Growth and gas exchange response to water shortage of a maize crop on different soil types

The effect of water shortage on growth and gasexchange of maize grown on sandy soil (SS) and clay soilwas studied. The lower soil water content in the SS duringvegetative growth stages did not affect plant height, abovegroundbiomass, and leaf area index (LAI). LAI reductionwas observed on the SS during the reproductive stage dueto early leaf senescence. Canopy and leaf gas exchanges,measured by eddy correlation technique and by a portablephotosynthetic system, respectively, were affected bywater stress and a greater reduction in net photosyntheticrate (AN) and stomatal conductance (gs) was observed onSS. Chlorophyll and carotenoids content was not affectedby water shortage in either condition. Results support twomain conclusions: (1) leaf photosynthetic capacity wasunaffected by water stress, and (2) maize effectivelyendured water shortage during the vegetative growth stage.