Nonparametric measures of phenotypic stability for commercial cane sugar yield in sugarcane

Nine sugarcane genotypes evaluated for commercial cane sugaryield undersixenvironments.The objective of this investigation was to identify sugarcane genotypes with good phenotypic stability for sugar yield over the environments using nonparametric measures. Further, the relationship among nonparametric as well as some classical parametric measures of stability were also studied. Based on estimates S_i⁽¹⁾ and s_i⁽²⁾, from uncorrected data, Co 1148 had shown maximum stability with low sugar yield, however, Colk 9710 was most stable with high sugar yield based on S_i⁽³⁾ measure. On the other hand, the values of Sill and S_i⁽²⁾ obtained from transformed data indicating that CoS 97264 had maximum stability. However, the estimate of s_i⁽³⁾ from transformed data, reflected the maximum stability in Colk 9606 for CCS yield. Based on the rank correlation among different measures of stability, s_i⁽¹⁾ and s_i⁽²⁾ were nearly perfectly associated with high significant positive value indicating that two measures were similar in classifying the genotypes according to their stability over the environmental conditions. The statistic S_i⁽³⁾ may be utilized for simultaneous selection for yield and stability.