EFFECT OF PREPARATIONS ON THE GROWTH AND DEVELOPMENT OF SPRING WHEAT (TRITICUM AESTIVUM L.)

For three years (2023–2025), spring wheat of the Zlata variety was grown on the sod-podzolic light loamy soil of the Gubino agropolygon of the All-Russian Research Institute of Reclaimed Lands, a branch of the V.V. Dokuchaev Soil Science Institute, under the N45P45K45 background. The crops were foliar treated twice with preparations developed at VNIIMZ: the humic preparation BoHum (1 l/ha, working solution rate of 300 l/ha) and the biological preparation LPB (3 l/ha, working solution rate of 300 l/ha) during the tillering and early heading phases. 2023 was characterized as optimal in terms of moisture, 2024 as insufficiently moistened, and 2025 as excessively moistened. It was found that both preparations affected the growth and development of wheat plants. The maximum changes in biometric parameters of wheat were observed in 2024. Overall, over the three years of the study, the use of BoHum contributed to an increase in the dry biomass of plants after the first spraying by 24.7% compared to the control variant, while the use of LPB after the second spraying – by 24.1%. During the same periods, an increase in the photosynthetic activity of plants was noted: the NDVI vegetation index values increased by 3.4% and 3.2%, respectively, for the variants with BoHum and LPB. In all years of the study, the preparations statistically significantly affected the increase in productive stems (on average over three years by 1.9% (abs.) in the variant with BoHum and 1.4% (abs.) in the variant with LPB). Over the period 2023–2025, the use of the preparations contributed to an increase in the number of grains per ear by an average of 8.4%. As a result, wheat yield increases with BoHum varied between 12.0 and 30.4% (average 20.5%), while those with LPB ranged from 7.7 to 22.2% (average 14.8%). The maximum effect of the products was observed in the insufficiently moistened 2024 year, and the minimum in the over-moistened 2025 year.