• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.52-57
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• 2006

This research was carried out to determine the effect of controlling nitrogen application on tiller development, yield, and quality of rice under scanty or excess seedling stands in direct-seeded rice on flooded soil surface. Seedling stand was set to 3 levels: scanty $(60/m^2)$, optimum $(120/m^2)$, and excess $(200/m^2)$. In the scanty plot, additional 4 kg/10a nitrogen was applied at the 3rd leaf stage to promote tiller development. On the other hand, applying 3.3 kg/10a nitrogen at 5th leaf stage in the excess plot was omitted to suppress tillering. Maximum numbers of tillers per plant were 15.2 and 8.6 in scanty and excess plots, respectively, as compared with 9.8 in optimum plot. Productive tiller rate decreased with the increase in number of seedling stands. Regardless of seedling density, the first tiller developed on the 3rd node of rice stem from the bottom. The primary tillers developed at 3, 4, 5, 6, 7 nodes in scanty plot, 3, 4, 5 nodes in optimum plot, and 3, 4 nodes in excess plot. The secondary tillers developed only in some portion of plants in scanty and optimum plots. The order of tiller emergence was negatively correlated to stem length, panicle length, non-productive tiller number, grain number per panicle, and fertility in scanty plot, and to perfect grain ratio in excess plot. In the optimum plot, however, the order of tiller emergence was not correlated to any of the mentioned characteristics. The perfect grain ratio of scanty plot was the highest because green-kerneled rice was a very small portion in the primary tillers as compared with those of optimum and excess plots. Yield indexes of scanty and excess plots were 99%, and 97%, respectively, of the yield (494 kg/10a) in optimum plot. In conclusion, when seedling stands are not at optimum level, rice yield and quality similar to optimum planting density level can be obtained by means of controlling nitrogen application.

• Korean Journal of Medicinal Crop Science
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• v.12 no.4
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• pp.279-284
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• 2004

This experiment was conducted to evaluate on agronomic traits of Korean local adlay (Coix lachryma L.) germplasm, 281 cultivars (lines). The largest collected cultivars was from Kyungsangbukdo (56 cultivars), and the next was in the order of Cheonlabukdo (48 cultivars), Kyungsangnamdo (44 cultivars), Kyunggido (39 cultivars) Chungcheongnamdo (23 cultivars), Kangwondo (23 cultivars), Cheonlanamdo (17 cultivars), and Chungcheongbukdo (16 cultivars) in distribution of collected region for 281 cultivars. In the growth stages, days to emergence from seeding were required $16.4{\pm}2.03$ days, days to heading from emergence was required $73.6{\pm}5.87$ days, days to ripening from heading was required $52.3{\pm}4.91$ days and cultivation period was required $142.5{\pm}5.87$ days. Culm length was $210.3{\pm}16.39$ cm, no. of tiller per plant was $10.4{\pm}2.13$, culm diameter was $11.7{\pm}1.09$ mm, fruiting position was $4.6{\pm}0.82$ node, no. of main culm node was $11.1{\pm}0.78$, degree of lodging was $5.3{\pm}3.42$ and severity of leaf blight was $56.1{\pm}0.78$ in the growth characteristics of the germplasm. In the yield of component, no. of grains per $m^2$ was $5,938{\pm}2,152$, percentage of ripening was $67.7{\pm}33.12$, 1,000 grains weight was $123.8{\pm}33.76$ g and grain weight was $473.0{\pm}207.90$ g. Grain weight was correlates significantly positively with no. of main culm node, percentage of ripening and no. of grains per $m^2$ among agronomic traits. Correlation coefficient between grain weight and 1,000 grain weight was positive, while grain weight and severity of leaf blight was significantly negative. Correlation coefficient between grain weight and days to ripening from heading was significant negatively.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.8-9
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• 2017

