• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.3
• /
• pp.259-267
• /
• 2010

This study was performed at Rice and Winter Cereal Crops Department of NICS during 2007 and 2008 to investigate the characteristics of rice leaf emergence and to obtain basic data which can be used for rice growth simulation model by which we can forecast rice growth stage and heading date accurately under different cultivars, transplanting date, and climatic conditions. To confirm leaf emergence rate according to rice maturing ecotype, we surveyed the leaf emergence rate and heading date of Unkwangbyeo, Hwayoungbyeo and Nampyeongbyeo which are early maturing, medium maturing and medium-late maturing cultivars, respectively, according to seedling raising duration and transplanting time. When seedling duration was 15 days, the growth duration between transplanting time and completion of flag leaf emergence on main culm were 51.5~78.3 days in Unkwangbyeo, 55.3~87.9 days in Hwayoungbyeo and 58.4~98.4 days in Nampyeongbyeo, respectively. When seedling duration was 30 days, they were 50.1~75.5 days in Unkwangbyeo, 52.4~84.7 days in Hwayoungbyeo and 56.4~93.8 days in Nampyeongbyeo, respectively. As transplanting time delayed, the emerged leaf number after transplanting decreased in all rice cultivars. The cumulative temperature between transplanting time to completion of flag leaf elongation on main culm were $1,281^{\circ}C{\sim}1,650^{\circ}C$ in Unkwangbyeo, $1,344^{\circ}C{\sim}1,891^{\circ}C$ in Hwayoungbyeo and $1,454^{\circ}C{\sim}2,173^{\circ}C$ in Nampyeongbyeo, respectively. Leaf emergence rate on main culm were precisely represented by equation, y = $y_0$ + a / [1 + exp( - (x - $x_0$) / b)]^c, when we used daily mean temperature as variable.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.13 no.3
• /
• pp.203-212
• /
• 1993

This experiments were carried out to estimate the optimum final cutting date in autumn and the selection of highly adaptable varieties in mountainous pastures of Taekwalyong area. The evaluations were based on the data of varietal differences of dry weight of plant(DW) and yield components of the 1st cutting as affected by various final cutting dates of last autumn. Nine varieties of tall fescue Barvetia, Fuego. Demeter, Safe. Barcel, Forager, Johnstone, Enforcer and Stef. were used and 4 final cutting date of autumn were $C_1$, cut on 30 Sept. $C_2$, on 14 Oct. $C_3$, on 28 Oct. and $C_4$. on 11 Nov.. respectively. The results obtained were as follows: I . Between the dry weight of plant(DM) and yield components of 1st cutting were different by various final cutting dates of autumn. The dry weight of plant(DW) was significantly positive correlated with heading characteristics of the 1st cutting in earlier cuttings($C_1- C_3$) of autumn, but there was not significant correlated with heading characteristics of the 1st cutting in the latest cutting($C_4$) of autumn. 2. The variety of Forager with heavier weight of heading tiller(HTW) and dry weight of tiller(WT) showed the highest dry weight of plant(DW) of the 1st cutting in earlier cuttings($C_1-C_3$) of autumn, whereas the variety of Barcel with high number of tillers per plant(NT) showed a high dry weight of plant(DW) of the 1st cutting in the latest cutting($C_4$) of autumn. 3. Optimum final cutting date and critical period of mountainous pastures in Taekwalyong area were estimated in late September($C_1$) and middle October($C_2$), sespectirety. 4. The dry weight of plant(DW) of the 1st cutting was significantly negative correlated with final cutting dates in growth period of autumn.

