Water and salt stress on gas exchange, chlorophyll and growth of sesame in brazilian semi-arid

Abstract

ABSTRACT Semi-arid regions face problems such as water deficit and salt accumulation in the soil, which compromise the physiological performance and growth of crops. This study evaluated the effects of salinity and water deficit on gas exchange, chlorophyll, and growth in sesame. The experiment was conducted at the Piroás Experimental Farm, belonging to the Universidade da Integração Internacional da Lusofonia Afro-brasileira, Redenção, Ceará, Brazil. The experimental design used was randomized blocks in a split-plot scheme, with four replicates. The plots correspond to five electrical conductivities of irrigation water (ECw - 0.8, 1.6, 2.4, 3.2, and 4.0 dS m-1), and the subplots correspond to two water regimes, 50% and 100% of crop evapotranspiration (ETc). Increase in the electrical conductivity of irrigation water above 1.6 dS m-1 reduces the CO2 assimilation rate, stomatal conductance, transpiration, and water use efficiency, resulting in lower vegetative development of BRS Anahí sesame. A 50% reduction in ETc reduced all physiological parameters, chlorophyll, and consequently growth in the sesame crop.