s:1249:"TI Preliminary pruning programme for Tectona grandis plantations in Costa Rica 
AU Kanninen, M. 
AU Perez, L. D. 
AU Viquez, E. 
AB End-users' requirements for fast-grown Tectona grandis timber include straight bole with least taper, reduced flutes and buttresses as well as wood free of knots. In Costa Rica and many other tropical countries, no official classification norms have been developed to differentiate wood quality improvements obtained from pruning. The aim of this research was to study the structure and composition of the crown biomass in order to develop a simple and practical pruning programme for T. grandis in Costa Rica. Regardless of site, the results indicate that the first pruning in T. grandis should be carried out when trees reach a total height of between 4 and 5 m, pruning up to 2-3 m. In a second intervention, trees should be pruned up to 4-5 m when the stand reaches between 9 and 10 m of total height. Finally, in a third intervention, all the branches up to 7 m should be pruned when trees reach 12 m of total height. According to the present results, the pruning of T. grandis in Costa Rica can be economically feasible for rotations of 15 years and more, if performed adequately and with precise timing. 
";