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.
Ethyl formate (EF) fumigation under green house condition is a new concept. Its concentrations inside and surrounding of the glass house (GH) and vinyl house (VH) were evaluated for 4 h (during daytime) and 12 h (during nighttime) after fumigation along with the evaluation of post-fumigation EF concentrations. The cumulative EF concentration × time (Ct) value of the 6 sampling positions in VH were 22.67 and 17.53 g·h/m3, respectively for day and night fumigation, which were 2.62 and 4.53 g·h/m3 respectively for day and night application in GH. The EF level (PPM) outside the VH and GH as well as after 20-min post fumigation were < 50 ppm revealing its safety level as its’ threshold limit value (TLV) is 100 ppm. The new technology using liquid EF fomulation could be a key option in smart-farm technologies in future. (Supported by PJ0133562018, RDA)
Biological control has emerged due to the side effects of chemical control such as residual and toxicity. One of the biological controls is entomopathogenic fungi. The entomopathogenic fungus used in this study was first detected in the insectary. The fungus was identified as Lecanicillium sp. based on the sequences of the ITS1 and 2 regions. Lecanicillium sp. infects aphids, scale insects and whiteflies, especially Myzus persicae and Aphis gossypii. In this study, we characterized the fungal phenotype, growth condition, and pathogenicity against green peach aphid. Mycelial growth of Lecanicillium sp. was 12.79±0.46 mm diameter during 7days on potato dextrose agar at 25℃. In addition, the fungus was able to annihilate 100% green peach aphids, after 8days of inoculation. Ultimately, this study would be provide new information on Lecanicillium sp. and suggest the potential utilization of this fungus as a biological control agent.
The sweet potato whitefly, Bemisia tabaci (Gennadius) and the western flower thrips, Frankliniella occidentalis (Pergande) are major insect pests that causes crop damage worldwide by piercing leaves, sucking sap and transmitting numerous plant viruses. A new strategy for IPM, the push–pull method uses a combination of repellent intercrops (push) and alluring trap plants (pull) to manipulate the distribution of insect pests and control their populations. So, we surveyed the responses of these pests of tomato to several plants in green house. Lavandula angustifolia, Petunia hybrid, Ocimum basilicum and Rosmarinus officinalis showed about forty-percent push response to F. occidentalis in tomato. However, Gypsophila paniculata attracted the F. occidentalis in tomato on the contrary. Pelargonium tomentosum showed about fifty-percent push response to B. tabaci in tomato. However, Mentha spicata and Gypsophila paniculata attracted the B. tabaci in tomato. The utilization technique of these plants should be more inspected in further study.
This study aims to estimate the Green-House-Gas emissions from domestic farmed flounder in the southern sea and Jeju-Do, where is mainly produced, by the assessment of energy consumptions and GHG emissions from domestic fish farms for establishing reduce standards of greenhouse gas from a sustainable perspective. It needs to analyze such GHG emission components as feed, electricity, fuel, fixed capital, fish respiration, and liquid oxygen in two locations by 4 stage running water type farm size of small, small and medium, large and medium, large scale. The result showed that the mean GHG emissions were 36.83 kg·CO2/year in the southern sea and 24.33 kg·CO2/year in Jeju-Do, respectively, in the stage of production per fish 1kg at 2 locations and farm size from domestic farmed flounders, and it will give to be useful for policy, planning, and regulation of aquaculture development with establishing GHG reduction standards.
The purpose of the study is to estimate the Green-House-Gas (GHG) emissions from domestic eel farm in the water recirculation system or still-water system by the assessment of energy consumptions and GHG emissions for establishing to reduce standards of GHG from a sustainable perspective. GHG emission components as seeds, feed, fuel, electricity, fixed capital, fish respiration, and others were analysed at the different culture type between water recirculation system and still-water system by 3 stage farm size of small, medium, large scale. The result showed that the mean GHG emission of the eel farm was 18.7kg·CO2 in the stage of production per fish 1kg at different culture type and farm size. Therefore it could be useful for policy, planning, and regulation of aquaculture development with establishing GHG reduction standards.
Accurate estimation of pest density is a prerequisite in achieving efficient pest management. An automatic pest detection system with image processing was installed on a robot to recognize brown marmorated stink bug (Halyomorphahalys) on leaves of paprika(Capsicumannuumvar.angulosum). The shape of pest was recognized and subsequently the robot arm was moved toward the leaves to spray pesticides. The detection system was efficient along with increasing population densities increased. The robot with image processing system was useful for estimating population densities in spatial and temporal domain efficiently.
Pyrausta panopealis is the major pest in green perilla. The larva weaves a web on the shoot of green perilla and damages. In case of extreme, The larva cuts the main branch of green perilla and the leaf of green perilla isn’t harvested anymore. A field study was conducted to estimate economic injury levels (EILs) and control thresholds (CTs) for P. panopealis injuring green perilla in green-houses. Different densities of P. panopealis ranged from 1 to 20 crops (2 units per crop) per 100 crops on 13. June, early inoculation. The number of injured leaf and the rate of injured crop were increased by 23. June, on the other hand were decreased after that day. Also, the amount of yield sow the same result above. The economic loss time calculated by the ratio of cost managing this moth to market price (C/V) (C: cost managing a moth, V: Market price) was 4.0%. The economic injury level was 5.1 larval per 100 crops. The control thresholds calculated by 80% level of economic injury level was 4.1 larval per 100 crops.
This study was conducted to explain degree of injury caused by P. panopealis larva which is the key component to develop economic injury level or control threshold in green perilla and was carried out in polyvinyl houses at Yuseong Daejeon, Geumsan and Yesan Chungnam from 2004 to 2006. Of 5 major pests in green perilla polyvinyl house, P. panopealis larva injured green perilla leaf by 48.5% on average under no insecticides application. The peak occurrence of P. panopealis adult was early August and late September in 2004 and 2005 studies. The feeding amount of P. panopealis larva among 1st to 3rd instar was not different, but from the 4th instar the feeding amount greatly increased and this result was consistent with daily feeding experiment in which the amount greatly increased from seventh day. The degree of injury which was investigated with different larval infestation levels showed that the degree of injury increased a little but was not different significantly as the density increased. The density of P. panopealis larva in damaged green perilla plant was less than three individuals/plant. This result indicates that P. panopealis adult lays egg on green perilla leaf dispersedly and larva hatched from egg injures only the leaf which egg is layed. These preliminary data seems to be very useful to design economic injury level and control threshold studies for P. panopealis in green perilla polyvinyl house.