Determining Rank and Stability of Lentil Genotypes in Rainfed Condition by Nonparametric Statistics

One of the applications of Non-Parametric methods is determination of genotypes rank in different environments, which is also used as a measuring stability. A stable genotype shows similar ranks across different environments and has minimum rank variance in different environments. Non-Parametric Stability Statistics require no statistical assumptions about the distribution of the phenotypic values and are easy to use. This study was carried out to determine the ranks of 10 Lentil genotypes (Lens culinaris Medikus) across ten environments in 2002-2004, using a randomized complete block design with four replications. Analysis of Thennarasu non-parametric statistics showed that genotypes 8 and 9 had high stability by NP(1) statistic and genotypes 9, 8 and 1 had stable yield in NP(2) method. Result of the NP(3) statistic was similar to NP(1) statistic. NP(4) statistic selected genotypes 9 and 1 as the most stable genotypes and ultimately NP(5) statistic introduced 9 and 1 genotypes as stable genotypes in this experiment. Also analysis of Nassar and Huhn non-parametric statistics revealed that genotypes 1 and 2 were most stable and well adapted across ten environments. In addition, it was concluded that plots obtained by both mean yield (kg ha-1) vs.Si(1) and mean yield (kg ha-1) vs. Si(2) values could enhance visual efficiency of selection based on genotype × environment interaction. According to these configurations, genotypes in section 1 can be considered as stable and well adapted to all environments, having general adaptable ability. For recognition a daptability,Si(1) and  Si(2) take preferred over other non-parametric statistics.