• KOREAN JOURNAL OF CROP SCIENCE
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• v.11
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• pp.121-126
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• 1972

Regim-8(TIBA), a Chemical pinching agent, was applied to soybean plants of 6 varieties at 6 leaf stage in oder to develop a chemical pruning method. The results are summarized as follows: 1) The more inhibition in plant height and rare lodging were abserved at 2, 000ppm level of treatment (50cc of Regim-8 diluted in 100ι of water). 2) Number of branches and grains per plant were increased by Regim-8 treatment, while number of main stem nodes were decreased. 3) It appeared that photosynthetic efficiency of the soybean plant community treated by Regin-8 were improved. This increased number of pod per plant and hence soybean yield increased by applying Regim-8. 4) Antilodging effects of Regim-8 were also appeared to result in better filling of pods and higher yield per unit area.

• Korean Journal of Plant Resources
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• v.29 no.4
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• pp.511-518
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• 2016

The subject of this experiment is to supply basic data to inhibit non-productive tillers which are uneconomical for mechanical harvesting and to evaluate optimum planting density and sowing date in central district. Total number of tillers and effective first and second of tillers according to different planting density was higher in 80 ㎝ ridge than 60 ㎝ ridge in proso millet. The wider between plant distance on the ridge, the more increased total number of tillers and effective first and second of tillers. The highest effective tillers (91.7 %) in the first tillers was obtained from the second sowing date (23 May) among different sowing date and next is in the order of 3^rd(13 June, 89.8%) > 1^st(2 May, 85.6%) > 4^th(4 July, 85.2%). The percentage of effective tillers in the second tillers was decreased in the order of 2 May (53.7%), 23 May (40.7%), 13 June (22.2%), 4 July (0%) as the sowing date was delayed. There was no significant difference in days to heading and days to ripening according to different planting density. Although culm length was increased as planting density was increased, whereas number of tillers, stem diameter, ear length, grains per ear and 1000 grain weight was decreased. In the growth and yield characteristics of proso millet according to different sowing date, days to heading and days to ripening, culm length, stem diameter, ear length, grains per ear and yield per 10a were decreased. After the sowing date of 13 June, the reduction of growth and yield characteristics were higher because of excess-moisture injury.

• Korean Journal of Medicinal Crop Science
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• v.4 no.3
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• pp.218-223
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• 1996

This experiment was carried out to investigate the effect of planting date and planting density on yield and yield components of Fritillariae bulbus from 1989 to 1991. The Chungbuk local variety was used, and the experimental materials were planted six times with 10 days interval from Aug. 20 to Oct. 10. 33, 22, 17 and 13 bulbs were planted by the square meter, respectively. The compound fertilizer for garlic $(N\;-\;P_2O\;-\;K_2O_5=9\;-\;14\;-\;10)$ was applied by 80kgs to the 0.1ha before planting. The experimental design was randomized block design with 3 replications. As the planting dates were earlier, the emerging dates were earlier, too. But the delay of 50 days in the planting affected to the delay of 14 days in the em­erging dates. The plant height was 22.7cms in the Aug. 20 plot. As the planting were later, the plant heights were shorter by $2.4{\sim}5.6cms$ than that. As compared with the 829kgs by the 0.1ha of Aug. 30 plot, the others recorded 1 percent increase in the Aug. 20 plot, 4 percent decrease in the Sep. 10 plot, 26 percent decrease in the Sep. 20 plot, 35 percent decrease in the Sep 30 plot, and 38 percent decrease in the Oct. 10 plot. So, the suitable planting dates were from Aug. 20 to Aug. 30.The emerging date of 33 bulb plot by the square meter was March 7, but as the planting densities were sparse, the emerging dates delayed by one to three days. The plant height of the 33 bulb plot by the square meter was 21. 8cms, but the other plots were short by $0.7{\sim}1.8cms$. The number of shoots of the 33 bulb plot by the square meter was 6.1. but the other plots recorded 0.4 increase in the 22 bulb plot, 0.6 increase in the 17 bulb plot and 0.5 increase in the 13 bulb plot compared with that of the 33 bulb plot. Accordingly, the number of shoots in the sparse planting plot was more than that in the dense planting plot. As compared with the 854kgs by the 0.1ha of the 22 bulb plot, the other plots recored 2 percent in­crease in the 33 bulb plot, 16 percent decrease in the 17 bulb plot and 34 percent decrease in the 13 bulb plot. All things considered, for the culture of Fritillaria thungergii MIQUEL in the middle region, Aug. 25 and 22 bulbs by the square meter were suitable for the planting date and density.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.20-25
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• 1977

