• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.329-336
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• 2017

This study examined the effects of polyphenols in grape pruning stem extracts (GPSE) using grape stems discarded after harvest. The inhibitory effects on allergy, proliferation, and apoptosis in UVB-induced HR-1 hairless mice were analyzed. The applicability as a material for functional food and functional cosmetics was evaluated. The contents of the active ingredients of GPSE were analyzed by HPLC. After UVB irradiation on the dermis of HR-1 hairless mice, the number of mast cells was determined by toluidine blue staining to confirm that the skin allergic reaction was caused by GPSE. The results were similar to the normal group in the group applied GPSE, and there was no allergic reaction in the GPSE application group and a significant decreased compared to the sun cream control. PCNA immunohistochemical staining of the epidermal proliferation factor had an inhibitory effect on epidermal epithelial cell proliferation in all concentrations of GPSE and serum base mixture as an average of 42% compared to the control group. The mixture of GPSE and serum base suppressed the apoptosis inhibition rate by 27% on average compared to the control. These results confirmed the inhibitory effects GPSE on the allergic, proliferation, and apoptosis activities by with a serum base on UVB-induced skin damage. GPSE is a functional ingredient with potential skin protection effects, and has a high utilization as an ingredient for functional cosmetics.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.32-37
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• 1986

Field experiments were carried out to investigate the effect of wollastonite and iron refinery slag on the paddy rice yield insandyloam soil in which available silica level is 56 ppm. The results are as follows: 1. Application of wollastonite and iron refinery slag reduced the tillering and the height of rice plant in the early growth stage, while promoted those in the late growth stage. 2. As the same amounts of wollastonite and iron refinery slag were applied, the effectiveness on yield increase was same between the two silicate fertilizers. 3. The recovery ratio as measured by absorbed $SiO_2$ on rice plant over applied $SiO_2$, was greater in wollastonite than in iron refinery slag. 4. The increasing of the ratio of $SiO_2$ over N absorbed in rice plant trends toward decreasing the infection rate of neck blast. 5. The left-over ratio of available $SiO_2$ in soil over applied $SiO_2$, was greater in iron refinery slag than in wollastonite. 6. As measured by silica soluble in 0.5 N-HCl solution, 1 kg application per 10a of both silicate fertilizers increased about 2.3 ppm in soil silica content after harvest, respectively.

• Weed & Turfgrass Science
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• v.4 no.1
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• pp.35-43
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• 2015

To assess the dormancy associated weedy risk of the F1 hybrid generated by hybridization between Brassica juncea (maternal) and Brassica napus (paternal), seed germination, dormancy and longevity were examined sequentially after seed harvest. The F1 hybrids exhibited the intermediate characteristics of their parents in seed germination and dormancy with relatively high dormancy rate of 41.1%. In summer, F1 hybrid seeds buried in the 3 cm soil exhibited greater viability (52.4%) than those in the soil surface with greater seed longevity (74.6%) than its maternal (63.3%) and paternal (33.7%) parents at 100 days of over-summering in soil. In winter, F1 seeds buried in the soil surface were more viable than those in the 3 cm soil with greater seed longevity (83.5%) than its maternal (39.0%) and paternal (71.7%) parents at 100 days of over-wintering in soil. Therefore, it is concluded that F1 hybrid resulted from gene flow from OSR to mustard has high seed dormancy and longevity during summer and winter, suggesting its weedy risk potential. Further studies are required to examine the reproductivity and fitness cost of F1 hybrid to make a clearer conclusion of its weedy risk.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.475-487
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• 2017

The aim of this study was to solve the problem of yield loss causing the lag of fertilizer efficiency after tiller stage, being originated by applying mixed expeller cake fertilizer on three day before rice transplanting in organic rice farmers. The mineralization degree of $NH_4-N$ of the mixed expeller cake fertilizer was increased until 7 weeks at flooding condition, and so did $NO_3-N$ until 5 weeks at non-flooding condition. The mineralization rate of nitrogen in paddy soil on 20 days before rice transplanting was the highest by 0.85% on 20 days before the transplanting treatment. The properties of yields during the harvest period have no difference with application time of the mixed expeller cake fertilizer, except soil organic matter. The plan length, culm length and panicle length were the longest on 20 days before rice transplanting. Also, the number of tiller, ripening rat and 1,000 grain weight were the highest on 20 days before rice transplanting, and thereby the yield of white rice were increasing by 9% on 20 days before rice transplanting compared with that of 3 days before rice transplanting. The whiteness values of the rice and amylose content made no difference, but the value of protein and palatability were the same between 20 days and 30 days treatment. In the conclusion, the relationship between rice yield, its quality and application time of the mixed expeller cake fertilizer has showed that the suitable time of applying it reveals 21.3 days before rice transplanting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.16-21
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• 2005

