Growth indicators of winter barley plants depending on fertilization and growth regulator application

Abstract

Aims. To determine the formation of winter barley plant height and lodging resistance under different fertilization and growth regulator application. Methods. Laboratory, measuring, comparative, analysis, statistical. Results. On average, over three years of research, the height of winter barley plants increased from 96 to 125 cm depending on the experiment variant, on the background without a growth regulator. At the same time, on unfertilized plots, this indicator varied from 83 to 115 cm depending on the research year. Lower air temperatures in the period of March-May contributed to lower plant height growth in 2023 and 2025. Optimum air temperature for the growth of winter barley plants in 2024 ensured the highest plant growth. It should be noted that in 2023, the height of plants increased by 37 %, in 2025 – by 22 %, and in 2025 – by 27 %. The research results indicate that the application of phosphorus and potassium fertilizers had the least effect on plant height. Over the research years, this figure has increased by only 2–5 cm. Variants with incomplete return of phosphorus and potassium fertilizers, as well as complete mineral fertilizer, did not significantly affect plant height compared to nitrogen systems. On the background of a plant growth regulator application, the height was in the range of 69–94 cm depending on the experiment variant and the research year. It should be noted that with the introduction of nitrogen fertilizers, plant height increased by 6–8 % compared to unfertilized areas. The area with fallen plants also changed depending on the weather conditions of the research year, fertilization and application of plant growth regulator. Conclusions. As a result of the conducted research, it was found that winter barley plants react differently to fertilizer application in field crop rotation. The use of nitrogen fertilizers has the greatest effect, and the least – phosphorus and potassium. Plant height varies from 83 to 115 cm in unfertilized areas and from 103 to 140 cm in systems with nitrogen component. The introduction of a plant growth regulator reduces their height to 69–94 cm or by 20–49 % depending on the experiment variant. Systems with the N150 introduction on the background of different returns of phosphorus and potassium fertilizers reduced plant resistance to 3 points. At the same time, plots without fertilizers, the phosphorus-potassium system and the application of N75 did not affect winter barley plant resistance. At the same time, plant resistance on the background of the growth regulator was at the level of 7–9 points depending on the experiment variant.