• Korean Journal of Weed Science
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• v.8 no.3
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• pp.309-316
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• 1988

Several experiments were conducted to investigate the achene viability and growth characteristics of Eclipta prostrata (L.) L. No dormancy and no after-ripening requirement were found for E. prostrata achenes. When achenes were stored at room temperature, germination did not decrease with up to 5 months storage. Large differences in loss of viability of E. prostrata achenes occurred when different dehydration methods were used. Immediate dehydration resulted in high viability, but slow dehydration resulted in severe loss of viability. Achene viability at shallow burial depths (5 and 10 cm deep) was lower under upland soil conditions than under lowland soil conditions. Seedling growth was greatly reduced when flooding to a depth of 10 cm occurred at or before the 4-leaf stage. Flooding after the 4-leaf stage stimulated stem elongation. Branching started from the second week and usually terminated at the tenth week. Leaf size was determined by the branch which are related to the assimilate supply. Flowering of E. prostrata started during the fifth week after emergence, and mature achenes were produced from the sixth week. Ten to 14 days were needed for the achenes to mature. About 14,000 achenes were produced on each plant. Achene production per week increased from the sixth week to the tenth week and thereafter it declined. The average number of achenes per inflorescence decreased with delay in flowering.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.49-52
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• 1986

The objective of this study was to find out the productivity of F_2 material derived from F_1 hybrid Maize (Zea mays L.) by multiplication and their response to plant population. Suweon 19 and Junju-Ok were grown at three population densities. Populations were ca. 8.3, 10.4 and 13.9 thousand plants per 10a. The results are summarized as follows; 1. The number of barren plants differed significantly for the two generations but other yield components comparisons were not significant at P(0.05). 2. Ear and TDN yield were higher from the $F_1$ hybird of Suweon 19 than from the F_2 material, while yields of Jinju-Ok and stover yield of both hybrids were not affected by generation. 3. Plant and ear height were not affected by population density but barren plants were increased at high population. Length and weight of a ear, and ear (including cobs)-to-stover ratio decreased with increased population. 4. Increasing population density resulted in significant decrease in ear and TDN yield, while stover yield not decreased.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.225-236
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• 1998

KSC-13906 [Erythro N-{(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl} -2-(2-fluoro-1-hydroxy-n-propyl) benzenesulfonamide, US Patent 5,461,025] was investigated how can control phytotoxicity fluctuation and what a good method apply to new rice herbicide. The growth inhibition was observed when the rice plants was transplanted at a shallow depth(0 - 1cm) and leaching was low(0 - 1cm/ day) from the paddy soil. KSC-13906 appeared to move readily down into the paddy soil with water by 3cm depth in the soil column(${\phi}$ 10cm) filled with loamy sand soil under 3cm/day of leaching condition. Artificial control releasing pattern, designed as treated with KSC-13906 of 9 or 18g ai/ha either at a once or daily treated dividing volume of 1/20, 1/25 and 1/30 of the total volume, increased the safety of KSC-13906 to direct seeded and transplanted rice. The safety of KSC-13906 was also enhanced when KSC-13906 was mixed with dymron. For example, the mixture of KSC-13906 and dymron effectively reduced injury of direct seeded rice plants at 18 and 500g ai/ha, respectively, treated 7 days after transplanting. However, combination of KSC-13906 and several herbicides didn't show any synergistic effetct on herbicidal activity and safening effect on rice. However, the combination of KSC-13906+dymron (9~12+250~500g ai/ha) or KSC-13906+mefenacet+dymron(9+250+250g ai/ha) controlled almost all weeds in paddy field without causing any injury to rice and thus the combination would successfully be used as an oneshot herbicide in rice culture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.23-28
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• 2011

