• 한국작물학회지
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• 제53권4호
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• pp.434-439
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• 2008

The amount of salt to make seed sorting solution of the specific gravity of 1.13 was reconsidered and determined as 3.8 kg salt in 18 L water, which is lower amount than currently used. Five rice cultivars were examined. Percent germination and seedling emergence were not similar. Seedling emergence rate of Japonica varieties, Nampyungbyeo and Daerypbyeo-1 were 87% and 95% under specific gravity of 1.13, respectively. Seedling emergence rate of Tongil type variety, Dasanbyeo was as high as 67% in specific gravity of 1.06. Seedling emergence rate of waxy rice, Hwasunchalbyeo and Aranghangchalbyeo were examined. Seedling emergence rate was 94% in both cultivars in specific gravity of 1.04. Seedling emergence rate was same in specific gravity of 1.08 which is generally used for selecting seed currently. Early growth (plant height, leaf number, and dry weight) were not significantly different by specific gravity within species. In all cultivars except waxy rice, highest seedling emergence rate was observed in specific gravity of 1.13 which is currently used for selection and decreased as specific gravity is lowed. However, considering total amount of seeds in each group of specific gravity, amount of seed in lower specific gravity group is relatively small and total seedling emergence rate within variety dose not show big difference. However, if seeds with low speicific gravity are produced due to the bad grain filling condition and consequently total seed content of low specific gravity increases, results will be differnt. Reduction in total growth and yield could occur. It will be important to comply with the seed sorting criterion of 1.13 for Japonica, 1.06 for Tongil, and 1.04 for waxy rice variety to ensure the maximum rice growth and yield.

• 한국작물학회지
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• 제44권3호
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• pp.225-229
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• 1999

Unstable seedling stand establishment of wet direct seeding culture of rice is one of the major elements preventing the extension of its culture area. In order to develop methods of seedling stand improvement in direct seeded rice on flooded surfaces, three field experiments were conducted on silty loam soil using a cultivar 'Donjinbyeo' for three years, mainly focusing on water management after seeding and seed soaking with plant growth regulators (PGRs). Under the condition of shallow flooding after seeding, seedling stand rate increased and floating seedling rate decreased in both early and normal season seeding compared to deep flooding. With earlier draining time after seeding, there was a tendency towards preferential growth of the seminal root, increase of seedling stand and decrease of the floating seedling rate. Therefore the highest seedling numbers per unit area and the lowest floating seedling numbers were found upon drainage at 1 day after seeding (DAS), while a contrary tendency was shown upon conventional drainage at 7 DAS. Seed soaking with PGRs such as Metalaxyl or mixing of Metalaxyl with gibberellic acid (GA$_3$) significantly increased the seedling stand. In addition the effects of PGR treatment on seedling stand and the early growth of plants were greater under flooded conditions than under drained conditions after seeding, although draining of water after seeding improved the seedling establishment rate more when compared with the PGR treatment. These results suggest that draining management after seeding or maintaining of shallow flooding for a week is the most effective method to improve the seedling stand rate in wet direct seeding.

• Journal of Ginseng Research
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• 제22권4호
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• pp.294-298
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• 1998

This study was conducted to investigate the effects of growth characteristics and mineral contents of ginseng seedling grown in different locations on ginseng growth and root yield. Ginseng seedling produced in 16 farmers' field at the semi-Yangjik seedbed were planted and cultivated in a field with same cultural practices. Missing plant was increased with increased year of ginseng age, especially severe at 5-year-old ginseng. Rate of missing plant was different among the origins of the seedling, even with the same weights. Negative correlation was noted between the missing rate of 3-year-old ginseng plants and NH4-N content of the seedling, but positive correlation between the missing rate and K2O and Ca contents of the seedling. Root yield of 6-year-old ginseng was also affected by the origins of ginseng seedlings. Root yield was high in ginseng plant from 0.6∼0.9 g see dings compared to those from over 0.9 g seedlings.

• The Plant Pathology Journal
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• 제22권1호
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• pp.11-15
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• 2006

Five seed samples of carrot were tested to detect Alternaria spp. by blotter method. A. alternata and A. radicina were detected from all the seed samples as high as $25.8-70.5\%$ and $37.5-63.5\%$, respectively. A. dauci was detected from four seed samples as low as $0.5-7.5\%$. The three Alternaria spp. were detected from the pericarp and the seed coat and endosperm of the carrot seeds but not from the embryo by component plating test. A. alternata and A. radicina were much more detected from the pericarp than the seed coat and endosperm. A. dauci was detected from the pericarp and the seed coat and endosperm at similar rate. The seed sample which was most severely infected with A. radicina showed the lowest rate of germination in the test on top of paper (TP). In the TP test, differences in total infection rate of A. radicina and A. dauci of the seed samples were very closely correlated with those in incidence of seedling rot on the seed samples. However, there was no correlation between infection rate of A. alternata and rate of germination or seedling rot of the seed samples. Soil test for seedling growth revealed that there was no correlation between differences in total infection rate of A. radicina and A. dauci and those in rate of normal seedlings of the seed samples.

