Timing and Duration of Drought Differentially Affect Growth and Yield Components Among Sugarcane Genotypes

Drought significantly impacts sugarcane yield, making drought resistance an important trait in drought-prone regions. The effects of the timing and duration of drought on yield and yield components, including relationships among these traits, were examined using a diverse set of sugarcane genotypes in a 2-year (planted cane and first ratoon) field study. Three drought treatments (no water stress (SD0), short-term (SD1), and long-term (SD2) drought) were assigned as the main plot and replicated four times. Within each plot, six genotypes were nested in a split-plot design. Drought reduced yield and its components, with the decline greater in SD2 than in SD1. Strong relationships between yield and its components like stalk height and density and height growth rate, especially under drought, make these traits potential surrogates for yield in drought screening experiments. The genotypes F03-362 and KK3 displayed high, stable yield potential across drought treatments, but KK3 lost potential in ratoon crop under drought. Although KK09-0358 displayed high yield potential, it was very sensitive to drought stress while UT12 and KK09-0939 displayed low yield potential and sensitivity to drought. TPJ04-768 displayed low but stable yield potential across drought treatments and crops. F03-362 and TPJ04-768 have utility in studies seeking to couple physiological with agronomic parameters promoting drought resistance and as parents for developing cultivars combining high and stable yield performance under drought.