Soybean yield has been low and unstable in Japan and other areas in East Asia, despite long history of cultivation. This is contrasting with consistent increase of yield in North and South America. This presentation tries to describe perspective of breaking stagnation of soybean yield in East Asia, considering the factors of the different yields between regions. Large amount of rainfall with occasional dry-spell in the summer is a nature of monsoon climate and as frequently stated excess water is the factor of low and unstable soybean yield. For example, there exists a great deal of field-to-field variation in yield of 'Tanbaguro' soybean, which is reputed for high market value and thus cultivated intensively and this results in low average yield. According to our field survey, a major portion of yield variation occurs in early growth period. Soybean production on drained paddy fields is also vulnerable to drought stress after flowering. An analysis at the above study site demonstrated a substantial field-to-field variation of canopy transpiration activity in the mid-summer, but the variation of pod-set was not as large as that of early growth. As frequently mentioned by the contest winners of good practice farming, avoidance of excess water problem in the early growth period is of greatest importance. A series of technological development took place in Japan in crop management for stable crop establishment and growth, that includes seed-bed preparation with ridge and/or chisel ploughing, adjustment of seed moisture content, seed treatment with mancozeb+metalaxyl and the water table control system, FOEAS. A unique success is seen in the tidal swamp area in South Sumatra with the Saturated Soil Culture (SSC), which is for managing acidity problem of pyrite soils. In 2016, an average yield of $2.4tha^{-1}$ was recorded for a 450 ha area with SSC (Ghulamahdi 2017, personal communication). This is a sort of raised bed culture and thus the moisture condition is kept markedly stable during growth period. For genetic control, too, many attempts are on-going for better emergence and plant growth after emergence under excess water. There seems to exist two aspects of excess water resistance, one related to phytophthora resistance and the other with better growth under excess water. The improvement for the latter is particularly challenging and genomic approach is expected to be effectively utilized. The crop model simulation would estimate/evaluate the impact of environmental and genetic factors. But comprehensive crop models for soybean are mainly for cultivations on upland fields and crop response to excess water is not fully accounted for. A soybean model for production on drained paddy fields under monsoon climate is demanded to coordinate technological development under changing climate. We recently recognized that the yield potential of recent US cultivars is greater than that of Japanese cultivars and this also may be responsible for different yield trends. Cultivar comparisons proved that higher yields are associated with greater biomass production specifically during early seed filling, in which high and well sustained activity of leaf gas exchange is related. In fact, the leaf stomatal conductance is considered to have been improved during last a couple of decades in the USA through selections for high yield in several crop species. It is suspected that priority to product quality of soybean as food crop, especially large seed size in Japan, did not allow efficient improvement of productivity. We also recently found a substantial variation of yielding performance under an environment of Indonesia among divergent cultivars from tropical and temperate regions through in a part biomass productivity. Gas exchange activity again seems to be involved. Unlike in North America where transpiration adjustment is considered necessary to avoid terminal drought, under the monsoon climate with wet summer plants with higher activity of gas exchange than current level might be advantageous. In order to explore higher or better-adjusted canopy function, the methodological development is demanded for canopy-level evaluation of transpiration activity. The stagnation of soybean yield would be broken through controlling variable water environment and breeding efforts to improve the quality-oriented cultivars for stable and high yield.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.923-929
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• 2010

This study was conducted to investigate the relations between soil chemical properties and Korean raspberry (Rubus coreanus Miq.) growth. Soils were collected from 54 sampling sites in 1 to 6 years old Korean raspberry cultivation fields (RCFs) at Gochang-gun, Jeollabuk-Do, Korea. In RCF with two to six years old plants, soil pH and exchangeable $Ca^{2+}$ and $Mg^{2+}$ contents were higher at the leaf-emergence time, but EC, available phosphorus content, CEC, and total nitrogen content were higher at the harvesting time; especially at the harvesting time, the content of available phosphorus in the RCF with 3~6 years old plants were at least three times higher than in the RCF with 2 years old plants. Water-soluble anions ($Cl^-$, ${NO_3}^-$, ${PO_4}^{2-}$, and ${SO_4}^{2-}$) in the RCF were also measured. The contents of ${NO_3}^-$ and ${SO_4}^{2-}$ were always higher in the RCF with older plants than in the RCF with younger plants, which were not affected by sampling time and sampling locations (rhizosphere and non-rhizosphere sites). However, soils collected from non-rhizosphere at the leaf-emergence time contained higher ${PO_4}^{2-}$ content, but $Cl^-$ content was higher in the soils collected from rhizosphere at the harvesting time. In general, soils in the RCFs contained excess amounts of inorganic nutrients such as available phosphorus and exchangeable $K^+$. Thus, optimal levels of soil properties for Korean raspberry cultivation should be reconsidered.

