• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.279-288
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• 2021

Low-density transplanting is a cultivation technology that reduces labor and production costs. In this study, the growth and yield of several varieties with different tillering characteristics were analyzed in order to establish an appropriate planting density for low-density transplanting. Varieties with Low-Tillering (LT), Medium-Tillering (MT), and High-Tillering (HT) were planted at a density of 37-80 hills/3.3 m². As the planting density decreased, the number of tillers per hill increased, but the number of tillers per square meter of hill decreased, especially for the LT variety. Decreasing density extended the tillering stage, which was longest in the LT variety. As the planting density decreased, SPAD(Soil plant analysis development, chlorophyll meter) values just before heading increased while canopy light interception decreased. Such changes were much greater in the LT variety than in the MT and HT varieties. The heading date tended to be delayed by 0-2 days as the planting density decreased, and there was no difference in the length of the period from first heading to full heading. As the number of spikelets per panicle increased, the number of spikelets per square meter did not differ according to the planting density. Decreasing planting density did not affect the grain weight; nevertheless, the yield ultimately decreased because of the decreasing ripening rate. The optimal planting density for stable low-density transplanting cultivation was determined to be over 50 hills/3.3 m2. In addition, these results suggest that LT varieties should be avoided, since these showed large decreases in growth and yield with decreasing planting density.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.104-111
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• 2007

As protein content of milled rice, generally used as a benchmark for rice eating quality, is greatly affected by N fertilization and nutrition status of rice plant, understanding its response to nitrogen rate and plant nitrogen status at different growth stage is important for recommending N fertilizer management for high quality rice production. The responses of milled-rice protein content were compared and quantified under various combinations of basal+tillering and panicle N application levels in 2001 and 2002. Protein content of milled rice was ranged from 6 to 9%, increasing significantly with increasing basal+tillering and panicle N rates. However, milled rice protein content was raised much greater by panicle N than by basal+tillering N fertilization. Even though basal+tillering N increased up to 20 kg/ha, protein content of milled rice was observed less than 7% in case that panicle N was applied below 1.8 kg/10a. Regression analysis revealed that nitrogen accumulated until harvest was partitioned with almost constant rates of 58.3% and 46.5% to panicle and milled rice, respectively. The partitioning rates was slightly but not significantly different between experimental years. Protein content of milled rice showed linear and quadratic responses to the shoot N accumulation until panicle initiation stage (PIS) ant shoot nitrogen accumulation from PIS to harvest, respectively. The increment of milled-rice protein content per unit N increase was much greater in shoot N accumulation from PIS to harvest than in that until PIS. Regardless of shoot N accumulation until PIS upto 8 kg/10a, protein content of milled rice was lower than 7% and ranged from 6.5 to 7.5% in case that shoot N accumulation from PIS to harvest was below 3.0 kg/10a and below 6.0 kg/10a respectively. It would be concluded that even under the same N accumulation until harvest milled rice protein content could be different according to the N fertilizer management and weather condition especially during ripening, providing rooms for controlling protein content by N fertilizer management without damage to grain yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.4
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• pp.305-312
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• 1992

This experiment was carried out to investigate seed set, variation in chromosome number, and agronomic characteristics of the progeny in the cross between hexaploid triticale variety, Sinkihomil(P$_1$) and tetraploid rye variety, Dooroohomil(P$_2$). Seed set rate obtained was 30.5% in the cross of Sinkihomil with Dooroohomil, whereas 3.26% in reciprocal cross using Dooroohomil as female. Alsoseed set was 8.75% in F$_1$/P$_1$, 7.20% in F$_1$/P$_2$, and 1.53% in F$_2$(=F$_1$ /F$_1$, respectively. Germination rate of crossed seed was 37% in cross of P$_1$ with P$_2$, 39.0% in F$_1$/P$_1$(BC$_1$), 50% in F$_1$/P$_2$(BC$_2$) and 43.0% in F$_1$/F$_1$(F$_2$), and 1,000 grain wight was 20.7g in the cross of P$_1$ with P$_2$, which have 41.9g and 47.7g, respectively, 24.5g in F$_1$/P$_1$, 23.6g in F$_1$/P$_2$, and 24.5g in F$_1$/F$_1$, respectively. In pollen fertility of F$_1$ plant, 69.8% turned out to be abnormal or sterile pollen grains, whereas 30.2% was fertile or normal. In meiosis of pollen mother cell of F$_1$ plant, 13.5 univalents, 8.89 bivalent and 1.24 trivalent were appeared. Somatic chromosome number of 35 in F$_1$, both 32 to 33 and 35 to 36 in F$_2$, 35 to 39 in BC$_1$ and 28 to 36 in BC$_2$ which mean producing female gamate was 14 to 18 chromosome in PMC of F$_1$ plant. Rate of fertile plant turned out to be 100% in F$_1$, 4.5% in F$_2$, 42.9% in BC$_1$, and 50.0% in BC$_2$, respectively. Number of seed set per spike appeared to be 1.17 in F$_1$ plant, 13.3 in F$_2$, 2.36 in BC$_1$, and 3.75 in BC$_2$, respectively. Days to heading of F$_1$ was intermediate, but F$_2$ was later than both parents. Plant height of F$_1$ , BC$_1$ ,and BC$_2$ was shorter than both parent, but F$_2$, longer than both parents.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.282-289
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• 2017

