Strategies for the analysis of single-tree plot experiments in Eucalyptus plantations

Abstract

To verify if the response by Eucalyptus clones in a single-tree plot is influenced by neighboring plants and to determine the effect of missing and/or dominated plants, seven eucalyptus trials in four Brazilian states were analyzed in a randomized complete block design with one plant/plot and 30 replications. Mean annual increment (MAI, m3 ha−1 per year) was determined for three-year-old clones. The influence of neighboring clones was estimated by a linear regression coefficient between the MAI of each clone/plot and the average of a clonal MAI and its eight neighbors. To determine the effect of missing and/or dominated trees, a correction between the MAI and the area available/plant was applied. Subsequent analysis considered unadjusted and adjusted data for missing and dominated trees. Estimate of accuracy and index of coincidence were used to compare the adjustments. In single-tree plots, clone performances were not influenced by neighboring plants. Experimental accuracy was not increased by any of the adjustments employed and the clone ranking was not altered, and therefore did not justify their use.