Maris Piper (as seedling X8/5) completed the official Immunity and Merit Trials in Scotland in 1963 and was recommended for “Commendation.”
Letter notifying the PBI that X8/5 had been recommended for Commendation , and the response from the Institute
Trials at the National Institute for Agricultural Botany (NIAB) continued for another year, and the variety, now named Maris Piper, was added to the Recommended List in 1966
Extract from the NIAB Farmers Leaflet No. 3, 1966 (the ‘Recommended List for Potatoes’), the first year Maris Piper was recommended.