Efeito da concentração de nutrientes no crescimento, produtividade e qualidade de morangos em hidroponia

Abstract

Aiming to study the effect of the nutrient solution concentration on plant growth, yield and chemical and phytochemical characteristics of strawberry fruits of cultivar Camarosa in NFT hydroponic system in Pelotas, Rio Grande do Sul state, Brazil, different ionic concentrations (EC) of the solution were evaluated: 0.9, 1.5, 2.1, 2.7dS m-1, in experiment carried out from May 19, 2009 to January 4, 2010; and 0.7, 1.2, 1.7, 2.2, and 2.7 dS m-1, in experiment carried out from June 07, 2010 to January 4, 2011. Fresh and dry matter of leaves, crown, roots and fruits, leaf area, number of fruits and the average fruit weight were evaluated. Fruit samples were analyzed regarding to total soluble solids content, acidity, concentrations of anthocyanins, L-ascorbic acid, total phenolic compounds and antioxidant capacity in the second experiment. The results indicated that EC from 1.2 to 1.5 dS m-1 promoted plant growth and fruit yield. When EC decreased from 1.7 to 1.2 dS m-1, soluble solids, anthocyanin and L-ascorbic acid content decreased by 17, 17 and 15%, respectively; and fruit yield and phenolic compounds concentration were increased by 52 and 22%, respectively. The average fruit weight was reduced with increasing EC in the first experiment and was not affected, as well as the acidity and the antioxidant capacity, in the second experiment. Nutrient solution from 1.2 to 1.5 dS m-1 EC can be indicated to obtain higher yield without major losses in fruit quality in NFT hydroponic system.