Crescimento e produtividade de alface hidropônico submetido à salinidade com uso de silício.

Abstract

Faced with the scenario of water scarcity, especially in semi-arid regions, hydroponic cultivation is a viable alternative to the production of vegetables, since this technique uses water rationally and without waste, however, silicate fertilization is necessary, a method that has been important. in the contribution of the increase in the production of vegetables. In this sense, the objective was to evaluate the growth and production of lettuce cultivars under different saline levels using silicon. The experiment was carried out in a protected environment, at the Vale dos Ipês Rural Property, located in the municipality of São Mamede-PB. The experimental design used was in subdivided plots with factors arranged in a 4x2x2 factorial scheme, with four saline concentrations (1.4; 2.0; 2.6 and 3.2 dS m-1), two doses of Si (potassium silicate ) (0.0; 0.6 mM) and two crisp lettuce cultivars (Leila (C1) ; Isabel (C2)), totaling 16 treatments with 8 replications. Physiological and growth parameters were analyzed; gas exchange and photosynthetic pigments (chlorophyll a, b and total and carotenoids). Salinity reduced physiological and plant growth variables 15 days after transplanting and nutrient solutions with EC up to 2.4 dS m-1 are recommended for lettuce production. Gas exchanges decreased with increasing salinity of the nutrient solution from the level of 2.2 dS m-1. There were decreases in water use efficiency with increasing salinity. The variation of photosynthetic pigments increased with the increase in EC from 2.2dS m-1. Silicon enabled a better use, positively influencing the analyzed variables; and its use is advisable in the hydroponic cultivation of lettuce.