• The Korean Journal of Ecology
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• v.25 no.4
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• pp.267-273
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• 2002

Regeneration process of the Korean beech (Fagus multinervis Nakai) forest was studied in relation to the distributional pattern and age structure. In this study, it was clarified that the Korean beech forest is regenerated in both way: seedlings(sexual reproduction) and sprouts(vegetative reproduction) formations. In the large gaps, seedling may be established, resulting in clusters of even-aged individuals. But in the small-sized gaps, there may filled by the extention of surrounding trees and/or by the young trunks, which have sprouted from the base of stumps. As most gaps in the F. multinervis forest were derived from falling of a single stem, regeneration by sprouts seems to be more common than that by the seedlings.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.298-305
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• 2011

This study was conducted to enhance the stem firmness of standard chrysanthemum 'Baekma' bred in Korea for commercial quality improvement and inhibition of stem breaking during transportation through foliar spray with calcium agents. Calcium agent screening 'Baekma' was examined using $CaCl_2{\cdot}2H_2O$, $Ca(NO_3)_2{\cdot}4H_2O$, and OS-Ca (natural liquid calcium compounds extracted from oyster shell) depending on each concentration (0, 0.001, 0.01, 0.1, and 1.0%, respectively). All calcium agents sprayed with 1.0% caused chemical injury such as stem bending or leaf burn. OS-Ca also showed more sensitive response to chemical injury than the other calcium agents because OS-Ca was absorbed very well by 'Baekma' leaves. Maximum stem firmness measured during the final harvest was greater in OS-Ca than in the other calcium agents. Especially, maximum stem firmness was greatest in 0.01% OS-Ca. However, elastic strength and maximum bending stress were greater in 0.001% OS-Ca than in the others. Thus, OS-Ca ranged from 0.005 to 0.05%, which did not show any chemical injury, was finally selected as the first candidate for hardening the stem of 'Baekma'. The next experiment using OS-Ca was conducted with the concentrations of 0, 0.005, 0.01, and 0.05%, respectively. From the results, 0.05% OS-Ca showed better plant growth and parameters such as plant height, stem diameter (upper and middle part), the number of leaves, and dry weights of each part than the other concentrations of OS-Ca and control. As for stem firmness depending on OS-Ca concentration, the Ca content within stem, maximum firmness, elastic strength, and maximum bending stress of stem in 'Baekma' sprayed with 0.05% OS-Ca showed the highest values among all the treatments and it turned out to be very high level of significance between control and OS-Ca treatments. However, the area and percentage of the inside cavity within horizontal stem section in 'Baekma' did not show any significance between any treatments including control. Thus, stem firmness of 'Baekma' did not show any correlation with the inside cavity area of stem. In conclusion, we recommend foliar sprays with 0.05% OS-Ca at vegetative growth stage to enhance stem firmness of 'Baekma' during transportation.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.237-243
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• 2021

The objective of this study was to evaluate the effect of stem number on plant growth, fruit quality, and yield of sweet peppers grown in greenhouses under supplemental lighting in winter. The seedlings were transplanted at 3.2 plants·m^-2 on October 26, 2020, and started supplemental lighting with 32 high pressure sodium lamps for 16-hour photoperiod from December 1, 2020 to May 25, 2021. Stems were differently trained with 2 and 3 numbers after branching nodes were developed. In the final harvest, the plant height was significantly shorter in the 3 stem-plants than in the 2 stem-plants. The number of nodes per stem and the leaves per plant were increased in the 3 stem-plants than in the 2 stem-plants, while the leaf area was less affected. There were no significant differences in the dry mass of leaves, stems, and immature fruits between the 2 and 3 stem-plants. The fruit fresh weight and fruit dry weight in the 3 stem-plants were decreased by 17% and 12% at 156 days after transplanting (DAT), and by 17% and 15% at 198 DAT compared to those in the 2 stem-plants, respectively. The marketable fruit rates were 93.6% and 95.4% in the 2 and 3 stem-plants, respectively. The total fruit yield in the 3 stem-plants was increased by 30.2% as compared to that in the 2 stem-plants. We concluded that the 3-stem-training cultivation positively affected the total fruit yield by sustaining adaptive vegetative growth of the plants. This result will help producers make useful decisions for increasing productivity of sweet peppers in greenhouses.

