Cultivo hidropônico de tomate cereja utilizando soluções nutritivas salinas e peróxido de hidrogênio.

Abstract

In the semi-arid region, saline water can be used for production during periods of water scarcity. However, it is necessary to use strategies capable of mitigating the impacts of salinization and/or sodification of soils and the effects of salt stress on plants. Among the alternatives, cultivation in a hydroponic system and foliar application of hydrogen peroxide stand out. In this context, the present study aimed to evaluate the effect of foliar application of hydrogen peroxide on the physiology, growth, production, and postharvest quality of cherry tomatoes grown in a hydroponic system using saline nutrient solutions. The assay was carried out in a greenhouse, in Pombal - PB, using a completely randomized experimental design, in a split-plot scheme, with the levels of electrical conductivity of the nutrient solution - ECns (2.1 – control, 2.8, 3.5, and 4.2 dS m-1 ), considering the plots and five concentrations of hydrogen peroxide – H2O2 (0, 12, 24, 36, and 48 μM), the subplots, with three replications and two plants per plot. The cultivation system used was the hydroponic type Nutrient Laminar Flow Technique - NFT. The foliar application of hydrogen peroxide at a concentration of 24 μM associated with a saline nutrient solution of 2.1 dS m-1 resulted in a greater stomatal conductance of cherry tomato plants, 65 days after transplanting. However, salinity increases from 2.8 dS m-1 . negatively affected the morphophysiology and photosynthetic pigments of cherry tomatoes. The electrical conductivity of the nutrient solution above 2.1 dS m-1 was detrimental to the yield components for number of fruits per plant, total yield per plant, average fruit weight, polar fruit diameter, and equatorial fruit diameter. However, it promoted improvements in postharvest quality for hydrogen ion potential, ascorbic acid, soluble solids, titratable acidity, and total fruit sugars. The concentrations of 22 and 25 µM of hydrogen peroxide attenuated the harmful effects of saline stress on the number of fruits and ascorbic acid levels, in addition to favoring a greater total production of cherry tomato fruits per plant.