Trocas gasosas em rúcula (Eruca sativa Miller) produzida em sistema hidropônico NFT com diferentes concentrações de solução nutritiva

Abstract

Hydroponics proves to be a valuable tool for the production of the most diverse vegetables, including in areas that would be considered unfit for agriculture. However, there is still a need to adapt this system to the most different means of production. This study proposed to use gas exchange as a parameter to determine a dilution of a standard nutrient solution that is ideal for hydroponic arugula production. The experiment was conducted in a greenhouse, using a randomized complete block design in split-plot scheme with two different irrigation period control equipment, a prototype (Equipment 1) and a commercial one (Equipment 2), with treatments consisting of dilutions of the nutrient solution proposed by Furlani (1997), in doses of 100, 80, 60, 40 and 20%. Gas exchange was evaluated at the plant-atmosphere interface with an infrared gas analyzer (IRGA), such as photosynthesis (A), stomatal conductance (gs), internal CO2 concentration (Ci) and leaf transpiration (E), which had its maximum of 4.31 mmol H2O m-2 s-1. Thus, it was found that there was no significant difference for most parameters when analyzing the different nutrient solutions, except for leaf sweating. Also, one of the equipment used to regulate the irrigation period demonstrated better potential for leaf temperature control, an important feature for more sensitive plants.