ASSESSING GENOTYPES IN SECOND ROTATION FOR LIGNOCELLULOSIC BIOMASS PRODUCTION

Optimizing the supply of woody biomass from dedicated crops is a key factor for ensuring raw material that will enable the development of the bioeconomy in Europe while contributing to the mitigation of climate change. The aim of this work is to characterize the productive response of the second rotation crop as well as its stability under different Mediterranean environments in plantations which include different genotypes suitable for coppice. These are: Populus spp. (Populus deltoides clone'Baldo', Populus x canadensis clones: 'Orion', 'Oudenberg', 'Ballottino' and 'I-214'), Salix matsudana x Salix spp. ('Levante'), Robinia pseudoacacia ('Nyirsegi') and Platanus x hispanica ('Girona'). The plantations, established in 2009 with 10,000 trees per hectare, will be assessed at the end of the second rotation, with six years of root growth and three of stem growth (R6S3). A multifactorial analysis of variance is used to evaluate the response of genotypes and environments for the dry biomass production under three different conditions. This analysis is complemented by the examination of the mean genotypic value along with the variability in clonal productivity. Since genotypic stability is an important issue in furthering our understanding of the plant material, a GGE biplot was performed to analyse the genotypic and environmental behaviour, as well astheir interaction. Significant differences in production were observed as well as different trends in the productive response stability, allowing us to assess the suitability of the different species for this productive purpose in the Mediterranean area.