Animal Welfare is spreading throughout the world, but remains weak in Korean swine farms. Therefore, the aim of this study was to identify the effect of floor type and hanging type environmental enrichment on the behavior of growing pigs under the traditional feeding environment. A total of 45 crossbred pigs (Yorkshire${\times}$Landrace${\times}$Duroc; average weight, $33.35{\pm}5.5kg$) were assigned into three treatments consisting of control, hanging type(T1) and floor type(T2) with three replicates in semi-slurry pen. The hanging enrichment was suspended at shoulder height of the pigs, and the floor enrichment was fixed in the center of the pens. Growth and cortisol were estimated at the end of the experimental period. Behaviour patterns were analyzed on the first and eighth days after starting the experiment. Growth was not differed among control and treatments. However, cortisol was decreased in T2 compared to control(25.28 vs. 46.75 ng/mL; p<0.05). On the first day, movement and aggression were lower in both treatments than in control(p<0.01). On the eighth day, time and frequency of playing action were increased in T2 compared to T1(p<0.01) and both treatment groups showed more active behaviour than control(p<0.01). These results suggested that the enrichment may meet the natural action requirement of pigs. Therefore, our data can be utilized as basic information for welfare with environmental enrichments in farm animals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.407-414
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• 2016

This study was conducted to investigate the effects of supplementation of dietary betaine on nutrient digestibility and physiological responses in finishing pigs. A total of twelve pigs with a body weight of $80.1{\pm}3.7kg$ were individually caged, and randomly assigned to one of the two experimental diets containing 0 (control) or 5 g/kg (treatment) of the betaine in a $2{\times}2$ Latin square design. The experimental period was 14 days-7 days adaptation and 7 days trial period-per phase. All data for the difference between control and treatment groups were statistically analyzed by student's t-test. Dry matter and crude protein digestibility in the treatment group were significantly improved by 1% and 1.3%, respectively, as compared with those in the control (p<0.05). The apparent absorption of dietary energy was increased from 82.3% to 83.7% by dietary betaine supplementation. Thus, the retention of energy was also significantly increased to above 6% in the treatment group compared with the control group (control 4,057 vs treatment 4,314 kcal; p<0.01). The physiological parameters indicating serum biochemical contents and stress-, immune-, and inflammatory- responses were not changed by the supplementation of dietary betaine. In conclusion, dietary betaine improves the nutrient digestibility without any negative effects in terms of physiology in finishing pigs. It suggests that the supplementation of dietary betaine may increase the productivity through the improvement of weight gain and feeding efficiency.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.276-283
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• 2007

This study was carried out to investigate the effect of isoflavone on the atherogenic effect in C57BL/6 mice. C57BL/6 female mice, 5 weeks of age, were fed on chow diets for 2 weeks during adjustment period. Mice weighing approximately $17.9{\pm}0.9\;g$ were divided into 4 groups and were fed on the experimental diets containing isoflavone for 8 weeks. Experimental groups were control (atherogenic diet), IF-10 (atherogenic diet with isoflavone 10 mg/100 g diet), IF-40 (atherogenic diet with isoflavone 40 mg/100 g diet) and IF-100 (atherogenic diet with isoflavone 100 mg/100 g diet). Food efficiency ratio was not different among the experimental groups. Plasma triglyceride (TG) concentrations were lower after 4 weeks in isoflavone supplementation groups than in control group, whereas monocyte chemoattractant protein-1 and thiobarbituric acid reactive substances (TBARS) levels of plasma were significantly (p<0.05) decreased in the isoflavone supplementation groups in a dose dependent manner. Both hepatic TG and cholesterol levels were significantly lowered in IF-100 than control. Hepatic glutathione concentrations were higher in the IF-100 group than in the other groups. Hepatic antioxidant enzyme activities including glutathione-reductase, glutathione-peroxidase, catalase, and Mn-superoxide dismutase were significantly higher in the isoflavone supplemen-tation groups in a dose dependent manner. From the above results, it is concluded that isoflavone may reduce the risk of atherosclerosis via hypolipidemic, anti-oxidative and anti-inflammatory effects.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.317-323
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• 2017

