• Korean Journal of Agricultural Science
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• v.44 no.2
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• pp.196-210
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• 2017

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia cepacia (C1) and Alcaligenes aquatilis (H6), was assessed in liquid medium and maize plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus (309.66 ?g/mL) into the medium, followed by single inoculation of B. cepacia (305.49 ?g/mL) and A. aquatilis strain (282.38 ?g/mL). Based on a plant growth promotion bioassay, co-inoculated maize seedlings showed significant increases in shoot height (75%), shoot fresh weight (93.10%), shoot dry weight (84.99%), root maximum length (55.95%), root fresh weight (66.66%), root dry weight (275%), and maximum leaf length (81.53%), compared to the uninoculated control. In a field experiment, co-inoculated maize seedlings showed significant increases in cob length (136.92%), number of grain/cob (46.68%), and grain weight (67.46%) over control. In addition, single inoculation of maize seedlings also showed improved result over control. However, there was no significant difference between single inoculation of either bacterial strains and co-inoculation of these two bacterial strains in terms of phosphate solubilization index, phosphorous release, pH of the media, and plant growth parameters. Thus, single inoculation and co-inoculation of these bacteria could be used as biofertilizer for improving maize growth and yield.

• Korean Journal of Medicinal Crop Science
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• v.20 no.6
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• pp.479-486
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• 2012

The production of adventitious roots derived from root explant of Echinacea angustifolia and its secondary metabolite content were assessed in different types and levels of auxin. The induction of adventitious roots from root explant cultured in Murashige and Skoog solid medium supplemented with 1.0 mg/L indole -3-butyric acid (IBA) attained highest as 20.87 mg fresh weight and 3.07 mg dry weight per culture but root suspension culture at the same concentration of IBA enhanced biomass production as 3.07 g fresh weight and 0.38 g per culture after 4 weeks in culture. 3.0 mg/L ${\alpha}$-naphthalene acetic acid (NAA) treatment had similar effect on root biomass production as 3.07 g fresh weight and 0.38 g per culture with liquid suspension culture, whereas adventitious roots exposed to over 3.0-5.0 mg/L IBA or 5.0 mg/L NAA were less responsive by reducing the number of adventitious roots and/or changing root morphology such as short and thick. The content of secondary metabolites such as phenolic, flavonoids and total caffeic acid in adventitious roots cultured on MS medium supplemented with 1.0 mg/L IBA were attained highest as 27.20, 9.60. 10.67 mg/g dry weight, respectively. Overall, the best production of root biomass and secondary metabolites were given by 1.0 mg/L IBA.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.269-275
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• 1999

For the purpose of sweet potato varietal improvement, yulmi, shinyulmi, gunmi, hongmi, and seonmi, whose source and sink are different, were cultivated at different planting densities, and then defoliation at initial stage of tuberous root weight increase on the relation of source and sink was observed as follows. The response of stem and leaf and tuberous root weight by planting density and defoliation rate of sweet potato varieties was different. Stem and leaf weight per m$^2$ increased along with dense planting by the following order; shinyulmi> seonmi> hongmi> gunmi> yulmi. Tuberous root number per m$^2$ was the most at 75$\times$20cm planting density, showing seonmi the most number. The number of stem and leaf and tuberous root increased along with the lowered rate of defoliation. In case of 75$\times$10cm and 75$\times$20cm planting density, tuberous root weight increased by increase of stem and leaf weight up to 50% defoliation and the difference of stem and leaf and tuberous root number was low as defoliation rate increases. The tuberous root and total dry weight matter was the most at 75$\times$20cm planting density. The increase and decrease of source synchronized with those of sink at 75$\times$10cm and 75$\times$20cm, however the relationship occurred less at 75$\times$30cm.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.49-61
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• 2001

