• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.359-365
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• 1994

A oat (Avena sativa) cultivar, 'Guiri 16', was seeded on Oct. 9, Oct. 24, Nov. 9, Nov. 24, Dec. 9 of 1991 and 1992 to determine usefulness of growing degree days (GDD) for predicting growth duration and the optimum seeding date of oats for grains in Cheju province. The later the seeding, the greater the number of days to emergence but the fewer the number of days to heading and maturity. As seeding was delayed, accumulated GDD from seeding to emergence generally tended to decrease but was less subjective to a constant downward tend over seeding date than the number of days. Accumulated GDD from emergence ot heading decreased with delaying seeding and accumulated GDD from heading to maturity decreased as seeding was delayed up to Nov. 24. As seeding was delayed from Oct. 9 to Dec. 9, to Dec. 9, leaf area index at heading decreased from 7.7 to 5.1 and dry matter yield at maturity from 1920 to 823 kg /10a in 1992-1993, and culm length 120 to 89cm on an average of 1991-1992 and 1992-1993. While the number of grains per panicle and test weight were not affected by seeding date in 1991-1992 and 1992-1993, the number of panicles per m$^2$ and grain yield were decreased when oats were seeded earlier or later than Nov. 9. 1000 grain weight was not affected by seeding date in 1991-1992 but greatest at Nov. 9 seeding in 1992-1993. The results indicate that optimum seeding date of oats in Cheju province would be early November. November.

• Korean Journal of Plant Resources
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• v.15 no.2
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• pp.144-149
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• 2002

This study was carried out to find out the effects of date and number of defoliation by different seeding date on growth and yield of perilla. Saeyuepsildlkkae was seeded from April 30 to June 30 at 20 days interval and defoliated from June 30 to Aug. 15 with different defoliation number. 1. Days to emergence, flowering, and maturing were not significantly influenced by defoliation, but those were shortened as seeding date was delayed. The interaction between defoliation and seeding date showed no significant difference. 2. Stem length, number of nodes on main stem, and weight of dry stem were not significantly affected by defoliation, but those were decreased as seeding date was delayed. 3. Yield of fresh loaves was not significantly influenced by seeding date up to May 20, but markedly decreased by the later seeding date. 4. Cluster length and number of cluster per plant were not affected by seeding date, but number of capsules per cluster was decreased from 32 to 25 and 1,000 grain weight was increased from 3.42 to 4.62g as seeding date was delayed. 5. Grain yield was not significantly affected by defoliation and seeding date up to June 10, but markedly decreased by seeding date June 30.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.370-375
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• 1996

This study was conducted to find out the feasibility in direct seeded rice cultivation on the reclaimed saline soil. Seedling emergence was tested under the different application rates of rice straw and seeding depth, and also under combined treatments soil moisture regimes and seeding depth on saline soils in a greenhouse. The comparison of seedling stand and yield performance of rice in rotary till after broadcast seeding and in non-plow after broadcast seeding were tested on a field that reclaimed saline soil. Seedling emergence ratio in application of rice straw(4 and 6 tons /ha) was higher than that in non-application of rice straw. Seedling emergence and plant height were remarkably increased with the shallow seeding depth in the application of rice straw(4 tons /ha). The seedling emergence under proper soil moisture condition(25%) was higher than that under excess soil moisture condition(35%). Under proper soil moisture condition, the plant height was increased with the shallowed seeding depth. The number of seedling stand per m$^2$ in non-plow after broadcast seeding was larger than that in rotary till after broadcast seeding. Panicle number per m$^2$ in non-plow after broadcast seeding was much larger than that in rotary till after broadcast seeding and the yield showed the same trends as panicle number.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.18
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• pp.124-155
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• 1975

