EFICIÊNCIA DA PRODUÇÃO HIDROPÔNICA DAS CULTIVARES DE ALFACE FERTILIZADAS COM DIFERENTES DOSES DE SILÍCIO

Abstract

Hydroponics is a technique of vegetable production that has been gaining ground in recent years in Brazil, but its technology is still little known by traditional farmers, generating fear and insecurity in adopting this production system. In this way, the objective of this work was to verify the effects of different doses of silicon on the phytotechnical and productivity parameters of two lettuce cultivars in NFT hydroponic system. The experimental design was completely randomized in subdivided plots, with four replications, and the plots consisted of five doses of silicon (0, 0.5, 1.0, 1.5 and 2.0 mmol / L) and the subplots for two cultivars: Brazil (cabbage type) and Great Lakes (American type) with 30 plants per plot (15 of each cultivar) with 4 plants useful for each cultivar. The characteristics evaluated were: head diameter, leaf number, stem length, fresh mass and dry mass of shoot and root, tip burn severity (based on Pedrosa's adapted score scale (2004)); of the Ca, Mg and K contents in the center and in the edges of the inner and outer sheets. The different concentrations of silicon used in the nutrient solution did not cause significant differences in any of the studied characteristics, except for the magnesium content in the center of the external leaves, independently of the cultivar used. The cv. Great Lakes, of the American type, presented greater tolerance to the "tip burn" physiological disorder, in spite of their lower calcium contents in the borders of the internal and external leaves in comparison to the cv. Brazil, of the cabbage type.