Apple exporters are optimistic, but at the same time realistic on shipping to an Australia market open after 90 years, as reported by the New Zealand Herald.

Pipfruit NZ chief executive Peter Beaven told the Herald that some early failures last year are seen a reality check on the rules of the trade, particularly the Aussies' biosecurity rules.

Beaven recalled there had been some small shipments last year but three had failed Australian biosecurity rules - one for apple leaf curling midge, one for the midge and trash contamination and another for trash.

The midge in general was not regarded as a pest in New Zealand because it stunted some growth that was unwanted and had to be pruned out, but it was an actionable pest for some markets including Australia, according to the Herald.

Beaven said late flowering in farms would delay by as long as one week the harvest time which would normally get underway in mid-February.

Tens of thousands of cases are expected to be shipped to Australia this year and a longer-term market opportunity for about 500,000 cases, Beaven said, adding, the Australian market could be worth $30 million or more to New Zealand growers in a few years, representing about 3 to 5 per cent of production.

A ban on New Zealand apple imports had been in place since 1921 because of fire blight, with apple leaf curling midge and European canker added later, but was lifted last year following the settling of a case in New Zealand's favour the previous year at the World Trade Organisation, the Herald chronicled.

Learning from last year's rejections, NZ Ministry of Agriculture and Forestry manager of plant imports and exports Stephen Butcher said the failure last year somehow proved useful for the NZ government and the country's exports business.

"The trial shipments have been successful in identifying what we need to work on for the coming season, when exporters will have larger quantities of fruit coming on stream," Butcher said.