Impacts of three different magnetic field applications on M. offininalis seed germination and seedling growth

The herb Melissa officinalis L., most commonly recognized as lemon balm, has been used as a treatment for problems with the brain and central nervous system, headaches, nervousness, digestive disorders, respiratory and circulatory conditions, various types of cancer and rheumatism. This investigation was designated to compare the impacts of 3 discrete magnetic field strengths (50 mT, 100 mT and 150 mT) with various time periods of exposure (5 min, 15 min, 30 min, 1 hr and 3 hr) on M. officinalis seed germination (rate and onset) and seedling growth (length of shoot-root, weight of fresh-dry and water content). The seeds, which were surface sterilized in petri plates, were subjected to different applications, including exposure to various magnetic fields and control (without exposure). Germination was assessed by observing the radicular protrusion. The number of germinated seeds was recorded over 20 days. In all 3 magnetic field applications, exposure to magnetic field for 1 hr caused the highest number of seed germination (36%, 52% and 50% for 50 mT, 100 mT and 150 mT, respectively) comparing to control (28%). The onset of seed germination was earlier with magnetic field application (day 7) compared to control (day 11). Growth elements and water contents of the seedling were assessed in order to understand the impact of different magnetic field applications. Implementation of 100 mT and 150 mT magnetic field for 1 hr increased shoot and root length in addition to fresh weight of the seedlings. The maximum dry weight increase was provided by 150 mT-5 min, 15 min and 30 min. The highest water content (%) was observed with exposure to 150 mT (68%) and 100 mT (66%) for 1 hr compared to control (44%). Magnetic field intensity of 100 mT and 150 mT for 1 hr was the most efficient in the seed germination and seedling growth.