• Title/Summary/Keyword: 조도 차이

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Effect of the Induced Molting with Low-Protein and Energy Diet on the Postmolt Performance and Egg Quality of Layers (저단백질, 저에너지 사료를 이용한 유도환우가 산란계의 생산성 및 난질에 미치는 영향)

  • Hong, Eui-Chul;Park, Hee-Du;Na, Seung-Hwan;Kim, Hak-Kyu;Yu, Dong-Jo;Park, Mi-Na;Jung, Kie-Chul;Choo, Hyo-Jun;Seo, Ok-Suk;Choi, Yang-Ho;HwangBo, Jong
    • Korean Journal of Poultry Science
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    • v.37 no.2
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    • pp.117-123
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    • 2010
  • This work was carried out to investigate the effect of the induced molting with low-protein and energy diet on the postmolt performance of layers. Eighty White Leghorn layers (61-old-wk) with over 80% egg production were used for 12 weeks in this work. Treatments were non-molt control (CO), fasting treatment for 10 days (FW), molt treatment with low-protein and low-energy molting diet for 3 weeks (LO), and molt treatment with standard molting diet for 3 weeks (ST) as 4 treatments (2 replications/treatment and 10 birds/replication). Body weight (BW) loss was 26.5% of initial BW at 2 week in FW treatment, and was 17.3% and 14.2% in both LO and ST treatments (P<0.05). Layers in molting treatments were fed with commercial layer diet after completion of molting since BW of layers was recovered for 7 weeks. Heart weight ratio was shown as 0.47, 0.43, 0.46 and 0.46% at CO, FW, LO and ST treatments, respectively, and liver weight ration of body weight was shown as 2.56, 1.30, 1.47 and 1.52%, respectively. Thus, those of molting treatments decreased compared to non-molt control (P<0.05). Oviduct weight ratio were shown as 3.95, 1.17, 1.54 and 1.67%, respectively, and similar with the results of liver (P<0.05). Feed intake decreased at LO and ST treatments during molting period and increased from the 5th week compared to control. Egg production decreased at 1 week in molt treatment and stopped at 2 week in FW, 3 week in LO, and 4 week in ST treatments. The birds started to lay egg at 4 week in FW and at 5 week in LO and ST treatments. Egg production was recovered until 50% at 6 week in FW and was recovered as 66.1 and 71.6% at 8 week in LO and ST treatment, respectively. Egg weights were similar among all treatments. Eggshell thicknesses were 0.41, 0.47, 0.46 and 0.46 mm at CO, FW, LO and ST treatment, respectively, but the higher in molt treatments than control (P<0.05). Eggshell breaking strength was 3.83 and 3.81 kg/$cm^2$ in FW and LO treatment, respectively, and high compared to control. However, eggshell breaking strengths were 3.54 and 3.78 kg/$cm^2$ and were not statistically different. Haugh units were 75.6, 81.1, 80.6 and 79.9 in 4 treatments and high in molt treatment. Finally, dietary low-protein and low-energy may induce molt as few effect on performance of layers.

Effect of Cryoprotectants on the Physico-chemical Characteristics of Chicken Breast Surimi Manufactured by pH Adjustment during Freezing Storage (냉동변성 방지제가 pH 조절법으로 제조한 닭가슴살 수리미의 냉동저장 중 이화학적 특성에 미치는 영향)