• Current Research on Agriculture and Life Sciences
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• v.11
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• pp.61-70
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• 1993

We investigated the effects of shading on the plant growth, flowering and the bulbil formation of Lilium species. As the shading treatment, we used full sunlight and various light intensity, 30%, 50%, 75%, 90% compared to full sunlight with shading net. The results obtained were as follows. The flowering rate and flower number of 'Roma' and 'Georgia' were not effected by various shading treatment. Days to flower in 'Roma' and Tiger lily showed similiar tendency like this. One of the shading effect was stem elongation of 'Connecticut king' markedly reduced compared with other cultivars in flowering rate and flower number. Leaf number of all cultivars was not consistent in tendency. But leaf number of Tiger lily and 'Connecticut king' reduced. The tendency of other experimented Lilium species weren't consistent. Bract leaf number reduced gradually as shading rate increased, plant height and internode length increased. Especially the height of 'Georgia' showed eminant increase compared with others. Total number and weight of bulbil of 'Enchantment' and Tiger lily reduced as shading rate increased.. But bulbil weight from bract part of 'Enchantment' in creased. The bulbils of 'Connecticut King' and 'Roma' appeared only on upper stem parts when treated serious shaded conditions, 75% and 90%. Only 'Connecticut King' and 'Enchantment' showed leaf emergence from bulbil among the L. elegans species.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.1
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• pp.59-66
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• 1992

An experiment was conducted to determine the effects of seeding rates and nitrogen fertilization levels on the agronomic characteristics, nutritive value and forage yield of spring oat(Avena sativa L.). This experiment was undertaken over a period of 2 months from September to November, 1987. The results obtained are summarized as follows : Increased seeding rates of 120, 160 and 200kg/ha decreased emergence rates by 93.4, 71.4 and 70.6 %, respectively(P<0.05). Tillering was decreased by higher seeding rates(P<0.05) and that of 120kg/ha of seeding rate with 200kg/ha of nitrogen fertilization level was highest by 3.3. Among three seeding rates, tillering of 200 kg/ha of nitrogen fertilization level was lowest by 2.1. Leaf width was influenced by seeding rates. When seeding rate was increased, narrow leaf width (P

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.4
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• pp.304-310
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• 1981

In order to observe the degree and response of drought-resistance and its physiological mechanism in barley and wheat, 5 species (16 cultivars) were tested for changes in plant height, seedling dry weight, chlorophyll content, leaf relative turgidity, soluble protein, reducing sugar and growth of seedling subjected to water stress by withholding watering for 8 days at 10 days (at the 3rd leaf stage) after emergence. The average rate of decrease of all cultivars was 15% in plant height, 24% in seedling dry weight, 32% in chlorophyll content, 27% in leaf relative turgidity, and 27% in protein. But reducing sugar content of control was increased 4 folds more than that of water stress. In the decreased rate of seedling dry weight of each cultivar, rye was shown to be lowest rate, and Baegdong, Mokpo #55, and 3 two-row barley were shown to be the highest rate. The degree of the decreased rate in 5 species was in the order of rye < < wheat < covered barley < naked barley < two-row barley. in the decreased rate of chlorophyll content, rye, Cheonggaemil and Olmil are the lowest group, and the highest one are Milyang #12, Bangsa #6, Hyangmaeg and Sacheon #4. In the decreased rate of leaf relative turgidity, the lowest group (22-25%) were rye, Cheonggaemil and Dongbori #1, and, on the other hand, the highest group (30-33%) were Baegdong and 3 two-row barley. In the decreased rate of soulble protein, the lowest group (14-17%) were Chogwang, Geurumil, Dongbori #1, and Mokpo #55, and the highest one was 3 two-row barley. The increased ratio of reducing sugar of water stress to control was 4 to 5 folds in rye and wheat, and about 2 folds in naked barley and 3 two-row barley. The degree of the increased ratio of 5 species was in the order of rye > wheat > covered barley > naked barley > two-row barley. In terms of the physiological and adaptive metabolism during the processing leading to drought-resistance, the degree of drought-resistance of 5 species to water stress at seedling stage was shown to be in the order of rye > wheat > covered barley > naked barley > two-row-barley.

