ASSESSMENT OF SUNFLOWER HYBRIDS AFTER ECONOMICALLY VALUABLE FEATURES AND PHENOTYPIC PLASTICITY

Sunflower in the Russian Federation is the main oilseed crop. To recommend the optimal cultiva-tion regions and the active introduction of sunflower varieties and hybrids into production, it is im-portant to know the adaptive potential, which is assessed by the value of the parameters of pheno-typic plasticity and stability. The selection of a variety should be determined by the limiting factors of the region in which it will be grown. In the conditions of the Penza region, sunflower hybrids of Syn-genta (four hybrids), Euralis (one hybrid), Maysadur (one hybrid) and Pioneer (one hybrid) were stud-ied for a set of economically valuable traits and phenotypic plasticity. It was found that the Bacardi hybrid had the shortest growing season of 114 days. The Mas 80 IR hybrid by Maysadur turned out to be late ripening, the growing season of which was 125 days. The plant height in the studied sunflower hybrids was in the range of 166-174 cm. The low-growing hybrid in the experiment was the Amis hy-brid by Euralis, the height of which was 166 cm, and the tall one was the Fortimi hybrid (174 cm). On average, for two years, the yield of sunflower hybrids in the experiment ranged from 2.05 to 3.25 t/ha. The average yield for all hybrids was 2.7 t/ha. The Fortimy (2.9 t/ha), Tristan (2.85 t/ha), Bacardi (3.25 t/ha) hybrids by Syngenta and the PE 63 LE 10 hybrid by Pioneer (2.95 t/ha) exceeded the average yield. The phenotypic plasticity index varied from 0.76 to 1.2. All hybrids of the Syngenta company (Neoma, Fortimi, Tristan, Bacardi) and the hybrid of the Pioneer company (PE 63 LE 10) are environ-mentally plastic. The phenotypic plasticity index is 1.0-1.2 and 1.09, respectively. The rest of the hy-brids require increased attention during cultivation.