Selection of Eucalyptus spp. clones for bioenergetic production in water deficit regions

Abstract

Eucalyptus cultivation plays an important role in the national economy since the wood generated in this activity supplies most of the national forest industries. Recently, forest plantations have expanded, reaching areas present in the Cerrado biome and in transition with the Amazon biome, with very different climate and soils from the regions where Brazilian forestry has developed over the years. This new forest frontier present new challenges to genetic improvement programs, which must develop genotypes adapted to new climatic and silvicultural conditions. Given this need, our objective was to evaluate the performance of 109 eucalyptus clones throughout the production cycle in different locations in the State of Goiás to select clones adapted in the region. The experiment area is characterized as tropical with dry winter climate type (Aw), with precipitation irregularly distributed throughout the year, with 5 months of water deficit. For that, three clonal tests were planted in Catalão, Corumbá-de-Goiás and Luziânia. The experimental design was a randomized complete block with single tree plots and 29 replicates. Estimates of variance components were obtained via REML (Restricted maximum likelihood) and genotypic values via BLUP (Best Linear Unbiased Prediction) for these traits. In this way, it was possible to evaluate the magnitude of the genetic, environmental, and the interaction these effects. The best clones at two and four years are, on average, 65% equivalent to the best clones at six years, when the average productivity was 255.8 m³ ha-1. All six most productive clones (CCL29, CCL35, CLR454, CCL27, CCL07, AEC144) have E. urophylla in their constitution. shows great adaptation in regions with seasonal water stress. Thus, the results indicate Eucalyptus genotypes able to develop well in regions with seasonal water deficit, which should become more frequent, with the intensification of climate change.