• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.4
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• pp.298-303
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• 1981

A study was conducted to find out the varietal difference in some important agronomic characters in response to different seeding time in barely from 1975 to 1976 at Chikugo Agric. Expt. Station in Japan. Thirteen varieties which are diverse in growth period were used. Nine seeding time were tried. Seedling emergence, primary tillering, and formation of flower primodia were delayed in proportion to the seeding time. And also heading and maturing time showed the same tendency. This tendency appeared more conspicuous in the late maturing varieties. Therefore, days to heading and maturing duration were inversely shortened by the delay of seeding time and by earliness of variety. Number of spikes as well as culm length and spike length was reduced in the late seeding. Grain yield was reduced in all varieties by late seeding, easpecially with late maturing varieties. In this test, widely adaptable variety to late seeding time was not found, but earliness and high tillering in growth habit appeared more favorable to yield increase.

• Plant Resources
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• v.3 no.3
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• pp.194-199
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• 2000

The result of this experiment which are conducted, to improve the cultivation technology of Alisma plantago, to increase its quantity and to contribute for stable production with Yongiun local group by examining the optimal planting density and transplanting period of double cropping of Alisma plantago in the southern region. The characters of plant height, leaf width and length tend to be reduced as the seeding period is later by the order of the 10th, 20th and 30th of July. The period required for flowering is reduced as the transplanting period is later and dense planting is applied. Plant height, the number of leaves and yield of dry root have much quantity at the dense planting density of 20$\times$ 15cm as they are transplanted later in the 30th of August or the 10th of September, but they are rather less in sparse planting density of 20$\times$25cm or 20$\times$35cm.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.50-50
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• 2022

Recently, the use of mulching film has increased in soybean cultivation. Polyethylene (PE) films and biodegradable films (BF) have the advantages of improving soil moisture retention, geothermal maintenance, and CO2 maintenance as well providing weed control. Furthermore, BFs are a material that can compensate for the shortcomings of PE because it has the ability to decompose naturally by soil microorganisms, sunlight, and geothermal heat. Many researches have been carrying out studies regarding the development of BFs for these very reasons. This study was conducted better understand which films are optimal for soybean cultivation after evaluations of soybean growth and film characteristics of various BFs. BFs Farmsbio (Farm Hannong), Heulgro Film (Sejin Bio), Vonto Film (Eco-Hansung), two unnamed biodegradable films (Seojin Bio and Taesung), and a PE film were used in this study. For the control plots, no mulching was used. Experimental fields were fertilized according to conventional cultivation methods, tilled, and then covered with either BFs or PE films. After 1 week, soybean (cv. Daechan) seeds were seeded. Germination rate and plant height were measured at weekly intervals after seeding. In addition, pH, EC, and decomposition and light transmittance levels of films were measured during the experimental period. Daily average temperatures and relative humidity in soils was measured during the experimental period. There was no significant difference in germination rates and plant height in both crops grown with BFs and PE films, but crops grown in the control plot had significantly lower germination rates and growth. Soil pH was not significantly different regardless of treatments (BF, PE, and non-mulching) at 14, 28, and 42 days after seeding. In general, the EC contents in the control plots was lower than in crops grown using BFs and PE films. With the exception of some BFs, light transmittance and decomposition levels of films did not, in general, increase up to 70 days after soybean seeding. Since this study is ongoing, we are continually investigating these parameters. The average daily moisture in soil was higher in crops grown with BFs and PE films than in the control plot. However, the daily average soil temperature was not consistent regardless of treatments. Therefore, the BFs used in this study can be used without negative impacts on soybean growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.443-447
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• 2002

This study was carried out to determine the differences in the growth, grain yield, and seed quality of sesame plant according to seeding date between P,E. vinyl-house and outdoor cultures. Reproductive growth period in vinyl-house culture was shorter than in outdoor culture. Stem length and capsule setting length of sesame were much longer in vinyl-house culture than in outdoor culture. Also, number of capsules per plant and 1,000 grain weight in vinyl-house culture were higher, specially the grain yield was approximately 57% more than in outdoor culture. In vinyl house culture, sesame plants sown on June 8 had longer capsule setting length, more capsules per plant, higher 1,000 grain weight, and higher percent ripened grain at the upper part of the capsule settings than those sown in May 9. They also had higher 1,000 grain weight at the middle and lower part of the capsule settings compared to May 9 seeding. However, no difference in grain yield of in seeding dates was observed. In outdoor culture, sesame plants, which was sown on May 9, had more effective branch number and capsule number and plant compared to those sown on June 8. Though sesame plants sown on May 9 had lower percent ripened grain at the upper and middle part of the capsule settings and lower 1,000 grain weight, the seed yield was similar to those sown on June 8. No difference in chromaticity value $L^*$ of sesame seeds between two culture conditions was observed. The $a^*$ value was higher in vinyl-house culture than outdoor culture while $b^*$ value was higher in outdoor culture. Sesaminol triglucoside content of sesame seeds was higher in vinyl-house culture than in outdoor culture. On the other hand, the content of sesamin and sesamolin from sesame seeds in vinyl-house culture were lower than in outdoor culture.

