• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.1
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• pp.17-22
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• 2005

This experiment was conducted to investigate the effect of seeding dates and rates on the productivity and nutritive value of hairy vetch(Vicia villosa Roth) at experimental field of Grassland and Forage Crops Division, National Livestock Research Institute, RDA, Suwon from 1999 to 2000. The experimental design was consisted of split-plot design with three replications. The main plot was seeding dates(25 Aug., 15 Sep. and 5 Oct.) and the subplot was seeding rates(20, 30 and 40 kg/ha). Late seeding dates increased the plant height and delayed the flowering stage as 1 or 2 days. The dry matter(DM) content was decreased with low seeding rates, and the trend was same in the all plots. Average crude protein(CP) content was $24.1\%$ and increased with delayed seeding date and lower seeding rate. The content of acid detergent fiber(ADF) and neutral detergent fiber(NDF) was increased with higher seeding rate, but seeding date did not affect. In vitro dry matter digestibility(IVDMD) of hairy vetch tended to decrease with high seeding rate, and total digestible nutrient(TND) did not show significant difference among seeding rates. Average relative feed value(RFV) of hairy vetch showed 140 which means very high quality. Dry matter and CP yield was decreased with delayed seeding date. The results of this experiments indicated that seeding in middle-August with 40 kg/ha would be recommended to produce the highest yield and quality f3r the cultivation of hairy vetch in middle part of Korea

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.483-487
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• 2001

This study was conducted to examined the effects of TIBA and ethrel on podding rate, percentage of seed numbers per pod, and seed yield of black soybean. The black soybean variety “Geomjeongkong 1” was used. TIBA of 50, 100, and 150 ppm and ethrel of 500, 1,000, and 1,500 ppm were applied at V6 (fifth leaf stage), V8 (seventh leaf stage), and R1 (flowering stage). The podding rate was increased by the treatment of TIBA at R1 stage while it was decreased by ethrel at all growth stages. Compared with control, TIBA decreased 100 seed weight a little bit but ethrel increased it slightly, on the contrary. Both TIBA of 50 ppm and ethrel of 500 ppm increased the sued yield by 8 to 28％ compared with control regardless of growth stages of application; the highest seed yield was obtained at V6 stage of application of 50 ppm in TIBA and 500 ppm in ethrel, respectively.

• Korean journal of applied entomology
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• v.15 no.4 s.29
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• pp.185-191
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• 1976

This study was conducted to evaluate the performance of 2,4-D amine salt (2,4-dichlorophenoxy acetic acid) 40EC in broadleaf weeds control under diverse conditions of rate and time of application and soil type in fall barley field. The results obtained were summarized as follows: 1) At the rate of 70cc prod./10a, 2,4-D amine salt treated during the fully tillered stage of barley was effective for the control of most broadleaf weeds without crop injury. 2) The fully tillered stage was a optimun time lot the application of 2,4-D amine salt in fall barley. Earlier(zero-to four-leaf stage) or late. (boot stage to flowering) application than this stage caused a crop injury and resulted in yield reduction. 3) It was possible to safely use 2,4-D amine salt in fall barley regardless of soil types if applied the rate of 70cc prod./10a at the fully tillered stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.50-54
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• 1984

To study the effects of planting dates and mulching on the growth and yield of summer type soybean, a variety, Damamidori introduced from Japan, was planted four times from April 13 with 10 days interval. Experimental plot in each planting date was devided into two sub-plots, polyethylene film mulching and non-mulching. By mulching, days to emergence and first flowering were shortened, especially in the early plantings; e.g. as much as 11 and 12 days, respectively, in the first planting. Compared to non-mulching, plant height, number of nodes of main stem, number of branches, and dry weight of stem and branches per unit area were also much increased by mulching. As the plantings were delayed, plant height, the total number of nodes and dry weight of main stem and branches, and 100 seed weight showed increasing trends, which were mainly due to lower infection rate of soybean seeds to pod and stem blight (Diaporthe phaseolorum) in the later plantings. The higher infection rate of soybean seeds to pod and stem blight, the lower infection rate to purple seed stain (Cercospora kikuchii) was shown in mulching but not in non-mulching.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.541-549
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• 1992

