The objective of this study was to evaluate the experimental plots size of Eucalyptus saligna Smith with 5.5 years old and for fifteen months old. The experiment were stablished in Barba Negra Garden Market located in Barra do Ribeiro District, Rio Grande do Sul State, Brazil. The Pimentel Gomes - E S ALQ/USP method's was used. It was observed that the optimal experimental plots size may range from 9 to 25 plantas for five year old trees and four plants to 15 m onths old.
planning; experimental errors