In this study, the heating performance and the energy saving effect of the heat pump system using hot waste water(waste heat) of the thermal power plant discharged from a thermal power plant to the sea were analyzed. The greenhouse area was $5,280m^2$ and scale of the heat pump system was 120 RT(Refrigeration Ton), which was divided into 30 RT, 40 RT and 50 RT. The heat pump system consisted of the roll type heat exchangers, hot waste water transfer pipes, heat pumps(30, 40, 50 RT), a heat storage tank and fan coil units. The roll type heat exchangers was made of PE(Poly Ethylene) pipes in consideration of low cost and durability against corrosion, because hot waste water(sea water) is highly corrosive. And the heating period was 5 months from October to February. During the heating performance test(12 hours), the inlet water temperature of evaporator was changed from $32^{\circ}C$ to $26^{\circ}C$, and heat absorption of he evaporator was changed from 175 kW to 120 kW. The inlet water temperature of the condenser rose linearly from $15^{\circ}C$ to $50^{\circ}C$, and the heat release of condenser was reduced by 40 kW from 200 kW to 160 kW. And the power consumption of the heat pump system increased from 30 kW to 42 kW. When the inlet water temperature of condenser was $15^{\circ}C$, the heating COP(Coefficient Of Performance) was over 7.0. When it was $30^{\circ}C$, it dropped to 5.0, and when it was above $40^{\circ}C$, it decreased to less than 4.0. It was analyzed that the reduction of heating energy cost was 87% when compared to the duty free diesel that the carbon dioxide emission reduction effect was 62% by recycling the waste heat of the thermal power plant as a heat source of the heat pump system.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.248-262
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• 1987

This experiment was conducted to study plant characteristics and dry matter production of several rice varieties. The results are summarized as follows. 1. Culm length was gradually shortened as varieties were improved and showed significant decrease in Japonica X Indica hybrids. 2. Panicle length seems to be shortened as varieties changed from group I to group III. However, varieties in group IV had longer panicle length in spite of shortening tendency in other groups. 3. Leaf blade length was decreased as varieties improved, but leaf blade width was increased. 4. Panicle exertion showed significant decrease as varieties improved. 5. Number of panicles per square meter among Japonica varieties was gradually increased and similar to the number of spikelets per panicle. Number of spikelets on Indica X Japonica hybrids were higher than Japonica varieties, whereas 1,000 kernel weight was slightly decreased. 6. Dry weight of leaf sheath and culm, and leaf blade was highest at the time of heading and the weight of panicle showed significant increase between 10 and 20 days after heading. 7. The maximum crop growth ratios of leaf blade, stem and panicles were attadined at the stage of heading, booting and milking, respectively. 8. The distribution ratio of dry matter was higher in leaf blade than in stem at the tillering stage. At the heading stage, the distribution ratio of dry matter was higher in order of culm, leaf blade and panicle. At the maturing stage, the ratio was higher in order of panicle, stem and laf blade. 9. Correlation coefficients among grain yield, harvest index, and biological yield were all significant and they were positive.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.166-173
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• 1983

To investigate the varietal differences of weed competitive functions under the three different seasons of transplanting, rice cultivars Milyang 23 and Sadominori were used with seven weeding methods, namely, weedy check, weed-free, once weeding at 3, 6, 9, 12 weeks after transplanting, and two times weeding at 3 and 9 weeks after transplanting, respectively. As a result, weeding stages and times for the proper weeding efficacies and reasonable rice productivities by respective weed group and total weed flora were estimated. Also, the constructive characteristics for yield formations under the different competitive conditions as affected by various cropping patterns were discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.308-313
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• 2008

This study was carried out to analysis the factor effected by milling rice rate, and to provide the developing rice varieties and cultivation technology. Panicle numbers per spike of Ilpumbyeo and Chucheongbyeo were 105 and 70, respectively. The primary branch panicle rate was Ilpumbyeo 56.2% and Chucheongbyeo 61.4%. The secondary panicle rate of Ilpumbyeo and Chucheongbyeo was 43.3% and 37.9%, respectively. Grain filling rate using specific gravity showed that Ilpumbyeo was the lower filling rate than Chucheongbyeo. Hull weight per one grain was Ilpumbyeo 41.9 mg and Chucheongbyeo 3.92 mg, and hull weight per rough rice 1 kg was Ilpumbyeo 157.36 g and Chucheongbyeo 151.31 g. In milling rate, brown rice ratio by ripening degree of llpumbyeo and Chucheongbyeo with combine harvest was 81.22% and 82.52%. Milled/brown rice ration of llpumbyeo and Chucheongbyeo showed 92.14% and 92.51%. The milling recovery ratio of llpumbyeo was decreased 1.67% then Chucheongbyeo, and the difference was mainly due to the hull weight (0.61%), milled/brown rice ratio (0.37%) and ripening degree (0.69%). Although the varietal differences were found in hull weight and millied/brown rice ratio between llpumbyeo and Chucheongbyeo, the ripening degree was considered as the factor that could be reduced by cultivation technology and post-harvest management.