Effects of water salinization on tomato seedlings (Solanum lycopersicum)

Tomato quality is directly related to the quality of the water used for irrigation and the adequate supply of nutrients, which can lead to damage due to soil salinization, with a consequent reduction in crop yield. This work aims to evaluate the emergence and initial development of 'Bartô' tomato seeds when submitted to different levels of saline water. Tomato cultivar seeds (Solanum lycopersicum) were subjected to five concentrations of sodium chloride (NaCl), 2.5; 3.5; 4.5; 6.5 and 7.5 dS m-1. The design used was completely randomized (DIC) with four replications of 25 seeds per modality. Sowing was carried out in petri dishes, on a paper towel disc. The papers were moistened with the saline solution in their respective concentrations. Then the plates were sealed to prevent moisture loss. The assays were kept in the BOD (biology oxygen demand), at a temperature of 25ºC. In addition to the electrical conductivity test, the physiological characterization of tomato seeds was carried out, such as: first germination assembly, emergence speed index (IVE); germination percentage; seedling length. The data were submitted to analysis of variance using the SISVAR Software, and were not transformed, as they followed a normal and homogeneous distribution. The maximum salinity in irrigation water that tomato plants can withstand without affecting productivity was 1.7 dS m-1. The salinity level that negatively affected the studied variables was from 4.5 dSm-¹.