• Korean journal of applied entomology
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• v.47 no.3
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• pp.193-199
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• 2008

Fifty potato cultivars were screened for potato aphid, Macrosiphum euphorbiae Thomas infestation degree in the field. Aphid honey dew secretion and contents of foliar substances(glycoalkaloids, total nitrogen, Ca, K and Mg) of the cultivars were measured in the laboratory to analyze the correlation between infestation degrees and those factors. The number of aphids ranged from 4.1 to 31.4 per five leaves. The lower density(less than 5 aphids) was found on cvs. Jidose, Recent, and Sebago. The aphid secreted highest(40.3 droplets) and lowest(15.7 droplets) honeydew on cvs. Jopoong and Anco, respectively. Degree of infestation is positively correlated to glycoalkaloids and total nitrogen contents of the potato leaf.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.154-159
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• 2000

This study was carried out to elucidate the symptom of leaf injury to ozone and to determine varietal difference to ozone injury in rice and soybean plant. Ozone was produced by electrostatic discharge in oxygen and was monitored by UV absorption ozone analyzer. The rice leaves were spotted red and rolling leaf edge, discolored to reddish brown or yellowish white in response to ozone, and the leaves that were severely stressed were withered from the tip of leaf. The soybean ones were also discolored to lemon yellow, yellow or dark brown. The leaf injury in both rice and soybean was clearly appeared at the reverse side of leaf and in lower leaves. Milyang 23 and Nonganbyeo among rice cultivars tested were resistant to ozone, but Chucheongbyeo was resistant to it. The ratio of leaf injury was increased and chlorophyll content was decreased as the extension of ozone exposure from 2 to 8 hours in rice. Keunolkong and Danyeopkong among soybean cultivars tested showed resistant reaction to ozone, but Kwangankong and Muhankong were susceptible to it. It was observed that the soybean plants grown for 45 days after seeding were severely damaged by ozone than those of other growth stages.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.4
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• pp.67-70
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• 1979

The Aphidiae injury was 12.98％ on average with a range from 2.0％ to 33.3％. Seventeen percent of the 320 tested varieties were injured as much as 4-6％ and only 0.4％ of the tested varieties were damaged for more than 20％.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.237-244
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• 2012

Barley yellow mosaic virus (BaYMV) and Barley mild mosaic virus (BaMMV) cause severe diseases in winter barley in Europe and East Asia. We investigated the effect of different level of resistance to virus disease on the plant growth and yield in whole-crop barley. In the virus infection, BaYMV was detected all tested cultivars in first diagnosis at 30th March. BaYMV infection was identified only in the susceptible Sunwoobori in 6th April, but not in the Yuyeon (moderate, M) and Youngyang (moderate resistant, MR) cultivars. Plant height was restrained about 14.6~32.9% in overwintered plant regeneration stage depending on the resistance of each cultivar. The tiller numbers also reduced to 8.7~19.7% by BaYMV infection in overwintering season. We evaluated culm length, spike length, and spike number in the virus-infected field and non-infected field. For the culm length, Youngyang (MR) reduced only 14.5% by BaYMV. However Sunwoo (susceptible, S) and Yuyeon (M) cultivars were decreased to 24.8~42.7%. The spike length and spike number also affected to 8.9~21.3% and 24.3~31.0%, respectively, depending on the resistance. After harvesting, dry-matter yield of whole crop yield reduced by approximately 21.6~58.0% according to cultivar resistant degrees. For example, Sunwoobori (S) decreased 58.0% in comparing to non-infected field. The grain yield was also significantly reduced in virus infected cultivars. Sunwoobori (S) was severely decrease more than 60.0%. Yuyeonbori (M) and Youngyangbori (MR) also decreased 30.0~47.5% by the viral infection comparing to those in the non-infected field.

