Producers have said it has been one of the most challenging seasons in living memory.
The warning came as a major conference looking at the latest developments in potato farming opened in Dundee.
Some 700 farmers have gathered at the Potatoes in Practice conference at Balruddery Farm. The event is Britain's largest field-based potato industry event.
The site is used by the James Hutton Institute to put research into practice, and gives farmers the chance to see the latest developments first hand.
Balruddery manager Ewan Cauldwell said: "It's been fairly bad, we've faced the same challenges as any of the other growers in the area.
"Right from planting it's been very wet, we've had a lack of sunshine, there's been a lack of temperature, the disease issues have been particularly bad, the pressures on disease have been bad, the ground conditions have been wet and the opportunity to get on control these diseases has been challenging in itself."
He said the season had been challenging for other crops as well not just potatoes, but the main concern for growers was just how bad harvests were going to be.
