• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.65-71
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• 2014

Cacalia firma is a perennial plant in Asteraceae, Parasenecio that distributed in Korea, China, and Japan. As dietary style changes for well-being life, consumer's demand of functional food and organic vegetables is getting increased. This study was conducted to investigate the optimum light conditions of P. firmus in forest farming. One year old seedlings were grown under four different light conditions 10%, 20%, 30%, and 50% of sunlight by shading (equals 50%, 30%, 20%, and 10% relative brightness respectively) and non-treated control under full sunlight. They were analyzed for early growth and physiological response. Seedlings grown under 75% shading showed similar height, root growth, and leaf water content to control. However, their leaf length, width, and total leaf area were increased, which caused increased leaf dry weight and total dry weight. Especially, seedlings under 95% shading showed 40% increase in height and more leaf growth and leaf water content, although they had shorter main root length and root collar diameter than control. In addition specific leaf area (SLA) and leaf area ratio (LAR) were higher than control and indicated that they were statistically significant difference from control. Higher SLA refers thinner leaf thickness, higher LAR means larger leaf area. The results indicate seedlings under 95% shading have higher water content, thinner leaf, and wider lightinterception areas. It is plausible that P. firmus is active in chlorophyll activities and carbon dioxide assimilation at even lower light conditions. These results suggest that the optimum light level of P. firmus for artificial cultivation in forest farming ranges from 75~95% shading (20%-10% of relative brightness). When salability as 'sanchae' (wild edible greens) is considered, P. firmus could be cultivated under 75% shading in forest farming and expected to have better taste and higher yield. We suggest these results as basic data of P. firmus for possible forest farming.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.98-104
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• 2010

Excess nitrogen (N) uptake of rice, which could cause much lodging, disease and reduction of rice quality, could be occurred at the paddy field with previous upland condition at which much soil N could be mineralized by soil-drying effect. N fertilizers of 0, 3, and 6 kg N $10a^{-1}$ were applied to early-maturity rice, cultivar Joanbyeo at the paddy field of first and second year after upland condition, and rice growth and nitrogen uptake were investigated to know the increase of rice N uptake at the paddy field with previous upland condition for one-year. Total dry matter (DM) and N uptake of rice at the paddy field with previous upland condition increased more than continuous paddy field. Total DM and N uptake of rice at the paddy field with previous upland condition increased linearly to N fertilizer 6 kg $10a^{-1}$ at the paddy field owing to vigorous growth compared to continuous paddy field. Rice N uptake was higher at the paddy field of the first year than the second year after upland condition in considering N uptake at the plot of no N fertilizer. Vigorous growth at the paddy field with previous upland condition resulted in higher rice yield which was related with high panicle and spikelet, but much N fertilizer as much as 6 kg $10a^{-1}$ at the paddy field with previous upland condition resulted in higher lodging and protein content of brown and milled rice. Particularly, protein content of brown and milled rice increased more when the same N fertilizer was applied two times splitly at transplanting and panicle initiation stage than when N fertilizer was applied one time at transplanting as basal N. N application with under 3 kg $10a^{-1}$ as only basal N was recommended at the paddy field with previous upland condition to obtain high quality rice without lodging.

• Korean Journal of Environmental Agriculture
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• v.23 no.4
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• pp.211-219
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• 2004

