• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.5 no.2
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• pp.4-10
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• 1984

옛부터 눈이 많은 해는 풍년이 든다는 이야기가 있다. 금년에도 틀림없이 대풍을 사전에 약속이나 해주듯 창밖에는 많은 눈이 내리고 있다. 금년 새해를 시작하면서 생각해 보는 이들중의 하나, 병해충과의 싸움에서 전년보다는 더욱 내실있고 알차게 추진되어야 할텐데$\ldots$ 우리나라 농사가 자연에만 의존하던 60년대에 이어 인공풍년을 만들어 가고 있다는 오늘날의 농사, 자연에 순응하면서 이에 적극 대처해 나가고 있는 우리들의 자세는 ''좋은 것은 더욱 좋게''라는 농촌 청소년들의 슬로건과 같이 더욱 노력하여 알찬 결실을 맺도록 해야겠다는 생각이 든다. 이에 금년도에는 취약지 중점 방제로 병충해 일소라는 큰 목표를 내걸고 병해충과의 싸움에 기필코 승리하고자 한다.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.5 no.11
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• pp.65-74
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• 1984

이제 1984년의 과수농사도 마무리 되어가는 늦가을의 뒷전에서 언제나처럼 금년에도 또한 어려웠던 농사일의 기억을 되살리며 잘 잘못을 가려볼때가 되었다. 금년의 농사는 년초부터 가뭄, 한파, 이상고온, 홍수등의 기상이변으로 과수병해충의 발생도 다양해서 그 어느해 못지않게 어려웠던 한 해였지만 그래도 농민 여러분의 피와 땀과 노력으로 이 어려움을 극복하여 지난해의 과실생산량에 비하면 적기는 하지만 ''82년에 비하면 $5\sim6\%$의 증수가 예상되며 이를 보더라도 농사에 쏟은 정열이 얼마나 뜨거웠으며 농사기술 또한 많이 향상되었음이 느껴진다. 본고를 통하여 열심으로 농사를 지어주신 여러분들께 감사드리며 금년의 과수 병충해 발생동향을 점검하고 분석하여 내년의 병충해 방제에 참고가 될 수 있기를 기대해 본다.

• Korean journal of applied entomology
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• v.49 no.3
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• pp.233-239
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• 2010

Seasonal occurrence and suitable time of control of Tetranychus kanzawai along with the control efficacy of the alternative use of natural predator and miticide was investigated in Rubus coreanus (Miquel). T. kanzawai appeared in late May with its peak between June and July, and decreased after August in R. coreanus. In Iksan, T. kanzawai estimates show peaks 2~4 times per year during the investigation periods from 2006 to 2008 in R. coreanus fields. Suitable time of control of T. kanzawai was in early to mid May. And control effects of T. kanzawai was improved with an alternated control plot, treating miticides in early-occurrence of T. kanzawai and then releasing the natural predator (Phytoseiulus persimilis Anthias-Henriot). Also, the yields of R. coreanus was highest in the alternated control plot of 638kg/10a compared to non-treatment of 559kg/10a.

• Korean journal of applied entomology
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• v.34 no.1
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• pp.75-81
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• 1995

To reduce crop damage from root-knot nematode, Meloidogyne spp. chemical, cultural, physical control methods were compared in commercial greenhouse for 3 years from 1992 to 1994. Timing of sol exchange for economic losses due to the nematodes is important: every 3 years for coarse sand (Masatto) and every 4 years for red-yellow soil. Control effects on Meloidogyne spp. in cucumber were 78.2% in Dazomet DP, 72.1% Carbo G+Soil reverse+submergence, and 66.3% in Carbo G+submergence. Pesticide effects were temporally different after treatment: 77.7~80.6% in 20 days and 33.7~49.5% in 60 days. Cropping system in oriental melon gave an excellent control effect of 81.1% at oriental melon/rice culture. All methods controled root-knot nematodes at the time of the treatment but the number of the nematodes increased at the end of the season. However, soil exchange was effective for 3 years. The most economic control practice is rotation with rice for every three years.

