Hot Water Treatment as a Quarantine Measure for Controlling Pratylenchus penetrans Cobb in Syngonium podophyllum Schott and Perilla frutescens Britton

Syngonium podophyllum Schott plants are increasingly being imported in Korea due to their ability to purify indoor air. Root lesion nematodes, Pratylenchus spp., are the most frequently occurring nematodes associated with S. podophyllum, leading to the disposal of plants or their return to the country of origin, due to inadequate phytosanitary treatments. We evaluated the effectiveness of hot water treatment in controlling Pratylenchus penetrans Cobb, present in S. podophyllum and Perilla frutescens Britton. The mortality rate (LT99%: the time at which 99% lethality is achieved) of P. penetrans at 44 to 52 °C water and treatment-caused plant damage were evaluated in vitro and in vivo. The in vitro test showed the LT99 at 44, 46, 48, 50, and 52 °C was 119.1, 27.0, 14.70, 1.40, and 0.48 min, respectively. The LT99 of hot water treatment on the nematodes infecting both plants was 18.4 to 1.7 min at 46 to 50 °C. S. podophyllum was undamaged at 30 days after treatment with 49 and 51 °C water for 30 min. This study demonstrates that hot water treatment is a potential phytosanitary disinfection method for Pratylenchus spp. infecting foliage plants, which can accelerate their trade by reducing incidents of disposal or return to the country of origin.