• Journal of Life Science
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• v.9 no.2
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• pp.127-135
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• 1999

Gentiana scabra Bunge var buergeri Max, can be widely used such as cut-flower, ornamental and medicinal plant among the native plants. Microscopic and Scanning electron microscopic observation plant were carried out to estimates the characteristics correlated with germinability and germination process, and the results were as follows. The seeds were germinated just after harvest, and it means that there is no or little dormancy of the seeds. Matured seeds showed higher germinability than those of immatured. As the storage period was longer, immatured seeds showed shorter longevity than those of matured. The average longevity was about 190 days. According to the observation results of morphological changes during the germination, seed coat was expanded with water absorption immediately after seeding, and radicals were observed 2 days after seeding. Root hairs were formed behind the growing tip of the root on 4 days after seeding and cotyledon were unfolded on 6 days after seeding. In the microscopic observation of leaf tissues, it could be easily distinguished between midrib, and leaf blade, and also observed upper epidermis, palisade parenchyma and spongy parenchyma consisted as a sing1e layer. Palisade parenchyma was consisted of a single layer of cell. Stomata were restricted lower surface, arranged as anamocytic type, and surrounded by guard cells. In the microscopic anatomy of stem were consisted of cortical layer, forming a single layer of epidermis and parenchyma, and vascular bundle which was consisted of continuous cylinder of vascular tissues.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.239-244
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• 2014

Barnyard grasses are dominant weed that are not eliminated easily in the direct water seeding cultivation. So, deep water treatment can reduce their growth at the early growing stage of submerged paddy. This study was carried out to investigate the reducing growth of the barnyard grasses through flooding at seedling stages of rice plant in the green house. Under the normal condition, the plant height of rice variety, Samgwangbyeo, and 3 species of barnyard grass, E. caudata, E. pratocola and E. utilis were not showed the difference up to 10 days after seeding while the plant height of 3 barnyard grass species, especially E. utilis, was more elongated than the rice at 25 days after seeding. Plant height of the 3 barnyard grasses were not elongated largely during 3, 5 and 7 days of flooding treatment at 10 days after seeding. Interestingly, the rice seedlings was grown over 20 cm, and the flooding tolerance of rice seedling was higher than the 3 barnyard grass varieties. However, after flooding treatment for 3, 5 and 7 days, the elongation of plant height of 3 barnyard grasses, especially E. utilis was more speedy compared to rice seedlings as 6 to 9 days passes. And the protein spots from barnyard grasses were also reduced and eliminated more than the spots of rice seedling after flooding treatment.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.177-182
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• 2010

This environment-friendly study was conducted to investigate the effects of winter barley as cover crop on the suppression of weeds and on the growth of dry direct seeded rice. The present study clarified the effects of winter barley as a cover crop on the weed vegetation, expressed as a multiplied ratio. In cultivation quality of rice, seedling stand was ranged from 104~112 $m^{-2}$. And, seeding stand of barley was the highest seedling stand 634 unit per $m^2$ in April 10 as compared to the other seeding dates. Furthermore, the dry weight of barley seeded in April 10 was heaviest at 146g $m^{-2}$. Rice yield was in 401kg $10a^{-1}$ in the April 10, and 517kg $10a^{-1}$ in the April 30, because of increased weeds caused by a low weed control. Effects of barley cover crop at same seeding with rice was ranged from 77~87% of control. The economic effect of barley as cover crop was analyzed to be increased by low herbicide using, despite of the slight decrease in rice yield during the period.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.615-626
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• 2020

