Inoculation with Pure Cultures of Mycorrhizal Fungi of Radiata Pine Growing in Partially Sterilized Soil

Abstract

Pinus radiata D.Don seedlings were successfully inoculated with Rhizopogon luteolus introduced in the mycelial stage into a nursery soil partially sterilized with methyl bromide at 3 lb, 5 lb and 7 lb per 100 cu ft or with aerated steam at 60°C, 71°C and 82°C. The sterilization treatments were also effective against damping-off and improved the growth of seedlings. Recolonization of soil by damping-off organisms was apparently slower after aerated steam sterilization than after methyl bromide. Short root production was reduced by methyl bromide applied at 7 lb per 100 cu ft, but was not affected by lower rates of application. Soil micro-organisms apparently detoxified methyl bromide. The effect of micro-organisms on the introduced fungus and the growth of seedlings is discussed.