• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.401-404
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• 2006

In order to select the seeding machine for mechanizing cultivation of rapeseed in southern areas of Korea, three different seeding machines, ridge rotary, power tiller ridge rotary, tractor ridge rotary were used for sowing one of the high yielding rapeseed cv. Hybrid with five different seeding methods. Seeding of ridge rotary was reduced the seeding effort with 45% and yield components such as plant height, ear length, number of branches and pods, pod length and seed setting rate were higher. The seeding of ridge rotary also was showed highest seed yield. On the basis of time requirement for seeding, vegetative and yield parameters ridge rotary seeding machine was a suitable seeding machine for rapeseed cultivation at the southern area of Korea.

• Korean Journal of Medicinal Crop Science
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• v.28 no.6
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• pp.463-470
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• 2020

Background: Evaluation of transpiration is required for agricultural and environmental management applications, as crop yields and plant growth are primarily water limited. This study aimed to determine the transpiration and carbon accumulation of Cnidium officinale. Methods and Results: The transpiration of C. officinale was evaluated using weighing lysimeter. The relationship between transpiration and factors such as solar radiation, air temperature, and leaf area was assessed. Transpiration increased as the leaf area increased with the growth stage. Furthermore, daily transpiration per unit leaf area was 0.69 ± 0.16 g·cm-2·day-1 and there were no significant differences in daily transpiration during the cultivation period. The maximum transpiration was 620.6 g m-2·h-1 and diurnal changes in transpiration were highly correlated with solar radiation although the maximum transpiration was observed at the air temperatures of 20℃ - 26℃. The ratio of carbon accumulation to transpiration was 0.12%. Conclusions: Our results indicated that the transpiration of C. officinale is primarily regulated by solar radiation energy on clear days and that 97% of the water is discharged through transpiration for heat dissipation. Therefore, weighing lysimeters can measure transpiration accurately and may be useful in interpreting plant growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.25-32
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• 2019

This study was carried out to investigate the changes in fatty acid composition and phytosterol content of the autumn sowing waxy corn during its ripening period for the production of high quality and value-added fresh ears. The content of crude oil in the waxy corn kernels steadily increased with days after pollination(DAP); the crude oil content in Heukjinjuchal (HC) was higher than that in Ilmichal (IC). The composition of fatty acids according to DAP showed a statistically significant change; palmitic and linoleic acid composition gradually decreased, but oleic acid increased, and the composition of unsaturated fatty acids in HC was higher than that in IC. The phytosterol content was increased until 33 DAP, and was 937.7 mg/100g and 867.9 mg/100g in IC and HC, respectively, but there was no statistically significant difference between the varieties. The phytosterol contents in IC varied in the following order: ${\beta}-sitosterol$ > stigmasterol > campesterol, but that in HC varied in the order ${\beta}-sitosterol$ > campesterol > stigmasterol. The campesterol content did not show significant differences between the varieties, but the stigmasterol and ${\beta}-sitosterol$ content was significantly higher in HC than in IC. Palmitic, linolieic, and linolenic acid were significantly correlated with campesterol and ${\beta}-sitosterol$, and stearic acid was positively correlated with stigmasterol. Oleic acid was positively correlated with campesterol and ${\beta}-sitosterol$ but negatively correlated with stigmasterol. As a result, it was suggested that fatty acids may affect the variation in phytosterol contents during the ripening period in waxy corn.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.402-412
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• 2023

To cope with climate change, we compared the quality of naked oats (Avena sativa L.) cultivated in different regions. Naked oats were collected from domestic farms in different cultivation regions grouped as G1 and G2 for 3 years (2020-2022). The appearance, quality, and nutritional and functional compounds in the samples were assessed. In terms of appearance quality, the brightness and yellowness of the samples from the G1 region were significantly lower than those of the samples from the G2 region in 2020; however, no differences were observed between cultivation regions in the other 2 years. The results of testing the vitality of naked oats seeds showed that the electrical conductivity value was significantly lower in the samples from the G1 region than in those from the G2 region only in 2022. Among the nutritional components, moisture content was higher in the G2 region than in the G1 region over all 3 years, and the crude protein content was significantly higher in the G2 region than in the G1 region over all years. Carbohydrate content was significantly higher in the G1 region than in the G2 region in all 3 years and was inversely proportional to the crude protein content. The crude fat content tended to be significantly higher in the G1 region than in the G2 region, except in 2022. The levels of beta-glucan, a functional compound rich in naked oats, ranged between 3.4% and 4.2%, and except in 2020, there was no significant difference between cultivation regions. In addition, the content of avenanthramides, representative functional compounds that exist only in oats, was assessed. Over 2 years, in 2021 and 2022, the avenanthramide content was in the range of 2.4-20.7 ㎍/g and tended to be significantly higher in the G2 region than in the G1 region in both years. According to a survey of the average and minimum temperatures during the growing season of naked oats from 2020 to 2022, the average and minimum temperatures in January in the G2 region, which is the cultivation-limit area, were similar to those in Haenam in the G1 region. In conclusion, differences in nutritional and functional compounds were observed in naked oats grown in different cultivation areas. Therefore, considering the cultivation area of naked oats is expanding because of climate change, changes in the compounds that affect quality should be investigated.

