PWD is caused by a soil-borne fungus, Synchytrium endobioticum, an internationally listed quarantine pest which can remain viable in the soil for over 30 years.
Once an area is found to contain the fungus, it can no longer be used for potato growing until subsequently given the all-clear. Around 700 "townlands" (administrative areas) covering 70,000 hectares were under such restrictions in the province.
From 2000 to 2011, inspectors from the Department of Agriculture and Rural Development (DARD) carried out a systematic programme of soil sampling and trial planting at the sites under the guidance of plant pathologists from the Belfast-based Agri-Food and Biosciences Institute (AFBI), before declaring all to be free of the disease.
Northern Ireland's agriculture minister Michelle O’Neill said: "I welcome the fact that the north of Ireland is alone internationally in achieving de-scheduling of the entire territory through this method.
"The availability of clean land, free of fungal disease will enable producers to grow varieties in demand for home ware trade and expand the availability of land for seed export production."