The effects of water stress during the formative phase on stomatal resistance and leaf water potential and its relationship with yield in ten sugarcane varieties

Abstract In sugarcane ( Saccharum officinarum L.), water stress during the formative phase (60–150 days after planting) increased the stomatal diffusive resistance ( K s ) on both abaxial and adaxial leaf surfaces. At the 90th day, variety Co 419 possessed significantly higher K s than varieties Co 997 and Co 740, and the variety × treatment ibteraction was also significant. Leaf water potential (ψ L) decreased due to drought and the treatment differences were not significant. On re-irrigation, varieties Co 285, Co 617, Co 740, Co 997 and Co 1148 on K s basis, and varieties Co 285, Co 312, Co 349, Co 740, Co 997 and Co 1148 pn ψ L basis recovered from stress. Although mean treatment differences in K s or ψ L were not significantly correlated with yield decline, K s at the 120th day and ψ L at the 135th day were correlated with cane yield (-0.46 ∗∗ and 0.47 ∗∗ respectively) under drought conditions.