Pre-sowing treatment of maize seeds by cold atmospheric plasma and pulsed electromagnetic fields: Effect on plant and kernels characteristics

The effect of cold atmospheric plasma (CAP) (45 kHz sinusoidal AC high voltage at 6 kV peak-to-peak for 5-15 min) and pulsed electromagnetic fields (PEMF) (amplitude 12.5 mT, repetitive frequency 3 Hz for 30 min) as pre-sowing treatments was studied on the germination, physiology, yield and quality characteristics of maize hybrid seeds with high and low germination capability. The measurements conducted during the plant growth were the dry weight, chlorophyll content, photosynthetic rate, transpiration rate and stomatal conductance, while for the harvested kernels, the color, texture, sphericity, size, ash, total protein and total crude content were estimated. The results showed that CAP and PEMF pre-sowing treatments favored the growth and physiology of both maize plants improving their germination rate significantly. Their chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance as well as dry weight were also improved. Both CAP and PEMF treatments, resulted in maize yield increase by 18-25% and by 10-20% compared to untreated samples for the low and high germination capability seeds, respectively. With regards to the quality of the harvested corn grains, their total protein and crude fiber content obtained by CAP treatment for 15 min were significantly increased by 26% and 29% for low germination seeds and by 36% and 42% for high germination seeds, respectively, compared to untreated samples. The results indicate that either CAP or PEMF pre-sowing treatments could be used as alternative ameliorative tools in order to improve maize growth, productivity, yield and quality of the final products.