• Current Research on Agriculture and Life Sciences
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• v.32 no.3
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• pp.111-117
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• 2014

Phytophthora blight caused by Phytophthora capsici Leonian is a dangerous disease threatening pepper growers worldwide. The efficacy of chemical control is generally low as the pathogen is soil-borne and rapidly spread by zoospores during the rainy season. Thus, based on the demand for resistant varieties, various good resistant sources, such as CM334, AC2258, and PI201234, have been reported and their inheritance of resistance studied by many different authorities. However, the mode of inheritance remains unclear, as 1 or 2 independent dominant genes, 3 genes, or multiple genes have all been reported as responsible for resistance. Recently, QTL mappings of the gene factors for resistance have been reported, and molecular markers for resistance used in breeding programs. With the release of many resistant commercial hybrid cultivars, differentiation of pathotypes of the pathogen is attracting interest among breeders and plant pathologists. Various authorities have already classified the pathogen strains into different races according to the inter-action between resistant host plants, including the source of resistance, such as CM334 and PI201234, and resistant commercial varieties and P. capsici isolates. However, no standard differential host sets have yet been established, so the results are good only for the pathogen strains used in the experiments. Thus, for breeding varieties with durable resist-ance, it is important to introduce resistance from different sources and use diverse local pathogen strains collected in the target area for distribution in a breeding program.

• Journal of Forest and Environmental Science
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• v.19 no.1
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• pp.85-98
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• 2003

The articles, published in the Journal of Korean Forestry from Number 1(1962) to Number 6, Volume 91(2002), were surveyed and investigated for the research trend analysis about resource-plants for special use or purpose, i. e., edible plants, medicinal plants, feed resource, landscape plants, fiber plants, industrial usuage, and bee plants. If the purpose or subject matter of the research was construction or furniture timber production, mushrooms and/or pulp and paper, such research was not included in this study. These articles were classified again depending on the content of research into 14 categories: habitat environment, ecology, physiology, propagation, silviculture (tending and culture), genetics and breeding, identification, insect and disease control, animal-related research, component analysis, vegetation survey, biotechnology, management, and review. Among the total 1.434 articles published, 396 ones (27.6%) were related with plants for special use or purpose. Vegetation survey was 60 (15.2%): physiology 56(14.1%) : genetics and breeding 56(14.1%): propagation 53(13.4%): and ecology 37(9.3%). Siviculture research field included 11 articles (2.8%), which indicates that the management of resource-plants is so far from economic income as seen in the low number of management research filed articles, i. e., only 6 reports (1.5%) Korean white pine was most popular for research and included 42 articles: Robinia pseudoacacia 23: Castanea crenata 14: and ginkgo tree 14. Research related with these species had focused mainly on propagation, physiology, genetics and breeding, ecology and pest control. Based on this survey and analysis, the followings are suggested: 1. More research is required on forest herbaceous plants. 2. Cooperative research work with other industrial and/or scientific area is recommendable for commercialization including medicine, cosmetics, and food etc. 3. Research on resource-plant conservation, which includes biology, social education and policy, should be supported for next generation. 4. Mutual correspondence and information exchange about the research results between researchers and institutes is more necessary than now.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.329-335
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• 2021

Chinese cabbage fields have been damaged by cyst nematodes in highland of Gangwon province in Korea since the year 2011, and clover cyst nematode (CCN) is one of the most problematic cyst nematodes in the crop. To investigate the plant resources for breeding new Chinese cabbage cultivar, which is resistant to CCN, screening for resistance of fifty-seven Brassicaceae plant resources to CCN was conducted. Among the plant resources, fifty-four plant resources (Brassica rapa subsp. pekinensis, B. rapa, Brassica sp., B. juncea, B. carinata, B. rapa subsp. nipposinica, B. rapa subsp. narinosa, B. rapa var. perviridis, B. rapa var. perviridis, B. napus var. napobrassica, and Eruca sativa) were very susceptible to CCN and the number of females on roots was more than 300. Two plant resources (B. carinata and B. tournefortii) with more than 100 females on roots were susceptible to CCN. However, African mustard (B. tournefortii, Korean Genebank accession no. IT218058) was resistant to CCN because of the small number of females (4±1.8) on roots. This study showed that African mustard (IT218058) was valuable as a breeding material for Chinese cabbage, which is resistant to CCN.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.273-281
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• 2018

Wet hill seeding (WHS) is one of the more famous labor and money saving methods technology used for rice cultivation. In WHS, rice standing percentage and weedy rice occurrence are the most important factors considered to secure a rice yield. We investigated the optimum seeding date of WHS in the Southern Plain area of South Korea. Weedy rice needed two weeks at $15^{\circ}C$ to show over 80% emergence. Germinated rice seed grown at $20^{\circ}C$ needed over for 10 days to achieve a shoot length over 3 cm. In field cultivation, the mean temperature for ten days after seeding showed a highly positive correlation with rice standing rate, spikelet number per square meter and yield index that favorably compared to machine transplanting. With these data, we suggest that the optimum seeding date of WHS that can secure over 98% of yield index of machine transplanting in Southern part of Korea is May. 21~Jun. 5 in Honam and May. 16~Jun. 5 in Yeongnam area.

