Production and postharvest quality of jambu in hydroponics under nitrogen application in nutrient solution1

Abstract

Jambu is a leafy vegetable from the northern region of Brazil and its cultivation in the soil has considerably reduced its production, due to pests and diseases. Based on this, the objective of this work was to evaluate the growth, yield and postharvest quality of hydroponic jambu plants in response to the variation of nitrogen (N) concentration in the nutrient solution. The design used was completely randomized with eight replicates and six treatments, consisting of N concentrations in the nutrient solution (11, 13, 15, 17, 19 and 21 mmol L-1). Main stem length (MSL), diameter (D), leaf area (LA), number of inflorescences (NI), shoot fresh mass (SFM), shoot dry mass (SDM), root fresh mass (RFM), root dry mass (RDM), inflorescence fresh mass (IFM), inflorescence dry mass (IDM), N content, total soluble solids (TSS), pH, titratable acidity (TA) and TSS/TA ratio were evaluated. Both growth and yield were explained by positive linear models, and the best results were obtained at the N concentration of 21 mmol L-1. As for the quality variables TSS and TSS/TA, these were also explained by increasing linear models with maximum responses at the N concentration of 21 mmol L-1. As the N concentration increased, there were reductions in TA. Based on the results, the N concentration of 21 mmol L-1 in the nutrient solution enables better response in terms of growth, production and postharvest quality in jambu.