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.16-30
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• 1992

A field experiment was done to evaluate the growth response, rhizobia nodulation and vesicular-arbuscular mycorrhizal fungi (VAMF) infection of soybean treated with the different concentration of three-herbicides, alachlor, simazine, linuron. The results obtained were summarized as follows ; Emergence rate of soybean was non-significantly decreased by increasing the herbicide concentration. In simazine treatment, low emergence rate showed even in recommended concentration, especially the lowest emergence rate in treble concentration of recommended dose was about 50%. The plant length of soybean lowered by increasing the herbicide concentration, but there were almost no differences in recommended dose. Particularly that in a high concentration of herbicides at three weeks after treatment(WAT) was decreased remarkably. In the plant diameter of soybean shoot, no differences in the recommended concentration of alachlor and linuron at 2 WAT, but those of recommended dose was decreased with the lapse of time, and the lowest treatment was simazine-treated plot. Leaf area and fresh weight of soybean tended to decrease over the control even in recommended concentration and it was decreased with the increment of the herbicide dose. Yield component, fresh weight of rhizobia nodule and chlorophyll content of soybean leaves were reduced with the increment of herbicide dose, espicially remarkable tendency was revealed in simazine-treated plot. Seasonal infection rate of VAM showed a slight decrease by increasing of herbicide dose, and the lowest infection was simazine treatment. Significant correlation was realized among the reduction of rhizobia nodulation, VAM colonization and the agronomic characters of soybean and it was considered that the reduction of rhizobia nodulation and VAM colonization by misapplication of the herbicides might be a causal factor for decrease in soybean yield.

• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.115-123
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• 2005

The effect of sodium hypochlorite treatment on the germination of cattail (Typha spp.) seeds was investigated in growth chambers maintained on a 14-h photoperiod with various temperatures and light intensities. Germination rates of seeds were, in general, enhanced by the increase of light intensity and temperature regardless of cattail species. Seeds of T. oreientalis had 4.3, 13.0 and $7.3\%$ germination at temperatures of 20, 25 and $30^{circ}$C, respectively, under light intensity of 7.5${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. T. angustata showed higher germination rate, thus, 10.7, 22.7 and $50.7\%$ under same temperature and light environment. Under high light intensity of 79.5${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, the germination rates of T. oreintalis and T angustata were $78.3\%$ and $88.7\%$ at $30^{circ}$C, respectively. Scarification of seeds with NaOC1 ($4\%$, available chlorine) increased germination rate in both species, especially even at low temperature of $20^{circ}$C. Germination speed was also enhanced by NaOC1 treatment. High light intensity further increased the germination rate. When NaOC1 treated seeds were sowed on the soil surface in plastic house, the seedling emergence was nearly $100\%$. Untreated seeds of T. oreintalis and T. angustara showed 40 and $50\%$, respectively, in germination under same condition. However, when the depth of soil covering was over 1.0 cm, seedling emergence was retarded more than 1 month. On the process of seedling development, emergence of mesocoty1 occurred firstly and after than primary root and first leaf were developed on the end of elongated mesocotyl. These results suggest that the promotion of seed germination by NaOC1 pretreament may be induced from the increase of light absorptivity as well as water permeability through scarifying and bleaching the seed coat.

• Korean Journal of Weed Science
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• v.11 no.2
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• pp.111-116
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• 1991

This studies were conducted to get the basic information on the growth habits of Scirpus planiculmis F. Schmidt for control in poldered paddy field. The distribution of corm was about 16% in 0-5cm, 66% in 5-8 cm. 18% in 8-10cm depth of underground. The mean depth of total corm distribution was about 6.51cm. Number of rhizomes and dormant buds per corm were one to four, respectively. Number of rhizomes. dormant buds and total buds(rhizome+dormant bud) were 2.34, 2.85 and 5.20, respectively. The phyllotaxy of S. planiculmis was 1/3 and bracteal leaf were showed from first to 4th leaves. The period of propagation to 100 plants from emergence was 58.52 and 48 days for corm seeded on March 25th, b4ay 7th and June 6th respectively. Days to emergence of S. planiculmis from emergence of previous plant was gradually shorted. as order of propagation from corm seeded progressed. The other side, length of rhizome, plant height and diameter of culm was increased. The plant height of S. planiculmis was higher than rice plant from early stage in rice direct seeding culture, and from 30 dats after transplanting in rice transplanting culture. Speed of propagation was faster in rice direct seeding culture than in rice trasplanting culture.