• Journal of Korean Society of Forest Science
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• v.97 no.3
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• pp.266-273
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• 2008

The effects of soil acidification on the seedling growth and nutrition of Pinus densiflora and Quercus acutissima were investigated. The relationship between the seedling growth and molar (Ca+Mg+K)/Al ratio of in soil solution was examined. The results suggested that growth inhibition of seedling Pinus densiflora and Quercus acutissima was due to the low pH of soil solution, which was followed by leach of Al into soil solution, and decrease of essential elements, such as Ca in aerial pant of the seeding caused by the increase of Al concentration in subterranean pant of the seedlings. The level of growth inhibition was determined not only by Al concentration, but also by the balance of inorganic elements, Al, Ca, Mg and K. The growths of two species in total dry weight were clearly inhibited when molar (Ca+Mg+K)/Al ratio of the soil was lower than 6.0. The growth in dry weight, in the condition of the molar ratio was 0.8, was decreased 60% or 50% for the seedling of Pinus densiflora or Quercus acutissima respectively. It was concluded that the molar (Ca+Mg+K)/ Al ratio could be an important index for evaluation of the effects of soil acidification, due to acid deposition such as acid rain, on growth of trees and nutrition. And it might be a more useful indicator for evaluation of critical load of acid deposition on forest ecosystems.

• Korean Journal Plant Pathology
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• v.11 no.1
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• pp.94-97
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• 1995

In 1994, an abnormal rice growth was observed in a 0.5-ha scale farmer's field located at Chogye-Myeon, Hapcheon-Gun, Gyeongnam Province where rice cv. Hwayeongbyeo was seeded directly in dry paddy field conditions. The major symptoms were less stands per acreage, short leaf length, and hypertrophy of root tip portion. The disorder was identified as rice seeding bight caused by Rhizopus sp. The average plant stand per m2 in the infested field was 108, while it was 375 in the normal field, and leaf growth was retarded to less than one-third of healthy plant. The average leaf lengths of infected and healthy seedlings were 12.8cm and 38.9cm, respectively. When the infected seedlings were transplanted to pots, flooded-soil conditions developed no new root growth but upland conditions allowed 11.2 new roots emerging. The length of newly emerged root in infested soil was 5.3cm in upland and 7.1cm in intermediate flooding conditions. However, it was 10.9cm in non-infested soil with intermediate flooding conditions. When the plants were matured, the stem length of infected plants was reduced slightly as compared to normal plants, whereas the length of panicle was not significantly different between infected and healthy plants. The number of panicle per plant, however, greatly different with variation of infection degree. Grain quality such as the number of complete and incomplete grains per panicle, the complete grain weight per panicle, and the weight of 1000 grains was not significantly different.

• Korean Journal of Medicinal Crop Science
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• v.25 no.4
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• pp.238-243
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• 2017

Background: The production method of ginseng seedlings for ginseng cultivation is very important to ensure healthy rooting system as well as high quality, and yield of the resultant plants. This study was carried out to compare the growth characteristics of 2-year-old ginseng plants that were produced from seedlings grown in self soil nursery (SSN), nursery soil (NS) or hydroponic culture (HC). Methods and Results: The shading prop used was composed of four-layered 4 polyethylene (blue 3 + black 1) shade screen. The management of main field was done by inserting oil cake (1,200 kg/10 a) and then allowing Sudan grass to grow for a year. Seedling transplantation was carried out on April 6. Root growth was measured on October 25. Root weight was observed to be excellent at 6.0 g, following SSN transplantation. Root length was 21.2 cm for HC seedlings, but these plants had a physiological disorder (i.e., rusty root), in 83.5% plants of this treatment. The ratio of PD/PT (protopanaxadiol saponins / protopanaxatriol saponins) was higher in NS seedlings. Plant analysis revealed that Fe content was lower in HC seedlings with high rustiness. The growth of 2-years-old ginseng was different following these varying seedling cultivation methods, but seedlings from NS were not different from those grown in SSN. Conclusions: For the propagation of 2-year-old ginseng plants, NS seedlings may be a good substitute for SSN seedlings.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.336-336
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• 2017

