REPEATABILITY OF DIFFERENT STABILITY PARAMETERS FOR GRAIN-YIELD IN CHICKPEA

The presence of genotype x environment (GE) interactions in plant bree ding experiments has led to the development of several stability param eters in the past few decades. The present study investigated the repe atability of these parameters for 16 chickpea (Cicer arietinum L.) gen otypes by correlating their estimates obtained from extreme subsets of environments within a year and also over years. Based on the estimate s of response and stability parameters within each trial, the ranking of genotypes in the low-yielding subset differed from that in the high -yielding subset. This indicates poor repeatability for response and s tability parameters over the extreme environmental subsets. The estima tes of mean yield and stability parameters represented by ecovalence, W-i(2), were consistent over years, whereas those of response paramete rs (b(i) and S-i(2)) showed poor repeatability. Our results suggest th at single-year results for yield and stability can be used effectively for selecting cultivars with stable grain yield if tested in a wider range of environments.