Silicon Use Efficiency and Response in Sugarcane Genotypes Under Greenhouse Conditions

Abstract Given the wide genetic variability of sugarcane ( Saccharum spp.) and the importance of silicon (Si) for this crop, this study aimed to assess the response of 50 genotypes to Si supply under greenhouse conditions, screening for genotypes with contrasting efficiency and responsiveness to Si supply and high capacity for Si accumulation. Two greenhouse experiments were conducted under contrasting Si availability conditions: Low Si (no Si application) and Adequate Si (application equivalent to 600 kg ha −1 Si). The experimental design was a randomized complete block design with four replicates. At 120 days after planting, the following traits were evaluated: Plant Height (PH), Stalk Diameter (SD), Number of Stalks per Clump (NSC), Shoot Dry Matter (SDM), Shoot Si Concentration (SSiC), and Si Use Efficiency (SiUE). A significant genotype × Si availability interaction was observed for all traits, except SD. On average, Si supplementation increased NSC by 28.6%, SDM by 32.7%, and SSiC by 48.7%. Among the tested genotypes, RB966928, CTC11, and CTC9006 exhibited higher Si-use efficiency indices and responsiveness, whereas RB047016 and RB147529 showed greater Si accumulation in the shoots. These results indicate substantial genetic variation in Si uptake and utilization among sugarcane genotypes and identify candidates for further evaluation under field conditions and in breeding programs.