Seeding depth and coleoptile length effects on cold acclimation and ice encasement responses of winter wheat

Winter wheat is susceptible to winterkill stresses, and management practices that target specific field problems, such as ice encasement, are needed. Therefore, a 2-year growth chamber study was conducted to assess the impact of two seeding depths (shallow: planted at 1.27 cm and deep: planted at 6.35 cm) on two winter wheat genotypes' survival following 0, 7, or 14 d of ice encasement. The two winter wheat genotypes used differed in coleoptiles length: 'DynaGro 9242W' (long coleoptile) and 'WhiteTail' (short coleoptile). This study measured chlorophyll fluorescence during acclimation, lipid peroxidation (as measured by malondialdehyde content) in leaf, root, and crown tissues, leaf area during recovery, biomass at harvest, and yield. Chlorophyll fluorescence parameters Fv/Fo, Fv/Fm, ET/ABS, ET/TR, VI, VJ, and Do were measured during acclimation and found to be significantly influenced by decreasing temperatures. Winter wheat sown deeper (6.35 cm) exhibited higher ET/ABS and ET/TR values, while the VI and VJ values were higher in plants sown at shallow depths, suggesting differences in the rate of stress-induced changes in the photosynthetic processes. Shallow seeding depth also appeared to offer advantages for plant growth. Plants sown at 1.27 cm had greater leaf area, biomass, and less lipid peroxidation in crown tissues under prolonged stress conditions. Additionally, DynaGro, with the longer coleoptile, demonstrated enhanced performance and resilience compared to WhiteTail, particularly under prolonged ice encasement stress. Results should be confirmed in field conditions to validate these findings.