Phosphite effects on sugarcane growth and biochemicals under in vitro osmotic stress

Background Biostimulants positively impact plant growth, yield, and chemical composition while enhancing tolerance to biotic and abiotic stress. Phosphite (Phi), a phosphate analog, has been proposed as a biostimulant due to its advantages over traditional phosphate fertilizers and herbicides. Methods This study evaluated the effects of Phi on sugarcane seedlings (CP 72-2086) under conventional (non-stress) and osmotic stress conditions during in vitro multiplication. Seedlings were treated with Phi at 0.1, 0.3, and 0.5 mM (derived from H 3 PO 3 ) for 30 days, followed by 7 days of osmotic stress induced with 10% polyethylene glycol 6000 (PEG). Results Phi significantly increased leaf length, width, and number, as well as shoot count. Additionally, it enhanced foliar concentrations of chlorophylls a and b , sugars, and amino acids under both conventional and osmotic stress conditions. In conclusion, Phi serves as an effective inorganic biostimulant for sugarcane (CP 72-2086) during in vitro multiplication, stimulating seedling growth and modulating essential biomolecule concentrations.