The influence of agrotechnical factors on the formation of indicators of seed productivity in winter bread wheat

Optimising sowing dates and selecting suitable preceding crops is crucial for realising the productive potential of modern winter wheat varieties under changing climate conditions. The aim of the study was to determine the effects of sowing dates and preceding crops on the formation of indicators of seed productivity in winter bread wheat varieties under the conditions of the Right-Bank Forest-Steppe of Ukraine. The research material included nine winter bread wheat varieties: ‘AFK Stabiliti’, ‘AFK Lait Hrin’, ‘AFK Elit Hrein’, ‘AFK Fentezi’, ‘AFK Yunion’, ‘AFK Premium’, ‘MIP Feieriia’, ‘MIP Roksolana’, and ‘Podolianka’. It was established that sowing dates, preceding crops, and varietal characteristics significantly influenced seedling formation, morphological traits, and biological yield of winter bread wheat. The optimal sowing date was determined to be September 30, which provided the fastest germination (13 days), the highest tillering coefficient (1.57), the maximum number of productive stems (5.5-5.6 million/ha), and a biological yield of up to 6.3 t/ha. The most favourable preceding crops were pea and rapeseed, which ensured dense seedling stands (4.1-4.2 million/ha) and a high tillering coefficient (1.57-1.67). After sunflower, almost all studied indicators decreased due to soil nutrient depletion. The greatest ear length (up to 13.5 cm) was recorded in the ‘AFK Lait Hrin’ variety sown on September 30 after rapeseed, while the tallest plants were observed after pea (82.2 cm) and in the ‘AFK Elit Hrein’ variety (up to 89 cm). The highest biological yields were formed by ‘AFK Premium’ (6.6-7.2 t/ha), ‘AFK Elit Hrein’ (6.3-6.8 t/ha), and ‘AFK Fentezi’ (5.8-6.4 t/ha). Analysis of variance revealed that varietal characteristics played the dominant role in determining productivity (up to 95% of variation), while preceding crops had the greatest influence on stand density, and sowing dates affected yield levels. The study demonstrated the effectiveness of applying different sowing dates after various preceding crops to differentiate winter wheat varieties by seed productivity indicators. The obtained results can be used in agricultural practice to improve the efficiency of winter wheat seed production across diverse soil and climatic conditions and to optimise crop rotation systems