Peróxido de hidrogênio como atenuante do estresse salino na formação de mudas de pitaia vermelha (hylocereus costaricensis)

The pitaia is among the exotic fruits with high potential for cultivation due to the organoleptic and functional qualities of its fruits. However, some factors such as salinity can hinder the growth of the seedling, affecting its productive yields. Based on this context, from March to July 2019, an experiment was conducted at the Science and Technology Center of the Federal University of Campina Grande, Pombal PB, where the objective was to evaluate the effects of saline water and hydrogen peroxide (H2O2) on the production of seedlings of red pitaia Brazilian Journal of Development Braz. J. of Develop., Curitiba, v. 6, n. 5, p.27295-27308, may. 2020. ISSN 2525-8761 26297 (Hylocereus costaricensis). The design used in the experiment was that of random blocks in a 5x4 factorial scheme, with the first factor corresponding to five levels of electrical conductivity of the irrigation water (0.3; 1.1; 1.9; 2.7 and 3,5 dS m), the second, four concentrations of H2O2 (0; 10; 20 and 30 μM) and four repetitions. The variables analyzed were Plant Osmotic Potential (POP), Number of Shoots (NB), Average Shoot Length (ASL), Fresh Mass Aerial Part (MFPA), Dry Mass Aerial Part (MSPA), Fresh Root Mass (MFR) , Root Dry Mass (RDM), Root Length (RL), Root Volume (RV) and Electrical Conductivity in the State of Final Soil Saturation (CEesf). Saline stress reduced the resistance of pitaia seedlings with negative reflexes, in general, on the analyzed variables. The different doses of H2O2 were not able to significantly attenuate the negative effects on the culture when exposed to different concentrations of salts in the irrigation water, except for the positive results in the variables NB, ASL.