Who likes pink ladies??

In a recent development with ripe opportunities for rotten puns it appears the WTO are about to overturn a ban on NZ apples into Australia. At present NZ apples are banned from Australia due to the presence of fire blight which is a contagious bacterium that can destroy an orchard and leave it looking burnt.
At present NZ exports apples to 65 nations although it is currently banned from Australia due to customs regulations. For NZ growers it could increase exports between $15-20 million per year.
Check out the link above for more info.

The ban has existed since 1919 and of course local Australian growers are not saying she'll be apples. Are customs regulations necessary or is it a form of protection?