The effectiveness of using the biological growth regulator Biosil (100 g/l of a mixture of triterpenic acids) with a consumption rate of 0.02 l/ha was studied in crops of ‘Yaromir’ spring barley (2021-2023) in the Ryazan region (Non-Black Earth zone of the Central Region of the Russian Federation) on dark gray soil of average fertility. The scheme of the field experiment: 1) control (without treatment); 2) single spraying of crops with a Biosil growth regulator in the "tillering" phase; 3) double – in the "tillering", "shooting" phases; 4) triple – in the "tillering", "shooting", "flag leaf emergence" phases. It was revealed that the yield value depended on the number of plants preserved for harvesting (r = 0.709). The maximum indicators of plant safety before harvesting (76.2 %) were recorded in the variant with three-fold spraying of plants, the minimum (58.9 %) – in the control variant. It was found that the treatment of Biosil crops in all experimental variants contributed to a statistically significant increase in the yield of spring barley grain in comparison with the control from 11.4 % (single spraying) to 20.7 % (triple spraying). A significant contribution to the formation of biometric elements was revealed: the length of the ear (r = 0.503), the number of grains in the ear (r = 0.830), the weight of grain from the ear (r = 0.746) and the weight of 1000 grains (r = 0.996). The greatest accumulation of protein (13.3 %) was due to single spraying of crops in the "tillering" phase, the least (12.6 %) was due to triple spraying. When calculating economic efficiency, it was found that the maximum indicators of conditional net income and profitability (74.8 %) were achieved with a single application of the Biosil growth regulator in the "tillering" phase with a yield of ‘Yaromir’ barley of 7.78 t/ha.