How long it had been in the affected orchards before symptoms emerged was "anyone's guess".
"The reality is that we are dealing with a wind-blown spore here, a minute thing that blows around in the weather ... it could be on your shoe right now, for example," he said.
"We're living with a pathogen forever and that's going to be in all of our orchards everywhere, except maybe Nelson, which has a distinct geographical advantage."
The long-term solution lay with genetics, he added.
"If they can breed cultivors that are more tolerant, eventually it means we won't have to spray so much," he said.
The future of the industry depends on how the disease is managed.
Ian Greaves, who is involved with the pastoral care of growers, said the way the kiwifruit community had pulled together was "absolutely inspiring".
"Across the industry is a myriad of people helping," said Mr Greaves, who works closely with KVH and New Zealand Kiwifruit Growers Inc.
"Rural people are pretty resilient."
Growers were being encouraged to eat well, sleep well and exercise to help them cope with anxiety and stress.
"What we're saying is look after yourselves as well as your plants," Mr Greaves said.
"And if it all becomes too much and they are overwhelmed they should talk to their doctor."
While financial concerns were a major stress factor, there was another layer to people's grief. "If you've spent your whole life developing an orchard it's your life. It's your business, where you go to work. It's not just money it's all your effort. Money is only a measure. To have it die in front of you really hurts you."
Turning Point Trust mental health support worker, Aubrey Quinn, who has been involved in a series of seminars to support people affected by Psa, said orchardists and their families were stressed, shocked, and anxious but they were coping well.
"The kiwifruit community is good at doing this sort of thing," Mr Quinn said.
Psa is Stressful, a seminar for kiwifruit growers will be held at Bethlehem Baptist Church on Monday, December 3, between 4pm and 5pm.