• Journal of Ginseng Research
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• v.37 no.2
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• pp.254-260
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• 2013

Greenhouse and field experiments with American ginseng (Panax quinquefolius L.) stratified seed sown at depths of 10 to 100 mm were carried out to determine effects of seeding depth on seedling emergence, growth and development and to calculate optimum seeding depth. The time to 50% seedling emergence ($E_{50}$) in the field increased linearly from 17 d at 20 mm seeding depth to 42.5 d at 80 mm. Seedling emergence and root weight (economic yield) at the end of the first year each increased quadratically with the increase of seeding depth. Maximum emergence and root yields were produced at sowing depths of 26.9 and 30.6 mm respectively. In a greenhouse pot experiment, increasing seeding depth from 10 to 100 mm increased partitioning of dry matter to leaves from 23.6% to 26.1%, to stems from 6.9% to 14.2%, and decreased dry matter to roots from 69.5% to 59.7%. Optimum seeding depth was 31.1 mm for a corresponding maximum root weight of 119.9 mg. A predictor equation [X (seeding depth, mm)=Y (seed weight, mg)/9.1+20.96] for seeding depth for ginseng, based on data for ten vegetable crops, their seed weights and suggested seeding depths, predicted a seeding depth of 28.3 mm for ginseng similar to that reported above for most pot and field experiments.

• Journal of Ginseng Research
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• v.12 no.1
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• pp.68-75
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• 1988

Yields of ginseng seedlings and cultivation methods were investigated in 29 Ban-Yang-Jik (semimodified soil) nurseries to obtain some information about the production of ginseng seedling. The average number of available seedlings (useful for transplanting in the main field) per Kan ($180{\times}90$ cm) was 362. The percentage of available seedlings to the total seedlings harvested (rate of available seedlings) was 45 %. Although there were severe variations in the numbers and rates of available seedlings among the nurseries surveyed, the number of available seedlings were reduced due to both the short weighted and poor shaped (obese shape with poor root development) seedlings. The number of poor shaped seedlings was negatively correlated with height of seed-bed and frequencies of irrigation. Quadratic relations were noticed between rate of available seedling and heights of front post and rear post of shade. On the other hand, negative correlation was recognized between rate of available seedling and breadth of shade, but positive correlation was noted between rate of available seedling and frequencies of irrigation.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.415-422
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• 2001

A seedling pick-up device for vegetable transplanters was developed and its work performance was evaluated at the laboratory. The pick-up device extracts seedlings from a 200-cell tray of seedlings and transfers them to the place where they are to be transplanted into the soil. The device consists of a path generator, pick-up pins and a pin driver. The path generator is a five-bar mechanism comprised of a fixed link, a driving link, a driven link, a connecting link and a slider. The slider is constrained to move along the driven link and a fixed slot of combined straight-line and circular paths. The connecting link joins the driving link and the slider. When the slider moves along the straight-line path of the slot it takes seedlings out from the cell and transfers them to the transplanting hopper when moving along the circular path. A proto-type of the pick-up device was built and tested under the various operational conditions such as age of seedling, approach direction and penetration depth of pins to the cell, holding method of seedling and extracting velocity. The device extracted 30 seedlings per minute with the maximum success ratio of 97% using the seedlings of 23 days old. Some design details were also discussed and suggested to enhance the performance of the device.

• 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.

• Journal of Ginseng Research
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• v.11 no.2
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• pp.111-117
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• 1987

The phase and times on the development of dormancy bud in seedling, and those of flower organs in 2-year-old ginseng are different to those of over 2-,3-year-old plant, respectively. The growing aspects of dormancy bud in seedling were investigated from rooting stage (April, 8) to Mid-June, and those of flower organs in 2-year-old plant had done once in two days late in April after compound leaves were unfolded. Firstly, the formation of dormancy bud in seedling was begun on Mid-late in March. This is early about one month compare with those of over 2-year-old plant. Fine bud in seedling was formed between cotyledons, at W spot under young shoot. Secondly, development of flower organs in 2-year-old plant was completed from late of April to early of May after compound leaves of transplanted plant were unfolded. In tare, this is very different characteristics because plants of any other ages form the flower organs one year ago. Thirdly, flower organs of ginseng plant, over 3-year-old plant, always develop in the rhizome formed one year ago, but those of 2-year-old plant develop in apical shoot meristem.

• Journal of Korean Society of Forest Science
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• v.84 no.3
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• pp.306-318
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• 1995

To investigate the effect of low light intensities and the inoculation of Frankia and/or Alpova diplophloeus on the symbioses development and their host growth, red alder(Alnus rubra Bong.) seedlings were grown in an air - filtered walk - in growth chamber with either $N_2$ - fixing Frankia inoculation or N - fertilization and live or dead spore inoculation of the ectomycorrhizal fungus A. diplophloeus(Zeller & Dodge) Trappe & Smith. When they were 20 weeks old, the seedlings were grown under three levels of light intensities of 680, 320 and $220{\mu}mol/m^2/s$ PPFD(photosynthetic photon flux density) for three weeks. PPFD of 220 significantly decreased the development of A. diplophloeus mycorrhizae and nodules, the rates of $N_2$ - fixation and $CO_2$ exchange, and the growth of tile seedlings. PPFD 320 significantly decreased the $CO_2$ exchange rate only. Frankia inoculation significantly increased mycorrhiza formation and seedling growth. Alpova inoculation significantly increased seedling growth but not nodule development and $N_2$ - fixation. None of the symbionts affected $CO_2$ exchange rates. Frankia was more critical for seedling growth and mycorrhizal development than the mycorrhizal fungus for seedling growth and nodule development.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.258-263
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• 1997

