Adaptabilidade e seleção em progênies de pinus tropicais aos três anos

Abstract

The selection of superior genotypes and adapted to the edaphoclimatic conditions of the region allows gains in productivity for the forest stands. Here, we were aimed at evaluating the genetic and dendrometric characteristics for the growth of progenies of Pinus spp. more adapted to the Lavras-MG soil conditions and as the current stability and adaptability to Iguape-SP, Lavras-MG and São José da Boa Vista-PR. For this, we used two experiments were performed in Chapter 2 and Chapter 3. The study conducted in Chapter 2, was arranged in a complete randomized block design with 30 replicates and one plant per plot. The treatments corresponded to three progenies of Pinus caribaea var. bahamensis, 33 from Pinus caribaea var. hondurensis and one of Pinus massoniana arranged in spacing 3x3 m. The responses variables were evaluated height (H), diameter at breast height (DBH) and crown projection area (CPA). We resulted show that the heritability in the restricted sense was 0.24 for DBH, 0.27 for H and 0.50 for CPA. The DBH and H characters presented positive correlation and of strong magnitude. Progenies P7, P15, P27, P31 and P33 presented superior performance for the evaluated traits. The direct and indirect selection showed close gains. The progenies of Pinus caribaea var. hondurensis presented superior performance to the other Pinus spp. for the region of Lavras-MG. However, this study suggests the possibility of expanding the production of Pinus caribaea var. hondurensis in the region of Lavras-MG with the progenies P7, P15, P27, P31 and P33. We studied conducted in Chapter 3 was arranged in three locations (Lavras-MG, Iguape-SP, and São José da Boa Vista-PR) and the experimental area was composed by complete randomized block design with 30 replicates and one plant per plot, with 26 progenies of Pinus Caribaea var. hondurensis. The resultes showed low heritability for H (0.03) and DBH (0.05), but the selective accuracy showed high accuracy H (0.70) and DAP (0.79). The São José da Boa Vista-PR site presented the best performance for the progenies tested. The progenies of Pinus caribaea var. hondurensis adapted to the edaphoclimatic conditions of the tested localities. The progenies of Pinus caribaea var. hondurensis P7, P26 and P27 presented stability and adaptability to Lavras-MG, Iguape-SP and São José da Boa Vista-PR. However, because it was an evaluation at an early age, it is recommended a future selection at the age of eight years to validate the productivity of these progenies, mainly in relation to resin production.