In order to find out the effect of five kinds of cultural treatments in fall crop production of potatoes the experiments were carried out with Simabara cultivar at Chonan in 1976. Sprouting of dormant seed pieces were induced by soaking in 2ppm GA and 250ppm Ethrel mixed solution for 60 minutes. Seed pieces with longer sprouts at transplanting, and increasing of urea(nitrogen) application from 10 to 30 Kg per 10a resulted better growth, yields, and quality. Application of total nitrogen at one time on 24th July(transplanting date) resulted lower emergence, yields, growth, and quality as compared with divided application on 24th July and 15th August and 5th September. Higher transplanting than 60$\times$20cm or 70$\times$17cm resulted slender growth and lower yields. Deeper mulch with wheat straw (from 4 to 12cm) induced lower maximal earth temperature in summer and higher minimal earth temperature in autumn.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.8 no.1
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• pp.17-29
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• 1970

To research the seeding systems and the varieties adapted to mechanization in barley and wheat culture in Korea, the studies were carried out from October, 1969 to June, 1970 at Suwon. In these studies, six kinds of seeding systems of drilling and dibbling that seems to adapted to mechanization were tested as compared with the customary seeding system, furrowing moderately or widely, using three varieties of barley, Suwon ＃18, Barsoy and Buhufng, and three varieties of wheat, Wonkwang, Yucseung ＃3 and Yeungkwang, under the two fertilizer levels of standard and double. The summarize results gained were as follows; 1. Buhung seemed to be the most suitable variety in barley as it yielded the most and matured early and grew the safest. Barsoy suffered from winter injury. 2. Yeungkwang seemed to be the most suitable variety in wheat as it yielded the most and produced the largest grain ani grew the safest, however it matured late. Wonkwang suffered heavily from lodging injury. 3. More yield were produced and there were no increase of cultural dangers except lodging in double fertilizer level. 4. Seeding system of drilling and dibbling seems to be able to put in practice safely under the double fertilizer level when lodging resistant varieties are selected. 5. Rate of yields increase in comparison with the customary seeding system of moderate furrowing were 16 percent in drilling of 20 centimeter spacing, 13 percent in wide furrowing and 12 percent in dibbling of 20 ${\times}$ 12 centimeter spacing in barley and also 9 percent in wide furrowing, 8 percent in dibbling of 20 ${\times}$ 12 centimeter spacing and 7 percent in drilling of 20 centimeter spacing in wheat. 6. The most important cause of above yields increase seems to be the increase of spike number per unit area. 7. Yields increase by drilling as compared with furrowing was not caused by higher rate of seeding. 8. The plants matured a bit earlier by drilling and dibbling. 9. Better stands of seedling were fount in dibbling due to the promotion of germination by tramping. 10. An increase of yields will be expected by decreasing the spacing in drilling and dibbling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.173-189
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• 1973

The followings are the results obtained in a series of experiments concerning of the varieties, the short-day-treatment, the fertilizer application, and the planting space of soybean, which were carried out to investigate the methods best suited for cultivating green soybean as the preceding crop of the rice. in the paddy-field in the middle parts of Korea at the practice farm attached to Agriculture College of Kon Kuk University in 1972. 1. Though the varieties of soybean was planted on the hot-bed on March 15 and then set in the main plot, none of them did flower within May 15, which is the limit time of flowering in growing soybean as the preceding crop of the rice in the paddy-field without the short-day-treatment being applied during raising seedlings. 2. The earliest-maturing variety groups such as HOKKAl#l, WASEMIDORI, YAEHUSANARI, MIT AKARAHAKUCHO, and VERDE flowered within May 15 by the short-day-treatment during raising seedlings. 3. The optimum hours of the day length was known to be 7 to 9 in the medium-maturing and late-maturing variety groups and 7 to 11 in the early-maturing and the earliest-maturing variety groups in the case of appling the short-day-treatment for 10 days from the beginning of the primary regular compound leaf development. 4 The optimum days in appling the short-day-treatment for 11 hours a day was recognized to be about 10 days regardless of the maturity of varieties. 5. Reduction of days required to flower by the short-clay-treatment, that is, light-sensitivity was remarkably higher in the medium-maturing and the late-maturing variety groups than in the earliest-maturing and the early-maturing variety groups. 6. The yield showed an increase of about 17 per cent in the case of appling the standard amount of nitrogen(4.0 kg/10 a), but it tended to reduce on the contrary in appling the increased amount of nitrogen. 7. The application of increased amount of phosphate had less significant effect on the yield increase than in the case of application of its standard amount( 4.0 kg/l0 a). 8. When the number of transplantation plant was changed from 54 to 130 per 3.3 $m^2$, the yield in 130 plant plot was about two times so higher than in 54 plant plot that the effect of close planting cultivation on the yield was proved to be remarkable. 9. Conditions possible for cultivating green soybean as the preceding crop of the rice in the paddy-field in the middle parts of Korea are turned to be as follows: (a) to plant the earliest-maturing-variety groups on the hot-bed on March 15. (b) to apply the short-day-treatment by 11 hours a day for 16 days from April 16, which is about the time when the primary regular leaf begin to develop. And it was, found to be a most remarkable in the increased yield that apply nitrogen 4.0 kg, phosphate 4.0 kg, and potassium 6.0 kg per 10 a as basic manuring totally and apply the close planting by 130 plants per $3.3{m^2}$(50 cm $\times$ 5 cm).

