Yield Stability of Guar Breeding Lines and Cultivars1

Abstract

Guar [Cyamopsis tetragonoloba (L.) Taub.] cultivars and breeding lines were evaluated at seven test‐sites in Texas and southwest Oklahoma for 3 years and at nine test‐sites for 5 years. Genotypes exhibited variation for maturity classes and primary growth habit. Data for 22 genotypes were analyzed to determine yield stability parameters. Based on those parameters, genotypes G‐3, G‐4, G‐5 and G‐12 were most stable in the early testing period, while G‐19 was most stable during the latter testing period. Medium maturing genotypes exhibited greater stability than either early or late maturing genotypes. Growth habit did not affect stability. Low coefficients of determination (r2) for most genotypes suggested a sizeable proportion of variability for yield could be attributed to environmental effects.