• Research in Plant Disease
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• v.29 no.3
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• pp.243-250
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• 2023

To explore the distribution and the resistance reaction of rice blast pathogens that may occur in North Korea, rice blast pathogens in the North Korean border regions of Dandong and Yeon-gil in China and the North Korean border region of Cheorwon in South Korea were analyzed. In addition, comparative analysis was conducted with rice blast pathogen in Suwon and Jeonju, inland regions of South Korea. Resistance reactions above average were observed in monogenic rice lines (IRBLzt-T, IRBL9-W, IRBL20-IR24, and IRBLta-CP1) in Jeonju, Suwon, and Cheorwon from 2018 to 2020. In Dandong and Yeon-gil, the monogenic lines IRBLz5-CA, IRBL12-M, and IRBL19-A consistently showed resistance reactions for three years. Notably, IRBL19-A exhibited strong resistance. Race distribution analysis in South Korea indicated a shift from KI to KJ dominance from 2018 to 2020, while in the North Korean border regions of Dandong and Yeon-gil, the KI race was dominant in 2021 and 2022. The race distribution of rice blast pathogens in China's North Korean border regions differed significantly from that in South Korea.

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.359-363
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• 2009

In order to establish labor-saving culture technology in Tartary buckwheat, three cultural practices: hand planting, drill sowing machine and soil cover direct seeding machine, were compared.The highest grain yield was found in soil cover direct seeding plot with a value of 3.4 g per plant. As a result, grain yield may be estimated to be 113kg in soil cover direct seeding and 80kg in hand scattering. In addition, for the weed control, three herbicide treatments: single use of Alachlor, mixture and combination of Alachlor and Paraquat dichloride were conducted. the mixture showed over 90% weed control value, and the highest grain yield was found in the combination treatment. Combine machine was effective to reduce the ratio of grain loss and working hour by enhancing the working efficiency to 15${\sim}$20min/10a.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.93-96
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• 2006

In order to prevent cones from being damaged by cone insects, Gravitarmata margarotana and Dioryctria abietella, sprinkler system was installed on the Pinus koraiensis Seed Orchard. Such a test was conducted at Chung-ju, Chungcheong buk-do, Korea in 2002. Insectides of Diflubenzuron 25% WP ${\times}2,500$ and Cyfluthrin 2%EC ${\times}\;1,000$ were sprayed at fifteen-day and twenty-day intervals during the period of insects adult occurrence by sprinkler system. The Gravitarmata margarotana generally emerged for about 53 days from middle April to early June, and peak emergence was 10 days from April 20 to April 30. Dioryctria abietella generally emerged for about 108 days from late April to early August, and peak emergence was 10 days from May 20 to May 30. Damage rate of cones were $8.7{\sim}9.7%$ and $10.9{\sim}12.7%$ on average with crown insecticide spraying with Cyfluthrin and Diflubenzuron, while 67.5% when not treated. Control effectiveness of this insecticide spraying was $85.6{\sim}87.1%$ and 83.9%와 81.2%, respectively. When it considers the forest environment, it is recommended diflubenzuron which is low toxic pesticide. In conclusion, effectual times and number of diflubenzuron 25% WP application with sprinkler system against cone insects were from early May through late August and six times at twenty-day interval.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.260-266
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• 2011

This study was carried out to control biennial weed which gives a lot of damage to landscaped and early growth of lawns in early spring. The results obtained from the mowing experiment are as follows. (1) Average of occurrence rate of weed species of the total treatments was 17.9%, (2) Occurrence rate of weed species was as 24.7% at 12.5 mm low mowing section. The rate indicates that the lowest weed depression effect was appeared at the lowest mowing among 4 mowing sections. (3) Occurrence rate of weed species was 10.6% at 22.5 mm mowing section. The highest weed depression effect among the 4 mowing sections was observed at the 22.5 mm mowing section. (4) Occurrence rates of weed species were 18.2% and 18.3% at 32.5 mm and 42.5 mm high mowing section, respectively.

• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.93-100
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• 2015

The objective of this study was to determine the effectiveness of rapeseed meal in controlling soil nematode. Two different rapeseed meals (Jeju local rape varieties and 'Sunmang' variety) were mixed with the soil to control nematodes environmentally. When soil physical properties in the rapeseed meal-mixed soils were analyzed, OM (organic matter), $P_2O_5$, Ca, Mg, CEC (Cation Exchange Capacity) value increased. Especially, the level of OM was 3-fold higher than control soil. Glucosinolate content of rapeseed meal was higher in Jeju local rape varieties than 'Sunmang' variety. The major components of glucosinolates were consisted of progoitrin, gluconapin, glucobrassiaca napin, and sinigrin. These components were likely to be involved in reducing nematode density.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.289-296
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• 1999

The availability of Bacillus polimyxa 'HB 26-5' as a biological control agent was investigated. The antagonistic bacteria Bacillus polymyxa 'HB 26-5' grew well on the media at pH 7.0 and the optimum growth temperature was $25^{\circ}C$. The pH of the media changed to weak acid(pH 6.1~6.5) at the beginning of incubation, but to weak alkali(pH 7.8~8.2) at 7days after incubation. The best carrier to enhance colonization of the bacteria were the mixture of rice bran and peat, or rice bran and kaoline, in those formulation the density of the bacteria was changed slightly, though the density was beginning to decrease 3 weeks after application at field. In view of the physical characteristics of the formulation for the density maintenance during storage such as the hardness and the size, the best one was the formulation consisted of sodium alginate 2%, kaolin 15% and rice bran 3%.