Plants in three glasshouses were removed and destroyed before Christmas after testing picked up potato spindle tuber viroid. (file picture) Photo: RNZ / Tracy Neal
Biosecurity officials are investigating how a plant disease got into the country, after it was detected on a commercial tomato crop in the Tasman district.
The Ministry for Primary Industries (MPI) said plants in three glasshouses were removed and destroyed before Christmas, after testing picked up potato spindle tuber viroid (PTSVd.)
Biosecurity director John Walsh said the virus was not harmful to humans or animals, but could cause a loss of production in plants from the tomato and potato family.
The virus had not been found anywhere else and MPI was working with the industry to monitor for any signs of it, Walsh said.
"Symptoms of infection can vary, and some infected plants may show no signs of disease but have a lower- than-normal yield. In this case, the strain was mild so symptoms may be difficult to recognise and differentiate from other common diseases or environmental conditions."
On two previous occasions, PTSVd had been detected in New Zealand and successfully eradicated, Walsh said.
As part of the biosecurity response, MPI was investigating how PSTVd had arrived into New Zealand, he said.
"Tracing of seeds and rootstock of the infected crop is being carried out to determine its pathway into the country."
Visible signs on tomato crops affected by a severe strain of PTSVd could include stunted spindly plants as well as fruit not ripening or having dead tissue.
In potatoes specifically, symptoms get worse with each generation and the potatoes are spindly with pointed ends with growth cracks.
