Abstract
The influence of storage temperatures and periods on the nodule formation of inoculated seeds was investigated. Seeds inoculated with coating, vacuum processing and adhesive were stored at cool or room temperatures. The number of viable rhizobia on seeds was estimated by the dilution-plate method, and nodule formation was examined in solution culture and field cultivation. The numbers of viable rhizobia after 6 months of inoculation declined differently depending on the inoculation method and storage temperature. Vacuum-processed seeds decreased markedly the number of viable rhizobia when stored at room temperature. A similar tendency of these inoculation methods was observed for the number of nodules in solution culture. Coated seeds maintained a high nodulating ability as well as at the start of inoculation, after 12 months' storage under cool conditions. In field cultivation, coated seeds stored for 3 months, regardless of storage temperature, formed large numbers of nodules. However, vacuum-processed and adhesive seeds decreased nodulation even if stored under cool conditions. When stored for 12 months at cool temperatures, coated seeds still possessed high nodulating ability, while adhesive seeds had little effect and vacuum-processed seeds had no effect on nodulation.