This study was carried out to determine the effect of various fertilizer levels, sowing time and planting density on the growth and yield of Scuteliaria baicalensis GEORGE cultivated after the barley in the southern coastal areas of Korea under the non- mulching condition by direct sowing culture. The flowering date of medium dressing plot(N : P$_2$O$\sub$5/ : K$_2$O=9 : 13.5 : 9kg/10a) and heavy dression plot(N : P$_2$O$\sub$5/, : K$_2$O=12 :18 : 12kg/10a) were July 23. The flowering date of the medium and the heavy dressing plot was delayed by 3days compared with that of non-fertilizing plot. The growth characteristics such as stem length, diameter of main stem, number of branch per plant, main root length, main root length, main root thickness and dry weight of stem leaves were more increased at medium dressing plot than that of other fertilizer levels, The root dry weight of in Scutellaria baicalensis GEORGE cultivated after barley was hlghest at the fertilizing plot of N : P$_2$O$\sub$5/ : K$_2$O=9 : 13.5 : 9kg/10a. The dried-root yield was 178kg in medium dressing plot, 167kg in standard dressing pot, and 126kg in non-dressing plot, The dried-root yield of medium dressing plot was 7% and 41 cie higher than that of standard dressing pot and non-dressing control plot, respectively. Emergence and flowering dates in the sowing time of June 1 were earlier than those of the other sowing times. In the sowing time of June 1, length and diameter of main stem, number of node per main stem, number of branch per plant and dry weight of stem leaves were greater than those of sowing times of June 10 and June 20. Yield components such as main stem length and diameter, main stem numbers, branches per plant, dry weight of stem leaves, main root length and thickness, number of large root and fine root per plant, and dry weight of root were the highest at the sewing time of June 1 as the yield of 71.3kg/10a. Optimum sowing time of Scuteilaria baicaiensis GEORGE cultivated after barley was June 1 in southern areas of Korea. Stem length was long in dense planting of 20${\times}$10cm and short in spacious planting of 30${\times}$10cm and 40${\times}$10cm by direct sowing cultivated after barley. Stem diameter was thick in spacious planting of 30${\times}$10cm and 40${\times}$10cm and was thin in dense planting of 20${\times}$10cm by direct sowing cultivated after barley. Length and dry weight of root per plant were decreased in dense planting of 20${\times}$10cm and were increased in spacious planting of 30${\times}$10cm and 40${\times}$10cm by direct sowing cultivated after barley. Yield of dry root was highest in optimum planting density(30${\times}$10cm 33 plants/㎡) by direct sowing cultivated after barley. The correlation coefficient between number of planting plant and stem length showed highly positive correlation. These characters of stem diameter, number of branches, main root length and yield of dry root mentioned above showed negative correlations with planting plants.

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.09a
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• pp.21-21
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• 2019

Approximately 80% of rice field in Africa conducts in rainfed (Nishimaki 2017). The rice is damaged by water stress because fields like rainfed lowland repeat drying and humidity of soil because of impossible water control. Then water stress is one of the major limiting factors for decreasing rice yield. So, in initial growth stage, quick and efficient root development is useful way to avoid drought stress by getting water from deeper soil layer with roots elongation as the hypothesis. Daniel et al (2016) reported that NERICA1 and NERICA4 show different patterns of root plasticity for drought stress. NERICA1 has greater development of lateral root in shallow soil layer, while NERICA4 has greater development in deep root elongation to underground. This study was aimed to evaluate the effect of root development in initial growth stage on growing NERICA1 and NERICA4 under different soil moisture condition in rainfed lowland rice field. They were grown in same water condition until 35 days after sowing (35DAS), and after that each varieties were separated in dry and wet condition. The rice plants were grown until 60DAS. The results of soil moisture, the root extension angle, shoot dry weight and bleeding ratio showed that NERICA4 can mitigate dry stress from surface soil compered to NERICA1.

• Journal of the Korea Organic Resources Recycling Association
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• v.1 no.2
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• pp.267-274
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• 1993

This experiment was carried out to determine the effect of mixture ratios of worm cast and soil on the growth orchardgrass seedlings, and estimate the adequate mixture ratio of worm cast for plant growth media. Mixture ratios of worm cast and soil were 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100, respectively. The results were summarized as follows; 1. The value of dry weight of shoot(SW), dry weight of root(RW), number of tillers per plant(NT) and biological yield(BY) were the highest in the mixture with 60% of worm cast. Particularly, the dry weight distribution to root in 20%-60% mixture ratios of worm cast were higher than those grown in 80%-100% mixture ratios of worm cast, it may due to the enhancement of root growth by adquate worm cast mix. 2. The orchardgrass seedlings in the 60% mixture ratio of worm cast grown in favourable soil conditions compared to those grown in other mixtrure ratios of worm cast and soil without worm cast. The soil analysis data showed that 60% mixture ratio of worm cast contained pH 6.16, 13.84% of organic matter, 0.84% of total nitrogen, 1,413.9ppm of available phosphorus and 16.7me／100g of cation exchange capacity, respectively. 3. Biological yield(BY) indicated positive significant correlation with the dry weights of shoot(SW) and root(RW). And, the dry weight of shoot(SW) had positive correlation with the number of tiller per plant(NT) and dry weight of tiller(WT).

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.100-108
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• 1988

This research was performed to estimate the influence of relative light intensity, planting density, growth period on the growth of fresh and dry weight of the stem and branches, and root in the pretreatment transplanting bed. 1. The growth of fresh and dry weight of the stem and branches per seedling varied in the order of 63%>100%>37%>19% in relative light intensity, and increased with decrease of planting density, and grew highly during the period from May to June. The contribution rates to the growth of fresh and dry weight of the stem and branches were 49.4% and 39.6% in shading treatment, and 4.3% and 6.4% in planting density, and 34.2% in growth period respectively. Of the three factors, that is, shading, density and period, all of the interactions between two factors, and among the three factors in the growth of fresh and dry weight of stem and branches were significant. The growth of fresh and dry weight of root per seedling increased with light intensity and decreased with increase of density. The best growth of root, showed during the period from May to June in fresh weight, but during the period from July and August in dry weight of root. For the three factors, that is, shading, density and growth period, all the interactions between any two factors, and among the three factors in the growth of fresh and dry weight of root were significant.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.198-198
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• 2017