• Korean Journal of Weed Science
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• v.17 no.4
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• pp.362-367
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• 1997

A field experiment was conducted to determine an optimum control time of water foxtail(Alopecurus aequalis var. amurensis Ohwi), a most troublesome weed, in no-tillage dry seeded rice. Paraquat, a non-selective herbicide, was applied at 1.5 days interval from March 15 to May 15 at a concentration of 3,000ml per hectar and its control efficacy to A. aequalis was recorded before and after seed sowing. In addition. other characters such as decayed injury of A. aequalis to rice seedling, and its influence of seedling stand were also investigated in relation to rice grain yield. Dry weight of A. aequalis was rapidly increased with delay in control time from 42g/$m^2$at March 15 to 237g/$m^2$ at May 15. The amount of its regrowth at seeding time was highest with 68.3g, when paraquat was applied at March 15, then decreased thereafter and it was less than 6.2g when paraquat was applied after April 15 which indicates above 98% control rate. The control rate of A. aequalis, at 30 days after paraquat application way likewise similar to that the seeding time. Rice seedling stands in the plot treated with paraquat before April 15 were not affected by decayed injury of A. aequalis while decayed injury of 3 to 4 degree for those after April 30 application was noted. Dwarf virus disease on rice seedling due to occurrence of A. aequalis was not observed when A. aequalis was controled from March 30 to May 15 while it was occurred in the plot of March 15 application and the untreated control. The control plot of A. aequalis at April 15 had the highest grain yield with 4.79ton/10a. Based on control rate of A. aequalis, seedling stands of rice, virus disease, and rice grain yield, the most suitable control time of A. aequalis in no-tillage dry seeded rice is considered to be about April 15.

• Korean journal of applied entomology
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• v.9 no.1
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• pp.25-32
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• 1970

This experiment was conducted to find out the simultaneous control effect of granulated insecticides on the several major rice insect pests in Korea. The granulated insecticides used were Terracur P$5\%$ (one of the phosphoric insecticides), Lebaycid $5\%$, and Sang-gamma (gamma-BHC) $6\%$. Those insecticides were broadcasted by hand on the paddy field at the ratio of 3kg. in June and 4kg. in August per 10 a, and the date of insecticidal application was based on the maximum moth occurrence of the rice stem borer in 1969. The rice insect pests tested in this study were rice stem borer (Chilo suppressalis W.), green rice leafhopper (Nephotettix bipunctatus cincticeps U.), smiller brown planthopper (Laodelphax striatellus F.), and white back planthopper (Sogotella furcifera H.). For the study of residual effectiveness of the insecticides, the rice stem borer larvae just hatched from the eggs were installed on the sheath of rice plants collected from the paddy field after insecticidal treatment, and the mortality was made at 48 hours after installation. High mortality was observed in Terracur P and Sang-gamma treatments and low mortality in Lebaycid treatment. The duration of residual effects giving about 50% mortality was about 14 days in Sang-gamma and about 6 days in Terracur P treatments. The study on the effectiveness of the insecticides to the rice stem borer in the paddy field was made by the number of dead blades and white heads of the rice plants injured by the larvae, and the number of survival larvae in the straws after crop harvest. The order of insecticidal effectiveness to the rice stem borer was Terracur P=Sang-gamm>Lebaycid. The study on the effectiveness of the insecticides to the leafhoppers and planthoppers in the paddy field was made by the population density by sweeping (5 times) at the given day intervals after treatments. Terracur P was highly effective for the control of the green rice leafhoppers and Lebaycid was moderately effective, but Sang-gamma seemed not to be effective. The effectiveness of the insecticides tested to the planthoppers was not clear, and it seemed to related with the low insect population density. Study on the determination of proper timing of insecticidal application was not also made clear, and it seemed to be short in the range of day intervals in the insecticidal application. For the study on the control effects of the rice insect pests, rice yield per 100 hills per plot was observed. There was no statistically significant difference among the treatments in rice yields, but the order of yield (Terracur P>Sang-gamma>Lebaycid>Control) was paralleled with the tends of control effects above mentioned. In a view point of simultaneous control of the rice stem borers and green rice leafhoppers by the application of granulated insecticides, Terracur P and Lebaycid were more effective than Sang-gamma which have been used.

