Effect of pre-germination treatment with direct magnetic field exposure: a systematic review and meta-analysis

The search for ecological technologies that favour germination processes in agricultural and forestry seeds is a topic of interest as an environmentally friendly option. This study was a systematic review and meta-analysis to examine whether magnetic field direct exposure of seeds has a specific effect on germination. Using Scopus (2000–2020) and Web of Science (2000–2020) databases, a bibliographic search was carried out using the following expressions (pre-sowing AND seed AND magnetic) to filter the references in the title, abstract and keywords of the articles published. The calculation and declaration of the effect size was performed by comparing binary results through applying the Odds-Ratio register with a 95% confidence interval (CI). The random effects model was applied with the DerSimonian and Laird method. A total of 175 articles were found, of which only 26 were accepted for systematic review and meta-analysis. Three subgroups were established according to the magnetic field strengths. The subgroup corresponding to intensities between 1 and 50 mT presented an Odds-Ratio of 0.49 with a CI of (0.19, 0.79), Q (14) = 24.77, p = 0.04, indicating that the treatment had a significant effect. The remaining subgroups showed no significant effect. Likewise, the global meta-analysis revealed a significant effect in favour of the treatment, with an Odds-Ratio of 0.68, a CI of (0.41, 0.94), Q (28) = 44.03, p = 0.03. From the studies included in the meta-analysis, the results show a significant effect of seed direct exposure to magnetic fields that can be used to increase seed germination.