Nutritional Requirement by Irrigated Brazilian Sugarcane Varieties

Aboveground biomass and nutrient accumulation differ among varieties of sugarcane ( Saccharum spp. hybrids) throughout the crop development. This study aimed to identify irrigated sugarcane varieties with similar pattern of aboveground biomass production and nutrient extraction using cluster analysis and to determine the nutritional requirement during the plant cane cycle. Aboveground biomass production and nutrient content (N, P, K, Ca, and Mg) of sugarcane varieties (SP79-1011, RB813804, RB863129, RB872552, RB94336, RB72454, RB763710, SP78-4764, SP81-3250, RB867515, and RB92579) were determined at 120, 180, 240, 300, and 360 days after planting (DAP). Sugarcane varieties were clustered using the Ward’s method based on aboveground biomass and nutrient accumulation. Next, the increase in aboveground biomass per month and nutritional requirement were determined for the varieties clusters. The sugarcane varieties were clustered in five groups: G1: RB92579; G2: RB863129 and SP81-3250; G3: SP78-4764 and RB867515; G4: SP79-1011; and G5: RB872552, RB813804; RB763710, RB72454, and RB943365. The RB92579 (G1) produced the highest aboveground biomass accumulation, corresponding to an average of 23 Mg ha −1 higher than the other varieties. The SP79-1011 (G4) exhibited constant aboveground biomass production in the last phase. The highest nutritional demand was observed for most of the varieties at the beginning of the stalk elongation phase (120 DAP), except for SP78-4764 and RB867515 (G3), which showed at beginning of the tillering phase (30 DAP). The nutritional requirements decreased during the final stage of stalks elongation phase. These findings suggest that nutritional management of sugarcane must consider the variety and growth phase.