Three sludge types from pharmaceutical byproducts and one sludge type from cosmetic waste-water sludge as raw materials of compost were used in a field based concrete pot ($4\;m^2$, $2\;m{\times}2\;m$) for investigating damage of red pepper cultivation. These sludges and pig manure (1 Mg/10a, dry basis) were incorporated into the upper of clay loam soil prior to transplanting with red pepper. Changes in concentration and properties of heavy metal for both of soil and plant were investigated 4 times during of red pepper growth. Plant height and stem diameter of red pepper in sludge treatments except to Pharmaceutical sludge 3 were poor than those of NPK treatment. This result were regarded as an effect of incompleted decomposition sludge which has a lot of organic matter concentration. Amount of total As was increased rapidly Jul. 8. in soil, total Zn Cu Pb Cd were in harvest time, and 1 N-HCl extractable Zn Cu Pb Cd As were in harvest at middle stage and then decreased. Amounts of nitrogen in plant (leaf and stem) were high in Phamaceutical Sludge 1 and fig Manure treatment in early and middle stage because of organic matter and nitrogen concentrations and characteristics. Amounts of Zn, Pb, and Ni in leaf and amount of Zn and Pb in stem were increased in harvest time so that we need to have a concern in detail. Total yield of red pepper was Pig Manure > Phamaceutical Sludge 3 > Phamaceutical Sludge 1 > NPK > Phamaceutical Sludge 2 and Cosmetic Sludge treatment was decreased considerably to compare to others. Amounts of Zn and Cu in green and red pepper in harvest time were higher than the other heavy metals. Finally these results can use to utilize that finding damage on crop for authorization and suitability estimation of raw material of compost.

• Research in Plant Disease
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• v.11 no.1
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• pp.28-34
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• 2005

This study was conducted to investigate the control possibility of garlic white rot causing severe yield losses of Allium species and cultivars using cultural practices such as optimal sowing date and burial depth, and lime application. Inoculum density in infested field soil was investigated at different soil depth, and that on the diseased plant debris was done. Inoculum density and recovery ratio of white rot pathogen of garlic was highly different between two species of Sclerotium cepivorum forming comparatively small sclerotia and Sclerotium sp. forming comparatively large ones. It was confirmed that S. cepivorum formed more sclerotia on bulbs of garlic than S. sp., and sclerotial recovery of S. cepivorum was higher than that of S. sp. Inoculum density of white rot pathogen in the infested field at garlic seeding period ranged from one to thirteen sclerotia per 30 g soil. Inoculum density of white rot pathogen decreased remarkably with increasing soil depth and above 95% of sclerotia were distributed within 5 cm of soil depth. Disease severity of white rot was higher on slightly planted garlics than deeply-planted ones. Garlic seed bulbs infected by white rot pathogens were confirmed to be one of main inoculum sources of white rot in the field and the disease incidences caused by garlic seed transmission showed big differences among garlic varieties. When nine garlic varieties harvested from infested plots were sown in the field, highly susceptible varieties, ‘Wando’, ‘Daeseo’, ‘Namdo’ and ‘Kodang’ showed high disease incidences, whereas other five varieties were not infected at all. It was confirmed that white rot occurred higher on early-sown garlics, before middle October, than on late-sown ones, after late October. Meanwhile, increasing application rate of lime ranged from 100 to 300 g reduced disease severity of white rot.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.461-470
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• 2019

This study was carried out to quantify the drought stress in grafted watermelon seedlings non-destructively by using chlorophyll fluorescence (CF) imaging technique rather than the visual judgment. Six-day old watermelon seedlings were grown under uniform irrigation for 3 days, and then given drought stress. Afterward, the sensor for the measurement of water content in plug tray cell unit was used to classify the drought-stress level into nine groups from D1 (53.0%, sufficient moisture state) to D9 (15.7%, extremely dry stress), and the 16 CF parameters were measured. In addition, re-irrigation was performed on the drought stressed seedlings(D5 - D9) to determine the growth and photosynthesis recovery level, which was not confirmed by visual judgment. The kinetic curve patterns of CF in three different drought stressed seedling groups were found to be different for the early detection of drought stress. All the 16 CF parameters decreased continuously with exposure to drought stress and drastically decreased from D5 (32.1%) where the visual judgment was possible. The fluorescence decline ratio (Rfd_Lss) started to decrease from the initial drought stress level (D5 - D6), and the Maximum PSII quantum yield (Fv/Fm) was significantly decreased in the later extreme drought stress range (D7 - D9) by re-irrigation recovery test. Thus, Rfd_Lss and Fv/Fm parameters were finally selected as potent indicators of growth and photosynthesis recovery in the initial and later stages of drought stress. Also, to the differences in the numerical values of the individual chlorophyll fluorescence parameters, the drought stress level was intuitively confirmed through the image. These results indicate that Rfd and Fv/Fm can be considered as potential CF parameters for the detection of low and extremely high drought stress, respectively. Furthermore, Fv/Fm can be considered as the best CF parameters for recovery at re-irrigation.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.520-524
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• 2009

