Ginger is generally consumed as food or medicine in Korea and mostly imported from China. During quarantine inspection,genus of nematodes, Meloidogyne spp. and Pratylenchus spp., are mainly detected and regulated under the procedure ofquarantine in Korea. We tested the susceptibility and mortality rates of Meloidogyne spp., which are infected in ginger,against a fumigant, Ethanedinitrile (EDN). Juveniles of the nematode showed 100 % mortality against EDN at 2.5 mg/Lfor 2 h at 13°C, meanwhile, egg mass showed 0 % hatching at 5 mg/L for 2 h at 13°C. A concentration × time product(CTP) was determined as 7.24 ghm-3. Under the 35% filling rate of ginger in cold chamber, 100% mortality was observedin both juveniles and eggs at 50 mg/L for 2 h at 13°C. At that condition, CTP was determined as 14.12 ghm-3. Basedon this study, EDN fumigation will be effectively apply to control of nematodes.
Wood pellets are used by Biomass-solid refuse fuel (Bio-SRF) has been imported from many East-Asia countries especially,Vietnam in Korea. Wood pellets are made through grind and high-pressure process shows different physical characterizationlike high methyl bromide (MB) absorption unlike other wood materials. Furthermore, detected pests in wood pellets havesimilarity with detected pests in stored grain. In this study, we analyzed susceptibility on pupa and adult stages of redflour beetle, Tribolium castaneum in wood pellets against mixture of MB and phosphine (PH3). Mixture treatment ofMB and PH3 was more effective than single MB treatment compare with control. Pupal stage showed more tolerant thanadult stage on each fumigant and 100% mortality was determined at 27 mg/L of MB only at 20°C. However, PH3 increasedMB toxicity on pupae that 100% mortality was observed at 100:1 ratio of MB (5 mg/L) and PH3 (0.05 mg/L) at 20°C.Based on this study, mixture treatment of different type of fumigant will be applied to control of quarantine pests.
Electrolysis techniques(electrokinetic) generally have been used mainly to remove the inorganic salts like Cu, Pb etc. in the soil. In the organic living, the effects of electrolysis has a direct impact on survival by dissociation of the ions inside the cell and accumulation of energy within cells. In this study, It was evaluated for susceptibility to nematodes(Meloidgyne javanica, Pratylenchus coffeae) in accordance with the voltage, current and electrolyte concentration. Using the electrolytic bath and electrolyte material(TAE buffer, Nacl), the susceptibility of nematodes was evaluated in the range of 30 ~ 60V, 0.02 ~ 0.77A. Unusually, the high voltage and amperage did not increase the death rate of nematodes and the most resistant stage was not clear because sensitivity of each stage could not be distinguished. In 30V 0.52A, 0.70A, 0.72A, M. javanica eggs processed for 10 minutes did not hatch at all. In 30V 0.58A, M. javanica juveniles processed for 5 minutes were showed 100% mortality and in 30V 0.77A, P. coffeae juveniles processed for 5 minutes were showed highest sensitivity compared to other treatment range.
The most effective way to control plant parasitic nematodes are immersed in hot water, but the larger-scale processing is difficult to adjust a target processing temperature. Thermal equilibrium formula used to fit the processing temperature was very accurate and effective. Use of the thermal equilibrium formula was determined to be well suited on commercial scale(1400L volume chamber) hot water immersion treatment that should be quickly processed. 1000L of water based on 10%(111kg), 12%(136kg), 15%(176kg) filling ratio was applied in 48oC for 30min treatment and only 10%, 12% filling ratio was applied in 49oC for 10min. In 10% filling ratio, thermal equilibrium has been proceeding rapidly in 1-2 min, and no juvenile hatched in all treatments(at 48oC for 30min, at 49oC for 10min). In 12% filling ratio, though thermal equilibrium has been proceeding in 2 min, few juveniles were hatched in boundary temperature at 49.0oC. In 15% filling ratio, it took 7-8 minutes to reach thermal equilibrium after dipping. The result of applying the two treatment conditions(at 48oC for 30min, at 49oC for 10min) to commercial scale field experiment showed nematodes were almost completely eliminated in hooker chive roots. However, some of living nematodes were observed in 15% filling ratio treatment.