• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.3
• /
• pp.370-375
• /
• 1996

This study was conducted to find out the feasibility in direct seeded rice cultivation on the reclaimed saline soil. Seedling emergence was tested under the different application rates of rice straw and seeding depth, and also under combined treatments soil moisture regimes and seeding depth on saline soils in a greenhouse. The comparison of seedling stand and yield performance of rice in rotary till after broadcast seeding and in non-plow after broadcast seeding were tested on a field that reclaimed saline soil. Seedling emergence ratio in application of rice straw(4 and 6 tons /ha) was higher than that in non-application of rice straw. Seedling emergence and plant height were remarkably increased with the shallow seeding depth in the application of rice straw(4 tons /ha). The seedling emergence under proper soil moisture condition(25%) was higher than that under excess soil moisture condition(35%). Under proper soil moisture condition, the plant height was increased with the shallowed seeding depth. The number of seedling stand per m$^2$ in non-plow after broadcast seeding was larger than that in rotary till after broadcast seeding. Panicle number per m$^2$ in non-plow after broadcast seeding was much larger than that in rotary till after broadcast seeding and the yield showed the same trends as panicle number.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.4
• /
• pp.297-303
• /
• 1993

Seedling emergence and .stand establishment in dry-seeded rice is unstable at present due to deep seeding, low temperature at seeding time, excessive drought or raining etc. This experiment was conducted to elucidate the effect of gibberellic acid(GA$_3$) on the seedling emergence and growth in dry-seeded rice. GA$_3$, IBA and Metalaxyl were treated by seed-soaking or-spray. Hwaseongbyeo, a japonica rice, was used. The seed-soaking treatment with GA$_3$ significantly increased the seedling emergence and plant height as compared with untreated seed. However, no difference was observed in IBA and Metalaxyl treatment. The optimum concentration of GA$_3$ to promote the seedling emergence and growth in dry-seeded rice was about 100ppm for seed-soaking and about 200ppm for seed-spray treatment. The seed-spray treatment of GA$_3$ with 200ppm promoted earlier and faster seedling emergence and elongated seedling height as compared with untreated seed.

• The Korean Journal of Mycology
• /
• v.45 no.3
• /
• pp.188-195
• /
• 2017

Despite the high commercial value of the pine mushroom (Tricholoma matsutake) around the world, its production still depends upon natural harvesting. In recent years, mushroom researchers in Korea and Japan have been successful in artificially cultivating T. matsutake by producing single mushroom through matsutake-infected pine seedlings. In this study, we determined the minimum seedling height required for the survival of matsutake mycelia in the infected pine seedlings in the field. The survival rate of matsutake mycelia in the matsutake-infected pine seedlings was 50% (14) in two years and 71% (10) in one year after their transplantation. The average height at time of transplantation of the matsutake-infected pine seedlings that bore surviving mycelia after transplantation was 25 cm (minimum 12 cm to maximum 40 cm). In conclusion, the matsutake mycelium of matsutake-infected pine seedlings was able to survive in field conditions if the height of the seedling at the time of T. matsutake infection was at least 12 cm. These results suggest that the height of the host plants used in conventional matsutake-infected pine seedling production should be greatly reduced to improve the matsutake cultivation. Therefore, standardization of the seedling height for artificial cultivation of pine mushrooms by the matsutake-infected pine seedling method is suggested.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.18 no.3
• /
• pp.79-95
• /
• 2015

To suggest ecological management plans for invasion of Salix gracilistyla, stepwise environmental sieve of seed dispersal, germination, seedling and juvenile stages were investigated. About 84% of total seeds were released between May 6 and 10. Germination rates significantly declined with decrease of light intensity from 100% to 30% and 0% (p<.001), but above 60% of seeds germinated in all treatments. Difference of germination rates with 0 and 2cm water level was not significant (p = .571). With increase of elapsed time after seed dispersal, germination rates significantly decreased (p<.001), and seed viability was lost within 16 days. Considering both germination rate of seed and survival rate of seedling, survival rate of all dispersed seeds was only 5% when 8 days passed after seed dispersal. All 22-day-old seedlings (height: 1cm) died under flooding of twice level as its height. With decrease of light intensity from 100% to 30%, survival rates of seedling decreased from 90% to 33% (p<.001). In the case of 45-day-old juvenile (height: 20cm), survival rate was 70% under the water level same as its height. There was significant interactive effect of water level and light intensity on the growth of juvenile (height: p<.001, dry weight: p<.01), and survival rate of juvenile was 10% under +20cm-water level and 30%-light intensity condition. The following management plans for invasion of S. gracilistyla are recommended from these results. (1) Dry condition should be maintained at fringe of wetlands for about two weeks at seed dispersal and germination stage (early May~mid May). (2) Water level should be raised to about 5cm at fringe of wetlands for about two weeks at seedling stage (mid May~early June). (3) Water level should be raised to over 20cm at fringe of wetlands for a long time at juvenile stage. Planting trees for shading can raise management effectiveness (mid June~). (4) As water level manipulating is performed as fast as possible for controlling seedling and juvenile, management become easier and more effective.

