Assessing Lignocellulose Quality Across Growth Stages in Diverse Sugarcane Genotypes

Sugarcane is a globally important C 4 crop traditionally bred for sucrose yield. However, its potential as a bioenergy crop depends on understanding lignocellulosic quality across developmental stages and environments. This study investigates the variability in fibre composition and theoretical digestibility among 17 sugarcane genotypes grown at two contrasting locations in northern Queensland. Plants were sampled at maximum vegetative growth and at peak sucrose accumulation. Fibre traits, including glucan, xylan, and lignin content, were quantified, and digestibility was estimated using cell wall composition ratios. The results revealed that digestibility declined with plant age, primarily due to increased lignin and xylan deposition. However, several genotypes maintained relatively high digestibility even at later stages. The study also identified substantial genotype–environment interactions influencing biomass quality. These findings suggest that harvesting sugarcane earlier in the cropping cycle, particularly when sucrose is not the main product, could improve fibre digestibility and biomass yield per unit time. This supports the use of sugarcane in circular bioeconomy systems and highlights opportunities for developing dual-purpose cropping strategies that align with sustainability goals.