Presowing treatment of seeds of spring wheat with low-frequency electromagnetic field

Seeking for effective natural stimulants that enhance crop productivity is relevant to ensure high quality yield production. The influence of physical factors (e.g. electric and magnetic fields, ultraviolet, infrared, laser irradiation) on seeds which contributes to an increase in sowing properties, plant photosynthetic activity, survival and yield is in the focus for researchers. However, a more detailed study of the mechanism of energy influence on the internal seed structure, plant growth and development sill remained relevant. Besides, it is necessary to develop effective, simple, reliable and low cost devices for agrophysical stimulation. The Federal Scientific Agroengineering Center VIM together with the Kazakh National Agrarian University has developed low frequency electromagnetic radiation construct which is mounted directly on combine-harvester to expose seeds to electromagnetic field during harvesting. The purpose of this study is to assess the sowing qualities of seeds and biometric indicators of the derived plants of spring wheat ( Triticum aestivum L.) variety Omskaya 18, as influenced by low frequency electromagnetic fields depending on intensity and time of irradiation. The seeds were harvested in September 2015 (Republic of Kazakhstan). The construct used was developed on the basis of the magnetotherapy apparatus Almag-02, placed on a combine-harvester Enisey 1200 NM (Russia). We compared different modes of seed exposure. These were flow treatment (a dynamic mode) at magnetic induction B = 6 mT and frequency f = 10 Hz; static treatment for 3, 6, and 9 min at 6 mT and 3 Hz/16 Hz, and flow treatment at 6 mT and 3 Hz/16 Hz. Irradiated and non-irradiated seeds (control) were used in further studies. Seed germination parameters were estimated in laboratory tests. The seeds were germinated on filter paper in Petri dishes in darkness in a thermostat LP-113 (Labor Muszeripari Muvek Esztergom, Hungary). To assess the growth and development of seedlings and plants we used a phytotron Vic-Terra (FSAC VIM, Russia). Treatment with low frequency electromagnetic field for 9 min in static mode increased seed germination energy and germination rate by 12-13 %. When irradiating seed flow, germination was below the control, e.g. at 6 mТ, 10 Hz this parameter decreased by 4.3 % in the laboratory test and by 3.5 % in the phytotron. Plant weight and height were higher in the irradiated samples. Under static irradiation for 9 min at 6 mТ, 3 Hz and 16 Hz the plant weight was 0.56 and 0.59 g, respectively. The smallest weight (0.46 g per plant) resulted from flow treatment at 6 mТ, 16 Hz. After storage of treated seeds at laboratory conditions for 3 and 7 months the indicators (germination energy and germination rate) remained satisfactory. The best result was noted for seeds, processed in static mode for 9 min at 6 mТ, 3 Hz/16 Hz. A decline in sowing properties did not exceed 6 %, indicating the preserving effect of the electromagnetic field.