Effect on germination and early growth characteristics in sunflower (Helianthus annuus) seeds exposed to static magnetic field

Seeds of sunflower (Helianthus annuus) were exposed in batches to static magnetic fields of strength from 0 to 250 mT in steps of 50 mT for 1–4 h in steps of 1 h. Treatment of sunflower seeds in these magnetic fields increased the speed of germination, seedling length and seedling dry weight under laboratory germination tests. Of the various treatments, 50 and 200 mT for 2 h yielded the peak performance. Exposure of seeds to magnetic fields improved seed coat membrane integrity and reduced the cellular leakage and electrical conductivity. Treated seeds planted in soil resulted in statistically higher seedling dry weight, root length, root surface area and root volume in 1-month-old seedlings. In germinating seeds, enzyme activities of α-amylase, dehydrogenase and protease were significantly higher in treated seeds in contrast to controls. The higher enzyme activity in magnetic-field-treated sunflower seeds could be triggering the fast germination and early vigor of seedlings.