  • Jin, Sang-Keun;Kim, Il-Suk;Kim, Su-Jung;Jeong, Ki-Jong;Lee, Jae-Ryong;Choi, Yeung-Joon
    • Food Science of Animal Resources
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    • v.27 no.3
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    • pp.267-276
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    • 2007
  • This study was conducted to determine the effect of cryoprotectants (sugar, sorbitol, polyphosphate) on the physico-chemical characteristics of chicken breast surimi manufactured by pH adjustment (pH 11.0) during freezing storage. The final surimi was divided into experimental units to which the following treatments were randomly assigned: C (Alaska pollack surimi: two washings, 4% sugar +5% sorbitol ${\pounds}'$ 0.3% polyphosphate additive): T1 (chicken breast surimi: pH 11.0 adjusted, 0.3% polyphosphate additive): T2 (chicken breast surimi pH 11.0 adjusted, 5% sorbitol +0.3% polyphosphate additive); T3 (chicken breast surimi: pH 11.0 adjusted, 4% sugar +5% sorbitol +0.3% polyphosphate additive). The crude protein content of the control was higher than all treated samples, however the moisture, crude fat and crude ash of T3 were higher than the control (p<0.05). The pH, WHC and collagen content of the control were higher than all of the treated samples, and these values decreased with storage time for all treatments and the control (p<0.05). The cholesterol content of the control was lower than all treated samples, but the myofibrillar protein contents of all treated samples were higher than the control (p<0.05). The cooking loss of T2 was lower than the control and the other two treatments (p<0.05). The $L^*,\;a^*\;and\;b^*$ values of all treated samples were higher than those of the control during freezing storage (p<0.05). The W value of T3 at 1.5 and 3 months of freezing storage was higher than the control and T1 (p<0.05). The myoglobin and met-Mb contents of the control were similar to all treated samples, and the met-Mb content of the control and all treated samples increased with storage time (p<0.05). Immediately after freezing, the hardness of the control was higher than all treated samples, however it was lower after 1.5 and 3 months of frozen storage (p<0.05). The cohesiveness and gumminess of the control were higher than all treated samples immediately after freezing, however the values for T3 were higher than those of the control and the other two treatments during frozen storage for 1.5 and 3 months (p<0.05).

The Characteristics and the Effects of Pollutant Loadings from Nonpoint Sources on Water Quality in Suyeong Bay (수영만 수질에 미치는 비점원 오염부하의 특성과 영향)

  • CHO Eun Il;LEE Suk Mo;PARK Chung-Kil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.28 no.3
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    • pp.279-293
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    • 1995
  • The most obvious and easily recognizable sources of potential water pollution are point sources such as domestic and industrial wastes. But recently, the potential effects of nonpoint sources on water quality have been increased apparently. In order to evaluate the characteristics and the effects of nonpoint sources on water quality, this study was performed in Suyeong Bay from May, 1992 to July, 1992. The depth-averaged 2-dimensional numerical model, which consists of the hydrodynamic model and the diffusion model was applied to simulate the water quality in Suyeong Bay. When flowrate was $65.736m^3/s,$ the concentration of pollutants (COD, TSS and VSS) at Oncheon stream (Sebeong bridge) during second flush were very high as much as 121.4mg/l of COD, 1148.0mg/l of TSS and 262.0mg/1 of VSS. When flowrate was 4.686m^3/s, the concentration of pollutants $(TIN,\;NH_4\;^+-\;N,\;NO_2\;^--N\;and\;PO_4\;^{3-}-P)$ during the first flush were very high as much as 20.306mg/1 of TIN, 14.154mg/1 of $NH_4\;^+-N$, 9.571mg/l of $NO_2\;^--N$ and l.785mg/l of $PO_2\;^{3-}-P$ As results of the hydrodynamic model simulation, the computed maximum velocity of tidal currents in Suyeong Bay was 0.3m/s and their direction was clockwise flow for ebb tide and counter clockwise flow for Hood tide. Four different methods were applied for the diffusion simulation in Suyeong Bay. There were the effects for the water quality due to point loads, annual nonpoint loads and nonpoint loads during the wet weather and the investigation period, respectively. The efforts of annual nonpoint loads and nonpoint loads during the wet weather seem to be slightly deteriorated in comparison with the effects of point loads. However, the bay was significantly polluted by the nonpoint loads during the investigation period. In this case, COD and SS concentrations ranged 2.0-30.0mg/l, 7.0- 200.0mg/l in ebb tide, respectively. From these results, it can be emphasized that the large amount of pollutants caused by nonpoint sources during the wet weather were discharged into the bay, and affected significantly to both the water quality and the marine ecosystem. Therefore, it is necessary to consider the loadings of nonpoint pollutants to plan wastewater treatment plant.

