Accumulation of biomass and lignocellulosic compounds in photoperiod-sensitive biomass sorghum genotypes

Abstract

Biomass sorghum [Sorghum bicolor (L.) Moench] has unique characteristics that allow its use as a feedstock for bioenergy production. This study aimed to analyse the growth and accumulation of biomass and lignocellulosic compounds in photoperiod-sensitive biomass sorghum genotypes and to evaluate interactions with the environment at different phenological stages using the absolute and relative crop growth rates. Four photoperiod-sensitive biomass sorghum genotypes were evaluated over two crop years and two sites in the state of Minas Gerais, Brazil. It was mensured agronomic and technological traits. The mean performance of the genotypes were adjusted using logistic and polynomial regression models, and the absolute (CGR) and relative (RCGR) growth rates were subsequently estimated. The environment (site and/or crop year) influenced the trait expression regarding plant height, cellulose and lignin accumulation. The genotypes at Sete Lagoas site matured earlier, with a greater plant height and greater accumulation of biomass and lignocellulosic compounds, except lignin, over a shorter period compared to Lavras site. Across genotypes and environments, CGRs with a peak inflection at approximately 90 days after sowing (DAS) were observed for growth and biomass production, but a decrease starting at 30 DAS was observed in the CGRs for lignocellulosic compounds and in the RCGRs for growth, biomass production and lignocellulosic compounds. In addition, at both sites, the crop could be harvested earlier, at approximately 120 DAS in Sete Lagoas and 150 DAS in Lavras, given the high biomass production, dry matter percentage above 30% and high content of lignocellulosic compounds.