Resveratrol has been associated with reduced cardiovascular disease and reduced cancer risk. This phytochemical has been reported in a number of plant species including grapes, peanuts and pine trees in response to stress such as fungal infection, heavy metal ions or UV irradiation. The objective of this study was to determine the resveratrol contents in leaves of mulberry varieties at different collecting times. Quantitative analysis of 16 cultivars showed a range of $102{\sim}466{\mu}g/100g$ on dry weight basis (which is equivalent to $25{\sim}116.5{\mu}g/100g$ on fresh weight basis). Resveratrol contents in mulberry leaves was higher in autumn than spring, and higher in fully matured leaves than in juvenile leaves. Among the tested samples, 'Kaeryangppong', 'Sugeppong' and 'Cheongilppong' collected in the middle of October showed high resveratrol contents of $838{\mu}g/100g$, $803{\mu}g/100g$, $800{\mu}g/100g$ on dry weight basis, respectively. Especially mulberry leaves dried in the shade showed of $1,030{\mu}g/100g$ on dry weight basis in resveratrol content, this result may contribute to utilization of mulberry leaves.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.1-7
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• 2010

Stress from excess water is one of the most harmful limiting factor in soybean yield during the wet season under the climate conditions. Soybean is very sensitive to excess water compare to other crops. This experiment was carried out to identify the growth responses for establishing a screening system related to waterlogging tolerance in soybean from 2003 to 2004. The root dry weight accumulation rate of per day for 21 days after waterlogging at V5 stage was the highest in Pungsannamulkong (47~56% of control) and was the lowest in Jangyeobkong (26~27% of control). The nodules dry weight recovery rate was the highest in Pungsannamulkong (83~91% of control), while the lowest in Myungjunamulkong (48~66% of control). After waterlogging, recovery rate of roots was high, which increased the root/shoot ratio of Pungsannamulkong, which also produced significantly more adventitious roots than in Jangyeobkong. The percentage of adventitious roots fresh weight to the total roots fresh weight was the lowest in Myungjunamulkong (14%), while the highest in Pungsannamulkong (38%). This results implies that the water and nutrients absorbing ability of Pungsannamulkong is more higher than that of Myungjunamulkong during late growth period.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.3
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• pp.131-137
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• 1986

Korean lawn, Zoysia japonica STEUD, is the type of a perennial warm-season lawn grass that has a naturally green period during 5 months from May to September. This study was carried out to detect the effects of N-P-K fertilization, regrowth capacity after mowing and chlorophyll contents on prolongation of the green period in Zoysia japonica grasslands. The results obtained are summarized as follows: 1. The effects of nitrogen fertilizer application on Zoysia japonica grasslands were affected on regrowth capacity after mowing, green color of leaf canopies and chlorophyll contents, respectively. 2. A the experimental plots which applied 45g/$m^2$/10 weeks of $N_3$ fertilizer, there were high significant effects on prolongation of the green period and the plots of phosphorus and potassium had additive effects. 3. Prolongation of the green period to the last ten days of October was obviously possible by slow degrees in proportion to increment of N-P-K fertilization. 4. However, it is interpreted that more prolongation of the green period is impossible with N-P-K fertilization and irrigation treatments, unless the intermediate turfgrasses between $C_3$ and $C_4$ plants must be found and bred.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.271-276
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• 2017

Waterlogging strongly affects maize (Zea mays L.) growth. It is necessary to find the screening method of waterlogging tolerant maize lines. This study was to investigate the growth characters at V3 stage of maize, when is very sensitive to waterlogging. Six Korean maize inbred lines were subjected to waterlogging at V3 stage for 30 days. The 30 days waterlogging treatment significantly reduced plant height, number of expanded leaves, and SPAD value, compared with the control plants. SPAD values were significantly different among the six inbred lines, KS140 was the highest. The dry matter accumulation of aerial and root part were significantly decreased by 30 days waterlogging. KS140 was the weightiest among inbred lines. The dry matter of adventitious root showed same trend. Waterlogging treatment significantly reduced to ear length and thickness, grains filling length, grain number per ear, and maize grain. Plant height, SPAD value, and number of fully-expanded leave showed high correlation with maize grain yield, but number of senescent leaves, dry matter of adventitious root and TR ratio did not, suggesting that the former three traits may be good indicator for evaluating 30-day waterlogging tolerance of maize inbred lines. KS164 was the highest yield by increasing of grains filling length and grain number per ear of among waterlogging inbred lines. According to the results, evaluation of maize waterlogging should be consider both early growth characteristics and resilience in the later growth stages.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.259-264
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• 1999

