Effect of Low Frequency Magnetic Field (LFMF) on the Germination of Seeds and Selected Useful Characters of Onion (Allium cepa L.)

Magnetic fields (MF) have been reported widely as pre-sowing seeds treatment to increase their vigour, seedling growth and the plants' yield. Although, it has been shown that MF could affect seed germination and the seedling root growth, still their further effect on plant's life has been found to be inconsistent, especially under field conditions. Commercial seed lots of onion (Allium cepa L.) of the cultivars 'Octavia' and 'Eureka' were soaked for 12 hours in the distilled water at 20 C. Next, they were exposed to low frequency magnetic field (LFMF) of magnetic induction B=20 mT, for 10, 30 and 60 minutes. The LFMF was generated using a standard medical device for magnetostimulation VIOFOR JPS. Next, the seeds were evaluated for germination and received bulbs were analysed for the selected useful characters including the root length, maximal diameters, dry matter and quercetin content. For the LFMF treatment of 60 minutes, for the cultivars 'Octavio.' and 'Eureka', the energy of germination increased from 75.8% and 65% (control) to 88.3% and 87.5%, respectively. For the LFMF treatment of 60 minutes, the germination capacity, for the same cultivars, increased from 85% and 76.3% (control) to 92% and 90%, respectively, Treated for 60 minutes with LFMF onion seeds had longer seedlings than the ones from the control seeds. These values, for both cultivars, increased from 5.3 cm and 4.2 cm (control) to 8.4 cm and 5.7 cm, respectively. LFMF used for 60 minutes on the 'Octavio.' onion seeds, increased their emergences in the field and length of the roots on the bulbs. LFMF used had no effect on the dry matter of bulbs grown out from the seeds when exposing them for 10 and 30 minutes. However, when exposing them for 60 minutes, LFMF decreased the dry matter and increased the amount of quercetin.