The direct magnetic field effects and the effects through magnetically treated water by a weak and extremely-low-frequency magnetic field (MF) 50 Hz, 105 microT on the growth of spruce seedlings were studied. The seeds were watered simultaneously with distilled and deionized water (DD), with DD + 0.25, 0.5 or 5 mM Ca2+ and with tap water (1.7 mM Ca2+). The results showed the inhibitory effect of the MF on total germination on day 5 of the experiment. The direct treatment of seeds yielded a significant inhibitory effect at 0.5 mM Ca2+, while the indirect treatment showed the significant inhibitory effect at 0.25 mM Ca2+. On the other hand the time distribution of germination showed a heterogeneous time response with the most frequently significant effects at 0.25 mM Ca2+. The comparison between direct and indirect treatment of the seeds reveals some similarities as well as differences in effects. There were no effects on the length of the seedlings after 7 days of exposure.

The following graph represent the direct effect of magnetic field on the germination of spruce seeds in dependence of various concentration of Ca.