South Australia will try and protect its apple and pear orchards from fire blight with new quarantine areas.
The federal government has cleared the way for New Zealand to export apples to Australia, lifting a ban introduced in 1919 for fear of fire blight disease.
SA's Agriculture Minister Michael O'Brien says Australian quarantine officers have already found in two consignments an apple with leaf matter that could have been carrying fire blight and an insect pest.
"Within three days the assurances we have been given, as a nation, have proved to be very, very flimsy," the minister told reporters on Tuesday.
Three quarantine zones will be set up - new ones in the Adelaide Hills, where 80 per cent of the state's apples and pears are grown and one just outside Mt Gambier.
The existing fruit fly quarantine area in the Riverland will be amended to include fire blight restrictions.
"This isn't about halting free trade. It's about protecting SA horticulture and jobs," the minister said.
"If we limit it to a tight quarantine zone over those areas, we believe that the quarantine zone proposition could not be challenged in the courts.
"They will be a quarantine zones similar to the fruit fly quarantine zone in the Riverland, you will not be permitted to take apples and pears into those areas."
The government will try and exclude large regional centres but where it can't, retailers will be asked to ensure the fruit they sell comes from disease free areas.
Apple grower Michael Stafford has welcomed the proposed quarantine areas for the state industry that is worth $80 million at the farm gate.
"Fire blight will have a devastating impact on my business and the state, whichever state it was found in, it would mean you would be excluded from the rest of the markets in Australia and potentially overseas as well."