This study was conducted to establish the elaborate nitrogen fertilization method to enhance N use efficiency in direct-seeded rice on flooded paddy. The nitrogen uptake by rice plants was insignificant until 25 days after seeding, and increased gradually thereafter. During this early growth stage, rice plants absorbed only the $4\%$ of basal applied N, while the $45\%$ of N fertilizer remained in the paddy soil. The absorption of basal N by rice plants was almost completed at 46 days after application. Nitrogen top-dressed at 5-leaf stage was well matched to crop nutrient demand, so it could be absorbed so actively in 8days after application. As a result, we could cut down the amount of N fertilizer to $36\%$ of the basal N level without significant difference in yield. Plant recoveries of fertilizer $^{15}N$ applied with different application timings were $7.8\%$ for basal, $9.4\%$ for 5-leaf stage, $17.1\%$ for tillering stage, and $23.4\%$ for panicle initiation stage, respectively. When urea was applied with nitrogen fertilization practice based on basal incorporation (BN), plant recovery of $^{15}N$ at harvest was $31.0\%$, which was originated from $13.7\%$ for grain, and $21.3\%$ of the fertilizer $^{15}N$ remained in the soil, and the rest could be uncounted. Plant recovery of fertilizer $^{15}N$ applied with nitrogen fertilization practice based on topdressing at 5-leaf stage (TN), where N rate was reduced by $18\%$ compared with BN, was $35.1\%$ (grain $15.6\%$), and $19.9\%$ of the fertilizer $^{15}N$ remained in the soil, and the rest could be uncounted. TN showed a higher $^{15}N$ recovery than BN because it was to apply N fertilizer at a time to well meet the demand of rice plant direct-seeded on flooded paddy. We concluded that TN would be the nitrogen fertilization method to enhance N use efficiency in direct-seeded rice on flooded paddy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.266-271
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• 2001

Soybean can produce high-N residue due to N-fixation, so soybean rotation may increase yield of subsequent corn and reduce N fertilizer on the corn fairly. To find out the contribution of nitrogen to subsequent corn following soybean cultivation, soil nitrate, corn yield, and nitrogen uptake were measured for three continuous corn cropping years after soybean rotation. Three N rates of 0, 80, and 160 kg/ha were applied to three continuous corn following soybean cropping. At 6-leaf stage, soil nitrate amount at the soil depth of 0-30cm ranged from 60 to 80 kgN/ha higher in the first corn cropping year than that in the second and third corn cropping years. Judging from corn N status such as SPAD value, N concentration of ear-leaf and stover at silking stage, N contribution of previous soybean to corn in the first corn year was N fertilizer of approximately 80 kg N/ha. Stover N uptake at silking stage increased from 47 to 52 kg N/ha at the 0, and 80 kg N/ha of N rates in the first corn cropping year compared with those in the second and third corn cropping years. Corn grain yield at the 0 kg N/ha of N rate was 6-7 ton/ha higher in the first corn cropping year than that in the second and third corn cropping years, respectively. When compared the first corn year following soybean cropping with the second and third corn cropping years, N uptake of grain and stover at harvest with low N rates such as 0 and 80 kg N/ha increased from 45 to 67kg N/ha, from 35 to 60 kg N/ha, respectively. N uptake of whole plant by soybean rotation increased from 93 to 118 kg N/ha in the first year compared with that in the second and third corn cropping years. However, the N contribution by soybean cropping was small in the second and third continuous corn cropping years. Therefore, it was concluded that the nitrogen fertilizer of 80-100 kg N/ha in the first corn cropping year could be saved by soybean rotation and annual alternative corn-soybean rotation could be the best rotation system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.2
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• pp.120-130
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• 2018

Improvement in rice grain yield has been approached by means of genetic amendment, cultural management, and environmental adaptation. Subjecting the plant during the grain filling period to an appropriate environment plays a key role in achieving a high grain yield in temperate rice. Field experiments were conducted for two consecutive years with two planting times to assess the relations among grain filling traits, loss of leaf activity during the ripening period, and the grain yield of temperate japonica rice with wide environmental variation. Higher grain yields were attained in 2017 than in 2016 and with late planting than with early planting. The high grain yield accompanied a comparatively lesser increase in grain weight at the early filling stage but more gain in grain weight occurred during the late filling stage. Final grain weight correlated positively with grain filling duration but negatively with grain filling rate. Extended grain filling duration was associated with higher cumulative temperature and cumulative solar radiation for an effective grain filling period. The reduction in SPAD value ${\times}$ leaf dry weight from heading to harvest significantly correlated with final grain dry weight in a positive manner. No significant relation was found between grain filling duration and the decrease in SPAD value ${\times}$ leaf dry weight during the grain filling period. The results suggest that grain filling duration and loss of leaf activity during ripening independently contribute to environmentally induced yield improvement in temperate japonica rice.

