• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.1
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• pp.9-14
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• 2002

Evegradies 71' kenaf (Hibiscus cannabinus L.) was grown at 160,000 plants per ha in a volcanic ash soil in Jeju island to determine the optimum frequency of split N application fer forage production. Nitrogen fertilizer was applied with 240 kg/ha, and frequencies of the split N applications were 1, 2, 3, 4 and 5 times. Plant height averaged across two harvests increased from 187 to 201cm as N was split-applied from one to three applications and then decreased to 201cm in five applications. This pattern held for the number of branches and leaves per plant stem diameter and weight of plant per plant. Fresh forage yield increased from 91.8 to 114.2 MT/ha. dry matter yield from 12.70 to 16.6 MT/ha, crude protein yield from 1.75 to 2.48MT/ha, and total digestible nutrients (TDN) yield from 5.39 to 7.63 MT/ha as N was split-applied from one to four applications, and then decreased to 106.6, 15.0, 2.32, and 7.22 MT/ha in five applications, respectively As N was split-applied from one to five applications, crude protein content increased from 13.8 to 15.4%. ether extract content from 4.1 to 5.9%, and TDN content from 42.4 to 48.1%. but crude fiber decreased from 38.2 to 37.1% and crude ash content from 11.5 to 8.6%. Nitrogen free extract content was about 19.0% regardless of cutting height.

• Journal of Bio-Environment Control
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• v.7 no.2
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• pp.109-115
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• 1998

This study was conducted to evaluate the growth and flowering responses of Eustoma grandiflorum cv. Azmasul, Azmahoon and Azmazo influenced by duration of storage at 1$0^{\circ}C$ of seedlings raised in warm season. The plants after cold treatment were cultivated in a glasshouse under natural day length with the minimum temperature of 12$^{\circ}C$. The stem thickness and number of leaves of Azmasul and Azmahoon were not affected by duration of cold treatment However, plant height, internode length fresh and. dry weights were significantly increased in the four-week treatment. In addition, four-week treatment increased flower weight and width. Bays to flowering of Azmasul and Azmahoon in four-week treatment were shortened by 20 days compared to the control or two-week treatment. Shoot growth and flower Qualify of Azmazo under the four-week treatment were promoted. Four-week treatment reduced the days to flowering of Azmazo by 31 and 36 days compared to the control and two-week treatment. The results of this study show that optimum duration for storage at l$0^{\circ}C$ for seedlings of Ewtoma grandiflorum cv Azmasul. Azmahoon and Azmazo grown in warm season is four weeks.

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.41-46
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• 1989

The seeds of Malus sieboldii were collected in late fall of 1988 and stored in cold stratification condition for 15 weeks. Growth regulators such as $GA_3$, BA and ABA were treated to the seed to know germination capacity and seedling growth. The results were as follows. 1) Higher germination was achieved in $GA_3$ and BA plots, But ABA treatment showed lower germination percentage and physiological dwarf and also induced to the secondary dormancy condition in partly. 2) Average length of time for germination was delayed over 2 days in ABA plot when comparing with the other plots. 3) Average length of plumule and radicle also was inhibited by ABA treatment. This means lower seedling vigor. 4) Fresh and dry weight of the seeding were higher in BA plot while ABA plot was lower and undesirable seedling was produced. From above mentioned results, it is believed that ABA treatment to the seed induced the secondary dormancy and physiological dwarf pattern. Therefore, utilization of BA can be produced the normal seedling, the authors believed.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.133-139
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• 2017

