Influence of autumn plant condition on cold hardiness of winter cereal crops at different sowing dates

Abstract

Research on the influence of autumn plant condition as a factor affecting the cold hardiness of winter wheat, rye, and triticale was conducted at the Siberian Scientific Research Institute of Plant Growing and Breeding, a branch of the Institute of Cytology and Genetics, SB RAS, from 2018 to 2021. Morphological indicators of pre-winter plant condition in cereal crops (plant height, number of tillering shoots, and green mass) are primarily associated with the sowing date (contributing to 54.68–85.86%) and genotypic characteristics of winter crops (contributing to 3.63–22.81%). The best morphological indicators were observed with the first sowing date, which decreased by the third sowing date. Over the research period, more vigorous growth, the formation of tillering shoots, and the development of green mass were observed in winter rye compared to triticale and wheat, regardless of the sowing date. In addition to morphological changes in plants, biochemical changes were also observed (sugar content in the tillering node). The accumulation of sugars was influenced by the meteorological conditions of the year (contributing to 30.36%) and determined by the biological characteristics of the crop (contributing to 18.69%). High sugar content in the node of tillering of rye was found in 2020 - 34.3–43.4%, in wheat - 22.8–32.5%, and in triticale - 28.4–37.3%, which can be explained by excellent vegetative conditions promoting the accumulation of more sugars in the node of tillering of plants. At different sowing dates, high sugar content was observed in winter rye: in the first - 36.5%, the second - 26.8%, and the third - 31.3%. Triticale exceeded winter rye in sugar content in the second - 29.5% and third sowing date - 33.0%. Winter rye exhibited high morphological and biochemical indicators in autumn, contributing to its high cold hardiness (80–100%) at different sowing dates. A positive correlation was established with plant height and tillering coefficient (r =0.90*–0.91*), indicating increased cold hardiness with these traits. Wheat and triticale significantly lagged behind rye due to their lower resistance to extreme negative temperatures compared to rye. It was found that an increase in linear growth promotes increased cold hardiness, the formation of tillering shoots, and the amount of sugars in the node of tillering (r =0.34…0.93*) in wheat and the maximum height and number of tillering shoots (r =0.84*…0.94*) in triticale in the autumn period.