• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.257-265
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• 2015

This experiment was carried out to determine the optimum planting density for rice pot seedling cultivation in wheat-rice double cropping system in Honam plain area. A mid-late maturing rice variety 'Chinnong' was raised in pot seedling tray and conventional tray for 30 days, and then transplanted on June 25 in 2012 and 2013. Four different planting densities (15.2, 18.9, 21.6, and 25.3 hills per $m^2$) in pot seedlings were applied as treatment. Conventional tray seedling was implicated as control at a single planting density of 27.8 hills per $m^2$. In this experiment, the number of effective tillers was increased as planting density increasing, but stem diameter was decreased. Pot seedling showed higher stem diameter and effective tillers than the control. Heading dates of pot seedling plots were not significantly different between the planting densities but 2 days faster than the control. Culm length, number of panicles, panicle length, and ripening grain ratio were higher in pot seedling compared to the control, but 1000-grain weight showed no significant difference. Milled rice yields in pot seedlings ranged from 5.19 to $5.43\;t\;ha^{-1}$, and the highest yield was observed in 21.6 hills per $m^2$. Head rice ratios in pot seedlings and the controls were not significantly different. Above results on planting density of rice pot seedling cultivation would be applicable to wheat-rice double cropping and also to late transplanting cultivation of rice single cropping.

• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.82-87
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• 2010

To investigate effects of kind of pot for raising of seedling (single plastic pot, double plastic pot, circular peat pot, square peat pot) and planting method of the pot (3/3, 2/3, and 1/3 by the buried degree of pot height) on watermelon (Citrullus lanatus) growth, this research was conducted under plastic film house. Since planting of seedlings, number, area and photosynthesis rate of leaves, plant height and weight were superior in seedling grown in double plastic pot than those grown in the others. In fruit characteristics harvested at 12 weeks after planting, fruit height, diameter and weight were longer in double plastic pot than in the others, also fruit peel thickness and hilum diameter were thicker and shorter. Initial growth of the plant after planting with seedling grown in double plastic pot was superior in method buried the 2/3 degree of the pot height than the other methods.

• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.48-57
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• 1979

In order to obtain a standard reference for designing an adequate power rice transplanter, the cutting forces depending upon variety of seedling, sowing density, seedling age and soil moisture content of mat-type seedling were measured by the rice transplanter installed with force measuring device of dynamic strain gage system in the laboratory. The result of this study are summarized as follows : 1. Cutting velocity and acceleration transplanting hoe obtained from jinematic analysis of planting mechanism was 1.32m/sec and 81.5m/$sec^2$ when planting crank-shaft rpm was 160. 2. Little difference between cutting forces on 30-days old seelings of japonica and Indica type was observed, as the cutting forces determined were 2.0kg per hill for Japonica type and 2.1kg per hill for Indica type. 3. Cutting forces determined on 40-days old seedlings were 2.5kg, 2.3kg, 3.1kg and 2.9kg per hill for Milyang No.15, Tongil, Akibare and Milyang No.23 compared to the other varieties. 4. The cutting force was not greatly affected by the sowing densities , only five percent of differences were observed epending upon the sowing densities. 5. Cutting forces were 2.7kg and 2.0kg per hill on 40-days old seedlings and 30-days old seedlings respectively. About 38 percent of more forces was required in cutting 40-days old seedling than in cutting 30-days old seedlings. 6. More cutting forces were required as soil moisture content of mat-type seedling was decreased. 7. Root length after cutting by the planting hoe and their relationships with soil moisture content on 30-days old seedlings, are as follows ; $y=4.147-11.384x+ 28.854x^2$ where , $y$=root length after cutting. (cm) , $x$=soil ture content of mat type seedlings.(%, d.b.) 8. Cutting forces were varied with the width of cuttings ; those on 40-days old mat type seedlings were 2.7kg and 2.2kg per hill when cutting with 14 mm and 10mm of width respectively, about 32 percent of more forces was required when cuting with 14mm of width compared to 10mm of width.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.81-85
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• 1989

One of the most important cultural techniques of pearl millet (Pennisetum americanum (L.) Leeke) is to encourage rapid and uniform emergence of seedlings to establish good stand and to let them grow well. Thus the objectives of the study were to investigate the effects of pre-sowing seed soaking and planting depth on dormancy breaking, germination and emergence of the seedlings, and to estimate the optimum planting season of pearl millet in Suwon, Korea. The seeds with dormancy germinated 99 to 100 percent when soaked in the H$_2$O$_2$ 1％ solution for 24 hours and rinsed with pure water, but germinated only 38％ and 83％ when soaked in pure water for 24 hours just after harvest and drying, and one month later from the harvest time, respectively. The seeds of Australia inbred line did not germinate at the constant 10$^{\circ}C$, but germinated at the constant 11$^{\circ}C$. It also was possible to estimate the optimum planting season by applying minimum temperature 11$^{\circ}C$ for germination. The minimum air temperature reached from late April in Suwon, Korea in regular years but fluctuated from late April to early May in 1986 and 1987. Thus, the safe planting season was mid-May for rapid and uniform germination of pearl millet seed. The optimum depth of planting was 2∼4cm under the optimum soil moisture condition, and 4 to 6 cm under the drier soil moisture condition. Subcoleoptile internode(mesocotyle) length increased according to increased depth of planting. Seedling crown placement also became deeper due to deeper planting of the seeds. The subcoleoptile internode length and seedling crown depth were positively correlated with actual planting depth, indicating that deeper planting would be not good for appropriate adventitious root and tiller development.

