Disease Prevention and Growth Promotion Effects of Actinomycete Strain D74 on Amorphophallus konjac Characterization of a Pectobacterium carotovorum subsp. odoriferum strain causing soft rot desease of celery (Apium graveolens L.) Characterization of Soft-rot-resistant Amorphophallus konjac and Preliminary Analysis of the Resistance Mechanism Disease Prevention and Growth Promotion Effects of Actinomycete Strain D74 on Amorphophallus konjac Pathogen identification from soft rot disease of onion bulbs in Jiayuguan, Gansu province