We have performed an experiment to evaluate the efficacy of salt and hot water treatments in soil for managing situations where high-risk plant-parasitic nematodes (PPNs) are detected in farms and flower shops that cultivate foliage plants. The density of Pratylenchus penetrans was reduced by 100% with salt treatments of 20 and 40 kg m-2, while decreases of 95% and 99.8% were observed with treatments of 5 and 10 kg m-2, respectively. In the hot water treatment, Pratylenchus penetrans decreased by 97.6% compared to the initial density. The salt treatment resulted in a decrease in pH and an increase in electrical conductivity (EC) compared to untreated soil. However, other characteristics, including organic matter content, available phosphorus, total nitrogen (T-N) rate, and exchangeable cations, did not differ from the control. In the case of hot water treatment, all properties were similar to those in the untreated group. As a result of this study, salt applications of more than 20 kg m-2 and hot water at 96°C could serve as effective control methods when high-risk PPNs are detected in flower shops and greenhouses located in urban or near-urban areas.

Current investigations provide a comprehensive understanding of the occurrence and biodiversity of plant-parasitic nematodes (PPNs) in the major citrusproducing regions of Jeju Island, South Korea. Our survey identified five genera and five species of PPNs from 82 infested Citrus unshiu field samples collected across 116 sites in the Jeju provinces. Community analysis revealed the highest prevalence of PPNs (39.02%) at Namwon-eup, significantly driven by Tylenchulus semipenetrans, followed by Paratylenchus sp., Helicotylenchus sp., Meloidogyne sp., and Pratylenchus sp. Data indicate that all 82 sites were infested with T. semipenetrans (70.68%), marking a considerable increase in prevalence compared to previous surveys and posing a significant threat to citrus cultivation. The study results also demonstrate the influence of soil type on PPNs communities, revealing correlations between soil texture and nematode diversity. Citrus orchards cultivated in black clay loam soil exhibited significant PPN infestations. Overall, the PPN survey underscores the economic importance of monitoring citrus nematode infection rates and maintaining economic threshold levels in citrus production. It also emphasizes the need for developing effective management strategies to control PPNs, which are essential for maintaining crop yield and ensuring agricultural sustainability.

Perilla plant is a special crop that is used as oilseed and food in Korea. Root lesion nematodes have caused great damage to perilla plants, so for effective management of root lesion nematodes, it is necessary to understand their ecology in perilla. In this study, we investigated the effect of temperature in the development of Pratylenchus penetrans (Pp) and Pratylenchus vulnus (Pv) when the nematodes infected the perilla plant. To estimate the effect of temperature, we assessed the reproduction factor (RF); final population/initial population (Pf/Pi) of these two nematode species. We used perilla plants as inoculated hosts and investigated the density of nematodes at 10 weeks after inoculation. As a result, the RF of Pp was highest at 20°C (0.41 (1st test), 2.2 (2nd test)) followed by 25, 30, and 15°C. The RF of Pv was highest at 30°C (9.84 (1st test), 31.39 (2nd test)), followed by 25, 20, and 15°C. Comparing the RF by temperature between Pp and Pv, Pv was higher than Pp at all temperatures used in the test. This study showed the optimal development temperature of Pp was 20-25°C and Pv was 30°C, respectively.