The objective of this work was to evaluate the effects of total defoliation at planting initial stages, and along the first year of cultivation, on Eucalyptus grandis growth, from planting to plantation cut. Five treatments were tested: without defoliation; one defoliation, at 56th day after planting (DAP); two defoliations, at 56th and 143th DAP; two defoliations, at 56th and 267th DAP; and three defoliations, at 56th, 143th and 278th DAP. Trunk diameter at 1.30-m height and the total height of 60 trees were measured from the 21st to the 92th cultivation months. The average growth of each treatment was described by nonlinear models and compared by identity tests in order to estimate the tendencies between control and the other treatments in each variable. Defoliation significantly reduces diameter of the trunk and height growth rates, and expressively decreases the income at the plantation cut. However, greater losses were verified after consecutive defoliation, along the first cultivation year. Maintaining areas that suffered severe defoliations at initial planting stages can become economically unfeasible.
Eucalyptus grandis; growth models; economic losses; forest productivity
