Frost resistance of newly created varieties of soft winter wheat of Mironov selection under different hardening conditions

Abstract

Goal. To study the frost resistance of the newly created soft winter wheat varieties of Myroniv selection under different hardening regimes in the conditions of the central part of the Forest-Steppe of Ukraine and to identify varieties with a consistently high level of resistance. Methods. After hardening of plants in the open field according to the standard method, they were subjected to free­zing in low-temperature chambers at a temperature of –18°C. The reliability of the obtained data was checked by Fisher’s test. Results. Research conducted over three years with contrasting weather conditions confirmed that the frost resistance of wheat varieties depended on the conditions of their hardening. In the case of a gradual decrease in air temperature, the hardening process of plants was much more efficient than during its sharp fluctuations. Under favorable conditions for the harde­ning phases in 2021/2022, the percentage of live plants after freezing was 84.4% on average by variety, under satisfactory conditions in 2020/2021 it was 68.1%, and under unfavorable conditions in 2019/2020 — 51.9%. Frost resistance of the refe­rence variety Myronivska 808 during the years of research varied from 56 to 94%. In 2019/2020 the level of resistance, higher than that of the standard, showed the variety Avrora Myronivska, at the level of the standard — varieties MIP Assol, MIP Fortuna, MIP Vidznaka, Vezha Myronivska, MIP Yuvileina, MIP Myronivska, MIP Nika. In 2020/2021, the varieties MIP Vidznaka and MIP Feieria had higher frost resistance than the standard, MIP Roksolana, Estafeta Myronivska, Vezha Myronivska, MIP Yuvileina, Avrora Myronivska, MIP Nika and MIP Fortuna were at the level of the standard. After freezing in 2021/2022, the percentage of live plants in the varieties MIP Fortuna, MIP Vidznaka, MIP Yuvileina, Estafeta Mironivska, Vezha Myronivska, MIP Nika was almost the same as in the variety Myronivska 808. Between the percentage of live plants after freezing and the temperature regime during the hardening period, a strong inverse correlation was established (r=–0.77). Conclusions. For three years of research, the highest level of frost resistance had such soft winter wheat varieties as MIP Fortuna, MIP Vidznaka, Vezha Myronivska, MIP Yuvileina, MIP Myronivska and MIP Nika.