• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.213-219
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• 2004

Soybean plants were exposed to HTO vapor in an exposure box for 1 hour at different growth stages. Relative concentrations of TFWT at the end of exposure (percent ratios of TFWT concentrations to mean HTO concentrations in air moisture in the box during exposure) decreased on the whole in the order of leaf > shell > seed > stem with the highest values of 40.2% and 6.4% for leaf and stem, respectively. TFWT concentrations reduced by factors of several thousands to several hundred-thousands from the end of exposure till the harvest. The reduction factor decreased in the order of leaf > shell > seed > stem. Relative OBT concentrations at harvest (ratios of the OBT concentration in the dry plant part at harvest to the initial leaf TFWT concentration, ml $g^{-1}$) were in the range of $2.2{\times}10^{-5}{\sim}9.5{\times}10^{-3}$ for seeds being the highest when the exposure was performed at the actively seed-developing stage. The exposure time-dependent variation in the OBT concentration was much greater in seeds and shells than in leaves and stems. It was indicated that OBT would contribute to almost all the radiation dose due to the consumption of soybean seeds in most cases after an acute exposure of growing plants to HTO vapor. Present results are applicable to establishing and validating soybean $^3H$ models for an acute accidental release of HTO.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.340-343
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• 2006

This study was conducted to find out the effect of rainfall time on growth and seed quality in safflower. Rainfall was done artificially and the treatment of rainfall time was divided into 6 parts. Each rainfall treatment was done from the first day of flowering up to the fifth day after flowering, from sixth day after flowering to the tenth day after flowering, from the eleventh day after flowering to the fifteenth day after flowering, from sixteenth day after flowering to twentith day after flowering, from the twenty first day after flowering to the twenty fifth day after flowering and from twenty sixth day after flowering to thirtith day after flowering. Rainfall time after flowering did not affect disease occurrence on the upper part and flower bud of safflower, which were infected at were 3.3 and 1, respectively. Ripened grain found on the main stem and primary branch was 37.4% and 65.0% at first day to the fifth day and sixth day to the tenth day rainfall periods after flowering, respectively. Yield was decreased by 14% in the sixth day up to the tenth day and eleventh day up to the fifteenth day rainfall periods (282-281kg/10a) compared to the one under control (327kg/10a). Hunter's L value was 73.5 and 69.9 in twenty first up to the twenty fifth day and twenty sixth up to the thirtith day rainfall periods after flowering, which decreased significantly to 79.3 under non-rainfall period. Therefore, it can be concluded that the optimum harvest time is twenty fifth day after flowering to maintain seed quality at rainfall time and before harvesting period.

• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.9-18
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• 2003

Rice plants at different seed-developing stages were exposed to HTO vapor in an exposure box for 1 h during daytime and nighttime to investigate the levels of tissue free water $^3H$ (TFWT) and organically bound $^3H$ (OBT) in different plant parts. In the daytime experiment, TFWT concentrations in leaves at the end of exposure $(h_0)$ were around 100% of the 1 hour mean HTO concentrations in air moisture whereas in the nighttime experiment, they were as low as $30{\sim}40%$ of the air concentration. TFWT concentrations in both experiments decreased very rapidly in the beginning but much mote slowly later and those at harvest were hundreds to hundred thousands times lower than those at $h_0$. OBT concentrations varied with time in different manners depending on plant parts and exposure times and differed between at $h_0$ and at harvest by factors of less than 10 on the whole. Even during nighttime exposures, OBT was produced at about a third the rate for daytime exposures. The degree of the conversion of airborne HTO into OBT in mature rice seeds, being several times higher in the daytime experiment than in the nighttime experiment, was highest after the exposure peformed at the most actively seed-developing stage for both experiments. It is estimated that OBT would contribute much more to the ingestion radiation dose than TFWT if rice plants are exposed to HTO vapor for the seed-developing period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.2
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• pp.225-230
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• 2009

This study was conducted to response the growth, seed yield, nitrogen content and different cation content of two soybean, flooding-tolerant cv. Pungsannamulkong (PNSK) and flooding-sensitive cv. Tawonkong (TWK) when these were subjected to flooding stress at R1 stage for cultivation in paddy field. Flooding, underground water levels (UWL) of 0 cm, 10 cm and 40 cm, was experimented from flowering time to harvest time. The dry matter and seed yield of soybean with UWL of 0 or 10 cm declined in comparison with UWL of 40 cm and these were more reduction in TWK than in PNSK. The amount of nitrogen uptake decreased in higher UWL and there was a high significant relationship $(R^2=0.872)$ between nitrogen content and seed yield at flooding stress. K content of leaf and stem in soybean plants had a small change with UWL but Ca content had a decrease (leaf and stem) or increase (root). Mn and Fe content were increased at higher UWL and were more in TWK than in PNSK.