• Korean journal of applied entomology
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• v.39 no.3
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• pp.157-163
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• 2000

In a previous report, 50 potato cultivars were screened for infestation levels by the coppery click beetle (Selatosomus puncticollis Motschulsky) in the field. Subsequently, we selected 10 potato cultivars (Anco, Atlantic, Bintje, Dejima, Denali, Jopung, Irish Cobbler, Namsuh, Shepody, and Superior) to evaluate feeding preferences by wireworms, and to analyze some factors associated with resistance. The injury rates and number of holes in potato tubers damaged by larvae of S. puncticollis were checked in the field and laboratory. Additionally, some of their chemical characters (contents of glycoalkaloids, total-nitrogen, Ca, K, Mg, sugars, and starch) were quantified. And finally correlation analysis was conducted to see whether there is a possible relationship between these characteristics and the damage level. The tuber injury rates by S. puncticollis larvae were generally high showing 19% to 73% of damage level. The highest number of tuber hole damaged by S. puncticollis larvae was found on cv. Namsuh, but generally fewer on cvs. Anco, Atlantic, Bintje, Denali and Superior. No activities for $\alpha$-chaconine, $\alpha$-solanine and $\alpha$-tomatine at a concentration of 2,500 ppm were found to S. puncticollis larvae. The contents of glycoalkaloids in tuber were different depending on cultivars. In tubers, cv. Superior contained the highest level of 18.8 mg%, but cv. Irish Cobbler had the lowest level of 6.39 mg%. Concentrations of reducing sugars and total free sugars in tubers of cv. Namsuh were 0.71 % and 2.95%, but 0.26% and 1.77% in those of cv. Dejima, respectively. For the content of potato starch, cvs. Bintje, Dejima and Irish Cobbler showed higher level, but cvs. Jopung and Shepody lower. The highest contents of total nitrogen, Ca, K and Mg in tuber were found on cvs. Anco, Atlantic, Anco and Jopung, respectively. From correlation analyses, injury rate by S. puncticollis larvae was correlated with total nitrogen content (r = -0.71435*) and total sugar content in tuber (r = 0.78018*). Such information will become essential in developing integrated pest management programs and also in breeding new potato cultivars resistant to the wireworms.

• Korean journal of applied entomology
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• v.2
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• pp.27-37
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• 1963

최근 농작물에 대한 각종 선충류의 피해가 주목되어 있는 실성에 비추어 필자는 선충류연구의 기초적 과제로서 온실내의 화훼류 근부에서 발견되는 선충류 중 농업상 비교적 중요하다고 인정되는 종류와 그밖에 몇 종류에 대하여 형태적인 특징을 기술하였다. 즉 취급된 종류들은 다음과 같다. 1. Meloidogyne arenaria Chitwood 2. Scutellonema coheni Andrassy 3. Paurodontus gracilis Thorne 4. xiphinema americaum Cobb 5. Rhabditis sp 6. Cephalobus sp 7, Diplogaster sp 그리고 이상 7종류의 기주식물 및 기생정도를 보면 Meloidogyne arenaria Chitwood는 Begonia에 만 기생하였고 그밖에 화훼류에는 기생을 볼수 없었다. Scutellonema choeni Andrassy는 꽃치자, 소펄, 이마리 리스, 제브리나에 가장 많이 발견되었고, Paurodonthus gracilis Thorne는 동백나무, 청목. 지내고사리, 카네이션, 충에서 가장 많이 발견되었다. 그리고 Xiphinema americanum Coob는 산호수, 서향, 코피나무, 시크라맨, 용설란, 동백 등에서만 발견되었으나 그중에 용설란, 동백에서 가장 많이 볼 수 있었다. Rhabditis sp.는 초본류 화훼류의 대부분에서 발견되었으나 그중에도 산세배리아에서 가장 많았다 Diplogaster sp는 대부분의 화훼류에서 발견되었으며 그중에 크로톤에 비교적 많았다. Cephalobus sp.는 전반적으로 발견되었으며 발견정도는 모두 비슷하였다. Monhystera app. , Mononchus spp. , Dorylaimus app. 등도 조사란 과반수의 화훼류들에서 발견되었으나 특히 많이 발견되는 화훼류는 없었다. 이상 선충류중 근류를 형성하여 피해가 가장 주목되는 Mceloidogyne arenaris Chitwood에 대해서 온실내에서 그의 유일한 기주식물인 Begonia의 품종별 기생정도를 비교조사한 결과 semperflorens 품종에 가장 기생률이 높았고 metarica 품종은 중정도였으며 erytholopylla와 argento-guttata 품종들에는 기생이 없었다. 이 점은 매우 의의있는 사실로서 앞으로 더욱 연구할 과제로 삼았다. 끝으로 Sanceberia에서 많이 발견되는 Rhabditis sp를 $18^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$, $35^{\circ}C$의 동온도별의 incubator에서 사육한 결과 본 종의 생육적온이 $30^{\circ}C$라는 사실을 알았다.