Cultivated varieties of sweet potato were from dry texture type to tender texture type on the basis of consumer preferences. There are many differences in the quantity of sweet potato, starch content, pigment, and sugar content depending on the cultivation season and area, even in the same variety. Therefore, in this study, we attempted to establish optimum time of harvesting through growth characteristics and variation in component like starch, sugar, polyphenol and flavonoid. Four sweet potato varieties were used in this experiment. Among them, Jinhongmi (JHM) & Yulmi (YM) were as dry texture type and Pungwonmi (PWM) & Hogammi (HGM) were as tender texture type. Sweet potatoes were transplanted on 23 May, 2016 and were investigated storage root weight and component contents every 20 days from 60 days to 120 days and surveyed yield at 110, 120, 130 days after transplantation. Result revealed that storage root weight of YM, JHM, and HGM were 30.1, 38.9, 20.8 g respectively in 60 days after transplanting. Storage roots of PWM gerw faster with the weight of 88.2 g. In 120 days after transplanting, storage root weight varied from 88.3 to 118.7 g, HGM was the smallest, and PWM was the largest. Sugar contents of sweet potato ranged from 21.0 to $23.8Brix^{\circ}$ in 60 days after transplanting and from 27.5 to $30.78Brix^{\circ}$ in 120 days after transplanting. In particular, the sugar content of HGM was the highest over $30Brix^{\circ}$ after 80 days. The starch content of dry texture type (YM, JHM) increased from 15.5% to 20.4% and tender texture type (PWM, HGM) increased from 11.0% to 17.3%. Starch content tended to be high in dry type sweet potatoes. The content of polyphenol and flavonoid were highest in 60 days after transplanting and was reduced according to cultivation period. The total yield of PWM was high as 3,154 kg/10a and large storage root of over 250 g accounted for 47.4% in 110 days after transplanting. Storage root (YM, JHM, HGM) of 81~150 g accounted for 34.9% ~ 43.2% in 120 days after transplanting. These are the most marketable. Because consumer in Korea prefers small, round and about 100g size sweet potato. The ratio of large storage root (over 250 g) were increased in all varieties at 130 days after transplanting. Therefore, it is considered appropriate to harvest PWM at 110 days and YM, JHM, HGM at 120 days after transplanting, which planted in late May.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.458-461
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• 1983

The field experiment was carried out in order to find out the factors affecting lodging of Korean soybean varieties. Among the variety groups which were grown under the same cultural conditions, 25 Korean local varieties were selected by 5 lodging degree, and investigated their root characteristics in relation to lodging. The results obtained were as follows; There were no significant relationships between root dry weight, number of primary roots, number of adventitious roots and lodging. There also were no clear relationships between shoot/root weight ratio and lodging. However, it was recognized that the shoot weight/number of thick roots was highly related to soybean lodging. The susceptible varieties to lodging showed less shoot/thick root ratio.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.3
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• pp.177-185
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• 1994

Slow seedling growth rate and nodulation failure of white clover (Trifolium repens L.) has been limited its good establishment to pastures. The experiment was done to determine the effect of removal of cotyledon and unifoliolate on the shoot, root growth, and nodule formation of 4 white clover cultivars for 8 weeks after the treatment. Four white clover cv. Regal (large leaf), Louisiana S-I (medium-large leaf), Grasslands Huia (mediumsmall leaf), and Aberystwyth S184 (small leaf), were grown in IOcm plastic pot containing 2:l:l soi1:sand:peat moss mixture until grown to cotyledon or unifoliolate stage and then removed one (Cl) or two cotyledons (C2) at cotyledon stage, and unifoliolate only (U), unifoliolate and one cotyledon (UCl) or unifoliolate and two cotyledons (UC2) at the unifoliolate stage, and the plants were sampled at 4, 6 and 8 weeks after the treatments. The intact plants had greater shoot and root dry weights, and no. of nodules than removal-treated ones. Removal treatments at cotyledon stage, the dry weight and no. of nodules more decreased in C1 and C2 than that of unifoliolate stage. While the severer cotyledon removal, the more reduction. Although the dry weights and no. of nodules steadily inclined with regrowing period, the former were higher in Regal and La. S-1 than in the others since 6 weeks after removal treatment but the latter was more in S 184 than in the others 8 weeks after removal treatment. Relationship between no. of nodules and shoot or root dry weight was analysed as linear mode while the earlier and severe removal, the steeper slope. It was concluded that severer damage of cotyledon and unifoliolate had detrimental effects on the shoot and root growth, nodule formation, and aftermath establishment of white clover.