Lodging and rainfalls during ripening periods and ripening patterns were studied by the different maturing varieties and different seeding dates in labour saving-direct seeding cultivation of rice. Period of emergency in earlier seeding plot was longer than later seeding plot and standing seedlings per unit area and rate of standing seedlings were more and high by the later seeding date. Number of panicles per unit area was decreased by the later seeding dates. On the other hand, the rate of effective tillers was lowest at later seeding plot. Days from seeding to flowering were shortened by the later seeding dates due to the increase of daily growth temperature and reduce of day length. There was much rainfalls during ripening period of early maturing varietal group, however not much rainfalls during ripening period of medium and late maturing varietal groups. The degree of lodging at field was severer by the amount of rainfalls during ripening period. Earlier seeding plots and earlier maturing varietal groups. of used varieties were revealed heavier lodging compared to later seeding plots and later maturing varietal groups. Yield and yield related characteristics were high and good by the earlier seeding dates, especially ripening rate was clear.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.247-252
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• 1995

This study examines the effects of the planting time of mother bulb and mulching materials for the seed production of onion on the amount of seed production, and the following results are obtained : Growth, bolting rate, flowering rate, floret numbers per scape and fertilization rate are best in the case of the seed production under transparent vinyl mulching between Sept. 10 and Sept. 25, and seed yield per plant and seed yield per 10a are increased in the case of the seed production under transparent vinyl mulching between Sept. 10 and Sept. 25, so it is found that it is appropriate to plant the onion mother bulb under the transparent vinyl mulching between Sept. 10 and Sept. 25 in the southern areas of Korea.

• Korean Journal of Medicinal Crop Science
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• v.4 no.4
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• pp.301-307
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• 1996

The experiment was conducted to clarify the effect of water stress treatment on growth character of Ligusticum chuanxiong Hort. The water stress treatment was imposed artificially on seedling, flowering and rhizome enlargement stage of the plant. The decrease ratio of leaf area compare with control decreased to 24.4% by water stress treatment at seedling stage and to 41.6% at rhizome enlargement stage. The reduction rate of chlorophyll content at the end of water stress treatment was 41.2% at the see­dling stage and no difference at the flowering stage. The chlorophyll content of water stress treatment on seedling and flowering stage was recovered to 95% at harvest time. The ratio of rootlet distribution from top soil to l0cm depth showed maximum to 90% at the seedling stage and to 20cm depth showed max­imum to 6.4% at the rhizome enlargement stage. The dry weight of rootlet was decreased to $19.3{\sim}40.3%$ by water stress treatment. Dry weight of aerial part and underground part of the plant decreased in the order of seedling, flowering, rhizome enlargement and control and the dry weight of aerial part decrease more severely than underground part.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.3
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• pp.143-150
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• 2003

This study was conducted to determine the response of main growth characters, yield and chemical composition of Jeju native soybean based on the difference between phosphate rates (0, 50, 100, 150, 200, 250kg/ha) from May 11 to September 10 in 2002 in Jeju island. Days to flowering was delayed from 92 days to 97 days as the increasing of phosphate rate. Also plant height grew longer from 109cm to 124cm. The number of branches and leaves, stem diameter, root length and weight of root grew powerful as phosphate rate increased from 0 to 250kg/ha. Fresh forage yield was 26.5MT/ha in the nonphosphate plot and then was 36.9MT/ha as phosphate rate increased to 250kg/ha. And the difference between 200kg/ha and 250kg/ha in phosphate rate was not significant. Dry matter, crude protein and TDN yield increased 6.0∼7.9MT/ha, 0.9∼1.4MT/ha and 3.4∼4.9MT/ha respectively, as the increasing of phosphate rate. Also crude protein, crude fat, NFE and TDN content increased 15.5∼18.3%, 2.2∼3.3%, 42.5∼43.5%, and 56.7∼61.9% respectively. In contrast with this, crude fiber and crude ash decreased 32.1∼28.1% and 7.7∼6.8% respectively. To reach the climax of forage yield was estimated optimum phosphate rate to be 200kg/ha.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.4
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• pp.69-79
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• 1982

