Abstract
A simple method of producing mycorrhizas is described which enables mycorrhizal plants to be used in a wide range of experiments including controlled nutritional studies of Eucalyptus. Plants are grown in a Leonard jar apparatus under either sterile or non-sterile conditions, on soil or pure crushed quartz with nutrient solution media. On the sterile quartz media, inoculation with the crushed fruiting body of Pisolithus tinctorius induced more than 70% of tested Eucalyptus gummifera seedlings to form mustard yellow mycorrhizas when the phosphorus concentration was optimal, but the formation of mycorrhizas was dependent on the phosphorus concentration. No mycorrhizas were formed when phosphorus exceeded 5 ppm. On non-sterile, nutritionally poor Hawkesbury sandstone soils 92% of inoculated plants were infected. Only a few of the non-inoculated plants in either medium were lightly infected. A simple but reliable method for inducing mycorrhizas is proposed.