Productivity of oil flax varieties, their ecological plasticity in Western Siberia

The objective of the study is to research oil flax varieties for their economically valuable traits and to assess the economic efficiency of their cultivation in the subtaiga zone of Western Siberia. On average, over three years of research (2022–2024), the shortest growing season of 100 days was observed for Severnyj, Avgust, and Chibis varieties, as well as for Yantar' and Azurit – 102 and 101 days, respectively. The formation of crop structure elements depended on weather conditions and the biological characteris-tics of the variety. On average, the field germination rate for the varieties in the warm spring conditions of 2022 and 2023 was the same and amounted to 69.9 and 69.2 %, respectively; in 2024, this figure de-creased to 63.8 %. The highest survival of plants for harvesting was observed in 2022 – 95.5 % on ave-rage for the year, in 2023 and 2024 – 96.5 %. Due to the high number of flax flea beetles, this indicator decreased from 87.3 to 73.7 %. The highest number of capsules per plant was formed in Yantar' (16.2 pcs.) and Azurit (15.6 pcs.) varieties. The least number of capsules was obtained in the Severnyj variety – 11.5 pcs., but it formed the most seeds in the capsules – 5.28 pcs., and they were the largest with a weight of 1000 pcs. – 7.89 g. The maximum and reliably high (LSD05 = 0.213) seed yield was ob-tained in the Azurit variety – 2.41 t/ha. The ecologically plastic varieties were Avgust and Azurit with a plasticity index of 1.073 and 1.095, respectively. The highest fat content was found in the seeds of Avgust (48.0 %) and Azurit (48.9 %) varieties, which provided an oil yield of 1133 and 1157 kg/ha, respectively. The Azurit and Avgust varieties stood out for their high economic efficiency of cultivation with a profitability of 134.7 and 130.4 %, respectively. They should be recommended when selecting varieties for cultivation in the subtaiga of Western Siberia.