SILICON IMPROVES SEEDLING PRODUCTION OF MORINGA OLEIFERA LAM. UNDER SALINE STRESS

Salinity is one of the most common environmental stresses, particularly in agricultural areas. This condition affects growth and development of crops, since it causes physiological, biochemical and morphological changes. Different techniques have been proposed to mitigate crops salinity damage, including application of silicon (Si). The objective of the present work was to evaluate the effect of salinity, Si and its interaction, in emergence, growth, biomass and ion concentration of moringa seedlings (Moringa oleifera Lam.). The experiment was set up in a completely randomized design with a factorial arrangement 3*3 and three replications per treatment. Seedlings were developed in nine nutritive solutions derived from combination of three electric conductivities (2.5, 6.0 and 9.5 dS/m by adding sodium chloride) and three Si concentrations (0, 50 and 100 mg/L by adding potassium silicate). Results showed that salinity reduced emergence, growth, biomass and concentration of K and Mg, and increased concentration of Zn, Cu and Mn in root, similarly reduced concentration of Mg and increased concentration of Na in stem and leaves. Si increased growth of aerial part, biomass and Ca concentration in root, meanwhile increased Mg concentration and reduced Na concentration in leaves. Salinity-Si interaction was found in root were Si reduced Na concentration and increased Fe concentration, both in high salinity. Similarly, Si increased K, Ca, Cu and Fe leaves concentrations when EC was high. These results suggest that Si should be considered as an alternative to reduce the effects of salinity in plants.