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Characterization and Evaluation of Melanocortin 4 Receptor (MC4R) Gene Effect on Pork Quality Traits in Pigs (돼지 Melanocortin 4 Receptor (MC4R) 유전자의 육질연관성 분석)

  • Roh, Jung-Gun;Kim, Sang-Wook;Choi, Jung-Suk;Choi, Yang-Il;Kim, Jong-Joo;Choi, Bong-Hwan;Kim, Tae-Hun;Kim, Kwan-Suk
    • Journal of Animal Science and Technology
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    • v.54 no.1
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    • pp.1-8
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    • 2012
  • This study aimed to investigate the single nucleotide polymorphisms (SNPs) of the porcine MC4R gene and validate the effect of the MC4R genotype for marker assisted selection (MAS). Six amplicons were produced to analyze the entire base sequences of the porcine MC4R gene and six SNPs were detected (c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, c.892A>G-Asp298Asn, and c.*430A>T). Linkage disequilibrium (LD) of the six SNPs was analyzed by performing haploid analysis. There was a perfect linkage disequilibrium in c.-780C>G, c.-135C>T, c.175C>T-Leu59Leu, c.707A>G-Arg236His, and c.*430A>T. Only the c.892A>G (Asp298Asn) SNP showed a very low LD with an $r^2$ value of 0.028 and the D' value of 0.348. As a result, the two SNPs-c.707A>G (Arg236His) and c.892A>G (Asp298Asn)-were selected to extract the genotype frequencies from the 5 pig breeds by using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotype analysis method. The SNP frequency of c.707A>G (Arg236His) indicated the presence of the A (His) allele only in Yorkshire, while the G allele was fixed in the KNP, Landrace, Berkshire, and Duroc. Association analysis was carried out in 484 pigs with the c.707A>G (Arg236His) SNP and the meat quality traits of four different pig cross populations: a significant association was noted in crude fat, sirloin moisture, meat color, and the degree of red and yellow coloration. The frequency of the c.892A>G(Asp298Asn) SNP genotype varied among the breeds; while Duroc showed the highest frequency of the A (Asn) allele, KNP showed the highest frequency of the G (Asp) allele. Association analysis was carried out in 1126 pigs with the c.892A>G (Asp298Asn) SNP and the meat quality traits of four pig populations: a highly significant linkage was noted in the back-fat thickness (P<0.002). It was found that the back-fat thickness was higher in individuals with the AA genotype than in those with the AG or GG genotype. Thus, in this study, we verified that the c.892A>G (Asp298Asn) SNP in the pig MC4R gene has a sufficient effect as a gene marker for MAS in Korean pork industry.

Effect of Dietary Streptococcus faecium on the Performances and the Changes of Intestinal Microflora of Broiler Chicks (Streptococcus faecium의 급여가 육계의 성장과 장내 세균총 변화에 미치는 영향)

