The cool wet weather has led to a spike in the number of newly identified PSA infected kiwifruit orchards in Bay of Plenty.
About 100 new orchards have been identified as having the plant-stunting bacteria in the past three weeks.
Chair of Kiwifruit Vine Health Peter Ombler says the drop in temperature and increase in moisture levels are ideal conditions for the bacteria.
He says autumn and spring are the times of year when PSA is most prevalent and so it's no surprise to see an increase in cases.
Mr Ombler says the increase in cases comes after the drought, which put the bacteria on the back foot and very few new orchards were identified as being PSA positive.