Different fertilizers effect on photosynthetic resistance to drought of barley (C3) and millet (C4) under two climate conditions

Abstract

The aim of this research was to evaluate the effect of different fertilization on photosynthetic resistance of C3 plant barley and C4 plant millet to drought stress under different climate conditions. Half of investigated plants were sown in peat substrate with mineral fertilizers and other in substrate with organic fertilizers. All plants were grown in automatically controlled climatic conditions under current (400 ppm CO2, 21/14 °C, day/night) and elevated (800 ppm CO2, 25/18 °C) climates, and well-watered and drought stressed conditions. There was obtained, that elevated climate increased the growth of both investigated plant and the effect was more pronounced for barley. Drought stress was decreasing growth parameters of barley, while for millet no statistically significant effect was detected. Single effect of different fertilization on dry biomass of both plants was week and statistically insignificant in almost all treatment variants, with exception for barley grown under current climate, when dry biomass of plants fertilized with mineral nutrition increased (p<0.05), compare to plants fertilized with organic fertilizers. Water deficit decreased photosynthetic rate of barley plants (p<0.05), while the effect on photosynthetic rate of millet was statistically insignificant (p>0.05) under both investigated climate conditions. Lower losses of photosynthetic rate of drought stressed barley were detected for plants grown with organic fertilization, and the effect was more pronounced under elevated climate. Lack of the water decreased transpiration rate of barley under both climates. Under current climate higher decreases were detected for barley plants fertilized with organic fertilizers, while under elevated climate conditions the changes were opposite. [...]