  • Kim, K.S.;Chee, K.M.;Lee, S.J.;Cho, S.K.;Kim, S.S.;Lee, W.
    • Korean Journal of Poultry Science
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    • v.18 no.2
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    • pp.97-119
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    • 1991
  • Effect of Streptococcus faecium(SF) and an antibiotic, Colistin(Col), supplemented to diets singly or in combination, on the performances and changes of intestinal population of microflora of broiler chicks studied. A total of 252, day-old chicks(Arbor Acre) of mixed sex(M:F=1:1) were alloted into six groups. A diet with no Col and SF was referred as a control diet. The basal diets were added with two levels of SF, 0.04 and 0.08%, singly or in combination with Col 10ppm Another diet was prepared by adding only Col 10 ppm. Numbers of the microorganism in diets added with SF 0.04% and 0.08% were 7$\times$10$^{4}$ and 1.4$\times$10$^{5}$ /g diet respectively The diets consisting of corn and soybean meal as major ingredients were fed for a period of seven weeks . During the feeding trial, fresh excreta were sampled at the end of every week in a sterilized condition to count microbial changes from each dietary group. Microbial changes of large intestine were also measured from nine birds sacrificed at the end of the 4th and 7th weeks each time per dietary group. Excreta from all the groups were also collected quantitatively at the end of 3rd and 6th weeks to measure digestibility of the diets, At the end of 7th week, nine birds from each group were also sacrificed to measure weight changes of gastrointestinal tracts . Average body weight gains of broilers fed the diets added with SF 0.08% (2.37kg) or SF 0. 08%+col 10ppm(2.34kg) were significantly larger than that of the control(2.18kg). The weight gains of the other groups were not statistically different from that of the control Feed/gain ratios of the supplemental groups were better than that of control (P<0.05) except that of birds fed the diet added only with SF 0.04%. Digestibilities of nutrients such as dry matter, crude protein, crude fat and total carbohydrates were not altered by the consumption of the diets added with SF and/or Col throughout the whole feeding period. As expected, the numbers of Streptococci in the excreta from birds fed diets added with SF increased significantly with a statistical difference between groups with SF 0.04% and SF 0.08% most of the time. However. addition of Colistin to the diets supplemented with SF did not give any effects on the number of the microorganism. Numbers of coliforms in the excreta were apparently reduced by feeding the diets added with SF and/or Col(P<0.05). There were, however, no additive effects observed between the two feed additives in this regard when supplementing Col to the SF diets. Distributions of intestinal microflora exhibited exactly the same pattern as those of the excreta. Length of small intestine of the birds fed diets added with SF 0.08% with or without Col 10 ppm became significantly longer with a range of about 10% than those of the birds fed diets without SF. However, the empty weight of the small inestine of the former group was lighter than that of control These changes resulted in a significant reduction in weight/unit length of the intestine of the birds fed diets supplemented with Col and SF singly or in combination. In overall conclusion, diet added with SF 0.08% appeared most effective in improving broiler performances. Colistin added at a level of 10ppm was not beneficial at all in itself or in combination with SF in terms of broiler performances or changes of intestinal microflora population. The efficacy of SF and Col could be attributed to the changes of wall thickness of the small intestine.

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Effects of Strains and Enviromental Factors on Economic Traits in Korean Native Chicken (한국재래닭의 경제 형질에 미치는 계통 및 환경의 효과)

  • Sang, Byeong-Don;Choi, Cheol-Hwan;Kim, Hak-Gyu;Kim, Si-Dong;Jang, Byeong-Gwi;Na, Jae-Cheon;Yu, Dong-Jo;Lee, Sang-Jin;;Lee, Jun-Heon
    • Korean Journal of Poultry Science
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    • v.30 no.4
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    • pp.235-244
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    • 2003
  • This study was carried out to estimate the effects of strain and generation on the major production performances of Korean native chicken. The data were collected from 11,583 birds of the 7 generations over the year 1995 through 2001 at National Livestock Research Institute, Korea. Results obtained were summarized as follows: The body weights at 150 and 270 days of age were 1,557.7 and 1880.7, 1,471.7 and 1,738.2, 1,393.5 and 1,694.9, 1,591.2 and 1,910.0, 1,545.6 and 1,763.6g in Red Brown, Yellow Brown, Gray Brown, Black, and White strains, respectively. The Coefficient of Variations (CVs) of the body weights at 150 and 270 days of age were 9.65~13.79% and 13.29~15.16%. The ages at first egg were 150.0, 148.3, 149.5, 152,8 and 147.7 days in Red Brown, Yellow Brown, Gray Brown, Black and White strains, respectively and the CVs were between 9.33 and 10.11%. The egg weights at the first egg and 270 days of age were 33.2 and 50.8, 32.2 and 49.2, 32.2 and 49.1, 33.0 and 50.0, 30.7 and 47.8g respectively. The CVs of the egg weights of the first egg and at 270 days of age were 13.54~15.27% and 6.93~7.36%. The numbers of eggs produced by 270 days of age were 77.0, 79.3, 77.3, 73,7, 75.4, respectively, and observed CVs were between 29.98~36.99%. The significant strain effects were investigated in all the major economic traits in Korean native chicken. The significant strain effects were investigated in all the major economic traits in Korean native chicken. The highest least square (LS) means of the body weights at 150 and 270 days of age were observed in Black strain as 1,594.38 and 1,911.57g. The earliest LS mean of the ages at first egg was 146.88days in White strain. The heaviest LS means of egg weights at the first egg and 270 days of age were observed in Red Brown strain as 32.20 and 50.74g. The LS mean of the largest number of egg production was 79.50 eggs in Yellow Brown strain. Also, The significant generation effects were investigated in all the major economic traits. The highest LS means of the body weights at 150 and 270 days of age were observed in the generation 3 as 1,599.74 and 1,905.01g. The earliest LS mean of the age at first egg was 143.31 days in 4th generation. The heaviest LS means of egg weights at the first egg and 270 days of age were observed in 7th and 5th generation as 35.68 and 50.42g. The LS means of the largest number of egg production was 78.53 eggs in generation 6. In general, light body weight, short time for the age at first egg, heavy egg weight, and large number of egg production were observed as the generation proceeded.

