摘要：This experiment were conducted with three cultivars of potato such as Agria, Satina and Caesar and four irrigation regimes (after 30 mm evaporation from class A evaporation pan, after 30 mm evaporation from class A evaporation pan with spraying by potassium humate, after 60 mm evaporation with spraying by potassium humate and after 60 mm evaporation from class A evaporation pan) in three locations of Ardabil in Northwestern Iran during 2007-2008 with split plot method. Potassium humate sprayed (250 mL ha-1) in the three stages of emergence, before tuberization and during tuberization period. Combined analysis of variance showed that were significant differences between locations, years, irrigation regimes and cultivars and their interaction on tuber yield. According to the NPi(1), NPi(2), NPi(3), NPi(4) and NPi(5) methods, Satina and Caesar were stable but Agria unstable and had the lowest value. Caesar cultivar is most stable and adapted across environments well; the highest mean of rank and yield and high ranking under normal, stress with potassium humate and stress conditions. In this study nonparametric statistics (S1(1)) selected.
