Selection of Pinus spp. progenies in Lavras (Minas Gerais, Brazil) at 36 months of age

Abstract

Background: The selection of superior genotypes and adapted to the edaphoclimatic conditions of the region of the introduction produces gains in productivity for forest stands. The objective of this study was to select progenies of Pinus spp. planted in Lavras, Minas Gerais (MG), Brazil.

Methods: The experimental site was located on dystrophic Haplic Cambisol. The progeny test was designed as a randomised complete block with 30 replicates and single plot. The treatments corresponded to one progeny of Pinus massoniana, three Pinus caribaea var. bahamensis and 33 Pinus caribaea var. hondurensis arranged with a 3x3 m spacing. The traits height (H), diameter at breast height (DBH) and crown projection area (CPA) were measured at 36 months of age.

Results: The results showed that heritability in the narrow sense was 0.24 for DBH, 0.27 for H and 0.50 for CPA. The DBH and H traits showed a high-magnitude positive correlation. The P7, P15, P27, P31 and P33 progenies showed better performance than the other progenies for the evaluated traits. Direct and indirect selection showed similar gains, which favors the use of indirect selection; i.e., when selecting progenies for DBH, progenies with better performance in H are also selected. Additionally, DBH may be used at advanced ages given the difficulty of measuring height. The progeny of Pinus caribaea var. hondurensis showed superior performance compared with Pinus caribaea var. bahamensis and Pinus massoniana for the region of Lavras, MG.

Conclusions: This study suggests the possibility of expanding the production of Pinus caribaea var. hondurensis in the region of Lavras with progenies P7, P15, P27, P31 and P33, because in the initial assessments they showed greater adaptability to the edaphoclimatic conditions. Nevertheless, performing a future selection with the aim of evaluating resin production is recommended.