NURSERY STERILIZATION AND INOCULATION REGIMES FOR ALDER PRODUCTION

Nursery experiments using common alder (Alnus glutinosa) to examine th e interaction of soil sterilization and inoculation with Frankia are d escribed. Seedling growth was stimulated when soil was sterilized with methyl bromide or dazomet at current recommended rates, but nodulatio n was reduced. Inoculation with cultured Frankia or a crushed nodule s uspension significantly improved nodulation, especially if the inocula nt was applied before seed germination. However, seedling growth was s ignificantly larger using cultured Frankia than the crushed nodule ino culant. If the latter is used to inoculate alder seedlings, a reductio n in the recommended rate of dazomet application to c. 285 kg ha(-1) i s likely to encourage nodulation, though seedling growth will be reduc ed slightly.