To obtain the fundamental informations on the varietal improvement of peanut and to study the ecological variations of the important agronomic traits and to the relationship between the traits studied, an investigation was made on varietal classification of 489 introduced on the basis of their morphological and ecological differences at Crop Experiment Station, Suweon in 1968, and the other study conducted at some location as above in 1969 was to investigate the ecological variations of the materials in accordance with changes of seeding date using classified varietal group under 5 different seeding times from April 16 to July 7 with twenty days interval. The results obtained were summarized as follows: 1. Peanut varieties tested were classified into Spanish, Virginia Erect, Virginia Runner, Southeast Runner. Valencia and Semirunner, on the basis of plant type, flowering time, number of grains per pod and grain size. 2. Characteristics of varietal group classified are as followings. (1) Spanish; erect, small grained and early maturing type. (2) Virginia Erect; erect, large grained and late flowering type. (3) Virginia Runner; runner, large grained and late maturing type. (4) Southeast Runner; runner, small grained and early maturing type. (5) Valencia; erect, small grained and early flowering type with 3-4 grains per pod. (6) Semi runner; semirunner, large grained and late flowering type. 3. Flowering period in respective varietal group was consistently shorted by delayed seeding date and the degree of shortening was more serious in late flowering varietal group. 4. Number of branches per plant was generally decreased in late seeding date in respective group. However, Spanish and Virginia Runner exhibited lower number of branches in the first seeding rather than the second seeding and the lowest number of branches was found in Spanish while the highest were Virginia Erect in all seeding date. 5. Shelling ratio was high in Spanish and Southeast Runner in any seeding date and decreased remarkedly by seeding after May. 6. Number of pod per plant in all varietal groups was remarkedly decreased by delayed seeding date and the degree of decreasing was more serious in large grain varietal group. 7. The higher pod weight per plant was found in second seeding date rather than first seeding and pod weight per plant was decreased obviously in all late seeding after the second. Therefore, among the cultivars tested, Southeast Runner noted the highest pod weight per plant while Virginia Runner showed the lowest. 8. Grain number per plant expressed the similar tendency as the pod weight per plant but was low in large grain group and high in small grain group in all seeding date employed. 9. 100 grain weight was heaviest in second seeding and was decreased remarkedly after the second and even the first seeding date. 10. Yield per 10a noted considerable variations in accordance with seeding date in all groups classified. However, the yield was increased in second seeding date (May 7) and decreased in the others. 11. Length of main stem and branches were exceptionally decreased in the first seeding date compare to the second in Spanish while other varieties were tend to be same between the indicated seeding date, but. these two traits were strikingly decreased in all seeding after the second. This tendency, however, strongly suggested the importance of environmental effects on peanut growth in terms of their changes due to the different seeding date. 12. Highly significant positive correlations were showed between yield and yield componets such as pod weight per plant, 100 grain weight and the number of grains per plant in all varietal groups except, Virginia Runner. However, the other characters were almost not correlated with yield and differences in correlation coefficients among the seeding dates were found. 13. Path coefficients estimated for yield components to yield was higher in number of grains per plant pod weight per plant and 100 grain weight in terms of direct effect and the other components were negligible in all varietal groups. 14. Heritabilities estimated were generally high in pod number per plant, shelling ratio, 100 grain weights and number of grains per pod and the other traits were relatively low.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.5-18
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• 2018

The field trial was performed to evaluate the rice growth and yield in direct seeding cultivation with iron-coated rice seeds. The required time for seed emergence was for 9~11days in the tested direct seeding methods. That was 1~2days earlier in direct seeding with pregerminated seeds than that of direct seeding with iron-coated seeds. The seedling establishment was highest in water seeding with iron-coated seeds but there was not significant difference in terms of statistical analysis. The rice plant height was taller in water seeding with broadcasting method than that of wet hill-seeding methods and in direct seeding with iron-coated seeds than that of direct seeding with pregerminated seeds. The tiller number in the rice plant was the highest in machine transplanting at 30days after direct seeding(June 17) and in water seeding with iron-coated seeds at 45days after seeding(DAS) and 60DAS. The tiller number of 75 and 90DAS in the tested rice cultivation methods being with 352~405/m² was not significantly different in terms of statistical analysis. The heading time was not different in rice direct seeding methods but 2 day earlier in direct seeding with iron-coated seeds than that of direct seeding with pregerminated seeds. The culm length was the highest in water seeding with iron-coated seeds and the panicle length was the longest in wet hill-seeding with pregerminated seeds. The panicle number per m² was highest in water seeding with iron-coated seeds but not significant difference among the tested rice cultivation methods. The water seeding with iron-coated seeds resulted in the highest spikelet number per m² and the heaviest grain weight of brown rice. Percentage of ripened kernel was the highest in wet hill-seeding with iron-coated seeds. But there were not significant among the tested rice cultivation methods. The milled rice yield in direct seeding methods was 3~21% higher than that in machine transplanting. Water seeding with iron-coated seeds recorded the highest milled rice yield being with 6.86t/ha.The occurrence of sheath blight was high according to machine transplanting>wet hill-seeding>water seeding. Weed occurrence was the highest in water seeding with pregerminated seeds. Weedy rice occurred not in machine transplanting but occured 0.6~0.7% in direct seeding methods with pregerminated seeds and 0.1% in direct seeding with iron-coated seeds.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.4
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• pp.217-224
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• 2001