Comparison of the Result of Radiation Alone and Radiation with Daily Low Dose Cisplatin in Management of Locally Advanced Cervical Cancer (국소적으로 진행된 자궁경부암에서 방사선 단독치료와 방사선 및 저용량 Cisplatin 항암화학요법 병용치료의 비교)

  • Kim Hun Jung;Kim Woo Chul;Lee Mee Jo;Kim Chul Su;Song Eun Seop;Loh John J K.
    • Radiation Oncology Journal
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    • v.22 no.3
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    • pp.200-207
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    • 2004
  • Purpose: An analysis was to compare the results of radiation alone with those of radiation with dally low dose cisplatin as a radiation sensitizer in locally advanced cervical cancer. Materials and Methods: A retrospective analysis of 59 patients diagnosed with locally advanced uterine cervix cancer between December 1996 and March 2001 was peformed. Thirty one patients received radiation alone and 28 patients received dally low dose cisplatin, as a radiation sensitizer, and radiation therapy. The median follow-up period was 34 months, ranging from 2.5 to 73 months. The radiation therapy consisted of 4500 cGy external beam irradiation to the whole pelvis (midline block after 3060 cGy), a 900$\~$l,000 cGy boost to the involved parametrium and high dose-rate intracavitary brachytherapy (a total dose of 3,000$\~$3,500 cGy/500 cGy per fraction to point A, twice per week). In the chemoradiation group, 10 mg of daily intravenous cisplatin was given daily from the 1st day of radiation therapy to the 20th day of radiation therapy. According to the FIGO classification, the patients were subdivided into 51 (86.4$\%$) and 8 (13.6$\%$) stages IIB and stage IIIB, respectively. Results: The overall 5 year survival rate was 65.65$\%$ and according to treatment modality were 56.75$\%$ and 73.42$\%$ in the radiation alone and chemoradiation groups, respectively (p=0.180). The 5 year disease-free survival rates were 49.39$\%$ and 63.34$\%$ in the radiation alone and chemoradiatoin groups, respectively (p=0.053), The 5 year locoregional control rates were 52.34$\%$ and 73.58$\%$ in the radiation alone and chemoradiation groups, respectively (p=0.013). The 5 year distant disease-free survival rates were 59.29$\%$ and 81.46$\%$ in the radiation alone and chemoradiation groups, respectively (p=0.477), Treatment related hematologic toxicity were prominent in the chemoradiation group. Leukopenia $\geq$grade) occurred in 3.2$\%$and 28.5$\%$ of the radiation alone and chemoradiation groups, respectively (p=0.02). There were no statistical differences in the incidences of vesical, rectal and small bowel complications between two groups. Conclusion: Radiation therapy with low dose cisplatin did not improve the rates of survival and response rates, but did improve the rate of disease free survival and locoregional control rates In locally advanced cervical cancer. The incidence of bone marrow suppression was higher in the chemoradiation group.

