Abstract
Exposure to power lines of the electric power stations generates electromagnetic fields (EMFs) which have been documented to produce various biological effects. In the present investigation, EMFs showed two diverse directions; one is stimulatory at low EMFs while the other is inhibitory at high EMFs. In maize (Zea mays), both the percentage of germination, the subsequent vegetative growth and yield criteria, significantly increased in plants grown at low EMFs as compared to the control. The fluorescence emission intensity of leaf chlorophyll had significantly increased in response to the low EMFs. In addition significant increments in the total soluble sugars, total soluble nitrogen and total phenol were recorded. Moreover, the contents of mineral ions as K, Ca, Mg, and P were significantly increased in low EMFs. Plants grown at low EMFs showed remarkable and significant increments in both the quantity and quality of the produced oil through decreasing the contents of saturated fatty acids by 57.5% and increasing those of unsaturated ones by 13%. Exposure of maize plants to high level of EMF significantly enhanced the content of H2O2, compared concurrently with significant increase in malonadialdehyde (MDA) as being compared with control plants. Furthermore, MDA content was utilized as biomarker for lipid peroxidation parallel to H2O2, content. Moreover, total phenols showed higher increases above those of the control and low EMFs. In addition, the level of unsaturated fatty acids of the yield grains was increased. In conclusion, electromagnetic fields of low dose have been known to act as bio-stimulators for the growth of maize plants.

Key words: Electromagnetic fields, Zea mays L., growth, metabolic activities, yield