The role of humic fertilizers and growth regulators in the cultivation of Achillea millefolium in the Western Ciscaucasia

The purpose of the study is to develop methods for increasing the yield of yarrow and increasing the content of essential oil in medicinal raw materials. A study of the effect of humic fertilizers on the productivity of common yarrow in the 2nd-4th growing season was carried out in the North Caucasus branch of the Federal State Budgetary Institution VILAR in 2021-2022. The soil of the experimental plot is represented by leached chernozems, which have a neutral reaction, pH is about 7. The humus content in the arable layer is 5.0 %; total nitrogen - 0.22-0.30; phosphorus (P2O5) - 9.17-10.22; potassium (K2O) - 1.7-2.1 %. Weather conditions (amount of precipitation and temperature) were favorable for the growth and development of plants. Research was conducted by setting up small-plot experiments, which were carried out in accordance with generally accepted methods. The effect of foliar treatments with humic fertilizers Lignohumat (0.5 l/ha), Normat L (0.3 kg/ha) and their complexes with the bioregulator Zircon (0.1 l/ha) on growth and development was studied plants, yield of raw materials and essential oil content. Treatment with humates was carried out at the beginning of plant growth and during the stemming phase. Double application of humic fertilizers Lignohumat (0.5 l/ha) and Normat L (0.3 kg/ha) contributed to the intensification of growth processes, an earlier onset (by 2-4 days) of the budding and flowering phases, and made it possible to obtain increase in yield of raw materials by 20-25 %, essential oil per unit area - 25-32 %, but the content of essential oil increased slightly - by 2-5 %. It can be increased (by 26-30 %) by treating plants during the budding phase with the growth regulator Zircon (0.1 l/ha). The complex use of humic preparations during the phase of intensive growth and Zircon at the onset of flowering leads to an increase in the yield of essential oil per hectare to 48 %.