PRODUCTIVITY OF SUNFLOWER HYBRIDS BAITEREK-S DEPENDING ON THE DENSITY OF PLANT STANDING AND SOWING DATES IN THE CONDITIONS OF THE STEPPE ZONE OF NORTHERN KAZAKHSTAN

Abstract

Results of research 2021-2023 on the realization of genetic potential sunflower hybrid Baiterek-S in the conditions of the dry zone of Northern Kazakhstan showed that it proved to be a mid-season hybrid with a growing season of 121- 136 days, depending on the elements of the cultivation technology used. The adaptation coefficient, which characterizes the sowing density, depended on the seeding rate; with an increase in the indicator, it decreased by 2-5% on an unfertilized background, by 2-3% on a fertilized one. On an unfertilized background with a sowing date of May 10 and a seeding rate of 45 to 55 thousand/ha, the adaptation coefficient increased slightly (by 4%). The structural elements of the basket productivity of the sunflower hybrid Baiterek-S had significant differences depending on agricultural practices. The maximum number of seeds per basket was formed at the sowing date of May 20 on a fertilized background with a seeding rate of 45 thousand/ha (982.0 seeds/per basket). When sowing on May 10, the decrease in this indicator was 70-53 units/basket at a rate of 55-45 thousand/ha. Reserves of productive moisture before sowing and timely precipitation during the growing season made it possible to form a fairly high level of sunflower yield in 2021 at the level of 21.9-34.4 c/ha. The highest productivity was observed for crops on May 20 on a fertilized background with a seeding rate of 65 thousand pieces/ha - 34.4 c/ha, and the option with a seeding rate of 55 thousand pieces/ha - 32.5 c/ha was slightly inferior in productivity. In 2022, a more humid year, the advantage in productivity was with sowing on May 10. The range of variation in yield according to the experimental variants ranged from 15.2 c/ha (sowing on May 20 with a seeding rate of 45 thousand pcs/ha) to 35.8 c/ha (when sowing against the background of P90, May 10 with a seeding rate of 65 thousand pcs/ha). Low moisture reserves at the beginning of sowing (102 mm) and the virtual absence of productive precipitation during the growing season reduced the productivity of the hybrid. Sowing on May 20 against both backgrounds (P0 and P90) resulted in higher productivity of the agrocenosis. In the sowing option on May 20 with a seeding rate of 55 thousand pieces/ha, the highest yield level of 9.5 c/ha was formed. Therefore, according to 3 years of research, it should be recommended to sow the Baiterek-S hybrid on May 10 on a fertilized background with a sufficient supply of moisture before sowing in a meter layer with a seeding rate of 55-65 thousand pcs/ha for the steppe zone of Northern Kazakhstan.