• Korean journal of applied entomology
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• v.54 no.3
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• pp.191-197
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• 2015

Fruit drop due to Eurytoma maslovskii infestations of Japanese apricot (Prunus mume) is a serious economic issue in most parts of Jeonnam Province, with the exception of the coastal areas such as Wando, Shinan, Yeosu, and Muan. The average incidence of fruit drop was 67% in 2013 and 33.3% in 2014. E. maslovskii larvae overwinter inside the pits of Japanese apricots. Larval survival rates decrease to less than 30% after a rainy summer season. The eggs are long oval of 0.68 mm, 0.29 mm and ivory white. Mature larva is of 6.56 mm, 3.18 mm. Free pupa are black, adult females and males of 6.97 mm, 4.90 mm lengths, respectively, while the ovipositor is 0.64 mm in length. Adult emergence occurs from early April to early May, when Japanese apricot fruits are from 4 mm to 17 mm in diameter. Adults persist for 13.5 d after emergence, and the sex ratio of females to males was found th be 45.9:54.1. Although up to four eggs may be oviposited per fruit, only one larva will ultimately survive, ans the larvae are cannibalistic. The period during which E. maslovskii is able to oviposit on Japanese apricots only lasts from mid- to late April (fruit diameter: 12~16 mm). When the diameter of the fruit is >16 mm, the pit of the Japanese apricot hardens and larvae have difficultly penetrating the stone. Therefore, the most effective method of controlling this pest is to spray orchards with a control agent 2~3 times, at 5 d intervals, beginning in mid- April.

• Weed & Turfgrass Science
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• v.3 no.4
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• pp.299-304
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• 2014

Effects of false seedbed procedures in organic corn field were evaluated as affected by preparation date and method. False seedbed was prepared at May 7, 14, 21, 28 and June 5 with shallow tillage or flame weeding. Weed suppression rate of each treatment was evaluated 3 weeks after sowing. Optimal false seedbed preparation time was between end of May and early in June. Weed suppression rate of early false seedbed preparation was quiet low. Flaming weed treatment was better than shallow tillage. Weed suppression rate by the second treatment was increased approximately 30-60% compared to $1^{st}$ treatment. Weed suppression rate at 3 weeks after sowing was 70-90% by the second false seedbed preparation. The results showed that the false seedbed technique between end of May and early in June preparation has some potential weed control to reduce weed population during crop growth. Therefore late planting time crop such as corn, sorghum and soybean would be possible to apply false seedbed for organic weed control.

• Research in Plant Disease
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• v.21 no.2
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• pp.89-93
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• 2015

This study was carried out to develop the economic thresholds for the control of bacterial spot of red pepper. The correlation between diseased leaf rate and yield in field was Y=-0.724X+281.58, $R^2=0.78$, $r=-0.88^{**}$. The correlation between diseased leaf rate and yield loss in field was Y=0.813X+15.95, $R^2=0.78$, $r=0.88^*$.We found that control thresholds was below 30.3% diseased leaves rate per plant in field. The economic control thresholds for bacterial spot of red pepper was below 16.3%.

• Korean Journal of Organic Agriculture
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• v.24 no.1
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• pp.123-130
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• 2016

The mortality was tested to organic control materials to the E. maslovskii adults by the dipping method in laboratory. As the result, in 2014, the extracts of Neem I was not shown control effect by 10.2% control efficacy to E. maslovskii adults in laboratory. The extract of Sophora flavescens roots was shown 84.7% mortality. And other 5 materials were shown 100% insecticidal activity to the adults in laboratory. I n 2015, Plant extract+pyrolignous acid Matrine 0.45% and Plant extract Matrine 0.5+paraffin oil 8% were shown 100% and 94.6% control efficacy, respectively. In the Japanese apricot orchards, the fruit damage rate was low on spray at 21th April in Daap, Gwangyang city, and 8th May Hwangjeon, Suncheon city in Jeonnam province in 2014. The fruit damage rate differed from spray timing and materials, but it was considered that the control of E. maslovskii should be in late April to early May. Otherwise, in 2015, the fruit damage was significantly low in late April spray in Daap, but no significant was in between one spray at 21th, 27th April and 2 spray that days. Meanwhile, the control effect was better 2 times spray of the days in Hwangjeon, Suncheon city in Jeonnam province. Therefore, in organic Japanese apricot, the use of insecticidal materials recommended to control over twice spay in from meddle to late April.