Evaluation of collection accessions of fiber flax according to flax fiber yield and adaptability parameters in the conditions of North-West of the Russian Federation

Studies on the evaluation of 20 accessions of fiber flax of domestic and foreign selection according to flax fiber yield and adaptability parameters were conducted in 2018-2020 in the conditions of the Pskov region on sod-weakly podzolic light loamy soil. The Dobrynya variety (Russia), the yield of which depending on the year of testing was 215...273 g/m2, was used as standard. The most favorable conditions for fiber flax were in 2018 (Ij = +24.3), and stressful conditions caused by hot and dry weather during the critical period of plant growth and development (GTK = 0.83) - in 2020 (Ij = -30.8). The samples from China V 51267, 97192-79, y 7S12-13, Vuan 2009, M0269-1, wsh2-5-4 were characterized by the highest average fiber yield over the years of testing (259...275 g/m2) and yield under contrasting conditions (254...279 g/m2), with an average varietal of 232 and 230 g/m2, respectively. The varieties Hon Jku 350, Honkei 28 (Japan), L-1 Soglasie х Alfa (Russia), V 51267 (China) showed the lowest yield variability (7.0...10.8 %). The same samples were distinguished by higher stress resistance. According to homeostaticity (Hom), Hon Jku 350 (Japan), L-1 Soglasie х Alfa (Russia), V 51267 (China) were distinguished: 106.9; 98.9 and 52.1, respectively. Highly responsive to growth conditions (bi>1) were samples 97192-79 (1.93), 97192-79-8 (1.88) from China and L-3 Orshansky-2 x Tvertsa (1.74), Nadezhda (1.56) from Russia; plastic - Heiya 8(1.06), 92199-6-5(1.08) (China) and st. Dobrynya (1.01) (Russia), weakly responsive (bi < 1) -L-1 Soglasie х Alfa (Russia), Hon Jku 350, Honkei 28 (Japan). The best in stability (Gd2) samples were Heiya 8 (13) – China; L-3 Orshansky-2 x Tvertsa (26), L-1 Soglasie х Alfa (179), L-2 Voskhod х Zaryanka (182) - Russia; Hon Jku 350 (186) – Japan. According to the yield of flax fiber and the complex of adaptability parameters, based on the ranking, the cultivars L-1 Soglasie х Alfa (Russia), V 51267, wsh2-5-4, 97192-79 (China) with the greatest adaptive potential were identified. They can be used as sources of adaptability when creating new varieties of flax.