Control of Ralstonia solanacearum in tomato hydroponics using a polyvinylidene fluoride ultrafiltration membrane
Root-infecting pathogens have been observed on various crops grown in hydroponic systems. We investigated the ability of a polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane to remove bacteria from the nutrient solution and control disease within an irrigation system. In this study, we inoculated tomato (Solanum lycopersicum) plants with the plant-pathogenic bacterium Ralstonia solanacearum. When plants were irrigated without the membrane, R. solanacearum was detected in the nutrient solution, which resulted in bacterial wilt on tomatoes; moreover, R. solanacearum was re-isolated from all seedlings. By contrast, when the irrigation water was filtered through a PVDF-UF membrane, R. solanacearum was not detected in the nutrient solution; moreover, symptoms of bacterial wilt were not observed and R. solanacearum could not be re-isolated from any seedlings. Thus, the PVDF-UF membrane removed R. solanacearum from the nutrient solution and controlled the incidence of bacterial wilt. Secondly, the proliferation of R. solanacearum in wastewater before and after filtration was investigated. Results showed that R. solanacearum decreased slightly in untreated wastewater but increased in UF-treated wastewater. These data suggest that the PVDF-UF membrane is an effective tool for disease control in hydroponics. Additionally, the PVDF-UF membrane is worthwhile if it is able to control pathogen proliferation after ultrafiltration in nutrient solution recycling systems.
Itoh, M. and Iwasaki, Y. (2018). Control of Ralstonia solanacearum in tomato hydroponics using a polyvinylidene fluoride ultrafiltration membrane. Acta Hortic. 1227, 299-304
disease control, plant pathogenic bacteria, recycling nutrient solution, waterborne disease, proliferation, eradication