Cultivo irrigado de pimentão sob estresse salino e aplicação de peróxido de hidrogênio.

Abstract

The cultivation of bell pepper in the semi-arid region of the Brazilian Northeast using saline waters can be made possible through the use of substances that attenuate the deleterious effects of saline stress. In this context, the objective of this study was to evaluate the effects of hydrogen peroxide on the growth, physiology and production of 'All Big' bell pepper under irrigation with saline water. The experiment was treated under greenhouse conditions, in Campina Grande-PB. The treatments were distributed in a randomized block design, in a 5 × 5 factorial scheme, corresponding to five levels of electrical conductivity of irrigation water - ECw (0.8; 1.2; 2.0; 2.6 and 3.2 dS m-1) and five concentrations of hydrogen peroxide – H2O2 (0, 15, 30, 45 and 60 μM), with three replicates and one plant per plot. The application of hydrogen peroxide at a concentration of 15 μM attenuated the effects of salt stress on the growth, physiology and production of 'All Big' pepper irrigated with water with an electrical conductivity of up to 1.4 dS m-1. Irrigation with 3.2 dS m-1 water was detrimental to initial fluorescence, initial fluorescence before the saturation pulse, and water use efficiency in 'All Big' pepper. The 'All Big' bell pepper was classified as moderately sensitive to saline stress, with a water threshold salinity level of 1.43 dS m-1, with a unit decrease of 8.25% above this saline level.