• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.101-101
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• 2022

In recent years, due to climate change, the livestock industry has become more interested in the production of forage crops. In Korea, more than 74% of forage crops are cultivated in winter rice fields. In particular, Italian ryegrass (IRG) is depends on imports for more than 70% of its seeds. In generally, the IRG rapeseed cultivation method involves sowing from early October to mid-October by drill sowing seeding or spot seedling. However, the sowing period is delayed due to frequent rainfall during. And, same period require a lot of seeds. However, raising seedlings and transplanted IRG will overcome weather conditions and reduce the amount of seeds. This study was intended to be applied to the domestic IRG seed industry in the future through growth and quantity evaluation according to transplant time and planting density for the production of good quality IRG seeds in rice paddy fields. In this study, transplanting time (October 20, October 30, November 10) and planting density (50, 70, and 80) were cultivated at the National Institute of Crop Science in 2021. The amount of fertilizer applied was adjusted to (N-P₂O₅-K₂O) 4.5-12-12 (kg/10a), and then 2.2(kg/10a) of nitrogen was added each year. For the growth survey, leaf area, canopy coverage, plant length, and seed yield were investigated. Along with the transplanting time, the plant length was higher on October 20 than on October 30 and November 10. On the other hand, leaf area index changes differed depending on the transplanting time and planting density, and were particularly high on October 20, 80 density and 70 density, but similar on October 30 and November 10. 1000 seed weight showed no difference with transplanting time and planting density. On the other hand, the seed yield was 215(kg/10a) for 80 density on October 20, 211(kg/10a) for 70 density, 118(kg/10a) for 50 density, and 80 density for October 30 and November 10. and 70 density did not differ. On the other hand, the 50 density on October 30 and November 10 were 164(kg/10a) and 147(kg/10a) respectively. As can be seen from this study, the earlier the transplant, the higher the seed yield. However, the 50 density was reduced in yield compared to the 70 density and 80 density.

• Current Research on Agriculture and Life Sciences
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• v.23
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• pp.1-8
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• 2005

The purpose of this study was carried out to determine the optimum sowing date and days after sowing (DAS) in automatic facility located at Uiseong of Gyeoungbuk province. The seedling height was rapidly increased with a delay of sowing time from April to May. The 10-day old seedlings with suitable plant height (> l0cm) for machine transplanting in the facility were obtained when the seeds sowed after May 20 at Uiseong in Gyeoungbuk province. The dry weight-height ratio of 10-day old seedlings was significantly decreased when the seeds sowed after June 20, and 15-days old seedlings did after May 10. No. of panicles/hill was reduced with increasing of days after seeding. But there were no significant difference among other yield components such as no. of grains/panicle, ratio of ripened grains, and 1,000 grain weight. The highest grain yield, 748kg/10a, was attained from the 10-day old seedlings transplanted at May 27 in comparision with those of 15-day and 20-day old seedlings. The grain yield of 10-day old seedlings transplanted at June 26 was also higher than that of 15-day old seedlings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.126-132
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• 2010

