The response of Sydney blue gum (.Eucalyptus salignaSm.) seedlings to additions of very small quantities of fertilisers and a number of soil treatments was investigated. Phosphorus was found to be the main limiting factor in seedling growth. There was a direct relationship between seedling height increase, dry matter weight and fertiliser phosphorus content, and an inverse relationship between root shoot ratio and fertiliser phosphorus content. Magamp, a high phosphorus content fertiliser, produced seedlings with a very low root-shoot ratio, which are difficult to transplant. The organic fertiliser blood and bone produced the most suitable seedlings for transplanting. The recommended rate is 1.60 g mixed with the soil in each 24 cubic inch capacity polythene pot before seedlings are pricked out. The use of mixed fertilisers considerably reduces the length of time that seedlings have to be kept in the nursery. The use of coral sand in potting mixtures is not recommended because it produces high soil pH.
展开▼
