Response of sugarcane varieties to phosphorus rates and sources in a pre-sprouted seedling system (MPB)

Phosphorus (P) is a critical nutrient for sugarcane productivity, but its efficiency depends on the applied source and the cultivated variety. This study evaluated the effect of five P₂O₅ application rates (0, 60, 120, 240, and 360 kg ha⁻¹) and two sources (Single Superphosphate – SSP and Triple Superphosphate – TSP) on two sugarcane varieties (IACSP01-5503 and RB975033) regarding the shoot dry mass of pre-sprouted seedlings (MPB). The experimental design was a randomized complete block design (RCBD) with four replications, arranged in a 2 × 2 × 5 factorial scheme (sources × varieties × rates). Data were subjected to ANOVA, Tukey’s test, and polynomial regression analysis. The RB975033 variety outperformed IACSP01-5503 by 47% in shoot dry mass, while TSP increased production by 12% compared to SSP. The estimated optimal dose was 367 kg ha⁻¹ of P₂O₅ for the combination of TSP and RB975033. It is concluded that selecting the RB975033 variety in combination with TSP maximizes productivity in soils with low phosphorus availability.