An outbreak of black sigatoka on bananas, a fungal disease that affects fruit and vegetables, is costing producers in North Australia over A$4m every week after an embargo was placed on fresh banana consignments. Inspectors from the Department of Primary Industries (DPI) are still looking for the source of the fungal disease.

A ban on the movement of all fruit and vegetables has been enforced on an area within a 50km radius of the first known case of black sigatoka, near Tully. Currently, over 400 farms are affected, and the quarantine zone will remain intact until all the farms are pronounced free of the disease.

Vicky Kippin-O'Connor, chairwoman of the Australian Banana Growers Council, commented: "A program of inspection to grant approvals to move fruit will start at the extremities of the 50km radius, and the area will be worked through systematically to recover the farms as quickly as possible. We have more than 30 DPI people […and] industry consultants helped out during the weekend, and this is one of the reasons we are so far ahead of where we expected to be."

Kippin-O'Connor added that infestation was not believed to be widespread, because it was spreading west on the wind and "all trees have been heavily de-leafed to stop the spread of windborne spores."

She stressed that the fruit and vegetable growers in Tully and neighbouring Innisfail are complying fully with the ban.

"At this stage, we are quietly hopeful we have identified the extent of the infestation," She said, "As soon as we can announce this, which could be this week, the industry will have to make a decision on what happens with the infested land… We are in a period of very high production, and 400,000 cartons, worth about A$4m, left the area the week before the embargo."