• Plant Resources
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• v.8 no.2
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• pp.91-95
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• 2005

In spring, to determine the optimal planting date and plant density of rapeseed in southern areas of Korea. $Taiwan^{\#1}$ variety for spring sowing, the highest yielding variety was grown under five different planting date and plant density. Yield components such as plant height, ear length, number of seedling stand per $m^2$, number of per ear and seed set percentage were highest at the plots with Mar. 5 of planting date and 50/20cm drilling of plant density. Yield of seed, oil, gas and 1,000 grains weight and erucic acid content were highest at the Mar. 5 of planting date and 50/20cm drilling of plant density. Judging from the results reported above, at optimum planting date and plant density of rapeseed seemed too be Mar. 5 of planting date and 50/20cm plant density in spring sowing.

• Journal of Bio-Environment Control
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• v.8 no.4
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• pp.242-249
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• 1999

This study was conducted to investigate the effect of seedling age and irrigation set point on the growth and yield of white spined cucumber cv Sharp-1. Leaf area, number of lateral vines and root weight measured 70 days after planting were the greatest in 30 day-old seedling treatment. Inorganic element content measured 30 days after planting was the greatest in 30 day-old seedling treatment. Total and marketable yields were greater in 30 day-old seedlings than those of 20 or 40 day-old seedlings. The early yield was the least in 20 day-old seedlings. 40-day old seedlings lost vigor quickly. No significant differences in growth and yield observed as affected by irrigation set point.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.2
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• pp.45-52
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• 2012

Enrichment planting is commonly used for increasing the density of tree species in secondary forests and one of forest rehabilitation programs in Lao PDR. This study aimed to determine the performance of five native species in enrichment planting using different canopy opening treatments, and to examine the suitable species and silviculture techniques applicable to a logged-over forest in Lao PDR. Results of the study showed that only crown height had significant difference among species and planting treatments. The survival rate and crown diameter were significantly different by species, but not by planting treatments. However, root collar diameter (RCD) and height of seedlings showed significant differences among planting treatments. Among the study species, Hopea odorata and Dalbergia cochinchinensis showed significantly higher survival rate and height growth, indicating their suitability in enrichment planting for rehabilitation of forest in Lao PDR. The results also suggested that 2 m width line planting stimulated RCD growth, but wider line planting, such as gap planting, promoted height growth of seedlings.

• Journal of Life Science
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• v.13 no.4
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• pp.428-432
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• 2003

This study was carried out to develop and investigate integrated mechanization system for culture of carrot. Compared with the conventional hand planting, use of a mechanical planter for pelleted seeds resulted in a saving of planting time by 225 hours. An additional saving of 460 hours was obtained for thinning the seedlings. Besides seeds could be saved by 72%, planting and thinning be done only in 35 hours per ha field when the pelleted seeds were planted with a planter. Work hour reduced by adopting the mechanical planting of pelleted seeds sharply contrasted to that of 720 hours required for hand-planting the thinning hours, resulting in a reduction of labor by more than 95%. SMP followed pelleting tended not only to increase the percentage of seedling emergence in the field but to induce an a day earlier germination.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.133-140
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• 2012

The study of Arundinaria munsuensis Y. Lee to this day was limited to the field of morphological species classification since its first discovery at Jiri mountain in the late 1990s. This native plants, one of Korean endemic species found in Jiri Mt. necessitates further studies about its use as revegetation plants or groundcover plants in urban areas. This study was launched from this need followed by summaries of results below related to its usage. This targeted species is a native Korean species which its natural distribution on the subalpine zone has merit for the wide range of climatic adaptation. Also, the coverage rate reached 78.3% in three years mostly by rhizome growth with an expectation of full coverage in four years providing less maintenance needs after planting. The net price for the construction of pot seedling methods of this plants is relatively economical than other normal revegetation construction methods. For these reasons, drilling for the plants on cut and fill soil slopes driven from pot seedling adapts Arundinaria munsuensis Y. Lee as efficient revegetation plant. Total construction cost for pot seedling work($30cm{\times}30cm$) of Arundinaria munsuensis was approximately 21,000won which is in reasonable price range when compared to other revegetation construction methods of disturbed slopes. As a native Korean plant, Arundinaria munsuensis has wide range of climatic adaptation with less maintenance requirement after planting. This study may suggest a strong possibility of Arundinaria munsuensis as a pot planting material in sloped area.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.787-791
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• 2000

Lettuce seedlings used in this investigation of planting distance and labor-saving efficiency were first grown in 100-hole paper trays for 30 days. Seedling height for transplanting ranged from 3 cm to 6 cm and plants had 3 to 5 leaves. The beds prepared for transplanting were of the arched type and were 35-40 cm in width, 15-20 cm in bed height, and between-bed furrow width was 20 30 cm. Typical seedling planting depth with the transplanter was 4-5 cm, although depth was quite variable because of the irregularities of the ground. Total transplanting time with the transplanter varied from 2.6 to 2.7 hours per 10a, while it took 38.1 hours per 10a with conventional planting. It was critical that the condition of both the seedlings and the bed be adjusted to the transplanter before planting. Considering yield and inter-plant distance, optimal transplanter performance resulted with $60{\times}20cm$ or $60{\times}25cm$spacing, and the labor-saving efficiency using the transplanter was improved by over 93% of that of conventional planting by hand.