The spread of the kiwifruit vine-killing disease Psa shows little sign of abating in New Zealand, with Kiwifruit Vine Health (KVH) revealing that further infections have been discovered this week.

KVH, which was established to lead the fight against Psa, said in its latest report that 30 new cases of the disease had been discovered this week, across Te Puke, Tauranga East, Tauranga West, Katikati, Whakatane, Opotiki and Franklin.

The total number of infections in New Zealand is now up to 1,305, with 49 per cent of the country's kiwifruit hectares on an orchard identified with Psa.

"Of course we're concerned that it's spreading but it was always expected to do that," said Peter Ombler, KVH board spokesman. "It's an airborne spore that can spread through an area very easily."