SUNFLOWER HYBRIDS TUR AND VILNYY

The article presents the agrometeorological indicators of the southern Steppe of Ukraine (Zaporizhia) and the reaction of new hybrids Tur, Mirny and Vilnyy to environmental changes. The most favorable of the four research years was 2021, all hybrids had the highest indicators of yield (t/ha), weight of 1000 seeds (g) and fat content in seeds (%). In 2020, all indicators had a significant deterioration of indicators of economic value.In the Tur hybrid, the formation of the vegetation period over the years of research was an average of 100 days, the variation between years was within six days, only in 2020 this indicator reached 115 days. which was the actual difference of 23 days.The yield index is the main feature of the sunflower hybrid, therefore, the study of ecological stability and plasticity, the formation of yield indicators when changing agrometeorological conditions is the task of breeding works. According to research data, the lowest yield indicators were formed by hybrids in 2020 (the average for hybrids was 1.60 t/ha), the highest yield was formed in 2021 (3.13 t/ha).The average annual yield of the Yason hybrid was 2.15 t/ha, the range of fluctuations in yield was 1.17 t/ha. The decrease in yield occurred due to the low formation of grain collection per unit area in 2020 (1.53 t/ha). In the Tur hybrid, the best indicators were formed in 2021 - 3.56 t/ha, the worst in the same year 2020 - 1.60 t/ha. The average over the years was 2.55 to the standard +0.40 t/ha. The Mirny hybrid also had the best yield in 2021 – 3.15 t/ha, which is 0.65 t/ha more compared to 2020 and 0.17 t/ha more than the long-term average compared to the standard. Vilnyy hybrid turned out to be the best of the studied hybrids, its average yield over the years was 3.26 t/ha, which is higher than the standard hybrid by 1.11 In the hybrid Vilnyy, the productivity within the range of 3.33 - 3.99 t/ha was formed for three years, and a decrease in productivity to the level of 2.11 t/ha is observed in 2020 t/ha. 2021 turned out to be the best year for the formation of high yields in the southern Steppe zone. The weather conditions of 2020 developed in such a way that the stages of organogenesis VI - VII - the formation of pollen and receptacle; VIII - IX stages - flowering and fertilization; X-XI stages of seed formation, deposition and accumulation of reserve substances took place in very harsh weather conditions. From July to August, precipitation fell by 83.1 mm less than the long-term average, and atmospheric temperatures were higher by 2.9 to 5.8 °C.The average mass of 1000 seeds of the Yason hybrid was 47.2 g, the best indicators of seed mass formation were in 2021 - 51.0 g, the worst in 2020 - 41.0 g. The analysis of the conducted studies showed that 2020 was also the year for seed mass formation turned out to be the worst. Practically all hybrids had a significant decrease in the weight of 1000 seeds, Tur in the range of 8.0 - 10.0 g, Myrnyi from 1.0 to 8.0 g and Vilnyy in the range of 8.0 - 11.0 g.Among the 4 hybrids presented in the table, the Vilnyy hybrid had the best indicators for the mass of 1000 seeds, the formation of the seed mass was almost stable over the years, in 2019 and 2021 the indicator was 60 g, in 2022 it was 3 grams lower. Myrny and Tur hybrids had seed weight values of 55.0-57.0 g and 48.0-55.0 g, respectively.It should be noted that the mass of 1,000 seeds and yield have a direct correlation, and it is the X-XII stages of organogenesis, which are followed by the formation of seeds, the deposition and accumulation of reserve substances, that form the basis of the formation of the yield of sunflower hybrids. The breeding work of scientific institutions is aimed at creating sunflower hybrids with a high content of fat in the seeds. Modern hybrids should have the ability, under adverse weather conditions, to accumulate fat in the seeds at least 46 g.According to the results of the analysis of fat accumulation (oiliness) in the seeds, it was proved that the oiliness indicators of both the standard hybrid and the studied hybrids were the best in 2021. Hybrid Yason had an accumulation of fat in the seeds at the level of 49.48 %. The best indicator of oiliness among the studied hybrids was Myrnyi hybrid -50.61% and Vilnyy 50.21%, the Tur hybrid had not significantly the lowest indicator - 49.11 %, its error was within the limits of NIR 0.05. In 2019 and 2022, all three hybrids significantly exceeded the oil content standard. On average, over the years, the highest accumulation of fat in seeds was in the Vilnyy hybrid, its average indicator was 49.01 %, which gives an increase compared to the standard of 1.48 %. Hybrid Tur, Myrnyi had the average oil content at almost the same level - 48.30 - 48.31 %, respectively, which is 0.77 and 0.78 % more than the Yason hybrid. The conducted research also confirms that the conditions of the XI-XII phase of organogenesis play a significant role in the accumulation of fat in the seeds, and it is precisely during this period that reserve substances are deposited and the accumulation of fat in the seeds.