Repeatability of yield and girth growth traits in rubber tree clones of series IAC 300
Adriano Tosoni da Eira Aguiar, Paulo de Souza Gonçalves, Erivaldo José Scaloppi Junior, and Juliano Quarteroli Silva
This study aimed to estimate the repeatability coefficients, to compare the efficiency of methodologies used in the estimation process, and further to determine the minimal number of evaluations in the selection of rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell. – Arg.] clones. The following methodologies were used: analysis of variance; principal component analysis based on the correlation matrix together with the phenotypic variances and covariance matrix; and the structural analysis. The r values for girth growth varied from 0.77 to 0.79 and rubber yield from 0.39 to 0.52. It was therefore admitted that the principal component method based on the correlation matrix as well as for the phenotypic variances and covariance matrix are the most efficient to estimate the coefficient of repeatability. At an accuracy of 90% and 80%, two measurements of girth growth and four to six measurements of rubber yield would be necessary for the selection of rubber tree clones, respectively.