• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.55-60
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• 2001

The efficacy of petroleum spray oil (PSO; D-C Tron $Plus^{(R)}$) against spirea aphid (Aphis citricola) and two scales (lcerya purchasi and Planococcus cryptus) on citrus was tested in Jeju, Korea. The control value of 0.33% PSO against spirea aphid was over 90% at 3 and 6 days after treatment (DAT), and then decreased to about 80% at 9 and 14 DAT. Spraying of PSO (0.33, 0.66, 1%) against cottony-cushion scale showed a much lower control value (less than 50%) during the investigation period compared to that of the conventional pesticide (Methion). When used against tile scale, Planococcus cryptus, the control value of 1% PSO was 95%, but that of 0.33% and 0.66% PSO only ranged from 50 to 80%, lower than the conventional pesticide. The results of this study, as with a previous study, suggest that spraying of 0.33% and 0.5% PSO not only controls the spirea aphid, but also reduces the density of two scales (lcerya purchasi and Planococcus cryptus) on citrus tree in Jeju, without phytotoxic damage.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.87-92
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• 2000

Recently, a new developed petroleiun spray oil(PSO; D-C Tron $Plus^{(R)}$) has been used to control key pests in integrated pest management (IPM) system of citrus orchards in Australia. The efficacy and phytotoxicity of the PSO against the citrus red mite (Panonychus citri) were compared with conventional pesticides (e.g.Tebufenpyrad, Bifenazate and Sun spray oil) in field condition in Jeju. And under PSO mixing spray with some fungicides, the occurrence of phytotoxic symptoms on citrus leaf was investigated. All concentrations of PSO spraying (0.25%, 0.33%, 0.5% and 1.0%) were significantly suppressed the citrus red mite to similar levels of other conventional pesticides. And the spraying of PSO levels ${\geq}0.5%$ was induced not only occurrence of some oil-sucked symptoms on leaf, but also increase of the dropping leaf and fruit rates. As results from mixing PSO spraying test with other fungicides, little burning on new flush shoot was founded only in PSO 1% plus Fluazinam treatment. From the results of this study, with the consideration of pesticidal efficacy and phytotoxicity, 0.25% and 0.33% PSO spraying level will be recommended for the control of citrus red mite during summer season in Jeju.

• Economic and Environmental Geology
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• v.36 no.6
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• pp.557-561
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• 2003

It is important to find out a new material having high removal efficiency for the harmful algal blooms because the dispersion of Hwangto in a large amount to the sea water may bring some ecologically unfavorable problems. For this purpose, the efficiency of several natural and synthetic mineral species for the mitigation of algal blooms was measured. The mixing ratio of monominerals and the sea water with 3,000∼5,000 cells/$m\ell$ of Cochlodinium polykrikoides was 10 g/${\ell}$ and the removal ratio was measured by counting the living cells after the dispersion time of 10, 30 and 60 min., respectively. According to the experimental results, the removal ratio by illite, kaolinite, montmonmorillonite, red mud, Na-A type of zeolite ranged 84-92% after 1hr of contact time, which is comparable to that of Hwangto. The size of above monominerals ranged 3∼50${\mu}m$. Meanwhile, the amorphose material and hematite with the size of 50∼100 nm showed excellent removal ratio of more than 99% after 30min. of dispersion. The results of the study showed that the removal ratio was not related to the chemical composition and pH of the minerals applied but to the grain size. The experimental results strongly suggest that the main mitigation mechanism would be the contact and coagulation.

• The Korean Journal of Mycology
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• v.44 no.4
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• pp.323-329
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• 2016

Water extract from spent mushroom substrate (WESMS) of Pleurotus eryngii suppressed bacterial wilt disease of tomato caused by Ralstonia solanacearum by 70% without any direct antibacterial activity against the pathogen. WESMS-treated tomato had increased contents of free phenolic compounds (increased by 3%) and total salicylic acid (increased by 75%), and significantly enhanced plant height, leaf number, and fresh weight compared to those of a water-treated tomato sample. These results suggest that the treatment of tomato with WESMS can suppress bacterial wilt disease by enhancing plant defense factors and overall plant health.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.201-209
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• 2006

Five strains of Korean entomopathogenic nematodes (EPN), steinernematids and heterorhabditids were evaluated and tried in laboratory, pot, and vegetable greenhouses for environmentally friendly control of diamondback moth (DBM), Plutella xyiostella, from 2002 to 2005. LC$_{50}$ values of five EPN strains against DBM were different depending on nematode strain and DBM instar. LC$_{50}$ value of Steinernema carpocapsae GSN1 (GSN1) was the lowest representing 2.6$\sim$3.9 infective juveniles (Ijs, 3rd stage) to 2nd to 4th instars of DBM. Pathogenicity of five effective strains against DBM was different depending on nematode strain, concentration, application times, and vegetable in pot. The most effective nematode was GSN1. Steinernema spp. was more effective than Heterorhabditis spp. against DBM. Two or three times of applications of EPN were effective regardless of nematode strain and concentration in pot. Efficacy of EPN was different depending on vegetable species. Efficacy was higher on Chinese cabbage, red mustard, and Ssamchoo than that on cabbage, kale, and leaf broccoli. Efficacy of GSN1, Steinernema GSNUS-10, Steinernema CSNUS-14, and Heterorhabditis GSNUH-1 was variable depending on nematode strain, concentration, application times, and vegetable in greenhouse experiments. GSN1 was the most effective and 100,000 infective juveniles per m$^2$(=$1\times10^9$ Ijs/ha) resulted in higher efficacy. Three times of application of nematodes led to higher control efficacy than one or two applications. Efficacy of nematodes was higher on Chinese cabbage than cabbage or kale in greenhouse.