• Korean Journal of Plant Resources
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• v.33 no.2
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• pp.86-92
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• 2020

This study was conducted to analyze ripening characteristics of the seed according to days after flowering. The seeds were harvested on land located in the Department of Herbal Crop Research in Rural Development Administration in 2019. Seed weight and germination rate were investigated according to days after flowering and the embryo:seed ratio was examined during the fruiting process. The results showed that the weight increased significantly by the days after flowering at each inflorescence and the seed began to germinate at different time. Further, given the embryo:seed ratio, we found that embryo continue to grow in the seed. Because Angelica acutiloba (Siebold & Zucc.) Kitagawa bloom in various inflorescences, the stage of embryonic development of the seeds can affect the germination of seed. Based on our results, the key seed harvest period for good seed is 50 to 70 days after flowering.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.540-544
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• 1991

Pod dehiscence in six rape varieties drying after harvest in the field was investigated with use of strain gauge. The development of rape pods was observed after 3-4 days of flowering. The length of pod and seed reached of their maximal size at the 20th and 35th days after flowering, respectively. The seed shape was nearly spherical 40 days after flowering, and pod width was maximal at the 45th days of flowering. Moisture content of seeds was 70% at cutting time, reduced to 30% at 5 days of drying in the plastic film house and 10% at 14 days. Pod dehiscence showed a diurnal change with moisture content of pods and relative humidity, and the dehiscence became difficult under low moisture content of pods and relative humidity of which seems to be related to the rapid drying condition of pod.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.34-41
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• 2008

This study was conducted to investigate antioxidant component content during maturity for judgement of optimum harvest time in black soybean. For high-functional black soybean production, accumulation pattern of isoflavone and saponin contents and anti oxidative activity according to maturity stage were investigated. Varieties used in this experiment were Ilpumgemojeongkong and heukcheongkong, which are the recommended black soybean in Korea. Isoflavone and saponin contents during maturity period in black soybean was the highest at $6{\sim}7$ days earlier than general harvesting time. It was indicated that optimum harvesting time for high quality soybean were $3{\sim}7$ days earlier than harvesting time for higher yield. As a result of investigation about accumulation pattern of antioxidant components by maturity stages in seed, total isoflavone content was the highest at 61 DAF in Ilpumgeomjeongkong and at 77 DAF in Heukcheongkong. Contents of total saponin were the highest at 61 DAF and at 71 DAF, respectively. In case of leaf, total isoflavone content was the highest at 55 DAF in Ilpumgeomjeongkong and Heukcheongkong. Contents of total saponin were the highest at 18 DAF and at $55{\sim}71$ DAF, respectively. It showed that black soybean's leaf could be developed as a new health food material, owing to high contents of antioxidant components and biological activity and it's suitable harvest time was at $R_7$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.260-264
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• 2009

Sufficient seedling establishment of Chinese milk vetch (CMV) is the most important factor in the CMV cultivation. In order to obtain sufficient seedling stand, CMV seed should be planted at right seed planting date. An optimum CMV seed planting time for stable seedling establishment was determined based on the final water drainage time for rice harvest in fall. Five planting times from 10 days before water drainage (DBWD) to 15 days after water drainage (DAWD) at five day interval were evaluated during the period of 2006-2007 and 2007-2008 and the optimum CMV seed planting time was determined based on seedling stand, winter survival rate, and dry matter production. CMV seedling stand before winter was high with $575{\sim}1,050\;plants/m^2$ regardless of seed planting times but after overwintering, it was greater in seed planting date between 5 DBWD to 5 DAWD than that of 10 to 15 DAWD treatments. Winter survival rate, dry matter production and seed production yield also showed similar trend to the seedling establishment. On the other hand, when CMV seeds were sowed early at 10 DBWD, seedling stand and winter survival rate were lower than that of 5 DBWD to 5 DAWD. This result indicates that an optimum CMV seed planting time based on the final water drainage could be between 5 DBWD (September 20) to 5 DAWD (September 30).

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.372-377
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• 2018

This study was investigated the effect of immature rhizome production according to harvest times-based treatment method for seed production of Gastrodia elata. The results revealed that when the tuber weight of G. elata harvested in spring (GEHS) was ${\geq}100g$, the rate of artificial fertilization, protocorm formation, and immature rhizome formation was 90.9%-94.8%, 3.1%-5.4%, and 10.1%-15.3%, respectively. When G. elata harvested in fall (GEHF) was treated at a low temperature for 4 weeks or more, the rate of artificial fertilization, protocorm formation, and immature rhizome formation was 70.4%-87.6%, 2.2%-2.6%, 8.7%-9.5%, respectively. Therefore, to produce seeds and immature rhizomes, GEHS must have tubers of more than 100 g, whereas GEHF requires breaking dormancy by low-temperature treatment for 4 weeks or more. Compared with those of GEHS, the rate of artificial fertilization, protocorm formation, and immature rhizome formation was lower in GEHF; however, it was higher than those in the natural germination state. Thus, it can be expected that G. elata can be produced throughout the year by ensuring that the seeds and immature rhizomes of G. elata are produced using a constant tuber weight and by breaking dormancy with low temperature treatment.

• Journal of Ginseng Research
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• v.26 no.1
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• pp.10-16
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• 2002

In replicated field trials, the efficacy of pentachloronitrobenzene (PCNB; quintozene) for control of damping-off of ginseng seedlings was found to be affected by timing of application and formulation. Application at the time of seeding and prior to placement of straw mulch was found to provide the moat consistent level of disease control. However, decline in plant stand during the four-year production cycle resulted in most treatments providing similar levels of plant populations at harvest. Soil residues of pentachloronitrobenzene were generally highest (1 $\mu\textrm{g}$ PCNB/g soil) in those treatments that exhibited the highest levels of disease control in the seedling year. Straw contained high levels of quintozene after application. Beet seed assays with artificially-infested soils indicated that current use rates provide an amount of product suitable for high levels of disease control.