Nutrient Distribution in Flowering Stems, Nutrient Removal and Fertilization of Three Proteaceae Cultivars

Several parameters of flowering stems of two cultivars of protea Leucospermum cordifolium (Knight) Fourc (‘Succession II’ and ‘Tango’) and one of protea Protea L. (Protea susannae x magnifica ‘Susara’) were studied in different commercial plantations. These included length and weight measures, nutrient concentrations of detached parts (flower heads, leaves and stems), and removal of nutrients of harvested flowers. A base for fertilization was also calculated. Harvested flowers of ‘Susara’ removed more P, K and Cu than ‘Succession II’ and ‘Tango’, and more Ca and Fe than ‘Tango’. ‘Succession II’ showed the highest Zn removal. The P and Cu removal by the crop of ‘Susara’ were significantly higher than those of both Leucospermum cultivars, while K, Ca, and Fe outputs of ‘Susara’ exceeded only those of ‘Tango’. The nutrient top removals amounted to 4.55 g m-2 of N, 0.48 g m-2 of P, and 5.26 g m-2 of K. Data as a base to supply fertilizer to each cultivar are given, with N:P:K ratios of 1:0.08:0.87 for ‘Succession II’, 1:0.08:0.83 for ‘Tango’ and 1:0.10:1.27 for ‘Susara’.