Sweet persimmons are valuable commodity in the export market. However, present of insect pest such as Asiacornococcus kaki can cause limit to many export markets. In this study, ethyl formate(EF), as alternative to methyl bromide(MB), was used in scale-up commercial trial(20ft reefer). Application of 50 g/m3 of EF for 6 hours at 5 ℃ showed proven efficacy against all developmental stages of A. kaki without LLDPE-packaging fruits and no phytotoxic damage on sweet persimmons. This study demonstrated that EF fumigation can be effectively control to target A. kaki before packaging with LLDPE-film of fruits.

As global warming and consumer’s preference for tropical/subtropical fruits increase, the number of orchards cultivating tropical/subtropical fruits in Korea is increasing. Accordingly, concerns about the introduction of exotic invasive pests that host tropical fruits. In this study, efficacy of ethyl formate(EF), as alternative to methyl bromide(MB), was evaluated. Commercial trial of EF was conducted in mango post-harvest storage conditions for controlling Scirtothrips dorsalis. Application of 10 g/m3 of EF for 4 hours at 10 ℃ showed proven efficacy on S. dorsalis without any phytotoxic damage on mango fruits in that condition.

Ethyl formate (EF) is a naturally occurring insecticidal compound and is used to control pests introduced from abroad, in quarantine, by a fumigation method. In particular, it is mainly used as a substitute for methyl bromide and is less toxic to humans and less harmful to plants. This study aimed to investigate the possible acute toxicity of EF to useful organisms, and how to reduce phytotoxicity in watermelon, zucchini, and oriental melon. After fumigation with EF for 2 h, the LC50 values for earthworms, honey bees, and silkworms were 39.9, 7.09, and 17.9 g m-3, respectively. The degree of susceptibility to EF was in the order of earthworms, silkworms, and honey bees based on the LC50 value, and EF fumigation induced stronger acute toxicity to honey bees. Phytotoxicity was observed in watermelon leaves treated with a concentration of 7.5 g m-3 EF, and when treated with a concentration of 10.0 g m-3, it was confirmed that the edges of watermelon leaves were charred and seemed to be damaged by acids. Zucchini and melon, and other cucurbits, showed strong damage to the leaves when treated with a concentration of 10 g m-3, and sodium silicate, at concentrations of 10% and 20%, was used to reduce phytotoxicity. Therefore, acute toxicity towards nontarget organisms and phytotoxicity during the fumigation of EF should be reduced for efficient agricultural pest control.

Ethyl formate (EF) is a potent fumigant replacing methyl bromide. The use of EF is limited to a quarantine process. Appling EF to agricultural field as a safe insecticide in greenhouse give us valuable benefits including less residual concern. In this regard, residual pattern after EF fumigation in greenhouse should be undertaken. In the previous study, we have established agricultural control concentration of EF to control pests in a greenhouse. EF was fumigated at 5 g m-3 level for 2 h. The concentration of EF inside a greenhouse was analyzed to be 4.1-4.3 g m-3 at 30 min after fumigation. To prepare an analytical method for residues in cucumber crops and soil in the greenhouse, the limit of detection (LOD) of the method was 100 ng g-1 and the limit of quantitation (LOQ) of this method was 300 ng g-1. R2 values of calibration curves for crops and soil were 0.991-0.997. In samples collected immediately after ventilation, EF concentration was determined to be below LOQ level. In addition, EF level was below LOQ in samples collected at 3 h after ventilation except that leaf samples of melon during the flowering period showed a level of 1,068.9 ng g-1. Taken together, these results indicate that EF used in quarantine can be applied to agricultural fields without residual issue as an effective fumigant for insect pest control.

Fumigation of fruits and vegetables during quarantine and pre-shipment (QPS) treatment should be effective with a shorter fumigation time to minimize phytotoxicity. In this research study, a shorter fumigation time, 2 hours exposure which is shorter than that of the current commercial fumigation procedures using a lower dose of ethyl formate (EF) mixed with phosphine (PH3) on strawberry was investigated. The reciprocal effect between EF and PH3 against nymphs and adult Myzus persicae (Sulzer) and Tetranychus urticae (Koch) was evaluated. In addition, L(Ct)50 and L(Ct)99 of EF only and EF mixed with PH3 were analyzed at 5°C and 20°C. The synergistic ratio (SR) of L(Ct)50 and L(Ct)99 for the nymph and adult stages of M. persicae were >1.0, which indicated a synergistic effect between EF and PH3. However, the SR values of L(Ct)50 and L(Ct)99 of the nymph and adult stages of T. urticae were ≤1.0 indicating that there was no synergistic effect between the two fumigants against T. urticae. Our results showed that the reciprocal effect between EF and PH3 has different effects on M. persicae and T. urticae. This could be attributed to the biological and physical differences between the class Arachnida and Insecta. The synergistic effect between EF and PH3 against M. persicae within a shorter exposure period and without phytotoxicity on fruits and vegetables will significantly benefit the horticultural industry.