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.49-52
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• 1986

The objective of this study was to find out the productivity of F_2 material derived from F_1 hybrid Maize (Zea mays L.) by multiplication and their response to plant population. Suweon 19 and Junju-Ok were grown at three population densities. Populations were ca. 8.3, 10.4 and 13.9 thousand plants per 10a. The results are summarized as follows; 1. The number of barren plants differed significantly for the two generations but other yield components comparisons were not significant at P(0.05). 2. Ear and TDN yield were higher from the $F_1$ hybird of Suweon 19 than from the F_2 material, while yields of Jinju-Ok and stover yield of both hybrids were not affected by generation. 3. Plant and ear height were not affected by population density but barren plants were increased at high population. Length and weight of a ear, and ear (including cobs)-to-stover ratio decreased with increased population. 4. Increasing population density resulted in significant decrease in ear and TDN yield, while stover yield not decreased.

• Korean Journal of Medicinal Crop Science
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• v.7 no.4
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• pp.308-313
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• 1999

Direct seeding is a cultivation method of Korean ginseng which can cut down production cost and increase productivity. This study was conducted to obtain detailed information about this method and to aid the development of it in Korea. Major pre-crops before ginseng cultivation were rice, corn and rye, and organic matters, such as rice straw, rye straw and poultry feces were used for basal fertilization. In direct seeding of the ginseng field, seeding density was 196 to 210 seeds per $3.3m^2$ and germination ratio was 67%. Survival ratio of 4-year-old ginsengs which were products of direct seeding was 51%, and more than 100 plants per $3.3m^2$ survived. The most critical diseases in the directly seeded ginseng field were grey mold, damping off, and stem diseases including stem spot disease. Plant growth of the ginseng cultivated by the direct seeding method was not different from the ginseng cultivated by transplanting method. But the root of the ginseng cultivated by the direct seeding method took the shape of a shorter main root compared to the ginseng cultivated by the transplanting method. Root yield per $3.3m^2$ of the direct seeding ginseng field was larger compared to the field of the transplanting cultivation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.237-242
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• 2022

'Jogreen' (Secale cereal L.) was developed for rye cultivars not fast heading but winter hardiness with high yields, which was open-pollinated by ten rye cultivars including 'Chochun' in 1995. Its average heading date was April 15, which was five days earlier on average compared with 'Gogu'. At harvest, the plant height of 'Jogreen' was 117 cm which was taller than 'Gogu' as much as 6 cm. The number of stems was 983 per m², which was higher than that of Gogu (979). 'Jogreen' did not show both winter kill and powdery mildew, but showed lodging as 3 which is similar to 'Gogu'. The biomass in the dry weight base was 8.1 MT ha^-1, and showing was 4% higher than 'Gogu'. The crude protein content of 'Jogreen' was 11.9%, 0.8% lower than that of 'Gogu', and the acid detergent fiber (ADF) and the neutral detergent fiber (NDF) contents were 36.9% and 64.5%, respectively, higher than that of 'Gogu'. The total digestible nutrients (TDN) content also was low, but the TDN content was 5.09 ton ha^-1, which was higher than that of 'Gogu'. The seed productivity of 'Jogreen' was approximately 3.1 ton ha^-1, which was similar to the check. 'Jogreen' was found to be resistant to winter kill and can be adapted to after-paddy-rice cultivation in all Korean provinces. 'Jogreen' is likely to lodge, therefore, farmers should follow the recommended seeding rate and fertilization rate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.398-410
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• 1982

Summer crops grown in uplands are greatly diversified and show a large variation in difference with year and location in Korea. The principal factor for the variation is weather, in which precipitation and temperature play a leading role and such a weather factors as wind, sun lights also influence production of the summer crops. Since artificial control of weather conditions as a main stress factor for crop production is almost impossible, it must be minimized only by an improvement of cultivation techniques and crop improvement. Precipitation plays a role as one of the most important factor for production of the summer crops and it is considered in two aspects, drought and excess moisture. This country, which belongs to monsoon territory, necessarily encounter one of this stress almost every year, even though the level is different. Therefore, the facilities for both drought and excess moisture are required, but actually it is not easy to complete for them. On this account, crops tolerant to drought, excess moisture and pests should be considered for establishing summer crops. For the districts damaged habitually every season, adequate crops should be cultured and appropriate method of planting, drainage and weed control should be applied diversely. Injuries by temperature is mainly attributed to lower temperature particularly in late fall and early spring, although higher temperature often causes some damages depending upon the kind of crops. Sometimes, lower temperature in summer season playa critical role for yield reduction in the summer crops. However, certain crops are prevented to some extent from this kind of stress by improving varieties tolerant to cold, hot weather or early maturing varieties. As is often the case, control of planting time or harvesting is able to be a good management for escaping the stress. Lodging, plant diseases and pests are considered as a direct or indirect damage due to weather stress, but these are characters able to be overcome by means of crop improvement and also controlled by other suitable methods. In addition, polytical supports capable of improving constitution of agriculture into modern industry is urgently required by programming of data for the damages, establishment of damage forecasting and compensation system.