STEM DEFORMITY IN PINUS-RADIATA PLANTATIONS IN SOUTH-EASTERN AUSTRALIA .1. RESPONSE TO COPPER FERTILIZER

Visual symptoms of stem deformity similar to those of Cu deficiency are common in P. radiata established on fertile sites previously used for agricultural production in south-eastern Australia. In this study, Cu fertiliser was applied at rates of 0, 2, 5, 10, 20 and 50 kg ha-1 to deformed P. radiata at ages 3 and 6 years. Available soil Cu and contents of Cu in the foliage increased significantly only in the younger plantation. Cu fertiliser did not affect growth nor did it improve stem form. Levels of N, Cu and Cu/N ratios in foliage of straight and deformed trees were similar. However, contents of Cu in apical buds were significantly lower in deformed trees. It was concluded that stem deformity in P. radiata as observed on these fertile pasture sites, cannot be corrected by application of Cu fertiliser. Differences in Cu levels in apical buds of straight and deformed trees suggest that Cu may still be involved in this syndrome. There was also no indication of other nutrient deficiencies that could be associated with the deformity. © 1990 Kluwer Academic Publishers.