Air-drying of eucalypts logs: Genetic variations along time and stem profile

Abstract

Knowledge of wood drying potential is relevant in forestry and biomaterials technology field, being directly related with timber transport, lumber properties, charcoal yield and pulping process. Using mixed models approach by REML-BLUP procedure, we aimed to evaluate the moisture content loss potential among different eucalypt genotypes, by means of genetic correlations, heritabilities, coefficients of variation and determination of wood air-drying over 154 drying days and in five tree stem heights. Moreover, we tested three possible auxiliary traits (Heartwood/Sapwood ratio, Log Circumference, and Basic Wood Density) for indirect selection on wood air-drying rate. The highest air-drying heritabilities occurred at the two most basal stem heights and only after the 98th day. However, genetic correlations across the drying measurements were considerably high from day 42. The three auxiliary traits demonstrated potential for indirect selection, suggesting the possibility of integrating wood air-drying to future Eucalyptus sp. breeding programs. There is no need to wait for industrial moisture content to carry out genetic evaluation. Besides, perform selection at trees basal region is the safest way to improve the air-drying rate of genotypes.