A newly developed rice variety "Pungmi 1" is a japonica rice(Oryza sativa L.) with high grain quality and multi-resistant to diseases. It was developed by the rice breeding team of Yeongnam Agricultural Research Institute (YARI), RDA. in 2004. This variety derived from a cross between "YR13616Acp 1", having short culm and multi-resistance to biotic stresses and "Milyang 122" with good grain quality. It has short stature of 73cm in culm length and mid-early flowering date of Aug. 13. This variety is moderately resistant to leaf blast showing durable resistance of lower 10% diseased leaf araea in sequential planting meothod. Milled rice kernel of "Pungmi 1" is translucent, clear in chalkness and good at eating quality in panel test. Milling recovery and head rice ratios were comparable to Milyang 122, while it has low protein content. The milled rice yield potential of "Pungmi 1" is about 5.59 MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to Yeongnam inland plains and southern coastal areas of Yeongnam province at ordinary transplanting as well as after barly cultivation.

• Korean Journal of Breeding Science
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• v.41 no.2
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• pp.177-181
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• 2009

'Pyeongwon' is a new japonica rice cultivar which is developed from a cross between Jinbu19 and Samjiyeon4 from North Korea by the rice breeding team of National Institute of Crop Science, RDA. Pyeongwon has about 107 days duration from seeding to heading in mid-northen plain, alpine, north-eastern coastal and southern alpine areas. It has about 67 cm culm length and tolerance to lodging. Pyeongwon has 13 tillers per hill and 82 spikelets per panicle. It showed tolerance to heading delay and spikelet sterility due to cold treatment similar to Odaebyeo. It also showed slow leaf senescence and moderate tolerance to viviparous germination during the ripening stage. Pyeongwon has resistance to blast disease but susceptible to stripe virus and brown planthopper. Milled rice of Pyeongwon has translucent kernels, relatively clear non-glutinous endosperm and medium short grain. It is characterized as a low gelatinization temperature and slightly lower amylose content (17.1%) variety compared to Odaebyeo (19.5%) and has good palatability of cooked rice. The milled rice yield performance of this cultivar was about 5.28 MT/ha by ordinary culture in local adaptability test for three years. This cultivar may be highly adaptable to the mid-northen plain, alpine, north-eastern coastal and southern alpine areas of Korea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.284-295
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• 2018

The safe and late marginal heading dates (SMHD, LMHD), cropping probability, and growth duration of rice were assessed using temperature data in the 27 regions of North Korea. The medians of SMHD and LMHD ranged Jul. 16 and Jul. 27 in Hyesan to Aug. 18 and Aug. 28 in Haeju, respectively, except Changjin, Pungsan, and Samjiyon that did not show any of the SMHD and LMHD. The medians of the days from early marginal transplanting date (EMTD) to heading date ranged 51 days in Hyesan to 109 days in Pyongyang for SMHD and those were delayed by 9~15 days for LMHD, compared to SMHD. Nineteen regions (Kaesong, Haeju, Yongyon, Singye, Sariwon, Nampo, Pyongyang, Anju, Kusong, Sinuiju, Changjon, Wonsan, Hamhung, Pyonggang, Yangdok, Huichon, Supung, Sinpo, Kanggye) and additional four regions (Kimchaek, Chongjin, Sonbong, Chunggang) had the rice cropping probability higher than 80% when analyzed based on the SMHD and LMHD, respectively. The representative SMHD ranged Jul. 24 for Pyonggang to Aug. 12 for Haeju. Compared to the days from EMTD to SMHD, those from EMTD to LMHD were delayed by 9~17 days. When applied SMHD, thirteen regions (Yangdok, Kanggye, Huichon, Supung, Yongyon, Kusong, Anju, Sinuiju, Singye, Pyongyang, Kaesong, Nampo, Sariwon) had the appropriate range of cumulative temperature during grain filling (CT) for grain yield and quality. Sinpo, Hamhung, Pyonggang, Wonsan, Changjon, and Haeju had the CT higher than $1,300^{\circ}C$. It is supposed that rice cropping could be extended to the regions where LMHD-applied cropping probability was higher than 80%. Delaying the heading date than SMHD could be also considered in the regions where the days to SMHD is small but CT is large.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.1
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• pp.24-30
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• 2019