• Korean Journal of Soil Science and Fertilizer
• /
• v.8 no.4
• /
• pp.199-217
• /
• 1975

For the establishment of efficient method of potassium topdressing on rice the optimum time and amount were investigated and discussed on the basis of available data from nutriophysiological studies, soil characteristics and fertilizer trials in fields. The followings were pointed out. 1. According to yield rice plants require more potassium around heading under water culture. 2. Potassium involves in harvest index, filled grain ratio, grain weight and number of spikelets per panicle. 3. Potassium is lost after heading in most fields in spite of highest requirement during this period. 4. The higher $K_2O/N$ ratio in straw at harvest is, the higher the yield. 5. Relatively low efficiency of potassium fertilizer under the field condition may be due to improper application method rather than natural supply from soil and irrigation water. 6. Appropriate topdressing time appears at in effective tillering stage for the prevention of nitrogen excess and at 15 to 20 days after transplanting, ear formation stage and 5 days after heading for the prevention of soil reduction damage. Two times of topdressing for clayey soil and three times for sandy soil seems reasonable in practice together with nitrogen topdressing, 7. The reasonable ratio basal to topdressing of potassium fertlizer seems to be 2/3 and $N/K_2O$ ratio of fertilization for ear formation stage appeared also as 2/3.

• Journal of Animal Science and Technology
• /
• v.63 no.2
• /
• pp.354-366
• /
• 2021

Limited data about the effects of various factors on forage quality and β-carotene content of rye produced in Korea are available, so this study investigated the effects of two preservation methods. Samples were collected from rye harvested every 5 days between April 25 and May 31, and comparisons were done among rye silage wilted for different periods of time and hay of three growth stages of rye. For the silage, dry matter (DM), acid detergent fiber (ADF), and neutral detergent fiber (NDF) contents increased with advanced maturity of rye, whereas crude protein, in vitro dry matter digestibility (IVDMD), total digestible nutrients (TDN), relative feed value (RFV), and DM loss decreased (p < 0.0001). Wilting increased the DM content and pH value significantly (p < 0.0001). Silage harvested at the heading stage had the lowest pH value (4.45), propionic acid (0.83 g/kg DM), butyric acid (0 g/kg DM), and fungi and yeast populations (3.70 Log CFU/g of fresh matter [FM]); conversely, it had the highest lactic acid (9.7 g/kg DM), lactic acid bacteria (LAB) (6.87 Log CFU/g of FM), total microorganisms (TM) (7.33 Log CFU/g of FM), and Flieg's score (70) (p < 0.0001). Wilting elevated LAB and TM populations, but it had no consistent effect on other fermentation products. Both delayed harvest and prolonged wilting decreased β-carotene content. Rye silage harvested around May 9 (heading stage) with 24 h of wilting was preferred for highland, Pyeongchang. For rye hay, advanced maturity decreased DM loss, IVDMD, TDN, and RFV, but it increased DM, ADF, and NDF significantly (p < 0.05). β-carotene was decreased by delay of hay-making. Consequently, to attain lower DM loss and higher hay quality, the harvest date of May 9 (heading stage) is recommended.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.2
• /
• pp.118-127
• /
• 1984

In order to find an appropriate model for rice crop-season, the possibility to utilize the geographical conditions instead of meteorological factors was examined on the data from the Local Adaptability Test(LAT) conducted over the country from 1962 to 1980. The mutiple regression model, $Y={\Upsilon}={\ss}{\sum}_{i=1}^n{\beta}^1X^iwas applied on seeding, transplanting, heading and marginal heading date, and multiple regression coefficients(\beta) and multiple correlation coefficients (R) were tested. Two varietal groups, japonica(1962-l971) and indica/japonica(l972-1980) were separately tested. The application of these established models, growth duration in nursery and paddy field, cultural season, and the relation between heading date and yield are reviewed.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.235-235
• /
• 2022

