Growth, leaf physiology and fruit development in salt-stressed guavas

Abstract

Two cultivars of guava (Psidium guajava L.) were grown in a porous medium irrigated with dilute nutrient solution containing 0, 25, 50 and 75 mM sodium chloride. The distribution of sodium and chloride between leaves, stems, roots and fruit of the two cultivars is described. Total biomass (and especially fruit fresh weight) was reduced by all salt treatments; however, fruit maturation was accelerated. Symptoms associated with high chloride concentrations developed only on leaves of plants treated with 25 mM sodium chloride. Different symptoms, associated with high sodium concentrations, developed on leaves of plants from the 50 and 75 mM treatments. Transpiration and photosynthesis were reduced in leaves of plants from the 50 and 75 mM treatments. Increased stomatal resistance and a reduction in apparent photochemical efficiency were largely responsible for the reduction in photosynthesis.