Improvement of Photosynthesis and Photosynthetic Productivity of Winter Wheat by Cold Plasma Treatment under Haze Condition

Haze stress has various destructive physical, chemical and physiological effects on the plants. Cold plasma treatment is recognized as a suitable technology to improve germination efficiency of numerous seeds. This study was carried out to evaluate the effect of cold plasma in order to reduce harmful effects of haze on winter wheat (Pishgam cultivar) in the greenhouse. Seeds of wheat were treated with cold air plasma at 50W during different time intervals of 60, 120, 180 and 240 seconds. In the greenhouse, simulation of haze stress with concentration of 1500 μg m-3 was performed at 13, 49, 61 and 69 Zadoks scales at agricultural research greenhouse of Tarbiat Modares University. Effects of plasma treatments on quality and quantity of wheat were determined by the rate of photosynthesis, leaf stomatal density, size of stomata, intercellular CO2 concentration, transpiration rate, chlorophyll content, Relative Water Content (RWC), stomatal conductance, spike yield, and grain yield. Results indicated a significant difference among plasma treatments and the control. Plasma treatment in 180 seconds ameliorated photosynthesis rate, chlorophyll content, and stomatal conductance by 34, 32, and 93%, respectively, compared with the control. In response to haze stress in plasma treatments at 180s plasma treatment, grain and spike yield were increased by 58 and 75%, respectively, compared with the control plants. The results showed that plasma treatments reduced damage of haze stress on winter wheat.