The objective of present experiment was to examine the impact of different organic nitrogen (N) fertilizer application rates and different harvesting periods on the forage yield and feed value of kenaf (Hibiscus cannabinus L.). This study was carried out from May to September 2019, the amount of 80 kg of kenaf seed/ha were applied with different rates of nitrogen fertilizer. The plants were sampled at 10 days intervals (100, 110, 120, and 130 days after seeding) from different harvesting dates. In the organic fertilizer treatments, the highest dry matter (DM) yield was observed in the application rate at 250 kg of N/ha. Crude protein (CP) content in leaves was similar between the organic fertilizer rates at 200 and 250 kg of N/ha and were higher compared with other fertilizer treatments. The highest CP content in the stem was 4.3% in the organic fertilizer application rates st 250 kg of N/ha. Neutral detergent fiber (NDF) in leaves showed no significant difference between the chemical fertilizer rates at 200 and 250 kg of N/ha, and the organic fertilizer rates at 150 and 250 kg of N/ha. In addition, DM yield of kenaf was highest in the harvest of 100 days after seeding, and tended to decreased significantly with increase of harvesting periods (p<0.05). As the growth progressed, the plant height and stem ratio increased but the leaves ratio decreased significantly (p<0.05) and the highest was found at 110 days after seeding. The highest CP, Acid detergent fiber (ADF), NDF and total digestible nutrient (TDN) contents in leaves were 13.9, 25.4, 40.5 and 71.1%, respectively that were affected by different harvesting periods. Also, the ADF and NDF in stem increased significantly with increase of kenaf maturity (p<0.05). In conclusion, the optimal organic fertilizer application rates and the proper harvesting periods for the forage yield and quality of kenaf were at 200 to 250 kg of N/ha, and 100 to 110 days after seeding, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.11
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• pp.1-9
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• 1972

For a measure against late transplanting, this experiment was conducted to investigate a reasonable seeding rate in nursery bed and a proper nursery size. The treatments applied to this experiment are as follows a) seeding rates: 0.2ι, 0.4ι and 0.6ι per 3.3$m^2$ b) nursery sizes. for 10a-field area: 39.6$m^2$, 49.5$m^2$ and 59.4$m^2$ c) transplanting dates: June 5, June 25 and July 15. The seeding date was April 26 and planting density was determined by the number of sound seedlings based on the combination of seeding rate and nursery size. The results may be summarized as follows: 1. In seedlings both increased nursery period and decreased seeding rate showed a remarkable-increase in plant height, number of leaves, dry matter weight and the ratio of dry weight to plant height. But their number of tillers and live leaves did not show such tendency. 2. Delayed transplanting date shortened culm length and panicle length as well as number of days from transplating to heading and it also delayed heading date. On the other hand the transplanting of 80-day seedlings resulted in premature heading. 3. As a result late transplanting reduced number of spikelets per panicle, maturing rate and 1000-grain weight. In the last analysis it linearly reduced grain yield. The decreasing rate of yield by late transplanting was 15.6% in June 25 plot and 41. 3% in July 15 plot, compared with the yield in June 5 plot. Such a remarkable decrease in yield of the extremely late transplanted plot was mainly due to markedly decreasing number of spikelets per panicle and 1000-grain weight. 4. Both increased seeding rate and nursery size gave a rise in number of tillers per unit area as well as number of transplanting hills but gave a fall in culm length and panicle length. 5. Accordingly, though thick seeded - dense planted plot increased number of panicles per unit area, decrease in number of spikelets per panicle and 1000-grain weight made no differences in yield between thick seeded - dense planted plot and thin seeded - sparse planted one. However, the yield in the thick seeded - dense planted plot transplanted on July 15 was reduced owing to the remarkable decrease in maturing rate and 1000-grain weight. 6. We came to the conclusion that as a measure against the extremely late transplanting the suitable seeding rate was 0.4ι per 3.3$m^2$ and the proper nursery size was 59.4$m^2$ for 10a-field area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.419-427
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• 2021

In South Korea, direct seeding of rapeseed (Brassica napus L.) is difficult during spring cultivation in early March because of the low yield production associated with late flowering and poor seed quality. To compare the period of direct sowing, the present study investigated the growth characteristics of rapeseed according to planting dates. Specifically, 35 day-old seedlings were transplanted or directly sown on four different dates (late February, early March, late March, and early April) in 2020 and 2021. As the planting date was delayed, the days to flowering of rapeseed decreased. Similarly, the plant height, seed set percentage, and seed yield of rapeseed were reduced upon delay in planting. The seed yield of rapeseed through direct seeding in late February was the highest, 2.76 ton·ha^-1. On all seeding dates, except for late February, the transplanted rapeseed produced a higher yields than the directly seeded rapeseed. The crude oil and oleic acid content, which is related to the quality of rapeseed, decreased with the delay in planting dates, and this decrease was greater, with the direct seeding of rapeseed depending on the sowing time. In the correlation analysis, the planting date was significantly and negatively correlated with the yield, crude oil content, and oleic acid content of the transplanted rapeseed, while the sowing date was negatively correlated with the plant height, silique size, yield, and seed quality of the directly seeded rapeseed. Finally, the effect of planting date on rapeseed growth was stronger in direct seeding than in transplanting. Therefore, during spring cultivation after late February to early March, transplanting, rather than direct seeding, in more advantageous in terms of seed quality and yield.