Agronomic Characteristics and Productivity of Winter Forage Crop in Sihwa Reclaimed Field (시화 간척지에서 월동 사료작물의 초종 및 품종에 따른 생육특성 및 생산성)

  • Kim, Jong Geun;Wei, Sheng Nan;Li, Yan Fen;Kim, Hak Jin;Kim, Meing Joong;Cheong, Eun Chan
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.40 no.1
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    • pp.19-28
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    • 2020
  • This study was conducted to compare the agronomic characteristics and productivity according to the species and varieties of winter forage crops in reclaimed land. Winter forage crops used in this study were developed in National Institute of Crop Science, RDA. Oats ('Samhan', 'Jopung', 'Taehan', 'Dakyung' and 'Hi-early'), forage barley ('Yeongyang', 'Yuyeon', 'Yujin', 'Dacheng' and 'Yeonho'), rye ('Gogu', 'Jogreen' and 'Daegokgreen') and triticale ('Shinyoung', 'Saeyoung', 'Choyoung', 'Sinseong', 'Minpung' and 'Gwangyoung') were planted in the reclaimed land of Sihwa district in Hwaseong, Gyeonggi-do in the autumn of 2018 and cultivated using each standard cultivation method, and harvested in May 2019(oat and rye: 8 May, barley and triticale: 20 May.) The emergency rate was the lowest in rye (84.4%), and forage barley, oat and triticale were in similar levels (92.8 to 98.8%). Triticale was the lowest (416 tiller/㎡) and oat was the highest (603 tiller/㎡) in tiller number. Rye was the earliest in the heading date (April 21), triticale was April 26, and oat and forage barley were in early May (May 2 and May 5). The plant height was the highest in rye (95.6 cm), and triticale and forage barley was similar (76.3 and 68.3cm) and oat was the lowest (54.2 cm). Dry matter(DM) content of rye was the highest in the average of 46.04% and the others were similar at 35.09~37.54%. Productivity was different among species and varieties, with the highest dry matter yield of forage barley (4,344 kg/ha), oat was similar to barley, and rye and triticale were lowest. 'Dakyoung' and 'Hi-early' were higher in DM yield (4,283 and 5,490 kg/ha), and forage barley were higher in 'Yeonho', 'Yujin' and 'Dacheng' varieties (4,888, 5,433 and 5,582 kg/ha). Crude protein content of oat (6.58%) tended to be the highest, and TDN(total digectible nutrient) content (63.61%) was higher than other varieties. In the RFV(relative feed value), oats averaged 119, while the other three species averaged 92~105. The weight of 1,000 grain was the highest in triticale (43.03 g) and the lowest in rye (31.61 g). In the evaluation of germination rate according to the salt concentration (salinity), the germination rate was maintained at about 80% from 0.2 to 0.4% salinity. The correlation coefficient between germination and salt concentration was high in oat and barley (-0.91 and -0.92) and lowest in rye (-0.66). In conclusion, forage barley and oats showed good productivity in reclaimed land. Adaptability is also different among varieties of forage crops. When growing forage crops in reclaimed land, the selection of highly adaptable species and varieties was recommended.

Studies on the Improvement Effects Associated with High Yielding Characters in Recommended Varieties of Winter Wheat(Triticum aestivum L. emend Thell) (밀 장려품종에 있어서 다수확 관련형질의 개량효과)

