Comparison of three C4 cereals for transpirational sensitivity to elevated evaporative demandSChoudharyauthorVVadezauthorAAnandauthorCMessinaauthorMCooperauthorMaize, sorghum and pearl-millet are leading C4 cereals for tropical regions where evaporative demand is high. The transpiration response to high VPD and leaf area of plants grown under different VPD conditions was compared among species to assess the degree of water conservation of these crops and then their potential fitness to different stress scenarios. Ten genotypes of each species were grown under moderate (2.2-2.8kPa) and high VPD (3.9-4.5kPa) conditions till early vegetative (V5-V7) stage with no water-limitation. At that stage transpiration was measured under elevating VPD (0.9-4.1kPa) in controlled conditions. All three species grown under moderate VPD conditions showed a variation in transpiration restriction above 3.0kPa, although the decrease in transpiration above 3.0kPa was high in the case of maize. Sorghum and pearl-millet grown under high VPD conditions showed significant reduction in leaf area whereas maize showed trivial differences in leaf area across VPD conditions. Therefore, under high evaporative demand when soil water was not limiting, maize saved water only by restricting water use during pre-flowering stages whereas sorghum and pearl millet bothreduced canopy sizeand transpiration under high VPD. The soil moisture thresholds where transpiration declined upon progressive water stress imposition did not differ significantly, regardless of different VPD in the growing conditions. Maize had also higher TE than sorghum and millet in the high VPD conditions. Therefore, water conserved in maize by restricted transpiration in high VPD condition, probably leading to higher TE, was sufficiently rewarded to sustain biomass accumulation in water stress period.Abiotic StressPearl Millet2017-02Conference or Workshop Item