• Animal cells and systems
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• v.2 no.1
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• pp.55-63
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• 1998

The effects of inflorescence herbivory and flowering time on plant architecture and reproductive yields were examined with a perennial herbacious species, Vicia cracca, occurring in Natick, Massachusetts, USA. Natural herbivory on inflorescences was observed among the total of 157 plants during a growing season. Vegetative and reproductive characters were measured in the field as well as in the lab depending on the characters. Approximately 64% of the plants were subjected to herbivory on inflorescences. Plants were classified into three groups; unbrowsed plants, partially browsed, and totally browsed plants, according to the level of herbivory on inflorescences of each plant. Plants were also categorized by their flowering time such as early vs late flowering plants. Herbivores tended to favor inflorescences on rather small plants, resulting in a pattern of totally contact or partially intact inflorescences on taller plants. The mean number of stems, which was assumed to be a direct result of severe herbivory in this population, differed among herbivory groups. There also was a tendency that plants flowering late in the season had more nodes with more leaves, suggesting that herbivory on stem tips early in the season before flowering might have induced growth of side branches or branchlets along the main stems. Comparison between unbrowsed and partially browsed plants showed that the latter compensated for browsing in terms of numbers of inflorescences, fruits, seeds and seed size (weight), though they did not compensate in flower number. The probability of fruit production (presence vs absence of fruits) and seed weight declined toward the end of the season. These results suggest that resources are deficient at the end of the season. Almost complete reproductive failure in totally browsed plants is attributed to the destruction of inflorescence display and the disadvantage of small vegetative size of those plants. After all, in this population, a moderate level of herbivory on inflorescences did not reduce the maternal fitness of the plants. However, severe herbivory on inflorescences resulted in antagonistic interactions between plants and herbivores.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.555-559
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• 2001

This research was conducted to estimate the chlorophyll contents of chrysanthemum leaves using SPAD-502 chlorophyll meter under different photoperiod and light intensity. Measurements were done at every third leaf intervals starting from the top of the stem to the bottom at harvest time. SPAD value was highest at 10 hours of photoperiods, followed by 13 and 16 hours of photoperiods. In particular, under short day condition, SPAD value was highest in the young leaves below the flower bud and decreased down the leaf profile. Under long day condition, SPAD value reached maximum at leaves between $15-27^{th}$ from the top and decreased to the minimum immediately below the flower bud (youngest leaf). These results may indicate that the younger leaves become strong source of supporting flowers in reproductive stage, while the younger leaves serve as sinks and older leaves support their development in vegetative stage. Changes of SPAD value at different levels of irradiance showed that highest SPAD value were observed at high irradiance and decreased with decreasing irradiance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.490-494
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• 2003

To understand flowering response under diverse day-length condition and the movement of floral stimulus, we used six perilla accessions which showed diverse days to flowering. Though the growth phase was reported as irreversible between vegetative and reproductive stage, perilla showed reversible growth phase according to day length increase in May and June. When it sowed in March, flowering response was started in early May and vegetative and reproductive phase was coexisted in late June. When a part of a perilla plant was treated under short day condition, only apical buds on main stem or branches were flowered but other long day conditioned apical buds were not flowered. With this result it is suggested that the floral stimulus can not be transferred to other part of perilla.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.97-102
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• 2000

This experiment was conducted to investigate the changes of harvest index and the relationship between harvest index and yield determination factors by different planting times in the determinate soybean cultivars, Shinpaldal and Danbaeg. Optimum planting were 23 May in 1995 and 1996. Late planting were 13 June in 1995 and 6 June in 1996. Growth period from planting to physiological maturity (R7) was shortened as planting time was delayed in two cultivars due to shortening of reproductive growth period in Shinpaldal, and of vegetative growth period in Danbaeg. Stem weight was distinctly decreased in late planting compared to optimum planting, but seed weight of both cultivars was not different between planting times. Also, seed number per pod and harvest index were significantly increased in late planting and the high correlation was found between two factors. It was suggested that increase of harvest index in late planting would be related with high assimilate use efficiency due to increase of sink capacity. The results of correlation and principal component analysis for yield determination factors showed that main factor on yield determination was pod number per plant at R5 stage associated with dry matter accumulation during early reproductive growth period, seed number per pod and harvest index were the second factor, and one hundred seed weight was the third factor. The result of this experiment indicated that yield determination in soy-bean was dependent mainly on pod number per plant related to dry matter accumulation by early reproductive growth period, and the increase of seed number per pod and harvest index could compensate for yield decrease by shortening of vegetative growth period in late planting. Such result suggests that optimum planting date can be delayed from mid May to early June in improved soybean cultivars in Korea.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.351-361
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• 2010