A field experiment was carried out to determine the optimum application level of dicamba herbicide for efficient control of Calystegia japonica in silage corn field. Six treatments of application levels (0 ; control, $0.75{\ell},\;1.0{\ell},\;1.25{\ell},\;1.5{\ell},\;and\;2.0{\ell}/ha$) were arranged at National Livestock Research Institute, RDA, Suwon in 1995. The hybrid silage corn was DK 729, and dicamba herbicide was applied at 5~6 leaf stage of corn. The growth of corn was poor in control plot, and the days for tasseling and silking were delayed 1~4 days when compared with the plots of herbicide application. The control efficiency of Calystegia japonica was excellent as 74.3~94.6% in the plots of dicamba application. A slight injury of herbicide was observed at early stage of corn when applied at $1.25{\ell}$ and $1.5{\ell}$ of dicamba per ha, and severe injury was found at $2.0{\ell}$ of dicamba. Forage dry matter(DM) yield, and length of ear in the plots of dicamba treatments were significantly higher than those of control. The DM yield of control(4,866kg/ha) was only about 30% of dicamba treatment plot (14,960~16,340kg/ha). However, there was no yield difference among dicamba application level. The percentage of ear to total DM yield was ranged from 33.6 to 39.4%. With application of herbicide, the contents of crude protein and nitrogen free extract were increased, and that of crude fiber was decreased in stover. However, nutritive value of corn ear was very similar among all treatments, regardless of herbicide treatment. From the above results, it is recommended that optimum application level of dicamba herbicide was $0.75{\sim}1.0{\ell}/ha$ for efficient control of Calystegia japonica and for silage corn production without herbicide injury.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.426-431
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• 2012

This study was conducted to establish an efficient screening method for resistant tomato to Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL). The resistance degrees of the six commercial cultivars of tomato to the pathogen were evaluated by dipping roots of the seedlings in spore suspension of five FOL isolates. On the basis of the results, two cultivars (Dotaerangmaster, resistant cultivar to FOL race 1; Supersunload, resistant cultivar to FOL race 2) and two isolates (KACC40043, FOL race 2; TF104, FOL race 3) were selected for system establishment. The disease development of the FOL isolates on the cultivars according to several conditions including root wounding, incubation temperature, inoculum concentration and dipping period of roots in spore suspension was investigated. The resistance of each cultivar to the disease was a race-specific response and hardly affected by the tested conditions except for incubation temperature of $20^{\circ}C$. The optimum temperature for disease development caused by FOL was 25 to $30^{\circ}C$. On the basis of the results, we suggest that an efficient screening method for resistant tomato cultivars to Fusarium wilt is to dip the non-cut roots of tomato seedlings at two-leaf stage in spore suspension of $1{\times}10^7\;conidia{\cdot}mL^{-1}$ for 0.5 hours and transplant the seedling to plastic pot with horticulture nursery media, and then to cultivate the plants in a growth room at $25^{\circ}C$ for 3 weeks with 12 hours light a day.

• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.401-410
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• 1997

This experiment was conducted to investigate the opimum media, media amount and planting density of nutri-culture for the high quality and yield of wild vegetable, Liguliaria fischeri Turez. The fried rice hull was recognized best media among perlite, sand and fried rice hull for nutri-culture of Ligularia fischeri Turcz. The yield on fried rice hull media at early growing stage was lower, but higher than in other media at late growing stage. Therefore, total yield in fried rice hull media was 15-29% higher than that of the existing perlite media. Growth and yield of Ligularia fischeri Turcz. were not significantly different between medium amounts, therefore considering economical efficiency and stability, the optimum medium amount was 105 $\iota/m^3$, Yield by planting density increased in the high density and 50 plants/$m^2$ was considered as proper planting density in nutri-culture of Liguliaria fishcheri Turcz.