• Korean Journal of Environmental Agriculture
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• v.20 no.1
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• pp.8-14
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• 2001

To investigate the effects of waste sludge from antibiotic fermentation on the growth of young radish and chemical properties of soil, five levels of fertilizer, control (recommended fertilizer, $N-P_2O_5-K_2O=160-59-104$ kg/ha), AS(control + sludge 1,000 kg/ha), AC(control + conventional compost 1,000 kg/ha), SNS(control - subtracting 30% N of sludge + sludge 1,000 kg/ha) and SNC(control - subtracting 30% N of conventional compost + conventional compost 1,000 kg/ha) were applied and radish was grown twice with same treatments on May and August in 1998. Germination rate and early growth of young radish grown with AS and SNS were lower than those grown in control and with AC, SNC. This negative effects by adding the sludge in the early growth seemed to be caused by damage of ammonia gas released during degradation of the sludge in soil. However, yield of young radish showed no significant difference among all the treatments including the AS and SNS at the 1st and 2nd experiment, and these suggested that the latter half of growth of young radish was accelerated by adding the sludge. Contents of T-N in young radish and inorganic N in soil showed a tendency to increase by adding the sludge while antibiotic substance, cephalosporin-C, was not detected in plant material and soils after harvest of young radish in both experiments. Consequently, waste sludge from antibiotic fermentation, which contains high levels of organic matter and nitrogen could be used as an useful resource in agriculture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.64-69
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• 2008

The objective of experiment was to investigate the effects of planting density on growth and yield of vegetable soybean, and to clarify the optimum planting density of vegetable soybean in the middle west region of Korea. The field experiment with 4 levels of planting density was carried out at Yesan area in $2005{\sim}2006$. The days from seeding to flowering and the days from seeding to harvesting and lodging were not significantly different among planting distance. The stem length was increased as planting distance was shortened but the number of node, branch, pod per branch, pod per individual, weight of stem and pod, one hundred pod weight and rate of 2+3 seed per pod were decreased as planting density was increased. The size of vegetable soybeans was not significantly different among planting distance, but the harvest index of vegetable soybean was decreased as planting distance was shortened. Yield of vegetable soybean was increased as planting distance was decreased. However, the approriate densities for stem and pod weight per a plant, number of pod per a branch and the vegetable soybean yield of 2+3 seed per pod were different from that density. The optimal planting distance of varieties was $60{\sim}25\;cm$ in Sunheukkong and Ilpumgeomjeongkong and was $60{\sim}35\;cm$ in Galmikong.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.3
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• pp.241-248
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• 2017

Yield of potato is largely influenced by drought stress. This study was conducted in Gangneung and Cheongju during the spring cropping of potato. Potatoes in the Gangneung area were affected by drought but there was no damage due to drought in Cheongju. During the early-growth stage, the contents of inorganic components like available phosphate and growth characteristics of the potato leaf in Cheongju were significantly higher than those in Gangneung but there was no difference after the flowering stage. It was considered that the potato plants cultivated in Cheongju could vigorously grow than that of Gangneung under drought stress. In addition, the content of calcium (Ca), which is a secondary messenger related to aging, was found to be higher in potato plants grown in Cheongju than in Gangneung and accumulated more quickly in potato plants of Cheongju. Because magnesium (Mg) was also found to be higher in potato plants from Gangneung by a wide margin, this phenomenon was thought be related with drought stress. The amounts of all inorganic components absorbed from soil were higher in Cheongju than in Gangneung, showing a relatively higher plant biomass in Cheongju. Correlations of development indexes related to leaf showed less or no relation in Gangneung. According to yield characteristics of the harvest stage, although yield was greatly reduced under drought stress condition, the rate of commercial yield was not significantly affected under the drought stress condition. Consequently, it was considered that these responses to drought stress could be utilized to stabilize potato production under the stressful conditions associated with abnormal climate.