In order to identify the growth characterization, the yield and chemical composition of Jeju barnyard grass (Echinochloa crusgalli var. fiurnentacea(Roxb) Wight) based on seeding date in Jeju region, seeding carried out the 10-day intervals from March 27 to September 30 in 2000, respectively. Plant height was 143.2 cm, showing the highest on seeding date, April 6 among that of any other seeding date. On the other hand, those of early and late seeding gradually decrease. Plant height was 119.2 an in May 16 seeding. The results of stem diameter, number of withering leaves, number of leaves and fresh weight per plant were similar to those of the plant heights. The yield of fresh, dry matter forage, crude protein and TDN found the highest on April 6 seeding, 63.5 MT/ha, 13.9 MTha, 1.1 MT/ha, and 7.6 MT/ha, respectively. In early and late seeding, the yield was gradually decreased. In seeding May 16, the yield found .38.2 MTIha in fresh forage, 6.2 MTha in dry matter forage, 0.7 MT/ha in crude protein and 3.7 MTha in TDN, respectively. According to delaying the seeding date, March 27 to May 16, the contents of crude protein (from 7.9 to 10.8%), ether extract (from 4.6 to 6.0%), nitrogen free extract (from 45.1 to 46.5%), and TDN (from 54.2 to 60.8%) were gradually increased, respectively. On the other hand, those of crude fiber (from 28.9 to 25.6%) and crud ash (from 13.5 to 11.2%) were decreased. These results showed that April 6 was the optimum seeding date with the sole object of feed production of Jeju barnyard grass under the environmental condition like as atmospheric phenomena and soil in Jeju region. (Key words : Jeju barnyard grass, Seeding date, Forage yield, Chemical composition)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.440-448
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• 1989

The present experiment was conducted to investigate the effects of seeding date on agronomic characters including seed weight of soybean (Glycine max (L.) Merr.) at Sunchon, the southern coastal area of Korea. One hundred eighteen native and improved varieties were used in this study. As the seeding date was delayed, the number of days to flowering for the cultivars was reduced. This trend was more obvious in late maturing cultivars(LMC) than in early and medium maturing cultivars (EMC and MMC). Late seeding also resulted in decrease in the number of leaves, stem length, and number of nodes. The heaviest seed weight was obtained with EMC and MMC planted on May, and seed weight decreased with delayed seeding date. Seed weight was positively correlated with number of days to flowering, number of total leaves at flowering, stem length and number of nodes on main stem at maturity. Based on seed weight the cultivars was classified into five types: Type I; Seed weight of the cultivars decreases with delayed seeding date. Type II; Seed weight of the cultivars does not vary with seeding date. Tyep III; Seed weight of the cultivars increases with delayed seeding date. Type IV; Seed weight of the cultivars increases when the seeding date approached the appropriate seeding date, but decreases thereafter. Type V; The reversed type IV. Type I, II, III, IV and V occupied 37, 16, 17, 10 and 20％ of the tested cultivars, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.287-293
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• 1987

