Evaluation of alternative substrates for hydroponics based on biological parameters of leaf lettuce (<i>Lactuca sativa</i> L.) and its stress response

ABSTRACT The study focusses on alternative substrates with the potential to replace common substrates, such as mineral wool and perlite, influence of these ecosystems resources is being debated. To this aim, wood fibre, sheep coco peat were selected for testing. Leaf lettuce ( Lactuca sativa L. ‘Lisboa’) taken model crop evaluation substrates. closed hydroponic system ebb flow growing in pots was used experiment. parameters nutrient solution EC 1.5–2 mS pH 6–7. Biological parameters, content nitrates, plant stress indicators, antioxidant activity (AA) % scavenging DPPH (AA), glutathione (GSH), ascorbate peroxidase (APX), total phenol (TPC) chosen elements drain from evaluated. According biomass production lettuce, can be ranked lowest follows: &lt; fibre perlite peat. levels GSH APX did not affect AA. TPC showed greatest effect AA response general. nitrate ranged between 426 686 mg · kg –1 fresh mass. Instead could a promising organic substrate hydroponics system. Wood still have unresolved circumstances regarding their physical chemical parameters.