Estimation of the Impact of Teratosphaeria nubilosa on Wood Production from Commercial Plantations of Eucalyptus globulus (L.)

The arrival of Teratosphaeria nubilosa drastically impacted the production of Eucalyptus globulus Labill in Uruguay. However, information regarding growth losses is scarce. The objective of this work was to quantify the effect of the disease on the productivity of E. globulus plantations through modeling and simulation of growth with different levels of disease. For this, diameter at breast height (DBH) and total height were measured in 7 year-old plantations and individual volume was calculated. This information was used to adjust linear and non-linear mixed models that would allow estimating DBH average, total height average of the stand and volume per hectare, relating growth parameters with the Crown Damage Index (CDI) at 6, 12 and 24 months old. The results indicated a significant negative relationship of CDI12 (P < 0.05) with DBH and volume (predictor variables). The estimated growth at 7 years by modeling with CDI = 0 (without crown damage) was higher than the observed growth (14.5 vs. 13.1 cm for DBH and 116.5 vs. 93.7 m³/ha for volume, respectively). The intensity of Teratosphaeria Leaf Disease (TLD) and the relative wood volume loss caused by the disease damage did not vary with site quality. This reinforces previous results showing that site selection does not significantly contribute as alternative management to mitigate the impact of the disease. This work allowed an estimation of the negative effect of TLD on E. globulus in Uruguay.