To find out the effects of seed maturity and seeding rate of two planting times on the seed emergence and silage and seed yields of rye, a local variety 'Paldanghomir' harvested 30 and 45 days after heading(DAH) were planted at five seeding rates on October(optimum) and November(late) in 1985. At the optimum planting, number of seedlings per unit area and number of tillers per plant were affected by seeding rate, but not by the seed maturities. However, at the late planting, number of seedlings per unit area and number of tillers per plant wer higher in the seed harvested 45 DAH, and they were not correlated with seeding rate in both seeds harvested 30 and 45 DAH. Heading date was 2 or 3 days earlier in the seeds harvested 45 DAH in both planting times. Silage yield was higher at the optimum planting and increased as seeding rate increased in both planting times. Number of spike and 1000~seed weight were higher at the optimum planting than late planting and higher in the seed harvested 45 DAH than 30 DAH in late planting, but were not different among seeding rates. Seed yield at optimum planting showed no difference between seed maturities and among seeding rates, and recommandable seeding rate was 600 seeds per $m^2$. At late planting the seed yield of the seed harvested 45 DAH in the seeding rate over 750 seeds per $m^2$ approached to the yield of the optimum planting. The seed harvested 30 DAH was unstable because of extremely low emergence rate and yield even at the higher seeding rate in late planting. planting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.405-411
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• 1994

This study was carried out to determined the optimum seeding rate and number of seedling stands per unit area for high yield with two varieties of rice, Nakdongbyeo (Japonica type) and Samgangbyeo (Indica x Japonica type), in direct water-seeded rice culture at Crop Experiment Station. Seeds coated with $CaO_2$ after germination were sowed at May 4 in 7 levels, such as 1.6, 1.8, 2.1, 2.7, 3.5, 4.0, 4.3kg /10a, and the number of seedling stands per square meter was adjusted to be 30, 40, 60, 80, 100, 120, 140 plants, respectively. The maximum number of tillers increased as the seeding rates increased, but the ratio of effective tillers decreased. The critical dates of effective tillering of tested varieties were delayed by the lower seeding rates, and the date was June 18 at the plot of seeding rate with 3.5kg /10a. The number of panicles per unit area increased in accordance with the increased seeding rates. The number of spikelets per panicle in Nakdongbyeo was not affected by the seeding rates, but in Samgangbyeo it decreased as the seeding rate increased. The optimum number of seedling stand per square meter appeared to be 78 in Nakdongbyeo and 120 in Samgangbyeo, respectively. It meant that the optimum seeding rates for Nakdongbyeo and Samgangbyeo were about 2.7 and 4.0kg /10a, respectively.

• Journal of Bio-Environment Control
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• v.16 no.1
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• pp.62-66
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• 2007

This study was carried out to develop the stable plug seedling production for hydroponics of spinaches by various nursery media, plug tray size and seed number per plug tray cell. When plant grown in various nursery media, the seeding stand rate was shown in order of granular rockwool with good water retention, granular rockwool>granular rockwool mixed with pearlite>cocopeat>pearlite>poly urethane foame. Thus, poly urethane foame indicated the lower seedling stand rate. There was no difference in growth of the seedlings md the seeding stand rate by the plug tray size, and no significant difference in the plant height and the number of leaves among the seed number per plug tray cell. But, leaf area of plant in 2 grains seeding per cell was $113.0cm^2$, was wider in compared with 5 grains seeding of which leaf area was $88.0cm^2$. Accordingly, the leaf area per plant decreased as more and more the number of seeds per plug tray cell increased. The fresh weight of a plant per plug tray cell was the heaviest with 12.5g in the 2 grains, and the total fresh weight of plants per cell was 33.9g in 4 grains seeding, thus it tended to was bigger compared with other treatments. Consequently, given that the number of seeds per cell was decreased, the fresh weight of a plant increased. On the other hand, the total fresh weight per cell showed a tendency to be reducing as more and more the number of seeds per plug tray cell decreased. The yield in the 4 grains seeding was increased by 46% as $14,910kg{\cdot}ha^{-1}$ in compared with the yield in 2 grains seeding as $10,200kg{\cdot}ha^{-1}$.