High mortality and slow growth of seedling generally occurred in tray due to cold, foggy weather and severe seedling blight. Mechanical transplanting is hampered, farmers having economic loss. A sustainable method for raising mat type seedling is necessary. Experiments were conducted on disease control and seedling growth in dry seasons. Fungicides treated/untreated seeds were sown 120-130g in each tray containing pulverized fine grain loam/sandy loam soils. Seed covered with a thin layer of soil and irrigated. It was polythene covered (PC) for 72h and then every night along with 2/3 sprinkler irrigation (SI) per day. Untreated seedlings infected 53-93%. Pyraclostrobin, Azoxystrobin and Azoxystrobin+Difeconazole treated seeds/sprayed (72h) seedlings had no disease. Seedling height was 11.7-13.2 cm with compact and thick root mat at 25 days. Seeds treated at 0.2-0.3% (18-20h) showed no disease but severely in untreated seeds in all locations. Seedling height (13.8 cm), leaf age (3.7) and root number (8.5) were better when NPK were applied at 3-4-3 g/tray. Spraying of urea (1%) in addition with MOP, theovit and $ZnSo_4$ at 0.6-0.6-0.2% on 7 and $15^{th}$ days was also effective. PC showed significant growth (29.1-34.5%). Root mat was not good in flooded irrigation (FI). Disease was higher in SI (66.7-97.3%) than FI (0.7-3.7%) in untreated seeds regardless of polythene use. The protocol would be effective for raising mat type seedling in cold environment.

• Journal of Biosystems Engineering
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• v.26 no.3
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• pp.253-262
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• 2001

This study was conducted to develop the vision system of a robotic transplanter for plug-seedling. A color image processing algorithm was developed to identify and locate empty cells and bad plants in the seedling tray. The image of pepper and tomato seedling tray was segmented into regions of plants, frame and soil using threshold technique which utilized Q of YIQ for finding leaves and H of HSI for finding frame of tray in the color coordinate system. The recognition system was able to successfully identify empty cells and bad seeding and locate their two-dimensional locations. The overall success rate of the recognition system was about 99%.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.395-402
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• 2018

The efficacy of formulated Trichoderma harzianum-based Tricho-compost, seed treatment with Tricho-inocula, and chemical fungicide Provax 200 WP against foot and root rot diseases of wheat caused by Sclerotium rolfsii was tested in the pot house and in the research field of Plant Pathology Division, Bangladesh Agricultural Research Institute, Gazipur, Bangladesh. Tricho-compost was prepared with a mixed substrate of cow dung, rice bran, and poultry refuse colonized by T. harzianum. Seedling mortality of wheat was significantly reduced by the Tricho-compost, Tricho-inocula, and Provax 200 WP both in the pot house as well as in the field experiments. The yield of wheat was sharply increased over the control due to the T. harzianum formulations and Provax 200 WP. Among the treatments, soil application of Tricho-compost was more efficient in reducing seedling mortality and accelerating plant growth with an increased yield of wheat with S. rolfsii-inoculated pot cultures and field experiments.

• Korean Journal of Plant Resources
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• v.33 no.1
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• pp.24-32
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• 2020

This study was aimed to establish the most effective approach for the cultivation of Veronica rotunda var. subintegra (Nakai) T.Yamaz. plants, which was expected as new ornamental plants. We conducted an experiment using plug seedlings, varied the seeding container type and seeding rate. We also varied seedling quality, planting container, soil type, and shading ratio. Seedling quality was used seedlings produced from different seeding containers and seeding rates. The seedling quality were seeding growth using 162, 200, and 288 trays, and seedings rate was used seedlings produced by sowing 1, 2, 4 and 6 seeds. As a result, 162 trays of seedlings were suitable for use in this study. Plants grown with one seed per cell in individual cells exhibited increased individual growth, but those grown with four seeds per cell exhibited better growth for the whole plant. According to seedling quality, seedlings produced in the 162 trays or with four seeds per cell showed higher growth than other seedlings. In the cultivation of V. rotunda var. subintegra (Nakai) T.Yamaz., seedling growth increased depending on container capacity for both shoot and root parts. Container material had no significant impact on seedling growth. Seedlings grew the best on horticultural substrate, and showed better growth on mixed soils with high decomposed granite content than on peatmoss.

