• Korean Journal of Medicinal Crop Science
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• v.4 no.2
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• pp.163-171
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• 1996

The influences of temperature, harvest time, sowing time, seeding media, moisture content of media and light on the seed germination of Lycoris are as follows, Both L. koreana and L. aurea had over 90% seed setting, and seed maturity came in September or early October. It took six months to have over 60% seed germination. The optimum germination temperature was $25^{\circ}C$, and the alternating treatment was effective at $20{\rightleftarrows}25^{\circ}C$. The optimum harvest-time was around Sep. 20, and the optimum seed-time was immediately after havest. The optimum seeding media was sand loam, and the optimum moisture content was PF 1. 9/400ml seeding media. The dark condition was more effective for the seed germination than the light condition.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.311-316
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• 2013

This study was conducted to evaluate the efficacy of two different formulations and application timings of benzobicyclon+penoxsulam+pyrzaosulfuron-ethyl (BPP) in rice field. BPP granule (GR) and tablet (TB) controlled more than 90% of four weed species 10 and 15 days after sowing in direct seeding when compared with untreated control. BPP TB was highly effective to control herbicide resistant Scirpus juncoides and Monochoria vaginalis both 10 and 15 days after transplanting (DAT). BPP GR controlled 94.0 and 96.5% of S. juncoides and M. vaginalis, respectively 10 DAT, but its efficacy decreased to 88.5 and 49.8% respectively 15 DAT. When compared with untreated control, no visual injuries were detected at 255 and 510 g a.i./ha of BPP. The yield of rice increased in both BPP GR and TB in transplanting and direct seeding rice cultivation when compared with untreated control. Based on these data, early application (10 DAT) of BPP GR and TB can be applied to provide effective weed control, especially in the field infested with herbicide resistant weed species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.5
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• pp.395-400
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• 2001

We investigated the variations of the flowering response to daylength in Perilla crop (var. frutescens). Seventeen accessions of Perilla crop and one accession of weedy type of var. crispa from China, Korea and Japan were cultivated under three daylength conditions, i.e., short-days, natural daylength and long-days. Most accessions of Perilla crop from China, Korea and Japan were divided into three types, early maturing type, intermediate maturing type and late maturing type by their natural flowering habit. In most of the accessions used, the flowering habit was significantly accelerated by short-day conditions and was delayed by long-day conditions. All the accessions of Perilla crops flowered within 57 days under the 10 hrs light treatment, whereas they did not flower at all even at 170 days after sowing under the 16 hrs light treatment. Thus, this finding suggested that there is a relationship between the types of flowering response to daylength and the geographical distribution which determines the planting season in traditional cultivation practices of Perilla crops. Positive correlation was observed between days to flowering and plant height or internode number in both the short-day and natural daylength conditions. Whereas, correlation was negative between days to flowering and inflorescence length or floret number in natural daylength condition, but it was positive in the short-day condition. Therefore, the daylength condition is considered as the most important environmental factor for flowering habit and morphological characters of Perilla crops. Flowering habit is considered as an important key character for the study of geographical differentiation of Perilla crop in East Asia.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.149-153
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• 1999

Prediction of rice developmental stage is necessary for proper crop management and a prerequisite for growth simulation as well. The objectives of the present study were to find out the relationship between the plastochrone index(PI) and the developmental index(DVI) estimated by non-parametric phenology model which simulates the duration from seedling emergence(DVI=0) to heading(DVI=l) by employing daily mean air temperature and daylength as predictor variables, and to confirm the correspondency of developmental indice to panicle developmental stages based on this relationship. Four japonica rice cultivars, Kwanakbyeo, Sangpungbyeo, Dongjinbyeo, and Palgumbyeo which range from very early to very late in maturity, were grown by sowing directly in dry paddy field five times at an interval of two weeks. Data for seedling emergence, leaf appearance, differentiation stage of primary rachis branch and heading were collected. The non-parametric phenology model predicted well the duration from seedling emergence to heading with errors of less than three days in all sowings and cultivars. PI was calculated for every leaf appearance and related to the developmental index estimated for corresponding PI. The stepwise polynomial analysis produced highly significant square-rooted cubic or biquadratic equations depending on cultivars, and highly significant square-rooted biquadratic equation for pooled data across cultivars without any considerable reduction in accuracy compared to that for each cultivar. To confirm the applicability of this equation in predicting the panicle developmental stage, DVI at differentiation stage of primary rachis branch primordium was calculated by substituting PI with 82 corresponding to this stage, and the duration reaching this DVI from seedling emergence was estimated. The estimated duration revealed a good agreement with that observed in all sowings and cultivars. The deviations between the estimated and the observed were not greater than three days, and significant difference in accuracy was not found for predicting this developmental stage between those equations derived for each cultivar and for pooled data across all cultivars tested.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.279-284
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• 2008

This study carried out to investigate the variation of flavonoids contents in mungbean (Vigna radiata L.) according to plant parts, harvesting time, growth stage, and sowing time. Vitexin and isovitexin were found only in the seeds but not in the leaves, petioles, stems, and roots. Vitexin and isovitexin in seeds were detected only in the seed coat at concentration of 51.1 and $51.7\;mg{\cdot}g^{-1}$, respectively, but not in the cotyledon. There were no differences in the content of vitexin and isovitexin in mungbean seeds according to early, recommended and late harvesting times. Rutin in leaves was isolated and identified as a functional substance. The content of rutin was the highest in the leaves and higher in the order of petioles and stems. However, there was no rutin in the seeds, roots, and pods. The highest rutin content in the leaves, petioles and stems was observed at the 3rd leaf stage, which was higher in the order of the 5th and 7th leaf stage.

