WAC is asking the judge to back its existing right enshrined in state law to collect $0.25 a box to promote and advertise Washington's fresh apple crop.

If the judge, who was examining the case last week, cannot make a decision it is likely to go to court in May.

The dispute is significant as the levy is under increasing pressure from growers opposed to it. There have also been similar debates in the US produce industry involving the peach, table grape and mushroom industries.

Apples are a hugely significant crop in the state of Washington with an estimated value of $1.1bn this season. The state accounts for roughly half of the US harvest and more than 80 per cent of its exports.