  • Chang-Hwan Cho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.2
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    • pp.123-133
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    • 1992
  • This study was conducted to clarify progressed changes of plant types and the effects of the physiological and ecological components on improving ideotype of winter wheat. 12 wheat varieties were planted at the experimental farm of Wheat and Barley Research Institute in Suwon in 1990. As results of intensive wheat breeding for early maturity since 1959, heading, flowering and maturing dates have been shortened by 17, 15 and 14 dagys, respectively. The shortened days from sowing to heading and from heading to flowering contributed to the early maturity to improved. Physiological factors associated with heading time of wheat could be reprsented by growth habit, photoperiod responses, earliness in narrow sense and winter hardiness. For improving an early maturity of winter wheat, it would desired to maintain some degree of winter habit(III-IV), and recombination of more insensitivity to short day length and more shortened earliness in narrow sense than that of Saemil and Chugoku 81, and higher degree of winter hardiness. For improving the early maturity the more effective way must be of shortened days from sowing to heading, and days from flowering to maturity than days from heading to flowering. Ideotype of wheat will be desired to recombine two semi-dwarf genes with erect plant type being about 70-80cm, less stem elongation by late spring, long spike and many grains per spikelet. Average spike weight ratio was about 45-49% in high-yielding varieties, stem fresh weight was lighter, but spike fresh weight was heavier in new one while leaf fresh weight was similar to each other during the maturing periods. Average spike dry weight ratio was higher about 40~48%, and stem and leaf blade dry weights were lower in the newly bred varieties. Stem dry weight was heavier than spike or leaf dry weight in the old varieties of Yungkwang, Jangwang and Jinkwang. Leaf area index for the varieties showed normal distribution curve as the maximum point in booting stage. The maximum point of this curve come in early maturing wheat, and late in old one. The maximum points of LAI were 6.4~6.8 in the high-yielding varieties. Totals of LAI in each period investigated of old one were higher than those of newly bred being 24.6~28.8. Chlorophyll content of the high-yielding varieties of Chokwang, Geurumil and Saemil as higher than that of the old varieties Jangkwang, Jinkwang, Wonkwang and Sinkwang from regrowing period to April 21. after then slightly and even after heading. Net assimilation rate (NAR) was higher in high-yielding varieties with good plant type, and lower in old ones. Grain yield of the newly released varieties increased rapidly but slowly in the old ones. Change in water content of grain at the growing stage in newly bred was lower than that of the old bred. Diminishing rate of water content of grain in establishment per day was 1.2% average that of the old varieties including Yungkwang was 1.5%, and those of the newly bred including Chokwang were 0.9~1.1%. Chokwang, Naemil, and Saemil were the highest-yielding varieties of the Korean cultivars. Yields were increased by spikes per m$^2$, grain weight for the varieties bred in Suwon, and by spikes per m$^2$ for the varieties bred in Milyang.

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Study on the Utilization of the Rice-transplanter in the Double Cropping Paddy Field (이모작답(二毛作畓)에 있어서 수도이앙기(水稻移秧機)의 실용화(實用化)에 관(關)한 연구(硏究))

  • Kim, Soung-Rai;Kim, Young-Rae;Jo, Jai-Seong;Lee, Sang-Woo
    • Korean Journal of Agricultural Science
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    • v.4 no.1
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    • pp.94-104
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    • 1977
  • In order to investigate the effects of mechanical transplanting on the rice, four rice varieties including Jo-saing Tongil were planted in case nursering bed for three times with 10 days interval beginning from April 16. Fourty days old seedlings were transplanted with rice-transplanter, and growth habits of seedlings in bed and rice plants in main field and yield were examined and summerized as follows: 1. The plant height and number of leaves of the 40 days old seedling in case nursery bed were appeared to be less than those of seedlings grown in ordinary nursery bed. In case nursery, the plant height and number of leaves of seedlings grown in case nursery were apparently higher than those of seedlings grown in upland case nursery. 2. The root of 40 days old seedlings were cut to investigate the rooting ability of seedlings, and the rooting ability of the seedlings grown in the case nursery bed were apparently lower in the rooting ability compared with the seedlings grown in ordinary nursery bed. The rooting ability of the seedlings grown in the lowland case nursery was higher than that of the seedlings grown in the upland case nursery. 3. The tip of leaves of the varieties derived from Indica type were becoming yellow and yellow-red in color 25 to 30 days after planted in the case nursery bed. Those varieties was almost stopped growth. 4. The seedlings transplanted by transplanter had shown more than five to seven days of delay in rooting, compared with the seedlings transplanted by ordinary method. The heading dates was delayed five to seven days when transplanter was used, even though the delay of heading dates was a little different depending on the varieties. 5. The yields of unhulled rice were a little lower than that of Yusin variety which was hand planted. When mechanically transplanted, the yield of Tongil variety was highest in the plot where seedlings were transplanted on May 26. When transplanted on June 15, Milyang#15 was highest in yield, indicating the importance of varietal selection in mechanical transplantation. 6. The rice transplanter could transplant from 73 to 108 seedlings per $3.3m^2$. If the seeds of rice were evenly planted in the bed, the two-row rice transplanter could be used five to six times more effectively with less than one percent of missing plant compared with the hand transplanting. This suggests that rice transplanter could be utilized in the mono cropping area. 7. Since the time of transplantings in the double-cropping area is rather limitted, mechanical transplantation might be possible without reducings yield providing better adapted varieties and improved case-nursery techniques.

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