The objective of this study is to contribute to drainage planning in the most realistic and economical way by establishing the relationship between rice yield reduction and overhead flooding by muddy water of each growth stage of paddy, which is the most important factor in determining optimum drainage facilities. This study was based on the data mainly from the experimental reports of the Office of Rural Development of Korea, Reduction Rate Estimation for Summer Crops, published by Ministry of Agriculture and Forestry of Japan and other related research documenta- tion. The results of this study are summarized as follows 1. Damages by overhead flooding are highest in heading stage and have the tendency of decrease in the order of booting stage, panicle formation stage, tillering stage, and stage just after transplanting. Damages by overhead flooding of each growing stage are as follows: a) It is considered that overhead flooding just after transplanting gives a little influence on plant growth and yield because the paddy has sufficient growth period from floo ding to harvest time. b) Jt is analyzed that according to the equation y=11 12x 0.908 which is derived from this study, damages by overhead flooding during tillering stage for 1, 2, 3 successive days are 11.1 %, 20.9%, and 30.2% respectively. c) Damages by overhead flooding after panicle formation stage are very serious because recovering period is very short after damage and ineffective tillering is much. Acc- ording to the equation y=9. 58x+10. Ol derived from this study, damages by overhead flooding fal 1,2,3,5 successive days are 19.6%, 29.2%, 38.8%, 57.9% respectively. d) Booting stage is the very important period in which young panicle has grown up almost completely and the number of glumous flower is fixed since reduction division takes place in the microspore mother cell and enbryo mother cell. According to the equation y=39. 66x 0.558 derived from this study, damages by overhead floodingfor 0.5, 1, 3, 5 successive days are 26.9%, 39.7%, 72. 2% and 97.4%, respectively. Therefore, damages by overhead flooding is very serious during the hooting stage. e) When ear of paddy emerges, flowering begins on that day or the next day; when paddy flowers, fertilization will be completed 2-3 hours after flowering. Therefore overhead flooding during heading stage impedes flowering and increases sterilizing percentage. From this reason damages of heading stage are larger than that of booting stage. According to the equation y-41 94x 0.589 derived from this study, damages by overhead flooding for 0.5, 1, 3, 5, successive days are 27.9%, 63.1 %, 80.1%, and 100% 2. Considering that temperature of booting stage is higher than that of beading stage and plant height of booting stage is ten centimeters shorter than that of heading stage, booting stage should be taken as a critical period for drainage planning because possi- bility of damage occurrence in booting stage is larger than that of heading stage. There-fore, it is considered that booting stage should be taken as critical period of paddy growth for drainage planning. 3. Overhead flooding depth is different depending on the stage of growth. In case, booting stage is adopted as design stage of growth for drainage planning, it is conside red that the allowable flooding depth for new varieties and general varieties are 70cm and 80cm respectively. 4. Reduction Rate Estimation by Wind and Flood for Rice Planting of the present design criteria for drainage planning shows damage by overhead flooding for 1 to 2, 3 to 4, 5 to 7 consecutive days; damages by overhead flooding varies considerably over several hours and experimental condition of soil, variety of paddy, and climate differs with real situation. From these reasons, damage by flooding could not be estimated properly in the past. This study has derived the equation which shows damages by flooding of each growth stage on an hourly basis. Therefore, it has become possible to compute the exact damages in case duration of overhead flooding is known.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.346-361
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• 2021

The range of D. spathulata identified in this survey was between N 35° 24' 58" ~ N 35° 26' 35", E 129° 05' 43" ~ E 129° 07' 04". It is located at an altitude of 98~592 m. The soil pH was strongly acidic in the range of 4.2~4.9, with a canopy openness of 18.56% and a chlorophyll index of 36.74 ± 2.80. As a result of the TWINSPAN analysis, 20 plots of 100 m² each were divided in 4 communities: Pinus densiflora community, Quercus monglica-Diabelia spathulata community, Quercus serrata-Diabelia spathulata community and Carpinus tschonoskii subassociation. The result of species diversity was 0.7615, and evenness and dominance were found to be 0.6077 and 0.3923, respectively. The height of D. spathulata is up to 3.4 m, and the average height is 1.1 m, with most of the species distributed as shrubbery and herbaceous. The average population density of the 20 plots was 1.635 individuals/m², the height range of flowering was 1.0 ~ 1.8 (aver. 1.39 m) and the rate of flowering was 27.37%. It's propagation pattern was mainly formed by extending the rhizome to the side, creating a colony of ground stems.