The result was summarized of basic test and field test to find what quantity of irrigation, what state of compaction and what size of transplanting hopper could induce the optimum taking root in the transplantation of plug seedling by transplanters, and thus acquired the basic data for the development of the related transplanters and the optimum growth and development control. Livability of vegetables after transplanting had no significant difference with respect to for the size of hopper, but was greatly affected by the length of seedlings. The longest possible length of seedling for transplanting and optimal length were found to be 30cm and 28cm, respectively. For irrigation when transplanting red pepper or Chinese cabbage it was thought that large-sized hopper was appropriate. The livability of plug seedling 10 days after transplantation was mainly affected by soil moisture content. Consequently it was thought no irrigation would be needed when transplanting at the soil moisture content of more than 18% ; irrigation of more than 50cc would be needed at the soil moisture content of 13% : initial irrigation of more than 100cc and subsequent irrigation would be needed at the soil moisture content of less than 3.8%. The improvement of soil compaction method (left and right side compaction) with conventional semi-automatic transplanter was not necessary, since there was no difference in livability depending on the compaction methods, left-right side compaction or back-forth-left-right side compaction.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.381-390
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• 2018

This study was conducted to examine the growth characteristics of seedlings of several major fruit vegetables and compare them between plants grown with the conventional plug seedling system (Plug) and those grown with the cylindrical paper pot system (CPP). There were no significant differences in shoot growth characteristics, such as plant height, leaf area, dry weight, and fresh weight, between tomato, cucumber, and watermelon plants grown with the CPP and Plug systems. The total root lengths of tomato and cucumber plants grown with Plug were longer than those grown with CPP at the beginning of seedling growth, and the total root lengths of watermelon grown with Plug were longer than those grown with CPP throughout the whole seedling period. The length of root that separated five steps according to the diameter of the root of tomato did not differ between CPP and Plug, but those of cucumber and watermelon were 20-251% longer with Plug than with CPP for all kinds of roots. The fresh weight of Plug-grown tomato roots was about 30% heavier than that of CPP-grown tomato during the seedling period, but the difference decreased as growth progressed. Finally, there was no difference between plants before and after transplanting. The fresh weights of the Plug-grown plants were about 20-30% heavier than those of CPP-grown ones in terms of the whole seedling. After transplanting to the Wagner pot, the shoot growth of Plug-grown watermelon plants in terms of dry weight was low until 7 days had passed. However, this tendency was reversed from 8 days after transplantation onward. In conclusion, there were no significance differences in the growth of shoots between plants grown with the CPP and Plug systems. However, root development was better with Plug than with CPP.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.719-726
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• 2016

The effect of high and low temperatures on seedling quality while raising of paprika (Capsicum annuum L.) seedlings, and their early development after planting was investigated. The control raising seedling temperature (RST) was $23^{\circ}C$; high temperature, $31^{\circ}C$; and low temperature, $15^{\circ}C$ throughout the raising seedling period. At $15^{\circ}C$ and $30^{\circ}C$, plant height, stem diameter, fresh weight, dry weight, number of leaves, and seedling leaf area were significantly lower than those at $23^{\circ}C$. At 4 weeks after planting, seedling's growth characteristics showed a similar pattern. Compared to $23^{\circ}C$, seedlings raised at $15^{\circ}C$ and $30^{\circ}C$ had an increased dry weight and leaf area per unit time after planting than during the seedling raising period. At 4 weeks after planting, crop growth rate and leaf area index were unaffected by RST, and relative growth rate and net assimilation rate at RSTs of $15^{\circ}C$ and $31^{\circ}C$ were higher than those those at RST of $23^{\circ}C$. At an RST of $15^{\circ}C$, growth speed and net assimilation rates were higher after planting than before planting, according to increased photosynthetic rate. Thus, high and low temperatures during the seedling raising period significantly reduced seedling growth and plant growth after planting. After planting, seedlings raised at $15^{\circ}C$ recovered more quickly than did those raised at $31^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.3
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• pp.199-203
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• 1990

Effect of a trial compound fertilizer for raising rice seedling in tray, was tested on varieties of Chucheongbyeo and Taebekbyeo and on soil media pH of 6.4 and 5.4. The trial product increased dry weight, number of leaves, and ratio of dry weight to plant height and decreased damping-off incidence. The soil media pH of 6.4. applied trial product, maintained pH 4.0 to 5.4 for seedling period, but the soil media pH of 5.4 was too lower. The nitrogen uptake by rice seedling in the trial product plot was lower at 15 days after seeding compared to the control of straight fertilizer application, but it was higher and 35 days after seeding, resulting in optimum rice seedlings.