This study investigated the effects of NaCl and jasmonic acid (JA) on the growth and physiological responses of spearmint (Mentha spicata L.). Spearmint was hydroponically grown for 3 weeks in modified Hoagland solution containing 0 (untreated control), JA ($20{\mu}M$ JA pretreatment), NaCl (50 mM NaCl treatment) and JA + NaCl ($20{\mu}M$ JA pretreatment + 50 mM NaCl treatment). Growth characteristics, chlorophyll, vitamin C, proline contents, DPPH scavenging activity and inorganic ion contents were evaluated. As a results, there were significant decreases in the plant height, leaf length, leaf width, and fresh weight of plants, treated with NaCl compared with control. On the other hand, the dry matters of shoot and root treated with JA + NaCl combination were better than control or NaCl treatment. Chlorophyll a and b contents in JA treatment was the highest. Vitamin C, antioxidant activity, and proline content in shoot were increased in NaCl treatment which showed low level of growth rate. The K/Na ratio, which is known to indirectly reflect the balance of ion uptake, was higher in a single treatment of JA than the control group, while lower in salt treatment (NaCl and JA + NaCl) because of high $Na^+$ absorption. In conclusion, these results showed that moderate stress treatment such as low level salt treatment and plant growth regulator jasmonic acid (JA) application would be potential strategies to improve the quality of spearmint by inducing the accumulation of secondary metabolites containing high antioxidant activity and essential oil.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.83-89
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• 2012

This study was performed to determine the effect of topdressing on maintaining the quality and density of zoysiagrass. An increase in the topdressing height from 2 mm to 16 mm (2, 4, 8, and 16 mm) led to an increase in the plant heigh, fresh and dry weight of shoots, roots, and stolons. The number of shoots, stolons and concentrations of chlorophyll and carotenoid also increased with increasing topdressing height. Moreover, total concentrations of nitrogen, phosphoric acid, potassium, magnesium, and lime in shoots and roots were enhanced as topdressing height increased. Acidity and the concentrations of organic matters, total nitrogen, and exchangeable cations ($K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$) of topdressed soil was higher than not topdressed soil, while the amount of available phosphoric acid in topdressed soil was lower than not topdressed. The topdressed soil enhanced the growth and density of zoysiagrass, while it was a crucial factor to affect the chemical property of the soil. Optimum topdressing height was thought to be 8 mm since topdressing the soil with topdressing height of 8 mm not only improved the growth of zoysiagrass but also resulted in the highest concentration of nitrogen and organic matters in the soil.

• Journal of Bio-Environment Control
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• v.23 no.1
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• pp.43-49
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• 2014

This study was designed to determine the effect of red LEDs during healing and acclimatization process on the survival rate and quality of grafted tomato seedlings. Red LEDs and no light (darkness) were used for treating three rootstock cultivars, which are 'B-Blocking', 'Kanbarune', 'High-power' in healing room. Results showed that survival rates of grafted seedlings in red LEDs were higher than those in no light treatment. Significant variation on survival rates of rootstock cultivars was observed in no light treatment but there was not significant variation in red LEDs treatment. Light treatment also reduced the percentage of infected plants, except for the 'Kanbarune' cultivar. Seedling quality in red LEDs was better than that in no light treatment by improving growth parameters such as plant height, leaf length, leaf width, leaf area, fresh and dry weight of shoot and root. Light treatments and rootstock cultivars did not affect number of leaves, leaf chlorophyll value and T/R ratio of seedlings, but seedlings in red LEDs were significantly more compact than those in no light treatment. Moreover, the root morphology of seedlings such as total root surface area, total root length, and number of toot tips in red LEDs was also greater than that in no light treatment.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.358-364
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• 2007

This study was carried out to investigate the effect of phosphorus concentrations in fertilizer solution on growth and development of nutrient deficiency in leaf perilla (Perilla frutesens). The nutrient concentrations in above ground plant tissue, petiole sap and soil solution of root media were also determined. Phosphorus deficiency resulted in a slow growth, lustreless leaves, suffused purple tining in older leaves and falling prematurely. Elevation of P concentrations in fertilizer solution increased the crop growth at 75 days after transplanting. The fresh weight in 0, 0.5 and 4.0 mM treatments were 0.48 g, 9.28 g, and 25.5 g, respectively, and dry weights were 0.06 g, 1.46 g and 4.13 g, respectively. The P concentrations in above ground plant tissue and petiole sap in 4.0 mM treatment were 1.78% and $2.040mg{\cdot}kg^{-1}$, respectively, at 75 days after transplanting. The soil P concentration in 4.0 mM treatment was $1.26mg{\cdot}kg^{-1}$ when it was determined by the 1:2 (sample:water) method. These results indicated that P concentrations higher than 0.3% in above ground plant tissue, $900mg{\cdot}kg^{-1}$ in petiole sap, and $0.57mg{\cdot}kg^{-1}$ in soil solution should be maintained to ensure proper growth of leaf perilla (Perilla frutesens).

