PRODUCTIVITY AND ADAPTIVE PROPERTIES OF VARIETIES AND HYBRIDS OF SUNFLOWER IN THE CONDITIONS OF THE OREL REGION

The studies were carried out in the conditions of the south-east of the Orel region on leached heavy loamy, medium-depth chernozem; pH – 5.0-5.2; humus content - 6.7-6.9% (according to Tyurin); mobile phosphorus - 80-90 mg/kg and exchangeable potassium (K2O) 122- 136 mg/kg of soil according to Chirikov in order to assess the yield and indicators of adaptive properties of sunflower varieties and hybrids. The yield, depending on weather conditions in 2019- 2024, ranged from 0,67 t/ha to 5,9 t/ha, the coefficient of variation (V%) varied between 31% - 48% and 53% - 68% for hybrids, the environmental conditions index (Jj) varied from - 1,718 to +1,659. In 2019, significant 1,5 t/ha and 2,3 t/ha yield increases for Spartak and Belochka varieties in comparison with the VNIIMK 100 variety. The Spartak sunflower variety was distinguished by high seed yields in 2020 and 2021, exceeding the yield of sunflower varieties VNIIMK 100 and Belochka by 2,3 t/ha and 2,1 t/ha. Among the hybrids tested in 2020 and 2021, the Kometa hybrid stood out with a large seed yield, compared with the Granada hybrid, which exceeded 0,9 t/ha and 0,4 t/ha. The Spartak variety and the Kometa hybrid produced high seed yields in an average of 6 years - 2,86 t/ha and 2,96 t/ha, and, respectively, 0,71 t/ha and 0,81 t/ha significantly exceeded the yield estimates of the VNIIMK 100 variety. Of the compared varieties and hybrids in 2019-2024, the optimal combination of average yields was 2,86 t/ha and 2,96 t/ha with stress tolerance (Ymin- Ymax) -3.73 and -5.12 t/ha, genetic flexibility (Ymin + Ymax)/2) 3,17 and 3,73 t/ha, KA =1,12 and 1,16, bi =0,99 and bi =1,36, the Spartak variety and the Kometa hybrid corresponded. The Spartak variety and the Кometа hybrid corresponded to the optimal combination of average yields over six years – 2,86 t/ha and 2,96 t/ha with stress resistance (Ymin-Ymax) -3,73 and -5,12 t/ha, genetic flexibility (Ymin + Ymax) /2) 3,17 and 3,73 t/ha, KA =1,12 and 1,16, bi =0,99 and bi =1,36. The most adapted to the conditions of the Orel region are grades 21 and 26 Spartak and Кometа hybrid. An average of six years а moderate positive correlation, r=0.64, was found between the yield and the number of leaves on a sunflower stalk. The high correlation was established between the seed yield of sunflower varieties and hybrids and the coefficient of adaptation (KA), r= 0,99 and the most informative indicator was stress tolerance (Ymin–Ymax) with significant correlations between (Ymin-Ymax) and (Ymin + Ymax/2), r= -0,9689), (bi), r =-0,9695, (Нom), r =0,9040 and (Sc), r =0,9259.