Perlite as a carrier for bacterial inoculants

Growth and survival of Rhizobium leguminosarum by. phaseoli, R. tropici, Br adyrhizobium japonicum and Bacillus megaterium in peat and perlite-based in oculants were evaluated. In general, survival was similar for all strains i n both carriers. Better survival was observed when inoculants were maintain ed at 4 degrees C compared to 28 degrees C. Studies with two different stic kers suggested the existence of interactions between carriers and adhesives and showed that combination of a sucrose adhesive with the perlite carrier gave better survival of bacteria on seeds. Bean and soybean field experime nts indicated that perlite-based inoculants produced similar number of nodu les, nodule dry weight, crop yield and nitrogen content, as peat-based inoc ulants. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.