A high sugar rice cultivar 'Danmi' which has been recently developed and released in the Functional Crop Resource Development Division, Department of Functional Crop, National Institute of Crop Science, has high glucose and sucrose contents but has a poor seed development. This defect poses some problem in ensuring stable seedling establishment in the nursery bed. We examined the germination and seedling emergence characteristics of 'Danmi' and determined an optimum seeding rate for seedling establishment. 'Danmi' seeds has a light 1,000-grain weight of 18.2g compared with Ilmibyeo's 26.7g. The 97.4% of 'Danmi' seeds has specific gravity below 1.0 while only 2.0% of seeds was fully developed with specific gravity above 1.12. However, the reverse is true in the Ilmibyeo seed used as a control cultivar. Although the seed germination of Danmi was 89-91% regardless of seed specific gravity but at a slower rate than Ilmibyeo regardless of water soaking temperatures of $20-30^{\circ}C$ because of high seed amount of specific gravity below 1.0 in 'Danmi'. It took 2～4 days longer of seed soaking in the Danmi seeds than Ilmibyeo before germination. 'Danmi' has low normal seedling emergence rate than Ilmibyeo in the seedbed soil due to high percentage of abnormal seedlings like stunting and incomplete growth. Normal seedling emergence rate of 'Danmi' in the seedbed was 62.6～64.9% for 10-day old seedling and 83.5～86.7% for 30-day old seedling which is lower by 29.6～30.0% and 11.3～12%, respectively than Ilmibyeo. Although 'Danmi' has low normal seedling emergence rate, but it has greater seed number per weight basis. Therefore, based on the normal seedling number per unit area of Ilmibyeo(control cultivar) for seedling rate of 10-day and 30-day old seedlings, the recommended seeding rate of 'Danmi' for transplanting rice is 220g seeds for 10-day old seedling and 130g for 30-day old seedling per nursery box, which is equivalent to 1.5 times seed volumes of Ilmibyeo.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.17-24
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• 2014

The experiment was conducted at the growth chamber to determine germination, seedling growth and fresh weight between the untreated control and iron-coated seeds in germination test of the rice seeds. There was of 95% germination in rice seeds regardless of treatments and days for seedling emergence was relatively 13-14days. Seedling height was 4.9cm of the iron-coated seeds but 0.4cm of the untreated control and there was 6.S roots of seedling in iron-coated seeds and 5.5 roots of seedling in the untreated control, respectively. The fresh weight of seedling was 107mg of the iron-coated seeds and 66mg of the untreated control at 35days after sowing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.1
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• pp.1-8
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• 2017

We investigated the effect of silicate coating of rice seeds on bakanae disease incidence and the quality of seedlings raised in seedling boxes and transplanted into pots. The silicate-coated rice seed (SCS) was prepared as follows. Naturally infested rice seeds not previously subjected to any fungicidal treatment were dressed with a mixture of 25% silicic acid at pH 11 and 300-mesh zeolite powder at a ratio of 50 g dry seed - 9 mL silicic acid - 25 g zeolite powder. The following nursery conditions were provided : Early sowing, dense seeding in a glass house with mulching overnight and no artificial heating, which were the ideal conditions for determining the effect on the seed. The nursery plants were evaluated for Gibberella. fujikuroi infection or to determine the recovery to normal growth of infected nursery plants in the Wagner pot. Seedlings emerged 2-3 days earlier for the SCS than they did for the non-SCS control, while damping-off and bakanae disease incidence were remarkably reduced. Specifically, bakanae disease incidence in the SCS was limited to only 7.8% for 80 days after sowing, as compared to 91.6% of the non-SCS control. For the 45-days-old SCS nursery seedlings, the fresh weight was increased by 11% and was two times heavier, with only mild damage compared to that observed for non-SCS. Even after transplanting, SCS treatment contributed to a lower incidence of further infections and possibly to recovery of the seedlings to normal growth as compared to that observed in symptomatic plants in the pot. The active pathogenic macro-conidia and micro-conidia were considerably lower in the soil, root, and seedling sheath base of the SCS. In particular, the underdeveloped macro-conidia with straight oblong shape without intact septum were isolated in the SCS ; this phenotype is likely to be at a comparative etiological disadvantage when compared to that of typical active macro-conidia, which are slightly sickle-shaped with 3-7 intact septa. A active intact conidia with high inoculum potential were rarely observed in the tissue of the seedlings treated only in the SCS. We propose that promising result was likely achieved via inhibition of the development of intact pathogenic conidia, in concert with the aerobic, acidic conditions induced by the physiochemical characteristics associated with the air porosity of zeolite, alkalinity of silicate and the seed husk as a carbon source. In addition, the resistance of the healthy plants to pathogenic conidia was also important factor.