Crescimento de Progénies de Pinus caríbaea var. caríbaea em Messica, província de Manica

Abstract

Tree planting has been, in recent decades, a priority in tropical and subtropical regions. However, improved seed is needed for these projects. Forest improvement consists in selecting the best trees for the production of genetically superior seed. Given the ineffectiveness of phenotypic selection due to the influence of the environment, progeny tests are presented as the best option for selecting trees for seed production. In these tests, the matrices are selected based on the behavior of the offspring, which faithfully reflects the genetic strength of the respective relatives. This study presents the results obtained in the progeny trial established in Bandula, Manica province, with the aim of evaluating the performance of the progenies of Pinus caribaea var. caribaea at 17 years of age.

The trial was established according to a randomized complete block design, with three replications. The treatments, that is, the progenies were a total of 58, the plots are linear with 10 plants. The parameters evaluated were: survival, total height, diameter at breast height, cylindrical volume, trunk shape, branching and bifurcation. The mean values ​​obtained in the trial at 17 years of age were as follows: (i) survival, 39%; (ii) total height, 19.1 m; (iii) DBH, 25.31 cm; (iv) cylindrical volume, 0.98 m ; (v) torso shape, score 4.63; (vi) branch, score 2.74; (vii) bifurcation, score 9.95. The analysis of variance performed detected significant differences in total height and DBH. Differences were not significant for survival, cylindrical volume, trunk shape, branching and bifurcation. The results indicate that the best progenies can be selected based on total height and DBH, characteristics that show significant differences at this age. It is recommended to evaluate the physical properties of the wood in the test, study the possibility of thinning, cleaning and protecting the test against fire(TRADUÇÃO NOSSA)