• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.55-59
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• 2005

Rice farmers can save labor and expenses by using expanded rice husk (ERH) as a seedling medium since ERH is lighter and cheaper than other commercial seedling media (CSM). This study was carried out to develop a method for rice seedling cultivation using ERH as a seedling medium. It is suggested that a mixture of $60\%$ of ERH and $40\%$ of a CSM could be used as a seedling medium; the planting densities would be 240g per tray for infant seedlings and 200 g for young seedlings; and nitrogen (N) would be applied at a rate of 1g per tray for infant seedlings prior to planting and 2g per tray for young seedlings with division. Great care should be taken to use $CO(NH_2)_2$ as an N-source fertilizer. These results would lay a foundation for the rice seedling cultivation with ERH as a medium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.360-365
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• 1993

The infant seedling of rice(8-to 10-day-old) has often suffered from submergence just after transplanting due to the too short seedling height, 5 to 8cm, This experiment was conducted to elucidate the effect of gibberellic acid($GA_3 : 25% soluble liquid) with the application methods of foliar spray and seed-soaking on the elongation of seedling height of infant rice seedling in machine transplanting, We used a japonica rice variety, Hwaseongbyeo, and the seeding rate was 200g per seed tray(30$\times60$\times3cm). Generally,$GA_3 and Metalaxyl increased the elongation of seedling height of infant seedling while Tetracycle decreased the seedling height, To increase the seedling height of infant seedling, the foliar spary application of $GA_3 was better than seed-soaking treatment. The optimum concentration of $GA_3 for the foliar spray was about l0ppm and the optimum application time of $GA_3 was 3 to 4 days after sowing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.6
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• pp.492-496
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• 1990

To utilize narrow space of vinyl house for rice seedling raising in three dimensions and raise infant seedling in large quantilies at once, shelves were constructed with few stories in inside of vinyl house and seedlings were raised by use of the shelve. Seedling characters, rice growth status on paddy field and rice grain yield were tested and the following results were obtained. Rice seedling raising was practicable to 10 days after sowing in the interval of 20cm height and 12 days, 30cm height on the shelve for seedling raising. Seedling characters, rice growth status on paddy field and rice grain yield were not varied according to the seedling raising height of the shelve. Seedling characters were not different according to irrigation intervals in raising box of rice seedling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.428-433
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• 1989

The objective of this experiment was to determine if there were feasible to transplant infant rice seedling for machine transplanting. Cultivars tested were Sobaegbyeo and Daecheongbyeo, ]aponica type cultivars. Infant seedling, young seedling and semi-adult seedling were raised with sailor rock wool in seedling tray from 1986 to 1988. Infant rice seedling raised more than 4 days after sowing with rock wool was uniform, and low in ratio of missing hill at machine transplanting. Tiller number per m$^2$ was more in infant rice seedling, young seedling and semi-adult seedling, in that order. Heading dates were not significantly different among seedlings applied, however rice plant sown directly was later 4 or 5 days than any other seedlings. Panicle number per m$^2$ was more in infant seedling than in semi-adult seedling, but ripened ratio was lower in infant seedling due to lodging. Thus there were not greatly different in yield among seedlings tested. Therefore infant rice seedling (more than 5cm in plumule length) raised for 7 days was most optimum, and rock wool would be used as a nursery soil instead of nursery soil for raising infant rice seedling in machine transplanting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.434-439
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• 1989

This study was carried out to investigate the minimum days for raising infant rice seedling with different temperature (day/night $^{\circ}C$ : 20/12, 25/18, 30/20) and to compare with seedling growth and rooting ability at 10 days after transplanting with endosperm-intacted and removed seedlings. The minimum days for raising infant rice seedling was shown differently with different temperatures, thus there were turned out by mat formation to be 10 days at 20/12$^{\circ}C$ (day/night), 8 days at 25/18$^{\circ}C$ and 6 days at 30/20$^{\circ}C$, respectively. Seedling height, leaf number and dry weight of top part at the minimum days for raising infant rice seedling were 8-12cm, 1.5-1.7 leaves and 6.9-7. 5cm per seedling, respectively. The seedling growth at 10 days after transplanting was better at high temperatures (25/18$^{\circ}C$) than low temperature (20/12$^{\circ}C$) at transplanting, and the growth of infant rice seedling with endosperm -intacted was better than that with endosperm-removed. This tedency was shown significantly in transplanting at 20/12$^{\circ}C$ (day/night) of 4 days seedling.

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.22-23
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• 1990

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.239-243
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• 2008

This experiment was carried out to elucidate the appropriate split application method of nitrogen fertilizer in infant rice seedlings which show poor seedling growth resulted from extended seedling nursery duration more than 12 days. The 16 day-old infant rice seedling (DOIRS) showed poor seedling growth than 8 day-old seedling. Early growth of transplanted 16 DOIRS was poor, compared with that of transplanted 8 DOIRS. However, the poor plant growth estimated by plant height, tiller number, and the number of newly developed roots was compensated by 70-0-30% (basaltillering-panicle initiation) of nitrogen split application. In 70-0-30% plots among split nitrogen application methods, tiller number, biomass, and leaf area at heading stage of rice showed the highest values. Sixteen DOIRS plots showed lower grain filling and 1000-grain weight, resulted in lower yield of rice than 8 DOIRS plots in the same nitrogen split application. However the lower yield in 16 DOIRS plots was recovered by 70-0-30% of nitrogen split application method to a similar level in 8 DOIRS plots in which nitrogen was split applied by 40-30-30%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.184-188
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• 2001

This study was conducted to find out the basic informations related to the rice cultivation using the infant seedlings. Infant seedlings with different nursery Periods were compared for the growth and grain yield of rice at the National Crop Experiment Station in 1997. The highest sound seedling ratio of 93.9% was observed in 8-day old seedling, followed by 88.9% of 12-day, 82.0% of 16-day, and 80.8% of 20-day, The endosperm remained 52.5% in the 8-day old seedling at transplanting and decreasingly with increasing nursery period. Missing hills at transplanting were more in 16-day and 20-day old seedling than in 8-day and 12-day old seedlings, 5.1-5.2% in 8-day and 12-day growing seedling, 6.7% in 16-day and 7.8% in 20-day old seedling. Rooting ability was observed highest in 8-day, followed by 12-day, 16-day and 20-day old seedling. The milled rice was lower by 5-16% in 12-day, 16-day and 20-day old seedling than in 8-day old seedling of 6.18 t/ha. It was found that the 8-day and 12-day old seedling provided more advantage for sound seedling ratio, endosperm remaining, missing hill during transplanting, rooting ability and grain yields than 16-day and 20-day old seedlings.

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.24-25
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• 1990

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.26-27
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• 1990