2024 年 62 巻 1 号 p. 11-15
The reutilization of hydroponic nutrient solutions in agriculture is important for increasing the utility of limited water resources. It is necessary to remove the contaminating plant pathogen before reusing the culture solution. Damping-off, caused by Pythium aphanidermatum, is a major disease in hydroponic and soil cultivation systems. Strategies to control P. aphanidermatum primarily involve chemical fungicides that are not effective in hydroponic cultivation systems. Therefore, novel methods are needed to control this pathogen. In this study, we investigated the inhibitory effects of ultraviolet-light emitting diode (UV-LED) irradiation (265, 280, and 300 nm) on P. aphanidermatum. UV-LED irradiation significantly and permanently inhibited the growth of P. aphanidermatum mycelia in water. Fungal DNA degradation was observed as early as 5 min after irradiation with UV-LED (280 nm), and fungal mycelia were unable to infect cucumber plants after being irradiated for 5 min with UV-LED (280 nm). These results suggest that UV-LED irradiation can control damping-off caused by P. aphanidermatum and be used for the recycling of hydroponic nutrient solutions.