• Korean Journal of Environmental Agriculture
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• v.19 no.1
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• pp.58-61
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• 2000

This study was conducted to determine the effect of low dose ${\gamma}-ray$ on the germination rate and physiology of germinative seeds of welsh onion ( Allicm fistulosum L. cv. Sukchangwoidae ) and spinach ( Spinacia oleracea L. cv. Chungrok ). The germination rate of irradiation group was much higher than that of the control. Especially it was noticeably higher in 1 or 2 Gy irradiation groups in the sowing spinach seeds on paper towel. On the welsh onion, the germination rate of the 1 Gy irradiation group increased by 17% compared to that of the control. Ion leakage from seeds irradiated with low dose of ${\gamma}-ray$ was decreased compared to that from the control especially at the early stage of incubation when examined by means of electric conductance. This tendency was confirmed in seeds of welsh onion and spinach. Starch hydrolysis was stimulated by ${\gamma}-ray$ irradiation in welsh onion. Furthermore ${\gamma}-ray$ irradiation was beneficial to keeping the vitality of seeds as determined through decarboxylation of glutamic acid.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.541-549
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• 1992

Lodging and rainfalls during ripening periods and ripening patterns were studied by the different maturing varieties and different seeding dates in labour saving-direct seeding cultivation of rice. Period of emergency in earlier seeding plot was longer than later seeding plot and standing seedlings per unit area and rate of standing seedlings were more and high by the later seeding date. Number of panicles per unit area was decreased by the later seeding dates. On the other hand, the rate of effective tillers was lowest at later seeding plot. Days from seeding to flowering were shortened by the later seeding dates due to the increase of daily growth temperature and reduce of day length. There was much rainfalls during ripening period of early maturing varietal group, however not much rainfalls during ripening period of medium and late maturing varietal groups. The degree of lodging at field was severer by the amount of rainfalls during ripening period. Earlier seeding plots and earlier maturing varietal groups. of used varieties were revealed heavier lodging compared to later seeding plots and later maturing varietal groups. Yield and yield related characteristics were high and good by the earlier seeding dates, especially ripening rate was clear.

• Journal of Bio-Environment Control
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• v.9 no.3
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• pp.146-150
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• 2000

This study was conducted to investigate the effect of seedling age on quality and yield in bag culture of sweet pepper. Seedlings of 20, 30, 40, 50, and 60 days old were compared. 60 days old seedlings grew faster than 30 or 40 days old seedlings. Mean days to bloom after sowing was fastest as 48 days in 30 days old seedling, followed by 20 days old seedlings. Rot activity was higher in 20 or 30 days old seedlings. Number and length of first lateral roots with thickness of 1.5mm or less, reached to 106.5 and 1.085 cm, respectively in 30 days old seedlings. Root weight, root length, and number of primary lateral roots were the greatest in 30 days old seedling. Greater early yield a obtained in 50 and 60 days old seedling, while late yield was grater in 30 or 40 days old seedlings.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.600-606
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• 2014

The objective of this study was to determine the effects of seedling ages of scions and rootstocks for grafting and light intensity during their cultivation in a closed transplant production system on the growth and development of grafted cucumber transplants. Cucumber scions and rootstocks were cultivated under 5 photosynthetic photon flux (PPF) levels: 100, 140, 180, 230, and $280{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in a closed transplant production system. The scions were grafted onto the rootstocks at 8, 9, 10, 11, and 12 days after sowing (DAS). Hypocotyl length of scions and rootstocks decreased significantly as PPF increased, and an increase in dry weight with increasing PPF was more pronounced in scions. After grafting, cucumber transplants were grown in a greenhouse until 22 DAS and were then transplanted for investigation of their growth and development. Plant height, leaf area, and fresh weight of cucumber transplants grafted at 8, 9, and 10 DAS were greater, but light intensity during cultivation of scions and rootstocks did not significantly affect the early growth of cucumber transplants after grafting. The number of female flowers in grafted cucumber after transplanting was highest when scions and rootstocks were cultivated under PPF 140 and $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and were grafted at 8 DAS. These results indicate that controlling environmental conditions in a closed transplant production system during the production of scions and rootstocks can advance grafting time and promote the growth and development of grafted cucumber transplants.

• Korean Journal of Plant Resources
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• v.19 no.6
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• pp.680-686
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• 2006

This experiment was conducted on wild vegetables; Gondalbi (Cirsium setidens), Deoduck (Codonopsis lanceolata Trautv.), and Jandae (Adenophora triphylla var. Joponica Hara) seed to study whether priming with deep sea water results in enhancement of seed germination and identify the optimum concentration of the priming solution, and duration of priming. Seeds were primed with 5 various concentrations (5%, 10%, 15%, 20% and 30%) of deep sea water (DSW) in 12 hours, 24 hours, and 48 hours at $24^{\circ}C$. Since Jandae had seed dormancy, it was kept for four weeks in refrigerator at $2^{\circ}C$ after priming treatment. In Deoduck, 5 percentage DSW priming significantly improved the early germination percentage, radicle length, and plumule emergence percentage. Among the priming period of treatments, 24 hours priming showed better performance in this treatment whereas, in Jandae, 12 hours priming with 10 percentages DSW significantly improved the germination percentage and germination rate. This treatment had increased the final germination percentage by 54%, 15% and 40% compared with control, plain water and $KNO_3$ priming respectively. But in Gondalbi, priming did not improve the germination of seed. However, among the priming treatments, 12 hours priming with 3% $KNO_3$ and 20% DSW gave better performance. In both the wild vegetables; Deoduck and Jandae, priming in deep sea water had improved the germination percentage and germination rate as compare to plain water, $KNO_3$, and without priming treatment. Hence the best seed priming treatment on Deoduck and Jandae are 24 hours with 5% DSW and 12 hours with 10% DSW respectively.