The primary purposes for using fire are to enhance marsh vegetation to support waterfowl, and to manage invasive plant species. The study was conducted for two consecutive years in 2004 and 2005, investigating the effects of prescribed fire regimes on vegetation biomass in tidal brackish marsh areas of the Blackwater National Wildlife Refuge located on the eastern shore of Maryland, USA, that are under relatively similar environmental conditions. Four different burn regimes (i.e., annual burn, 3-5 year burn, 7-10 year burn, and no burn) were applied in the study. Above- and below-ground vegetation biomass samples as affected by the different burn regimes were harvested in each year for five plant species native to the marsh; Distichlis spicata, Spartina alterniflora, Schoenoplectus americanus, Spartina cynosuroides and Spartina patens. No significant difference was found either in total above-ground biomass or in above-ground biomass by species between burn regimes in 2004. However, more total above-ground biomass was produced in annual burn regime in 2005 than in the other burn regimes. There were no consistent effects of burning on vegetative biomass production by species, but it seemed D. spicata was somewhat benefited by prescribed burning for its biomass production. Moreover, the stem density for D. spicata under annual burn regime was significantly higher than that in the other burn regimes, showing some positive effects of burning on vegetation. The below-ground biomass was significantly greater in 2004 than in 2005, yet with no significant difference between burn regimes in either year. A longer-term monitoring is strongly recommended.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.358-358
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• 2017

The plant type is generally one of the most important factor for crop production and be influenced by nitrogen absorption. Soybean plants have nodules in their roots, supplying nitrogen at the vegetative and reproductive stages. Root nodules seem to effect plant type of soybean plants, but there are few reports on the relation nodules and plant type. We tried to clarify the effects of root nodules on the plant type, especially internode length and petiole length, comparing non-nodule soybean with normal soybean. The pot experiment and field experiment were carried out at Mie University and Utsunomiya University in 2015 and 2016. Enrei, a popular cultivar in central Japan, and En1282, non-nodulating isogenic line of Enrei, were used. The petiole length on main stem was measured after defoliation and internode length and yield components were measured after harvest. In the field experiment, the patterns of the final length in internode and petiole on main stem were consistent in both cultivars, and a positive correlation was found between the Nth petiole length and the N-1th internode length, belong to the same phytomere. Therefore, the petiole and internode on the main stem make similar response for environmental factors. In pot experiment, Enrei grew with the same pattern as field experiments, but in En1282, the elongation of petiole and internode in the upper part was suppressed, especially the petiole was suppressed greatly. The main stem becomes the basis of the plant type. These results were considered that the nitrogen is distributed preferentially to the internode than the petiole. It seems that the pot cultivation restricted the rhizosphere and caused nitrogen deficiency in En1282. These results suggested that the slight nitrogen deficiency provided from the root nodules was compensated by the increase of the amount of inorganic nitrogen absorption due to the expansion of the rhizosphere, and the severe nitrogen deficiency suppressed elongation of petiole and internode. It is clear that root nodules effect the plant type by supplying nitrogen to internodes and petioles.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.5
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• pp.449-460
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• 1992

The main purpose of these studies was to obtain the basic informations necessary to develop soybean varieties. Two determinate soybean varieties, Hwangkeumkong and Jangyeobkong, and two indeterminate varieties, Clark and Williams were used to study the differences in growth and yield characters. Indeterminate varieties showed 30 days longer in days from intial flowering to terminal leaf stage and increased 7-8 more nodes on mainstem after initial flowering than determinate varieties. Determinate varieties were greater at middle-upper part, while indeterminate varieties were greater in middle part for the dry weight of the pods and stem at maturity. Total dry weight per unit area was greater in determinate varieties than in indeterminate ones from the early growth to maturity. However, the duration of vegetative growth was longer and the ability to keep leaf area index in the late growth stage was higher in indeterminate varieties. Variations among plants were greater in the order of branch related characters > mainstem, total vegetative, and yield related characters > morphological characters of mains tern and 100 seed weight. In general, variations of vegetative characters formed in the early growth stage were greater than those of yield characters formed in the late growth stage. On the other hand, the variations of those characters were greater in indeterminate varieties than in determinate ones. Variation of a seed weight within a plant was much smaller in determinate varieties than in indeterminate ones : i.e. coefficients of variation of a seed weight within a plant were from 13.6 to 13.8% in determinate varieties and were from 18.5 to 21.1% in indeterminate varieties, respectively.