• Korean Journal of Plant Resources
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• v.33 no.4
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• pp.245-254
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• 2020

This study was conducted for the comparison of antioxidant activities in different cultivation areas, harvest date and processing statuses in the new variety 'Sammany' of Gomchwi (Fischer ligularia). The lowland was Gangneung, 20 m above sea level, and the highland was Daegwallyeong, 750 m above sea level. The total phenolic contents, flavonoids, DPPH free radical scavenging activities, and reducing power were analyzed by freezing and drying the raw and blanched of Gomchwi leaves from April 18th to July 15th, and extracting them through in the use of methanol. Total phenolic contents, flavonoids, DPPH free radical scavenging activities and reducing power were found to be more pronounced during May than they were in the period of early harvest on April 18th in the lowland, as well as to be more effective during June than in May in the highland. Total phenolic contents, flavonoids, DPPH free radical scavenging activities, and reducing power by region, harvest date, and processing status were more effective in May than the early harvest of April in flat areas, and antioxidant activity in the highlands was elevated as of June. When compared with raw and blench leaves, raw leaves exhibited higher antioxidant activities across the board. Highland cultivation also displayed higher antioxidant activities than did lowland cultivation. Combining the above results, the 'Sammany' variety of Gomchwi was found to be more active in terms of antioxidants, which were harvested in May in flat areas and June in the highlands. Also, consuming them raw showed higher antioxidant activity than when blanched.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.191-199
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• 2003

Optimum transplanting time for extremely early rice cultivation as an after-crop of fruit and vegetables under greenhouse conditions in the southern area was determined. Rice was transplanted on March 10, March 20, March 30, April 10 and April 20 far three years from 1998 to 2000. Meteorological computations for rice production were high for heading between early May and early July, but they were too low for heading between late July and early August. Especially the expected yield predicted with 35,000 spikelets, the average spikelets per $m^2$ for extremely early transplanting. Computation for heading between late July and early August was low by 106 kg/10a compared with that yield at heading during the same period in the field. As the transplanting date in extremely early rice cultivation was earlier) rice growth at early stages was more retarded by low temperature. Rice growth at heading stage recovered with high temperature, showing less difference for the transplanting date. Abnormal tillers occurred by 15.5∼22.2%. The contribution of 1,000 grain weight${\times}$ripened grain ratio to yield of the extremely early rice cultivation in the greenhouse was 50.6%, indicating 16% hi일or than the degree of panicle per $m^2$ on yield. The estimated optimum transplanting time on the basis of yield for the extremely early greenhouse rice cultivation ranged from March 19 to April 28, and the estimated critical transplanting date on the basis of accumulated effective temperature was March 12. Rice reduced the amount of NO$_3$-N by 97.1% and EC by 90.5% in greenhouse soil with continuous fruit/vegetables fer more than a 10-year period, and completely removed the root-knot nematodes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.1-15
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• 2014

