Cultivo hidropônico de tomate cereja utilizando-se solução nutritiva salobra e aplicação de ácido salicílico.

Abstract

The semiarid region is characterized by high temperatures, low rainfall and high evapotranspiration rates, leading to limitations in agricultural production. In addition, the waters available in the Northeast, in large part, have high concentrations of dissolved salts, making it necessary to use strategies to mitigate the effects of saline stress on plants. Among the alternatives, cultivation in a hydroponic system and foliar application of salicylic acid stand out. In this context, this study aimed to evaluate the effect of foliar application of salicylic acid on the physiology, production and postharvest quality of cherry tomatoes using saline nutrient solutions in a hydroponic system using the Laminar Nutrient Flow Technique (NFT). The research was conducted in a greenhouse at the Federal University of Campina Grande, Pombal Campus - PB, using a completely randomized experimental design in a split-plot scheme, with the plot consisting of five levels of electrical conductivity of the nutrient solution - ECns (2.1 - control; 2,6; 3,1; 3,6 and 4,1 dS m-1) and the subplot with five concentrations of salicylic acid (0; 0,8; 1,6; 2,4 and 3,2 mM), with three replicates and two plants per plot. The foliar application of salicylic acid at a concentration of 3.2 mM promoted an increase in the synthesis of photosynthetic pigments and in the rate of CO2 assimilation of cherry tomatoes, 61 days after transplanting. The saline nutrient solution from 2.1 dS m-1 increased the internal CO2 concentration and reduced the transpiration, stomatal conductance and maximum fluorescence of cherry tomatoes plants. The salicylic acid concentration up to 3.2 mM promoted a beneficial effect on cherry tomatoes production. The ECsn of 4.1 dS m-1 increased the soluble solids, ripening index and flavonoids contents of cherry tomatoes fruits. The titratable acidity and ascorbic acid contents were increased under 3.2 mM salicylic acid concentration and ECsn of 2.1 and 2.6 dS m-1, respectively.