Abstract:
The objective of this work was to determine the necessary number of replicates, of plants per plot, and of measurements for evaluating growth traits in eucalyptus (Eucalyptus spp.) clonal tests. Data on height, diameter at breast height, and wood volume were evaluated in three clonal tests, performed in a randomized complete block design with 30 (tests 1 and 2) and 10 clones (test 3), with six replicates of six (test 1) and 10 (tests 2 and 3) plants. The evaluations were performed from 14 to 74 months of age. The coefficients of repeatability and determination were estimated, as well as the effects of increasing measurement frequency on selective efficiency. Wood volume is the trait with the greatest variability in the plot and the lowest repeatability; therefore, it requires more plants to obtain high accuracy in the estimate of the individual's true value. In Eucalyptus grandis xE. urophylla hybrid clonal tests, the use of three replicates of six plants per plot and of three evaluations, at ages above 2 years, is recommended in order to achieve a selective accuracy around 90%.
Index terms:
Eucalyptus; intraclass correlation; selection efficiency; Urograndis hybrid; mixed models; repeatability
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), variância de parcelas (
) (clone vs. bloco), de planta dentro de parcela (
) [planta vs. (clone vs. bloco)] e de ambiente temporário ( 
), em três testes clonais(1) com híbridos Eucalyptus grandis x E.urophylla, avaliados em diferentes idades quanto às variáveis diâmetro à altura do peito, altura das plantas e volume comercial sem casca.
), número de plantas na parcela (
) e número de repetições (
); dos coeficientes de determinação, em razão do número de avaliações (Ra2), do número de plantas na parcela (Ri2) e do número de repetições (blocos, Rb2); e do coeficiente de correlação devida ao ambiente comum da parcela (C2), para os caracteres diâmetro à altura do peito (DAP, cm), altura das plantas (m) e volume comercial sem casca (m3 por árvore) em três testes clonais(1) com híbridos Eucalyptus grandis xE. urophylla, avaliados em diferentes idades.
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