Pulsed Electric Fields-Driven Enhancement of Tomato Seed Quality and Resilience: Improving Germination, Stress Tolerance, and Microbial Disinfection

Seed quality is vital for agricultural productivity, as it directly influences the crop yield and resilience to environmental stressors. This study evaluated the effectiveness of a pulsed electric field (PEF) treatment in enhancing the tomato (Solanum lycopersicum) seed quality, seedling growth, and microbial safety. Tomato seeds were treated with PEFs at energy levels ranging from 1.07 to 17.28 J, and several parameters were assessed, including the germination rate, normal seedling development, tolerance to cold and salinity stress, electrical conductivity, and microbial inactivation. The highest germination rate (72.81%) was observed at 15.36 J on the seventh day of germination, whereas the highest normal seedling rate (94.62%) was recorded at 17.28 J (p ≤ 0.05). The germination under cold stress (5 days at 24 °C) was highest, with a 46.67% germination observed at both 1.92 and 10.88 J. PEF-treated seeds exposed to 100 and 200 mM of NaCl exhibited significantly improved germination compared to the controls (p ≤ 0.05). The electrical conductivity (EC) was more influenced by the incubation time than by the PEF intensity, as the EC of all samples showed a significant increase from 4 to 8 h. The samples treated with 17.28 J exhibited the highest germination rates under salt stress, reaching 62.00 ± 0.90% and 50.00 ± 0.60% under 100 mM and 200 mM of NaCl, respectively (p ≤ 0.05). The initial mean counts of the total mesophilic aerobic bacteria and the total mold and yeast—4.00 ± 0.03 and 3.06 ± 0.03 log cfu/g, respectively—were reduced to undetectable levels by the application of 17.28 J, with higher energy levels yielding greater inactivation. These findings demonstrate that the PEF is a promising technique for enhancing seed quality, promoting seedling vigor, and reducing microbial contamination, supporting its application in sustainable agriculture.