Differential Nutrient Use Efficiency and Biomass Partitioning of Interspecific Hybrids and Commercial Sugarcane Genotypes Under Early Drought Stress and Recovery Conditions.

Drought significantly impacts nutrient use efficiencies and sugarcane biomass. Interspecific hybridization between Saccharum officinarum and Saccharum spontaneum may improve drought resistance and enhance nutrient use efficiency. This research enhances the understanding of nutrient (N, P, and K) use efficiency and the biomass of interspecific hybrids and commercial sugarcane genotypes under early drought and recovery. The experiment was conducted using a split plot in a randomized complete block design (RCBD), with three replications. The main plot consisted of two water regimes (well-watered, WW, and early drought stress, DS), whereas the subplot consisted of six diverse sugarcane genotypes. Biomass, nitrogen use efficiency (NUE), phosphorus use efficiency (PUE), and potassium use efficiency (KUE) were measured 6, 8, and 12 months after transplanting (MAT). The results showed that drought reduced NUE, PUE, KUE, and biomass in all sugarcane genotypes throughout the drought period at 6 MAT. F03-362 and KK09-0358 had high biomass and NUE under drought stress. Meanwhile, F03-362 displayed consistently high biomass, NUE, PUE, and KUE during the recovery phase (8 MAT) as well as at 12 MAT under DS conditions, whereas TPJ04-768 showed high biomass only at 12 MAT. These contrasting responses highlight the important implications of selecting parental genotypes to improve nutrient use efficiency and biomass under early drought stress.