Northern Ireland potato prices have recently fallen below the cost of production. Official figures showed non-contract prices averaging 73 pounds (US$117.50) a ton-well below the break-even prices of $161 a ton.
The present price is 42 percent below last year's $201 a ton.
Ulster Farmers' Union Crops Secretary Alex McGarel blamed a Europe-wide potato glut. He said growers should look for markets and agree on a price, variety and tonnage before planting next season's crop.
"You need to know your market and target your production at it," she said.