The fatal Italian strain of the Psa bacterial virus is spreading in the eastern kiwifruit orchards of Te Puke.

Kiwifruit Vine Health Incorporated general manager John Burke says the number of orchards affected with the worst of the two strains of the bacteria has risen to 37, up from only three prior to Christmas.

John Burke says Psa is here to stay and the focus is on managing the disease, not eradicating it.

The strain, which kills kiwifruit vines in Italy within two to three years, is their main focus, says John.

Testing is being carried out in and around the ‘Italian high priority zone' with the Asian strain found in most of the Psa positive orchards outside the eastern area.

'There is 240 hectares of orchards confirmed with the Italian infection,” says John.

'We are mapping these orchards to see where the infection is and to what extent; in most cases it is probably not right through.”

In the Gold orchards, the Italian Psa is killing canes and in the Green orchards there is primary infection with spotting on the leaves; leaves are curling up and dying.

'The Green seems to be a bit tougher.

'It's killing vines over there so we suspect we will get the same effect. With Gold it's very rapid, with Green it's a little slower.”

John says the priority now is working out a management plan to stop PSA spreading further.

'We won't be able to eradicate it, but we are trying to contain it.”

Currently they are using copper-based sprays to reduce inoculum levels, but John says they will need to remove infected vines.