Nutrient solution experiments were conducted in the growth chamber to study the influence of rootstock, solution Ca/Mg ratios and solution nickel on K uptake. The experimental plants were one-year-old prune trees: ‘French’ prune (Prunus domestica L.) scions grafted on Myrobalan 29C (P. cerasifera Ehrh.), Marianna 2624 (P. cerasifera × P. munsoniana?) or Nemaguard (P. persica × P. davidiana) rootstocks. Ion uptake parameters Imax, Km, and Cmin were calculated from ion depletion measurements over a 6 to 10-hr period.
- calcium/magnesium ratios