Yield Stability of Maize Hybrids Evaluated in National Maize Cultivar Regional Trials in Southwestern China Using Parametric Methods

Assessment of yield stability is an important issue for maize (Zea mays L.) cultivar evaluation and recommendation. Many parametric procedures are available for stability analysis, each of them allowing for different interpretations. The objective of the present study was to assess yield stability of maize hybrids evaluated in the National Maize Cultivar Regional Trials in southwestern China using 20 parametric stability statistics proposed by various authors at different times, and to investigate their interrelationships. Two yield datasets were obtained from the 2003 and 2004 national maize cultivar regional trials in southwestern China. A combined analysis of variance, stability statistics, and rank correlations among these stability statistics were determined. Effects of location, cultivar, and cultivar by location interaction were highly significant (P<0.01). Different stability statistics were used to determine the stability of the studied cultivars. Cultivar mean yield (Y) was significantly correlated to the Lin and Binns stability statistic (LP, r=0.98** and 0.97** for 2003 and 2004 trials, respectively) and desirability index (HD, r=0.38 and 0.84** for the 2003 and 2004 trials, respectively). The statistics LP and HD would be useful for simultaneously selecting for high yield and stability. Based on a principal component analysis, the parametric stability statistics grouped as four distinct classes that corresponded to different agronomic and biological concepts of stability.