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.311-319
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• 2011

Overusing chemical fertilizers involves potassium accumulation in the soil, which can become a toxicity problem in agriculture. This study was conducted to investigate the effect of potassium (K) treatment on growth, physiological characteristics, and morphological changes using Chinese cabbage (Brassica rapa L. ssp. campestris). With high (600 mM) K treatment, the plant growth traits of leaf length, leaf area, and fresh and dry weight of shoots and roots decreased, whereas chlorophyll content increased. As the concentration of K increasing, total N, P, and K increased in leaves, but concentrations of Ca, Mg, and Na decreased. However, Mn, Fe and Zn contents were highest in 100 mM K treatment. Chlorophyll a, b, and carotenoids increased with increasing K concentration. Maximum photochemical efficiency ($F_v/F_m$) was not significant in the all treatments, whereas $CO_2$ assimilation decreased with increasing K level due to stomatal degradation. Total free amino acids increased with the 10 and 100 mM K but decreased at 600 mM K treatments. Therefore, the growth and physiological characteristics of Chinese cabbage ascertained that tolerance up to 100 mM K when grown with nutrient solution in pot culture.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.139-145
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• 2016

The objective of this study was to compare the growth and light use efficiency of red leaf lettuce grown under three types of combined light-emitting diodes (LEDs) and fluorescent lamps (FL) in a closed-type plant production system. The eighteen days-old lettuce seedlings of red leaf lettuce (Lactuca sativa L., 'Jeokchima') were transplanted to the close-type plant production system equipped with three types of combined LEDs with red (R, 655 nm), blue (B, 456 nm), green (G, 515 nm), and white (W, 456 nm + 558 nm) (R:B=8:2, R:W:B=8:1:1, R:G:B=8:1:1) and FL. The seedlings were grown under normal growth conditions ($20^{\circ}C$, $181{\pm}4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 12 h photoperiod) for four weeks. Lettuce plants grown under FL had significantly higher leaf shape index than those under all LED treatments. Although growth of shoots and roots was not show any significant difference among LED treatments, all of the LED treatments induced about 34% higher shoot fresh weight than that of the FL. On the other hands, the total power consumption of FL was 145 kW for 4 weeks, while the mean value of LED treatments was 54 kW, which was about 3 times lower value than that of the FL. The light use efficiency based on dry matter in LED treatments was about 34 mg/W and this was about 3.5 times higher energy saving value than the FL. In conclusion, this study showed that irradiation of optimal combined LEDs in closed-type plant production systems can improve the lettuce growth as well as maximize in light use efficiency through energy saving than the FL.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.502-506
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• 2009

"Hongyoung" was bred within the potato breeding program of National Institute of Highland Agriculture (NIHA). It was originated from a cross made between Atlantic as a female and AG34314 as a male parent in 2003. "Hongyoung" was evaluated as a clone number Daegwan 1-102 for the growth and tuber characteristics, yielding ability, and resistance to major diseases in the regional yield trials from 2006 to 2007. Finally, this clone was renamed as "Hongyoung" and was presented to Korean Seed & Variety Service in 2007 for registration as a new potato cultivar. "Hongyoung" has a round shape, shallow eye depth, red skinned and fleshed tuber characteristics. Its mean tuber yields from the regional yield trials was 37.4 MT/ha, and it showed the highest yield in spring cropping. "Hongyoung" showed high resistance to common scab (Streptomyces scabies) and potato leaf roll virus (PLRV), however it was susceptible to both potato virus Y (PVY) and late blight (Phytophthora infestans). The dry matter content of "Hongyoung" was low to medium 17.7%, therefore it is suitable for table use. Its anthocyanin content was the highest in autumn cropping with 31.8 mg/100g fresh weight and it contained 3.6 times higher anthocyanin than the control, Jasim.