Abstract

Cotoneaster dammeri ‘Coral Beauty’ C.K. Schneid. were grown in a peat:perlite:sand container medium amended with either 4.8 kg/m³ (8 lb/yd³) dolomite, or combinations of CaSO₄ and MgCO₃ providing medium concentrations of 0.l, 0.5, 0.9, l.4 or 1. 8 kg/m³ (0.2, 0.9, 1.5, 2.4, 3.0 lb/yd³) Ca or Mg. Plant growth was greatest in plants grown with dolomite at the end of 4 months. At low [0.1 or 0.5 kg/m³ (0.2 or 0.9 lb/yd³)] Ca medium concentrations, growth was reduced as Mg medium concentration increased above 0.5 kg/m³ (0.9 lb/yd³). There were smaller adverse effects on dry weight as Ca medium concentration increased above 0.9 kg/m³ (1.5 lb/yd³) at low [0.1 or 0.5 kg/m³ (0.2 or 0.9 lb/yd³)] Mg. The smallest plants were associated with foliar Ca:Mg ratios less than 1 and, to a lesser extent, greater than 5.