• Korean journal of applied entomology
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• v.41 no.3
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• pp.217-223
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• 2002

The chestnut brown chafer, Adoretus tenuimaculatus Waterhouse, is serious insect pests in golf courses. Adults feed on the leaves of latifoliate trees but larvae feed on roots of turfgrases such as bentgrass, Agrostis spp. Damage of A. tenuimaculatus larvae was observed at the Jinju golf club which showed damage symptom on perennial ryegrass, Lolium perenne in tees and fairways in July, 2000. Damaged turf by A. tenuimaculatus larvae became yellowish and wilted. Symptom of laval damage of A. tenuimaculatus was similar to summer depression in warm season turfgrasses but not recovered by irrigation when Korean isolates of entomopathogenic nematodes were evaluated for the control of A. tenuimaculatus larvae in laboratory and field as a possible biological control agent. The nematodes used were Heterorhabditis bacteriophora Jeju strain, Hererorhabditis sp. Gyeongsan strain, Steinernema carpocapsae Pocheon strain, S.glaseri Dongrea strain, and S.longicaudum Nonsan strain. In the laboratory test H.bacreriophora Jeju strain and Heterorhabditis sp. Gyeongsan strain were highly effective for 3rd instars with 95% mortality. In the field test reduction rates of A.tenuimaculatus larvae were higher by ranging from 28 to 57% by H. bacteriophora Jeju strain, Heterorhabditis sp. Gyeongsan strain, and S.carpocapsae Pocheon strain compared to 7% by natural cause.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.62-69
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• 2013

The black cutworm, Agrotis ipsilon (Hufnagel), damages various cultivated crops and it can also be a serious pest of turfgrass, especially on golf courses. Essential oils have potential as alternative control agents for insect pests. Sixteen essential oils (anise, camphor, cinnamon, citronella, clove, fennel, geranium, lavender, lemongrass, linseed, neem, peppermint, pine, thyme, turpentine and tea saponin) and paraffin oil were assessed in the laboratory, the green house and field trials for their efficacy against black cutworms in turf. Treatment of potted cores of perennial ryegrass turf with anise, cinnamon, neem, paraffin or turpentine reduced black cutworm damage in a greenhouse trial, and in a similar trial, applying neem oil at 4000, 2000 and 1000 ppm resulted in 100, 100 and 64% mortality, respectively, of black cutworms. Weight of survivors at the 1000 ppm rate was 5- fold less than weight of comparably-aged controls. Neem oil (2000 ppm) reduced growth of black cutworms feeding on treated clippings. A high rate of neem oil followed by irrigation (0.1 L of 20000 ppm neem oil with 0.9 L watering/$m^2$) was more effective than a lower concentration (1 L of 2000 ppm neem oil/$m^2$) against $2^{nd}$ and $3^{rd}$ instars in potted turf cores and field plots, respectively. However, not even the aforementioned higher rate effectively controlled $4^{th}$ instars in the field.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.17-23
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• 2012

Large patch caused by Rhizoctonia solani AG2-2 (IV) is one of the most serious diseases in zoysiagrass. The objectives of this research were to evaluate the in vitro fungicidal effect and in field control of large patch disease of Paraffin oil. In the field experiments, paraffin oil was applied with 1 L/$m^2$ after diluted at 5 ml to 20 ml of oil/1 L of water for the control of large patch on Zoysia japonica in golf course. The same material was tested for inhibition of mycelial growth in vitro. Paraffin oil at 0.5% and 2.0% had a fungicidal effect by 43 to 67% on R. solani AG2-2 (IV) in vitro. In two locations of the field experiments, the paraffin oil provided moderate protection of large patch. It was effective in suppressing large patch development by 48.0% in comparison with a water check after one time application on mid-September in golf course. Paraffin oil may be used as an alternative control agent for environment friendly management of large patch on Zoysiagrass in golf course.

• Research in Plant Disease
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• v.17 no.1
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• pp.25-31
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• 2011

Rust causes significant losses in the yield and quality of various crops. The development of new effective and environmentally benign agents against the pathogen is of great interest. In the course of searching a natural antifungal compound from medicinal plants, we found that the methanol extract of Angelica gigas roots had a potent control efficacy against wheat leaf rust (WLR) caused by Puccinia recondita. The antifungal substance was isolated from the methanol extract by silica gel column chromatography, alumina column chromatography and $C_{18}$ preparative HPLC. It was identified as decursinol angelate by EI-MS and $^1H$-NMR data. In in vivo test, decursinol angelate effectively suppressed the development of WLR and red pepper anthracnose (RPA) among the 6 plant diseases tested. In addition, the wettable powder-type formulation of ethyl acetate extract of A. gigas roots significantly suppressed the development of WLR. The crude extract containing decursinol angelate and the chemical appear to be a potential candidate for control of WLR. In addition, this is the first report on the in vivo antifungal activity of decursinol angelate against WLR as well as RPA.

• Food Science and Industry
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• v.53 no.1
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• pp.33-42
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• 2020

In accordance with the recent trend of environmentally friendly agricultural policy, product registration of agricultural chitosan among the organic materials has been displayed in various forms such as soil improving agent, crop growth, and pest control. Chitin production industry is expected to bring competitiveness by producing low-quality and low-cost chitin for agriculture, rather than high-quality and high-cost for food, medical products. Since there are various soil microorganisms that can decompose chitin and chitosan in farm soil where crops are produced, it can be applied usefully to agricultural sites suitably for crop growth and pest control using chitin and chitosan as substrates. The purpose of this study is to compare and analyze the registration status of organic materials companies using chitin and chitosan raw materials in the organic materials information system of the NAQS, and to provide an opportunity to further expand the agricultural use of domestic chitin and chitosan.