

New Zealand sells about 80 percent of its export crop to Australia, with South East Asian countries Vietnam and Singapore also taking New Zealand berries.

South Korean consumers will have to pay a premium for the New Zealand fruit.

"They do have a choice at the moment, they've got their own domestic product," Bezuidenhout said.

"In the southern hemisphere window there are Chilean blueberries in there at the moment and we'll have to compete with those.

"Typically their product will probably be at a lower price point so we'll have to prove ourselves that it's worth paying a premium for great New Zealand product."

New Zealand sells about 80 percent of its export crop to Australia, with South East Asian countries Vietnam and Singapore also taking New Zealand berries. Photo: Facebook / Bay Blueberries farm

Growers had been laying the groundwork at a recent trade fair Asia Fruit in Hong Kong to make inroads in the new market.

Bezuidenhout said the removal of tariffs certainly helped.

"It's a new market. We've got to do the leg-work in market to get the trade established."

Cyclone Gabrielle devastated crops last year, he said, but growers are on track this year for a bumper harvest this season.

McClay said the agreement unlocked an estimated $5 million in annual export opportunities, while Bezuidenhout said that figure was a target as growers establish a foothold in South Korea.

"Increased market access is a key part of the government's strategy to increase trade value for New Zealand's safe and high-quality produce," McClay said.

"We are steadfast in our efforts to reduce barriers, open new markets and return greater value to exporters back pockets."

Officials from MPI "will now move to implement the necessary compliance measures" to ensure that New Zealand exporters are able to begin shipping blueberries to Korea as early as December.

New Zealand exports about half the blueberries it grows, with the rest sold to the domestic market.