How green alternatives to chemical pesticides are environmentally friendly and more efficient

Various soil management strategies that use disinfestation are important in the control of soil-borne diseases before planting. However, only a few studies pay attention to preventing pathogen reinfestation during host plant cultivation, which is also important for the stable control of soil-borne diseases. Here we used various pre-planting management strategies to disinfest a field severely infested with Fusarium oxysporum, and then investigated changes in the potential pathogen and microbial communities during the 11 months of host plant cultivation. The soil microbial numbers, diversity, community structure and composition varied considerably across the soils treated by dazomet fumigation and reductive soil disinfestations (RSDs) using ethanol, bagasse and bean dregs. The Fusarium inoculum decreased to the same degree in the disinfested soils with the various methods. After the cultivation of lisianthus (Eustoma russellianum (Hook.) G. Don), microbial numbers, diversity and community structure tended to be similar and Fusarium increased markedly in these soils. Furthermore, the increase in relative abundance of Fusarium, especially in the RSD-treated soils amended with bagasse, was significantly less than in the soils amended with non-plant residues. Further analyses showed that the increases in microbial diversity and relative abundance of Zopfiella and Mycothermus were significantly and negatively correlated with the increase in Fusarium relative abundance. The additional sources of carbon supplied in the disinfested soil positively affected the development of the soil microbiota and prevented Fusarium reinfestation resulting from host plant cultivation, which should be considered for achieving stable disease suppression in the future.