Yield structure of safflower under the influence of row width and seeding rate

Abstract

Purpose. To establish the peculiarities of the productivity formation of different safflower varieties under the influence row width and seeding rate in the Right Bank Forest Steppe of Ukraine. Methods. The research was carried out in typical chernozem at the agronomic research station of the National University of Life and Environmental Sciences of Ukraine in 2021–2022 as a three-factor field experiment. Factor A (variety): ‘Dobrynia’ and ‘Soniachnyi’; factor B (row width): 19, 38, and 57 cm; factor C (seeding rate): 100, 200 and 300 thousand seeds/ha. Results. In the experiment, plant height of the variety ‘Dobrynia’ varied between 100.7 and 114.3 cm and 'Soniachnyi' between 93.5 and 108.9 cm.  The number of heads per plant was 15.5–20.6 and 7.0–19.8, 1000-kernel weight 40.6–45.4 g and 38.8–47.7 g, respectively; number of seeds per plant 148–513 and 145–508, seed weight per plant 6.9–22.5 and 6.9–22.7 g/plant. As for plant height, in both varieties, its indicators increased with an increase in the seeding rate for all variants of row widths, reaching maximum values with a row width of 19 cm and a seeding rate of 300,000 seeds/ha. The rest of the biometric parameters, on the contrary, showed a clear regularity to decrease along with an increase in the seeding rate. At the same time, the highest number of heads and the seed weight per plant were in variants with a row width of 38 cm; the highest 1000- kernel weight was for the row width of 57 cm; the highest number of seeds per plant was for the row width of 19 cm. The biological yield of seeds in the experiment ranged from 1.25 to 2.55 t/ha in ‘Dobrynia’ and from 1.21 to 2.52 t/ha in ‘Soniachnyi'. In both varieties, biological yield increased with an increase in the seeding rate, reaching maximum values at a row width of 38 cm. Conclusions. Both studied varieties demonstrated the highest yield for the row width of 38 cm and a seeding rate of 300,000 seeds/ha: 2.55 t/ha ‘Dobrynia’ and 2.52 t/ha ‘Soniachnyi’. Despite the fact that these safflower varieties are recommended for the cultivation in the southern regions, they are quite adaptive for the cultivation in the north of Ukraine as well, taking into account the gradual increase in average annual temperatures and high soil fertility.