Influence of early cattle entry on the development of eucalyptus clones in a silvopastoral in the Amazon

ABSTRACT This study aimed to compare the development of two eucalyptus clones under the influence or not of the early animal entry into a silvopastoral system in Capixaba, Acre. The region's climate is AWI, with annual rainfall between 1,680 and 2,580 mm and a dry season between May and September. The design was entirely randomized in a 2 x 2 factorial scheme with six replications and four treatments: a) Clone I144 with cattle access at nine months (TR1); b) Clone I144 without cattle access at nine months (TR2); c) Clone VM01 with cattle access at nine months (TR3); and d) Clone VM01 without cattle access at nine months (TR4). Data was collected from the 16 central trees of each plot at 9, 12, 19, 24, 32, and 36 months of age. Total height (TH) and diameter at breast height (DBH) were measured, and the individual volume with bark from each stem per clone was obtained by rigorous cubing. Growth curves were generated as a function of age for HT, DBH, and Volume per ha using the Logistic model. Clone VM01 displayed higher survival, diameter, and volume per ha than clone I144, with higher values for these variables for the treatment without early animal entry. Clone VM01 demonstrated estimates of maximum production volume per hectare 83.8% higher than clone I144. The early animal entry into the silvopastoral system negatively influenced the growth and survival of the eucalyptus clones.