GROWTH STRESS EFFECTS ON YIELD AND QUALITY OF Eucalyptus dunnii TIMBER

The growth stress effects on yield and quality of Eucalyptus dunnii green sawn boards were evaluated. A total of 45 trees were sampled from a 19-years-old trial located at Corrientes, Argentina. Each tree was felled and crosscut to produce a 2 m log. Subsequently each log was sawn to obtain tangential boards 2,54 cm thick. Growth stress indicator (GSI, CIRAD-Foret) and log end split index (IR) values taken from these trees in a previous research were used. Length of boards and end checks were measured and the percentage of boards with end check (P) was determined. An index to quantify end checks for the whole sawn boards (IRTC) and another for the sawn boards per log (IRT) were calculated. Sawlog gross yield (R) and a quality sawlog yield (R-C) which exclude the end check defects were calculated. The IRTC was 54,4 mm/m and the IRT was 27,87 mm/m +/- 19,85. More than half of the boards had end checks (P); nevertheless the sawlog yield did not show a high decline (R: 44,2 % and R C : 41,7 %). The association between IRT and growth stress indicator GSI and log end split index IR was moderate (r: 0,46 -0,52).