• Korean Journal of Breeding Science
• /
• v.43 no.5
• /
• pp.391-398
• /
• 2011

Physiological responses to salinity stress were evaluated in six rice genotypes differing in their tolerance to salinity at the seedling stage. Susceptible genotypes ('Dongjingbyeo', 'Hwayeongbyeo', and 'IR29') showed salt injury symptoms (mean 8.8) and higher visual score under salt stress than that of tolerant ones ('Pokkali', 'IR74009', and 'IR73571'). As salinity affects growth and physiological parameters, the six genotypes thus showed significant reduction because of salt stress. Tolerant Japonica/Indica bred lines ('IR74009', 'IR73571') showed lower reduction, 33.9%, 34.5%, and 50%, respectively, in plant seedling height, dry shoot weight and dry root weight than those of the susceptible Japonica varieties ('Dongjingbyeo', 'Hwayeongbyeo'), and the highest reduction under salt stress was observed in dry root weight, followed by dry shoot weight and seedling height, respectively. Shoot $Na^+$ concentration of IR74099 and IR73571 was lower than that of the susceptible varieties, 'Dongjinbyeo' and 'Hwayeongbyeo'. There were no significant differences among genotypes in root $Na^+$ concentration. Shoot $K^+$ concentration showed a reverse tendency compared to shoot $Na^+$ concentration. IR74009 and IR73571 had considerably lower ratio compared to 'Dongjinbyeo' and 'Hwayeongbyeo' in $Na^+/K^+$ ratio of their shoot and was not different the tolerant check, 'Pokkali'.

• Journal of Bio-Environment Control
• /
• v.32 no.4
• /
• pp.442-448
• /
• 2023

This study aimed to develop an optimal greenhouse model for strawberry seedling during the summer high-temperature period based on the results of field surveys. We conducted a survey on the structure types of 46 strawberry seedling farms nationwide, including width, ridge height, eaves height, ventilation method, seedling bed width, and spacing. Based on the survey results, we derived the optimal greenhouse model by considering various factors. The greenhouse width was set at 14 meters to maximize the efficiency of seedling beds and overall space. The height was determined at 2 meters, taking into account ventilation during the summer season. To reduce stress on the supporting structure due to snow loads, we established a reinforcement installation angle of 50 degrees. We analyzed two different models that use support beams with dimensions of φ48.1×2.1t and φ59.9×3.2t, respectively, to ensure structural safety against meteorological disasters, considering regional design wind speeds and snow accumulation. We utilized these developed greenhouse model to conduct strawberry seedling experiments, resulting in a high survival rate of average 93.2%. These findings confirm the usefulness of the strawberry seedling greenhouse in improving the seedling environment and enhancing overall efficiency.

• Journal of Plant Biology
• /
• v.22 no.3
• /
• pp.59-62
• /
• 1979

Distribution and standing crops of seedling and sapling as undergrowing tree were investigated in a Pinus rigida forest. The relative light intensity(RLI) on the ground level was 3.9∼59.3% which indicates a wide range. Under this range of RLI seedlings and saplings distribute well in the stand. Eight trees were selected from the stand, then measured dry weight of stem, branches and leaves using thestratified clip technique. A possible relationship between the diameter at the bottom of the tree (Do) and standing crops was investigated. As Do increased from 0.8cm (T1) to 7.2cm (T8), the standing crops also increased from 42.6g to 7,410.4g. Since semi-log values between Do and standing crops clearly indicates a straight line, there is close relationship between these two factors. Therefore it is possible to estimate the standing crops of seedling and sapling by measuring Do. Productive structure shows that phytosynthetic layer is located above the 1/2 height of the tree and maximum photosynthetic layer apperars on 2/3 level in height.

• Current Research on Agriculture and Life Sciences
• /
• v.5
• /
• pp.1-11
• /
• 1987

This study was conducted to evaluate the effect of several fungicides and growth regulators on rice seedling growth and damping-off in seedling boxes for machine transplanting. Fungicide treated plots were better seedling growth, shoot regrowth, rooting ability, change of moisture content than those of nontreated plot. Metalaxyl application of Samgangbyeo and SF8002 application of Nagdongdyeo apparently increased plant height, length of the third leaf and fourth leaf. And metaiaxyl application highly increased dry weight. Fungicide treated plots were highly effective in reducing the incidence of damping-off. Benzyladenine application of Samgangbye and $GA_3$ application of Nagdongbyeo apprently increased plant height. But ABA application highly decreased plant height. ABA application and aCE application resulted in highly increased rooting ability. Fungicide and $GA_3$ treated plots, Metalaxyl and growth regulator treated plots resulted in highly increased plant height. I soprothiolane and growth regulator treated plots resulted in decreased plant height. Dachigaren and lAA treated plot apprently increased dry weight and shoot dry weight/plant height. Fungicide and growth regulator treated plots were highly effective in reducing the incidence of damping-off.

• Journal of the Korean Society of Tobacco Science
• /
• v.19 no.1
• /
• pp.18-23
• /
• 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.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.132-132
• /
• 2022

The application of direct seeding cultivation reduces time, labor, and cost. However, this application often has poor seedling establishment and leads to lower yield as compared to transplanting system. The tolerance to anaerobic and low temperature germination is important to improve seedling establishment and the wide-spread application of direct seeding method. This study was carried out to evaluate the responses of three japonica cultivars to different temperatures (15℃, 18℃, 21℃, 24℃, and 27℃) and different flooding levels (1 cm, 4 cm, 7 cm, 10 cm) during germination and seedling development. The mean survival percentage significantly increased (P<0.05) when the flooding level decreased and when temperature increased. There were significant effects of the interaction between temperature and water depth on survival percentage and seedling height. When temperature decreased from 27℃ to 15℃, the germination duration significantly increased from 6.4 days to 16.3 days while the germination speed, survival percentage, and seedling height decreased from 5.3 seeds day^-1, 61.9% and 190.6 cm to 2.2 seeds day^-1, 33.2%, and 47 cm, respectively. The increase in temperature under submergence condition was associated with the increased expression of Amy3D and ALDH2a but the decreased expression of ADH1 and PDC1. The results of this research would be used for further studies and breeding programs to improve rice seedling establishment and the application of direct seeding cultivation.