Biophysical approaches to assessing stress resistance and ecological plasticity of spring barley in modern conditions

Barley is one of the cereal crops that plays an important role in food in many countries. Currently, its cultivation may be threatened by climate problems. Biologists and agronomists are trying to find ways to increase the resistance of plants to extreme conditions and study their adaptability. The authors conducted experiments between 2022 and 2023 to study the effects of various biostimulant plant growth factors (Epin-Extra, Zircon, Gibberellin, Albit, Restart, and Zh) on photosynthetic activity in spring barley at different hydrothermal humidity coefficients. They also assessed the effect of these biostims on main photosynthetic parameters. Epin-extra and Albit preparations showed the highest rates of photosynthetic activity for all parameters. In these variants, the leaf area was higher than the control by 26.3%, the photosynthetic potential (PP) - by 4.4-14.3%, the net productivity of photosynthesis (NPP) - by 6.8-10.2%. The other preparations also gave positive dynamics in improving the PPP indicators. The chlorophyll content in barley leaves was most significant in the BBCH 13 phase in the variants with treatment with growth biostimulants.