In this study, the authors used alternating electromagnetic fields of low intensity (at the level of natural geomagnetic noise) to investigate the effect on the rate of seed germination and plant development.
1 mHz–10 Hz
Exposure duration: 5 - 60 min continuous
The dried corn seeds were the most sensitive to the electromagnetic field exposure. The stimulatory effect of the electromagnetic field was observed throughout the experiments, until the third-leaf stage. Exposure to the electromagnetic field for 15 minutes at the stage of germination led to a 30% increase in the rate of plant development compared to the control. The exposed plants entered the stage of the second leaf 1.5 times more rapidly than the control plants. As the duration of exposure increased, the stimulatory effect decreased.
The effect of exposure on dried wheat seeds was less pronounced. The stimulatory effect of the electromagnetic field was manifested most distinctly on the plants with a decreased germinating capacity. 15 minutes exposure of seeds increased their germinating capacity from 30 to 55%. However, exposure for 60 minutes suppressed germination.
The stimulatory effect of the electromagnetic field exposure on amaranth seeds also tended to decrease as the duration of exposure increased. A low germinating capacity of the control seeds (25%) increased as a result of electromagnetic field exposure to 47%. The stimulatory effect of exposure became weaker when the duration of exposure increased to 20-30 minutes. The exposure of amaranth seeds for 40-50 minutes inhibited their germination.
The rate of preliminary moistened germinated wheat seeds decreased under 15 minutes exposure. The germinating capacity of exposed dry and preliminarily moistened seeds was 56 and 25%, respectively (control seeds: 30%). Statistically significant effects of exposure on seed germination rate depending on seed state (dry or moistened) were obtained for amaranth. Similar data were found for moistened corn seeds.
The authors hypothesize that the fluctuations in the geomagnetic field parameters may change the content of hydrogen peroxide in natural water, which will affect the rate of plant growth.