Comportamiento de clones de teca (Tectona grandis Linn. F.) en Costa Rica y Nicaragua

Abstract

The first chapter presents the evaluation of two clonal teak trials in Guanacaste, Costa Rica, where the behavior of 49 genotypes at an age of 4 years was analyzed. Each clone was represented by 24 repetitions, randomly distributed in 6 blocks. Through the SELEGEN software, mean clonal heritability values of 0.80, 0.80 and 0.81 were obtained for the DBH, number of total branches and commercial volume, respectively. The genetic correlation between localities in the variable number of branches, DBH and commercial volume registered r = 0.91, 0.89 and 0.88, indicating a low genotype x environment for this clonal population in these two locations. If the best 10 genotypes are selected, it is estimated that a genetic gain in DBH of 14,05% will be obtained; that will allow to reduce the harvest turn in 2.5 years. While the genetic gain of commercial volume is estimated at 34.70%. The second chapter presents the results of two clonal trials planted at 1.5 m x 1.5 m and 3 m x 3 m in Siuna, RAAN, in Nicaragua. The total volume registered average heritability by origin (company) of 0.76 and 0.77 for the low and high density tests, respectively. The genotypes of Malaysia registered significant differences in total volume, with respect to all the Costa Rican clones. The third chapter presents the evaluation of seven clonal teak trials in Costa Rica and Nicaragua. The genetic correlation for the seven trials was r = 0.14, 0.16, 0.22, 0.27, 0.34, 0.39 and 0.42 for the number of branches, trunk quality, total volume, presence of thick branch, DBH, total height and phytosanitary status, respectively,