Three categories of incursion would apply - localised, medium-scale and large-scale.
To be eligible for assistance, those affected would need to show they have taken all reasonable steps to mitigate and manage biosecurity risks.
New Zealand Kiwifruit Growers Incorporated (NZKGI) president Neil Trebilco said the group had worked with the Government to have biosecurity issues such as Psa included in the definition of Adverse Effects.
The move is a first step to having relief measures available for those growers hardest hit by Psa, Mr Trebilco said.
"The next step is for NZKGI to continue to work with Government to communicate the hardship that some growers are facing so that relief measures can be made available. At least now there is a framework to work with."
Mr Trebilco said the reality was that any relief made available as a result of the change will only help those hardest hit by Psa.
While Psa was tough for all affected growers, it was expected that around 120 growers might qualify for the sort of relief available under the Primary Sector Recovery Policy.
The policy covered production businesses within the agriculture, horticulture, forestry and aquaculture sectors.