• 한국작물학회지
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• 제42권2호
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• pp.196-201
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• 1997

참당귀 묘크기와 저온처리가 추대에 미치는 영향을 알아보고자 수행한 시험결과를 요약하며 다음과 같다. 1. 저온처리 기간에 따른 추대율은 30일, 60일과 90일 처리에서는 각각 69.4％, 69.3％과 75.2％로 처리기간이 길어짐에 따라 추대율이 높았으며, 무처리에서는 29.6％로 낮았다. 2. 묘크기별 저온처리에 따른 추대율은 소묘일수록 낮고, 대묘일수록 높아지는 경향이었다. 정식후 추대까지의 기간은 저온처리 기간이 길수록, 대묘일수록 추대가 빨라지는 경향이었다. 3. 추대시 생육은 저온처리 기간이 길어지고 대묘일수록 초장이 짧고 추대엽위가 낮으며 진전엽수가 적어지는 경향이었다. 추대율은 추대시 생육과는 부의 상관을 보이고, 후기생육과는 정의 상관을 보였다.

• 한국자원식물학회지
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• 제11권3호
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• pp.315-318
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• 1998

This study was carried out to investigate the effect of seedling growth with different seedling rate for machine transplanting with turf. Chosun Zoysia was sown on May 17 with three levels seedling rates. The plant charactersitics were greater in 500g/box plots than the other seedling rates on the seedling box. It ws shown that the 30-40day old seedlings of 1.000 and 2,000g/box seedling plots appeared to be proper methods for Sprigging as the high seedling density. The 70 day old seedling plant with 500g/box were shown to be propoer methods for Sprigging. The seedling periods need to be 60 days for 500g/box plots and 40 days for 1,000 and 2,000g/box plots as forming the mats.

• 한국연초학회지
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• 제19권1호
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• pp.18-23
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• 1997

The study was carried out to clarify reasonable production of healthy seedling, optimal Pot depth, and appropriate transplanting time, which can be deduced from understanding of seedling quality. Seedling quality results from growth of root and shoot, morphology and distribution of root system under influence of Pot depth during seedling growing period. Stem height, shoot dry weight, leaf area and leaf number were increased in proportion to depth of pots. Growth of shoot and root during seedling growing period showed the most dramatic development between 20th and 25th day after temporary planting. Root number increased as pot depth decrease and total root length and dry weight increased as pot depth increase. In 5cm pot, relative multiplication rate was higher and mean extension rate was lower than other depth of Pot. The limitation of pot volume in which rhizosphere was located enhance the development of roots of second and third order. At 20th days after temporary Planting root distribution was relatively uniform in length and development of adventitious root on stem base was poor as Pot depth decreased.

• 한국작물학회지
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• 제43권4호
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• pp.214-222
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• 1998

These experiments were conducted to investigate water uptake, electrical conductivity, germination percentage, seedling growth, and seedling establishment rate in direct seeding cultivation of rice. The rice seeds of six japonica type varieties were coated with 12 kinds of polymers in a standard concentration of 0.2% using seed coating machine. The water absorption of the polymer-coated seeds under saturation conditions was not different among varieties, and was the highest in kulcel, maltrin, and waterlock on the polymer-coated seeds. The electrical conductivity with waterlock (55.0 $\mu scm^{-1}g^{-1}$) was higher than the control plot (45.6 $\mu scm^{-1}g^{-1}$) and other treatments. The germination of the polymer-coated seeds was 95.9% at control plot, 92.7% at low temperature and 35.7% at high temperature. The total dry weight of seed decreased in the order of low temperature, control plot, and high temperature, and was effective in pvp (polyvinyl pyrrolidone), opadry, and sacrust. The seedling establishment rate in direct seeding cultivation ranged from 74.9 to 81.0% in flooded paddy surface, and ranged from 64.7 to 76.6% in dry paddy. In both cases, it decreased in the order of early, medium and medium-late varieties, but was enhanced in daran 8600, sepirect, and sacrust. According to this study the recommended polymers for direct seeding cultivation of rice are daran 8600, sepirect, and sacrust.

• 한국작물학회지
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• 제50권2호
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• pp.120-124
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• 2005

Expanded rice husk (ERR) is different from commercial rice seedling media in chemical and physical properties such as pH, permeability, and water content. This study was conducted to test a possibility of improving rice seedling growth by improving the texture of ERR as a rice seedling medium. The seedling media used were a commercial seedling medium (CSM), rice husk, and ERR 1, 2, 3, and 4 with different expansion degrees. The pH of the ERHs ranged from 6.3 to 6.8. As the expansion rate increased, ERR particle sizes decreased, and water permeability and absorption rates improved. No significant differences in shoot dry weight and rate of maturity were found among the seedlings cultivated in the different ERH media. However, the mat formation of seedling roots became loose as the expansion rates were decreased. Further studies are necessary to determine the cause of poor root growth in ERH media.

• 농업생명과학연구
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• 제46권2호
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• pp.63-73
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• 2012

본 연구에서는 소나무 용기묘와 노지묘를 대상으로 조림과정에서 5가지 시비 처리(무시비, 심층시비 20, 50, 100g 및 표층시비 20g)에 따른 생존율, 생장 특성 및 묘목품질지수를 조사 분석하였다. 조림지에 묘목 식재 시 시비처리에 따른 생존율은 처리구별 뚜렷한 차이가 없었으며, 심층시비 100 g 시비를 실시하여도 과량 시비에 의한 피해를 보이지 않았다. 소나무 용기묘와 노지묘의 연차별 근원경과 묘고 생장은 심층시비 100 g에서 가장 높았으며 또한, 물질생산량과 묘목품질지수에서도 생장 특성과 같은 경향이 나타났다. 모든 시비 처리구에서 전반적으로 용기묘가 노지묘보다 우수한 생장을 보였으며, 적정 시비 처리에 따른 효과 또한 용기묘가 노지묘보다 더 높은 것으로 조사되었다.