• Korean journal of applied entomology
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• v.39 no.3
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• pp.141-147
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• 2000

This study was carried out to investigate the population changes of Liriomyza trijolii (Burgess) on chrysanthemum and its relationship to plant growth and damages. In spring culture of chrysanthemum, L. trifolii adults begun to be attracted by the yellow sticky trap from early May and maintained high population until the middle of July. Larval density increased gradually from late May and reached peak in early July. In autumn culture, the population density of adult was lower than that of spring culture but the number of adult was great in late September and the middle of October. This trend was similar to that of larval stage. Damaged leaves by larva could be found from 4 weeks after transplanting and its rate was low until 5 weeks but increased abruptly after 6 weeks and maintained 70% level until flowering stage in spring culture. Damaged leaves increased with plant growth in some varieties tested in this experiment.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.454-459
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• 2010

This study was conducted to investigate the phytotoxic reaction and the impact on the growth of apple fruit included the yield amount by misuse of non-selective herbicide, glufosinate-ammonium in apple field and for the study, 4 cultivars of apple were tested. The results showed that the highest phytotoxic degree was observed on Sansa-cultivar and then the degree was diminished on Tsugaru, Hongro and Fuji in order in the application year. In one year after application, the highest phytotoxic degree was showed on Fuji and then diminished on Tsugaru, Hongro and Sansa in order. However, in one year after application, the phytotoxic symptom was negligible in comparison with the degree in the year of application and the flowering and fruiting were reduced 30% only in Fuji, but in the other cultivars, the phytotoxic symptoms were not observed. Meanwhile, the residue of glufosinate-ammonium was below the detection limit as 0.04ppm in all tested cultivars and in 2years after application, the phytotoxic symptom was not observed in all cultivars of the apple.

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.71-76
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• 2002

The one year old persimmon twigs were collected to know cold tolerance at different temperatures. The selected persimmon cultivar were mast commonly growing in southern part of Korea, such as Bong-Ok, Chungdo-Bansi, Naju-Pasi and Kiwonbang growing at attached farm of Kyungpook Nat. Univ. Browning of bud was the most significant at $-15^{\circ}C$. Naju-Pasi showed no difference in damage between $-5^{\circ}C$ and $-15^{\circ}C$ so called, it is cold tolerant cultivar. Browning of the woody part showed the same tendency with the bud at $-15^{\circ}C$. Chungdo-Bansi was shown the mast weak in cold tolerance than the other cultivars. Electric conductivity was higher at $-15^{\circ}C$ in all persimmon cultivars. Naju-Pasi and Bong-Ok cultivars were weak in cold tolerance even at $-10^{\circ}C$. Bud bursting was occurred at $-15^{\circ}C$ but few on another twigs tested. Naju-Pasi was the lowest while Kiwonbang was higher in the bud bursting. From these result, Naju-Pasi and Bong-ok cultivars were lower in cold tolerance. Kiwonbang cultivar was shown cold tolerance than the other cultivars. These results can be utilized for the persimmon cultivation at different localities in future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.338-343
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• 1997

The response of seventy-five rice cultivars to ozone (O$_3$) were tested in the open-top chamber with ozone producing and monitoring system to determine the varietal difference of resistance to $O_3$ stress. Ozone was produced by electrostatic discharge in oxygen and was monitored by UV absorption ozone analyzer. Difference in response of rice to ozone was more clearly appeared on rice plants treated for 2 to 4 hours at 0.3 ppm concentration of $O_3$. Varietal resistance of rice to ozone was more distinctly classified at 21- to 35-day seedlings compared with 14-day rice plants. Most of indica and Tongil(indica$\times$japonica) type rice cultivars were more resistant than that of japonica cultivars based on the leaf injury to $O_3$. Eight Korean cultivars belong to japonica groups showed highly resistant reaction to $O_3$. Ozone exposure during booting stage caused lower grain fertility than exposures during seedling, maximum tillering and heading stages of rice.