The cultivation situation of Korean wheat of 175 farmers in nationwide for two years, 2010/2011 and 2011/2012, was analyzed to obtain basic data for extension cultivated area and enhancing the self-sufficiency ratio of Korean wheat. Compared to the mean temperature and precipitation in the normal year, the mean temperature was lower before the heading stage and higher amount of precipitation after the heading stage in 2010/2011 and higher the mean temperature and lower amount of precipitation after the heading stage in 2011/2012. Average cultivation career and area were 7.7years and 2.4~3.3ha, Keumkang cv. was mainly cultivated for two years and Jokyung and Baekjoong cvs. were increased cultivation areas in southern part of Korea, Gyeongsangnam-do, Jeolllanambuk-do and Kwangju metropolitan city, including in 2011/2012. Most farmers (144) sown wheat seeds from late October to the beginning November with broadcasting method and the other famers were sown using the drill method. Average amount for basal fertilizer was 29.7 kg/10a with complex fertilizer mixed for wheat and barley cultivation, which was higher amount compared to recommended rate of fertilizer amount by rural development administration. Top dressing using nitrogen fertilizer was applied from in the late February to the beginning March. Heading date was the beginning May in 2011 and the late April in 2012, which the mean temperature from regeneration stage to tillering stage in 2011 was higher than that of 2012. Most farmers harvested wheat in mid-June and Pre-harvest sprouting and Fusarium head blight were occurred in 2011 due to the high amount precipitation during grain filling period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.80-84
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• 2002

In spite of simple and cheap cultivation method, water broadcast-seeded rice demonstrates uneven and unstable seedling establishment per unit land area and requires more herbicide and labor-input for weed control. Three experiments were conducted in a phytotron at 18$^{\circ}C$ to evaluate the adaptability of seed-mat mulching cultivation technologies in water seeded rice for the uniform seedling establishment and the inhibition of weed occurrence without herbicide application. Five different kinds of mat with different mesh sizes and fabric properties were tested. The emergence of rice was the highest in Lawn-mat treatment, being comparable with the control, in which seeds were sown without mat. The Lawn-mat also exhibited the lowest mat tension. Mat tension may influence the emergence of rice. And once it was soaked in water, it didn't maintain its original shape any more. The emergence rate of rice was the lowest in Safer-mat treatment. In Lawn-mat treatment, which was the most effective for rice emergence in the first study, the differences of emergence and seedling establishment of rice depending on the seeding position (upper, beneath, and between mats) treatments were negligible, while they were higher in dry seeds than in pre-germinated seeds treatment. The emergence as affected by the kinds of mat also showed the same trend when tested using barnyard grass. Depending on the kinds of mat, the inhibition effect of weeds was the greatest in Safer-mat and the poorest in Lawn-mat. These results strongly suggest the possibility that the uniform seedling establishment and weed management without chemical could be achieved simultaneously by seed-mat mulching through the combination of effective mat for the emergence of rice and another efficient mat for the inhibition of weed occurrence. This possibility was also tested in the field.

• Korean Journal of Medicinal Crop Science
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• v.4 no.2
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• pp.109-113
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• 1996

This study was conducted to know the effect of cultivation area with different sea levels on essential oil content and its composition and content of major active compounds in Valerian fauriei var. dasycarpa HARA and Valerian officinalis L. The total contents of essential oil were not different according to the locality in both valerian, however, its compositions were varied. The major components in V. fauriei were detected bornyl acetate and sesquiterpene alcohol in three cultivation areas. The major compounds were borneol, borney acetate, ${\beta}\;-sesquiohellandrene$ in V. officinalis other. Among the valepotrate components known as major pharaceutically active components in Europe and Nepal valerian, valtrate was detected in a small amount in V. fauriei, but its quantity was not changed according to the cultivation area.

• Korean Journal of Medicinal Crop Science
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• v.25 no.2
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• pp.102-107
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• 2017

Background: The present study was conducted to investigate the fatty acid content and habitat conditions of Glehnia littoralis in the Korean midwest region. Methods and Results: The emergence area of G. littoralis was 36.1 m from the coastline at an elevation of 4.2 m and slope of 4.3%. The soil of the habitat was sandy, the pH was 8.4, organic matter content was 0.4%, $P_2O_5$ content was 9.1 mg/kg and the content of K, Ca, Mg and Na were 0.09, 9.31, 0.43 and $0.23cmol^+/kg$, respectively. Other plants growing in this area with G. littoralis included 16 taxa. Plant with high coverage and frequency were Carex kobomugi, Elymus mollis, Imperata cylindrica var. koenigii, Lathyrus japonicus, Calystegia soldanella and Carex pumila. In the seeds of G. littoralis, the maximum fatty acid content was 65.5% oleic acid, 28.7% linoleic acid, 4.3% palmitic acid, 1.5% stearic acid, and 0.2% linolenic acid. Conclusions: In G. littoralis of Korean midwest, the scope of collection and cultivation for medicinal purposes was broad, because differences in associated vegetation, soil composition, and fatty acid content owing to habitat conditions was low.