Influence of the hydrocarbons diesel, gasoline, and benzene on the growth and mineral and antioxidant concentrations of tomato plants

The produced water is obtained during the extraction process of hydrocarbons, whose characteristics, composition and concentration depend on the reservoir that contains them. The waters produced contain hydrocarbons and heavy metals, and may contain essential elements for plant nutrition. Some studies indicate that for plants the most toxic components of the produced water are the hydrocarbons. This research aimed to evaluate the response in the pH and the electrical conductivity (EC) of irrigation leachate, morphological variables, mineral concentration and the generation of antioxidants in the tomato plants treated with diesel, gasoline and benzene in concentrations of 15 and 30 mg L^-1, simulating the use of water produced for irrigation. An analysis of variance and tests of means of least significant difference was performed. The hydrocarbon treated plants reached the fifth cut of ripe fruits, except the treatment of diesel at 30 mg L^-1, in which only 45% of the plants survived, and only the first harvest of ripe fruits was obtained. According to their type and concentration, the hydrocarbons produced both favourable and unfavourable changes in the pH, EC, stem diameter, plant height and dry fruit weight. Also, the hydrocarbons produced both beneficial and detrimental changes in the mineral concentration of the plants; however, the hydrocarbons inhibited the mineral concentration in the fruits. The level of ascorbate in the fruits was decreased, and the diesel treatments limited the accumulation of lycopene.