Some Factors Influencing the Growth and Survival of Root Nodule Bacteria in Peat Culture

Abstract

SUMMARY The growth and survival in peat culture of Rhizobium spp. from 3 inoculation groups was markedly affected by the gas exchange properties of the container. Complete restriction of aeration caused rapid reduction in numbers after only 1 week. Low moisture contents restricted growth but higher levels up to 60% (on a wet weight basis) favoured survival. Within the range tested the size of the inoculum was unimportant in determining the number of rhizobia in sterilized peat provided sufficient time elapsed for multiplication. Storage temperatures between 4° and 26° affected the rate of growth but not survival of rhizobia in pure culture for periods up to 26 weeks provided moisture was not limiting.