This study was conducted to investigate the effect of seeding dates on grassland productivity and botanical composition in oversown pasture located in Cheonan of South Korea. Four treatment groups were established based on the seeding dates: 18th August, 1st September, 15th September and 29th September. Evaluation of seasonal changes in botanical composition of pasture showed that the highest ratios of grass in 18th August and 1st September (pasture species 93% and weeds 7%) and the lowest in 15th September (pasture species 75% and weeds 25%). In the plant length, there is no significantly different in 5% probability level. In the total dry matter yield of grass, 18th August ($13,362kg\;ha^{-1}$) and 1st September ($13,988kg\;ha^{-1}$) were higher than 15th September ($11,883kg\;ha^{-1}$) and 29th September ($11,459kg\;ha^{-1}$). The findings of the this study suggest that seeding by early September the most desirable results for botanical composition and grassland productivity in oversown pasture, Cheonan of South Korea.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.185-196
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• 2019

Abstract. This research was conducted to figure out the optimal size of the plug cell and seedling raising period in 'Nongwoo' and 'Nonghyeop' cultivars. In the first experiment on effect of plug cell size on growth of squash, seedlings were transplanted into hydroponic cultivation beds at different growing stages: Those in 32-cell trays with 3-4 true leaves at 25 days after sowing, those in 50-cell trays with 2 true leaves at 15 days after sowing, those in 105-cell trays just before a true leaf development, and those in 162-cell trays with only cotyledons at 8 days after sowing. In the second experiment on effect of seedling raising period on growth of squash, it was conducted to have different sowing dates. But the same transplanting date, based on the results of Experiment 1, and compared the differences in growth and fruit productivity as affected by plug cell size in the same way with experiment 1 including the cultivars and environmental conditions. After setting the transplanting date in advance, the number of days for sowing were calculated back for each treatment. In the first experiment, plant height was the greatest in 105-cell trays followed by 162, 50 and 32-cell trays in both cultivars. The best fruit quality was found in different treatments depending on the cultivars, although it was the lowest in 32-cell trays in both cultivars. The fruit quality was not significantly different among those from cell sizes. Therefore, when raising seedlings in 105-cell trays, the period of raising seedlings can be shortened as compared with the conventional 32-cell trays, and this change could reduce the workforce required for growing and transplanting seedlings. In the second experiment, after transplanting, shoot height and leaf width in the first measurement in both cultivars were greater in the 32-cell treatment. However, the last measurement after four weeks showed no significant difference in plant height, but significantly greatest leaf width in the smallest cell treatment, even as compared with that in 32-cell treatment. In case of 'Nongwoo', length and weight of the first harvested fruit showed the highest values in the treatment of 105-cell trays. In case of 'Nonghyeop' the 162-cell treatment along with the 105-cell treatment showed greatest length and weight of the first fruits. From these results, zucchini plug seedlings can be raised in plug trays with reduced cell sizes than the conventional 32-cell trays with improved fruit productivity.