A potato virus which has the potential to affect crop production has been found to be widespread, meaning eradication is impossible.
The Potato Mop-Top Virus (PMTV) was first discovered in grower paddocks in Canterbury in September 2018.
It was the first time the virus had been found in New Zealand, however it is common in other countries.
A national survey to determine the extent of the disease has now been completed, confirmed it has spread throughout the country.
Biosecurity New Zealand acting director readiness and response services Sam Leske said the joint Biosecurity New Zealand and Potatoes New Zealand response to PMTV would now be closed out, with the industry taking the lead on long-term management.
"It became evident earlier into the response that this disease couldn't be eradicated, and that the best outcome for potato growers was for industry management long-term," he said.
"Biosecurity New Zealand will continue to support industry in helping them develop the long-term management plan, which will include non-regulatory controls and voluntary agreement."
It's the first time the two organisations have worked together on a biosecurity response since signing up to the Government Industry Agreement (GIA).
Potatoes New Zealand chief executive Chris Claridge said it was a successful end to the first joint response and management of the virus had been successful so far.
"We've got a plan in development and that will incorporate research from world experts, in line with best practice. A positive outcome to date is that there have been no significant losses to growers attributed to the disease," said Claridge.
"This response is an example of how a good partnership between government and industry works to eventually help industry to be in a position to mitigate impacts posed by biological incursions and to support decision making for the future."
Affected potatoes can display symptoms including distortions to the skin, deep cracking, and rust-coloured arcs, streaks or flecks in the tuber flesh.