• Korean journal of applied entomology
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• v.4
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• pp.25-28
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• 1965

The study was carried on a new disease of rice seedling which named 'Black rot of rice seedling'. None of papers on this disease was reported recently. The symptom of this disease was quite different from other seedling rot of rice plant. Submerged mycelial growth in water was black colored and it was surrounded whole surface of seed. Soil on which diseased seedlings were placed was black colored by this disease and the seedlings, finally stopped to grow within 3 em in height, and appeared with black rot symptom. Sporulation of the pathogen does not occurred under both of natural and artificial conditions. The mycelium appeared in dark color and with distinguished septation under the microscope. With those results it is easily recognized that the pathogen does not belong to those which causal organism:; of other seedling rot of rice plant like as Phycomycetes or Fusarium species. The study should be continued on identification of the causal organism. Favorable environments for the disease did not differ from other seedling rot of rice plant, and varietal resistance also did not significantly differ among the varieties used in this experiment. Dissemination of the disease was carried out not by planted seeds but by infected soil.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.208-208
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• 2017

No-tillage practices are expected to provide several benefits such as increasing soil organic matter, reducing labor time and saving energy cost compared with conventional tillage practices. This study was conducted to investigate the effects of no-tillage dry-seeding on rice growth and soil properties in comparison with other rice cultivation methods, machine transplanting and wet-hill-seeding on puddled paddy. Rice seedling establishment was slightly higher in no-tillage dry-seeding treatment ($145seedling\;m^{-2}$) than wet-hill-seeding on puddled paddy treatment ($111seedling\;m^{-2}$), but the seedling establishment in both treatments fell within the optimum range for direct seeding rice cultivation. Plant height, number of tillers and chlorophyll content (SPAD value) of rice in no-tillage dry-seeding treatment were higher than those of the other treatments. However, no significant differences in grain yield was observed among three cultivation methods, and the yield ranged 5.8 to $5.9ton\;ha^{-1}$. The heading date from seeding under no-tillage dry-seeding treatment was on average 109 days, which was similar to that under machine transplanting treatment (112 days), but 10 days later than that under wet-hill-seeding on puddled paddy treatment (99 days). Grain quality characteristics grown in no-tillage dry-seeding were similar to those grown in the other cultivation methods. These results indicate that no-tillage dry-seeding practice is comparable to conventional tillage system in terms of seedling establishment, growth, yields and grain quality.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1303-1310
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• 2016

Although many studies on the effects of genetically modified (GM) crops on soil microorganisms have been carried out over the past decades, they have provided contradictory information, even for the same GM crop, owing to the diversity of the soil environments in which they were conducted. This inconsistency in results suggests that the effects of GM crops on soil microorganisms should be considered from many aspects. In this study, we investigated the effects of the GM drought-tolerant rice MSRB2-Bar-8, which expresses the CaMSRB2 gene, on soil microorganisms based on the culture-dependent and culture-independent methods. To this end, rhizosphere soils of GM and non-GM (IM) rice were analyzed for soil chemistry, population densities of soil microorganisms, and microbial community structure (using pyrosequencing technology) at three growth stages (seedling, tillering, and maturity). There was no significant difference in the soil chemistry between GM and non-GM rice. The microbial densities of the GM soils were found to be within the range of those of the non-GM rice. In the pyrosequencing analyses, Proteobacteria and Chloroflexi were dominant at the seedling stage, while Chloroflexi showed dominance over Proteobacteria at the maturity stage in both the GM and non-GM soils. An UPGMA dendrogram showed that the soil microbial communities were clustered by growth stage. Taken together, the results from this study suggest that the effects of MSRB2-Bar-8 cultivation on soil microorganisms are not significant.