TY - JOUR T1 - The Influence of Calcium Supplementation on the Freezing Tolerance of Woody Plants JF - Arboriculture & Urban Forestry (AUF) JO - JOA SP - 285 LP - 291 DO - 10.48044/jauf.1999.038 VL - 25 IS - 6 AU - Glynn C. Percival AU - Celia Boyle AU - Lynn Baird Y1 - 1999/11/01 UR - http://auf.isa-arbor.com/content/25/6/285.abstract N2 - The effects of calcium (Ca2+) supplementation on the freezing resistance of white poplar (Populus alba, frost hardy) and hornbeam (Carpinus betulus, frost sensitive) were studied by monitoring alterations in leaf fatty acids, chlorophyll fluorescence emissions, necrosis, mortality, and growth. Calcium supplementation had no significant effect on leaf fatty acids before, and from weeks 2 through 8 after, freezing. Percentages of the saturated fatty acid C16 were significantly higher in Ca2+-supplemented plants immediately following freezing (day 1) only. In P. alba, leaf chlorophyll fluorescence and necrosis values were significantly higher and lower than in controls immediately after freezing; readings from weeks 2 through 8 did not significantly differ from controls. Leaf chlorophyll fluorescence and necrosis values in C. betulus after freezing were significantly higher and lower than in controls throughout the experiment. Calcium concentrations were significantly higher in supplemented plants. Lower mortality rates and root and leaf electrolyte leakage values, and higher root, shoot, and leaf dry weights and leaf area recorded in Ca2+-supplemented plants indicate that freezing tolerance may be increased by application of Ca2+ fertilizer. ER -