Formation of winter hardiness in winter wheat depending on varietal characteristics and elements of cultivation technology

Aim. To determine the effect of varietal characteristics and biological preparations, and of the methods of applying them (seed treatment and foliar spraying), on the winter hardiness of winter wheat. Methods. The research was conducted in 2023–2025 at the farm “KoLoSoK”, located in the Right-Bank Forest Steppe zone of Ukraine. The experimental design included winter wheat varieties, seed treatment with a mycorrhiza-forming preparation, and foliar application of biostimulants. Field, laboratory and mathematical-statistical methods were used. Results. The number of plants surviving until the end of autumn vegetation was highest where the seed was treated with Mikofrend-T: 410–414 plants/m² for ‘LG Aneri’, 419 plants/m² for ‘RGT Linus’ and 423–427 plants/m² for ‘RGT Reform’, which was on average 8.5, 7.8 and 7.6 % higher than in the variant without seed treatment. The greatest number of plants before winter was recorded for ‘RGT Reform’. The highest spring plant density and winter hardiness were obtained where Mikofrend-T was used for seed treatment and Kelpak and Aminorost for foliar dressing. The average number of plants after winter was 385–397 plants/m² for ‘LG Aneri’, 390–402 plants/m² for ‘RGT Linus’ and 398–409 plants/m² for ‘RGT Reform’, which exceeded the corresponding control values by 12.2–13.2 %. Average winter hardiness was 94.0–95.7, 94.0–95.8 and 94.1–95.9 % respectively, exceeding the control by 4.0–4.1 %. Thus, the best plant survival after winter was observed in ‘RGT Reform’ with the combined use of Mikofrend-T, Kelpak and Aminorost. Conclusions. The varieties studied (‘RGT Reform’, ‘LG Aneri’ and ‘RGT Linus’) showed high resistance to overwintering. The highest spring plant density and winter hardiness were obtained where Mikofrend-T was used for seed treatment and Kelpak and Aminorost for foliar dressing. The average number of plants after winter was 385–397 plants/m² for ‘LG Aneri’, 390–402 plants/m² for ‘RGT Linus’ and 398–409 plants/m² for ‘RGT Reform’, which exceeded the corresponding control values by 12.2–13.2 %. Average winter hardiness was 94.0–95.7, 94.0–95.8 and 94.1–95.9 % respectively.