WATER-STRESS REVEALS EFFECTS OF ELF MAGNETIC-FIELDS ON THE GROWTH OF SEEDLINGS

We studied the effects of weak and extremely low-frequency (ELF) magne tic fields (MFs) on the growth of spruce seedlings Picea abies that we re exposed simultaneously to stress conditions. The drought environmen tal stress conditions were simulated by watering the seedlings with po lyethylene glycol (PEG) at two different concentrations: 88 and 176 g/ L. The experiments showed that a weak, sinusoidal magnetic field (50 H z, 26 and 105 mu T, 12 h/day), which was computer controlled and was g enerated by a system of Helmholtz-like coils, inhibited the germinatio n and the growth of seedlings, whereas under normal conditions (withou t PEG), the effects were either zero or stimulatory. When the seeds we re soaked in water, the effects of MFs were reversed; i.e., they were stimulatory. This strongly supports some findings that biological syst ems under stress may demonstrate higher sensitivity to ELF EMFs. Our e xperiments demonstrate that the inhibition of germination was greater at the greater concentration of PEG (at 105 mu T), whereas the growth as well as fresh weight did not show this concentration dependence. Al ong with well-known frequency and power windows, we suggest physiologi cal windows as well, because even the quality of responsiveness to MFs (i.e., stimulation or inhibition) may strongly depend on the physiolo gical state of organisms.