Genome selection is a promising tool for plant and animal breeding, which uses genome-wide molecular marker data to capture large and small effect quantitative trait loci and predict the genetic value of selection candidates. Genomic selection has been shown previously to have higher prediction accuracies than conventional marker-assisted selection (MAS) for quantitative traits. In this study, the prediction accuracy of 10 agricultural traits in the wheat core group with 567 points was compared. We used a cross-validation approach to train and validate prediction accuracy to evaluate the effects of training population size and training model.As for the prediction accuracy according to the model, the prediction accuracy of 0.4 or more was evaluated except for the SVN model among the 6 models (GBLUP, LASSO, BayseA, RKHS, SVN, RF) used in most all traits. For traits such as days to heading and days to maturity, the prediction accuracy was very high, over 0.8. As for the prediction accuracy according to the training group, the prediction accuracy increased as the number of training groups increased in all traits. It was confirmed that the prediction accuracy was different in the training population according to the genetic composition regardless of the number. All training models were verified through 5-fold cross-validation. To verify the prediction ability of the training population of the wheat core collection, we compared the actual phenotype and genomic estimated breeding value using 35 breeding population. In fact, out of 10 individuals with the fastest days to heading, 5 individuals were selected through genomic selection, and 6 individuals were selected through genomic selection out of the 10 individuals with the slowest days to heading. Therefore, we confirmed the possibility of selecting individuals according to traits with only the genotype for a shorter period of time through genomic selection.

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

• International Journal of Highway Engineering
• /
• v.13 no.2
• /
• pp.175-185
• /
• 2011

Geometric information is a key element for evaluating traffic safety and road maintenance. This study developed an algorithm to identify horizontal alignment using global positioning system(GPS) and inertial navigation system(INS) data. Roll and heading information extracted from GPS/INS were utilized to classify horizontal alignment into tangent, circular curve, and transition curve. The proposed algorithm consists of two components including smoothing for eliminating outlier and a heuristic classification algorithm. A genetic algorithm(GA) was adopted to calibrate parameters associated with the algorithm. Both freeway and rural highway data were used to evaluate the performance of the proposed algorithm. Promising results, which 90.48% and 88.24% of classification accuracy were obtainable for freeway and rural highway respectively, demonstrated the technical feasibility of the algorithm for the implementation.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.19
• /
• pp.100-131
• /
• 1975

To obtain basic information on the improvement of naked barley production. and to clarify the relation-ships between yield or yield components and some meteorogical factors for yield prediction were the objectives of this study. The basic data used in this study were obtained from the experiments carried out for 16 years from 1958 to 1974 at the Chon-nam Provincial Office of Rural development. The simple correlation coefficients and multiple regression coefficients among the yield or yield components and meteorogical factors were calculated for the study. Days to emergence ranged from 8 to 26 days were reduced under conditions of mean minimum air temperature were high. The early emergence contributed to increasing plant height and number of tillers as well as to earlier maximum tillering and heading date. The plant height before wintering showed positive correlations with the hours of sunshine. On the other hand, plant height measured on march 1st and March 20th showed positive correlation with the amount of precipitation and negative correlation with the hours of sunshine during the wintering or regrowth stage. Kernel weights were affected by the hours of sunshine and rainfall after heading, and kernel weights were less variable when the hours of sunshine were relatively long and rainfalls in May were around 80 to 10mm. It seemed that grain yields were mostly affected by the climatic condition in March. showing the negative correlation between yield and mean air temperature, minimum air temperature during the period. In the other hand, the yield was shown to have positive correlation with hours of sunshine. Some yield prediction equations were obtained from the data of mean air temperature, mean minimum temperature and accumulated air temperature in March. Yield prediction was also possible by using multiple regression equations, which were derived from yield data and the number of spikes and plant height as observed at May 20th.

• Journal of the Korean Society for Library and Information Science
• /
• v.46 no.2
• /
• pp.157-174
• /
• 2012

This study tries to describe personal name access point control ontology for the American novelist Mark Twain using RDF/OWL axiom to control access point based on the ontology. The Axiom used in this study are disjoint with class, domain and range, property cardinality, inverse functional property, individual and literal data property. As a result, in the ontology environment we can accept various access points as equal access points exclusive of authority heading and heading concept. It can successfully describe Mark Twain's personal name access point control ontology and display using the OntoGraf.