Use of hydrogen peroxide in acclimatization of melon to salinity of irrigation water¹

Uso do peróxido de hidrogênio na aclimatação do melão à salinidade da água de irrigação

HIGHLIGHTS:

Hydrogen peroxide (15 µmol L^-1) increases transpiration, stomatal conductance, and net CO₂ assimilation in melon plants.

High concentrations (15 µmol L^-1) of hydrogen peroxide in plants irrigated with 5.0 dS m^-1 salinity reduce melon fruit production.

Hydrogen peroxide at 6.35 and 10.23 µmol L^-1 attenuates the deleterious effects of salt stress in melon plants.

ABSTRACT

In the semi-arid region of northeastern Brazil, soil and climate conditions can increase the risk of soil salinization, particularly when poor-quality water is used for irrigation. Therefore, techniques that improve the yields of melon culture under adverse conditions, such as salinity, are of great relevance to the production sector. The objective of this study was to evaluate the effectiveness of hydrogen peroxide (H₂O₂) in acclimatizing melon trees subjected to irrigation water with different salinity levels. The treatments consisted of irrigation water with two electrical conductivities (0.3 and 5.0 dS m^-1) and four concentrations of H₂O₂ (0, 5, 10, and 15 µmol L^-1). The experimental design used was randomized blocks, arranged in a 2 × 4 factorial scheme, with four replicates and four plants per plot. Increase in salinity of irrigation water reduced the growth, gas exchange, and production of melon plants. However, H₂O₂, at a concentration of 6.35 µmol L^-1, yielded improvements in physiology, growth, and production, in addition to reducing the deleterious effects of saline stress on melon production.

Key words:
Cucumis melo L.; physiology; saline water