The Effect of Varying Levels of Potassium on the Frost Resistance of Birch Seedlings

1989

S. 21-31

7 Abb., 5 Tab., 37 Lit. Ang.

Unselbständiges Werk

200014366

Seven hundred one-year-old Betula pendula Roth seedlings were given different concentrations of potassium fertiliser. Over the study period seedlings were subjected to artificial growing and dormant phases. Frost resistance of the seedlings was assessed by artificial freezing tests and electrical impedance measurements on stem cuttings. In general, high concentrations of potassium fertiliser reflected a low tolerance to frost. Pre-freezing impedance readings decreased with increasing potassium fertiliser dosages. Results from pre-freezing impedance measurements were found to be in broad agreement with the hypothesis that high impedance readings indicate a frost hardy tissue whereas low readings imply the opposite.