KEY POINTS:
A tiny louse with the potential to cause headaches for the wine industry has been discovered in Wairarapa.
Phylloxera was found three weeks ago at Matahiwi Estate, 5km north of Masterton, infesting 25ha of ungrafted and non-resistant grapevines, said Matahiwi Estate general manager Jane Cooper.
"The rest of the vineyard is planted in grafted vines that are resistant to phylloxera and while there is little negative effect on the quality of wine produced from affected vines, crop levels lower over time, making replacement economically inevitable," she told the Wairarapa Times-Age.
She was unsure how the vineyard came to be infected with phylloxera.
She said the infection was either from plant material or soil traces brought in on vehicles from affected regions.
"Given that phylloxera is already present in most wine-growing regions in New Zealand, it's impossible for us to conclusively determine where this has come from."
She said Matahiwi Estate would undertake a five-year replanting programme where 20 per cent of affected vines would be replanted every year.
Phylloxera is present in the winegrowing regions of Marlborough, Hawke's Bay, Gisborne, Nelson and Central Otago.
The phylloxera pest nearly wiped out the European wine industry in the late 1800s after it arrived from America.
European winemakers were forced to import resistant American rootstocks and graft their vines onto them.
- NZPA
