Almost 48,000 affected apple and stonefruit plants and small trees were secured at 50 sites nationwide following a July 31 MPI directive to destroy or contain material imported from a specific United States facility since June 2012 that could not be confirmed as being free of pests and diseases.
The sites included eight Central Otago stonefruit orchards, although there was no information on which orchards had been affected, and no sign of disease had been found in the district.
The MPI directive was challenged by a group of North Island growers and a judicial review was held.
The MPI announced this week 20,000 apple plantings and 400 stonefruit plantings had now been released from all restrictions following additional testing of the plants for pests and diseases of concern.
"As all the test results were negative and we are satisfied the biosecurity risk has been minimised, we're pleased to be in the position to release these plants back to their owners," MPI director of plant and pathways Pete Thomson said.
Another almost 20,000 stonefruit plants needed further testing over spring and summer, when diseases of concern "will be most evident if they are present", Mr Thomson said.
More than 1000 apple plants from 12 owners and more than 6000 stonefruit plants from 20 owners were voluntarily destroyed after the MPI directive.
Mr Thomson said MPI "remains open to receiving requests for payment for direct and verifiable losses incurred as a result of destroyed or contained plant material".
A statement from the growers who challenged the original directive said they were encouraged by the release of some of the affected plantings, but there was "still a way to go".
Industry member and owner of McGrath Nurseries, Andy McGrath, said the new MPI announcement had "vindicated" the industry's challenge of the directive and was the "first step towards rectifying the unlawful actions imposed by MPI".
But he said issues over the testing and release of the remaining stonefruit plants still needed to be resolved.
"The vast majority of stonefruit plants remain in containment and the testing plans that have been proposed by MPI are, in our view, overly strict."
