Effect of silicates on morpho-physiological and nutritional characteristics of Lactuca sativa L. under a floating root hydroponic system

Abstract

Hydroponics is an efficient alternative for vegetable productiondue to the optimized use of water and nutrients.Although silicon promotes growth and stress tolerance inplants, there are few studies evaluating the effect of differentsources of this element in lettuce in hydroponic systems. Theobjective was to evaluate the effect of K2SiO3 and CaSiO3,applied in different concentrations, on morphophysiologicalparameters and nutrient absorption in lettuce (Lactuca sativaL.) under a floating root hydroponic system in greenhouses.Nine treatments were evaluated: a control and applicationsof K2SiO3 and CaSiO3 at concentrations of 25, 50, 75 and 100μM. Variables of growth, biomass, photosynthetic pigmentsand nutritional content were determined. Significant differenceswere observed between treatments for most of thevariables evaluated. K2SiO3 promoted greater growth andcarotenoid content, while CaSiO3 favored the absorption ofFe, Zn and Cu. Likewise, K2SiO3 increased the availability ofN, P, K and Mg. In conclusion, K2SiO3 represents an alternativeto improve the growth, physiological quality and mineralnutrition of lettuce in hydroponics.