The Effect of Phenyl-Substituted Derivatives on the Overwintering of Wheat Agrocenoses

Abstract

Despite the considerable amount of research on the use of various compounds for pre-sowing seed treatment of cereal crops, the effects of new phenyl-substituted derivatives on the winter hardiness of winter wheat remain insufficiently studied. In particular, there is limited information on the dynamics of sugar concentration in the tillering node and on the multivariate analysis of treatment variants. Purpose. To evaluate the effects of two phenyl-substituted derivatives – FA-55 (5-phenyl-imidazolidine-2,4-dione) and FA-59 (N-(1-hydroxy-2-oxo-2-phenylethyl)benzenesulfonamide) – on early development, carbohydrate reserve formation in the tillering node, and overwintering of bread winter wheat varieties. Methods: Field and laboratory investigations were conducted during 2024–2026 in the steppe zone under sub-humid conditions. Seeds of seven varieties were soaked for 24 h in aqueous solutions of the tested compounds at concentrations of 0.01, 0.02, and 0.04%; water soaking served as the control. Field emergence, plant condition before winter, post-winter survival, and soluble sugar content in the tillering node at the main stages of the winter period were determined. Results. The compounds showed divergent effects. FA-55 demonstrated a clear concentration optimum at 0.02%, which was associated with improved emergence, better plant preservation before winter, higher soluble sugar accumulation, and increased post-winter survival. At 0.04%, the stimulatory effect of FA-55 weakened and winter losses increased. FA-59 showed a weak or neutral effect at 0.01%, whereas concentrations of 0.02–0.04% caused suppression of growth and physiological parameters, reduced sugar content, and poorer overwintering. The most informative criteria for differentiating the treatments were post-winter plant survival and soluble sugar concentration in the tillering node. High values of the discriminant functions for these parameters during plant ontogenesis indicate that the response to treatment was not limited to a single effect during the initial phases of growth and development, but extended throughout the entire overwintering period. The obtained results demonstrate the potential of FA-55 at a concentration of 0.02% as an agent regulating growth and development processes to enhance the winter hardiness of winter wheat agrocenoses. Findings. For practical use, the most promising pre-sowing treatment regime is FA-55 at a concentration of 0.02%. Further studies should focus on verifying the stability of this effect under different growing conditions and on clarifying the biochemical mechanisms of action of the compound.