• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.515-521
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• 1997

Tobacco plant was grown for 40 days hydroponically in nutrient solutions composed of different forms of nitrogen, like NO$_3$$^{[-10]}$ -N, NH$_4$$^{＋}$-N, and a mixed formulation of NO$_3$$^{[-10]}$ -N and NH$_4$$^{＋}$-N. Uptake response, nitrate reductase, and glutamine synthetase activity at growth stage were investigated to understand the basic knowledge of nitrogen metabolism. The better growth of shoot and root was observed in the mixed nutrient solution than NO$_3$$^{[-10]}$ -N or NH$_4$$^{＋}$-N, alone. The plant growth in NH$_4$$^{＋}$-N nutrient solution was poor due to ammonium toxicity. The pH of nutrient solution containing NO$_3$$^{[-10]}$ -N increased up to 40 days after transplanting. But the pH of solution containing NO$_3$$^{[-10]}$ -N decreased drastically to 3.42 at 20 days after transplant. The pH in the mixed formulation dropped to pH 3.64 at 30 days after transplant and showed re-increase. It is assumed that nitrogen of NH$_4$$^{＋}$-N form was taken up preferentially at early stage and NO$_3$$^{[-10]}$ -N form was taken up preferentially at middle stage in the treatment with the mixed solution. The result indicates that the relative proportion of nitrogen forms affected the uptake patterns at each growth stages. The contents of chlorophyll and soluble protein were high with the mixed solution. Total nitrogen content was the highest in NH$_4$$^{＋}$-N solution and the content also increased by the application of the mixed type of nitrogen. The amount of nitrate in leaves was high in NO$_3$$^{[-10]}$ -N treatment and the amount of ammonium was high in NH$_4$$^{＋}$-N treatment. The activity of nitrate reductase or glutamine synthetase was highest in the leaves grown in mixed nutrient solution than in those with any other single of nitrogen form.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.1013-1022
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• 2004

This study investigated the effects of silkworm droppings(SWD) added diet feeding on chemical composition of pork loin meat. Pigs were divided into 7 treatment groups(10 pigs/group) and subjected to one of seven treatment diets(O, 1 0/0, 2 0/0, 3% SWD for 4 weeks, 1 0/0, 2 0/0, 3% SWD for 8 weeks, SWD diets; total fed diets) before slaughter. Pork loin were collected from the animals(1l0 kg body weight) slaughtered at a commercial slaughter house. Pork loin meat were aerobic packaged and then stored at$4^{\circ}C$ for 2, 5, 8, or 12 days. Samples were analyzed for TBARS, sensory evaluation, myoglobin content, fatty acid composition, amino acid and mineral content. TBARS value was not significantly different between the control and SWD treatment groups. Myoglobin content of SWD fed group pork was significantly increased than that of control group(P<0.05). Marbling score and acceptability were increased in SWD fed pork compared to those in control pork. Na, Mg, Ca, Mn and Fe content of SWD fed group pork was significantly decreased than those of control group(P<0.05). P content was significantly increased than that of control group(P< 0.05). In the change of amino acid composition, the contents of aspartic acid, serine and tyrosine were decreased by dietary SWD-supplementation, whereas the SWD-supplementation resulted in the higher glutamic acid, alanine and isoleucine. As dietary SWD was increased in feed, the content of oleic acid was significantly increased, but stearic acid was significantly decreased(P<0.05).

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.377-385
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• 2011

This study was carried out to investigate quality characteristics of dry-cured hams in the domestic market. Two kinds of dry-cured hams were processed with pork leg (T1) and pork neck (T2). Five 24-month dry-cured legs (T1, 5.3-6.1 kg) and twenty 4-month dry-cured pork necks (T2, 1.5-1.9 kg) were used in this experiment. They were stored at $4^{\circ}C$ chilling room and quality characteristics were investigated. Moisture content, water activity, cholesterol content, CIE $L^*$, VBN, total plate counts and lactic acid bacteria of T1 were significantly higher (p<0.05) than those of T2, whereas fat content, ${NO_2}^-$, CIE $a^*$, TBARS and Warner-Bratzler shear force values of T2 were significantly higher (p<0.05) than those of T1. In fatty acid compositions, palmitoleic acid and stearic acid in T2 were significantly higher (p<0.05) than T1, however, oleic and linoleic acid in T2 was significantly lower (p<0.05) than T1. In free amino acids, the total content and individual content of asparagin, leucine and phenylalanine in T1 were higher than those of T2 (p<0.05). The aroma score of T2 was higher than that of T1 in sensory evaluation (p<0.05). In conclusion, two kinds of dry-cured hams were different in their final characteristics and could enhance the consumer's appeal of pork meat in Korean market.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.3
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• pp.193-200
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• 2004

This pot experiment was conducted to investigate the effects of systematic variation application of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover. The treatments of systematic variation were 0/100, 25/75, 50/50, 75/25, and $100/0\%$ in the Fe/Cu(trial-1), Mn/Zn(trial-2), and Fe+Cu/Mn+Zn(trial-3), respectively. The treatments of Fe/Mn/Cu/Zn(trial-4) were composed of $70\%$ in main element and $10\%$ in other 3 elements, respectively. 1. By the systematic variations of Fe, Mn, Cu, and Zn, the yields were more significantly influenced in white clover than in orchardgrass. In addition, the yields of white clover were closely correlated to the trends of root/nodule growth and flowering. In the Fe/Cu trial, the relatively high yields were obtained at the $100/0\%$ in orchardgrass and at the $75/25\%$ in white clover. The yields of white clover were more negatively influenced by the 100/0(Cu control) than by the 0/100(Fe control). The yields of orchardgrass, however, tended to be opposite to the above trends. 2. In the Mn/Zn trial, both forages showed generally high yields at the high ratios of Mn/Zn. Compared with orchardgrass, the yields of white clover were greatly decreased by the Mn-deficiency(low ratio of Mn/Zn). The effects of Zn on forage yields, however, were not recognized. 3. In the Fe+Cu/Mn+Zn trial, the yields of orchardgrass tended to be slightly different among the treatments. The yields of white clover, however, were relatively' high at the 75/25, and showed a severe decrease at the 100/0 in the 2nd half cuts. In the Fe/Mn/Cu/Zn trial, the yields of white clover tended to be relatively high at the Cu and Zn treatments. It was likely to be caused by the balanced Fe/Mn ratio.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.3
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• pp.217-224
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• 2004

This study was carried out to select the promising forage crops for forage production in paddy field of HARI, RDA, Iksan from 1999 to 2001. The species of forage crop used in this experiment were barley(5 varieties), wheat(2), rye(3) and Italian ryegrass(IRG, 3). Stage of heading, milk and yellow ripe of barley were 26 $April{\sim}l$ May, middle May and late May, respectively. In milk to yellow ripe stage, dry matter(DM) yield of barley was $6.64{\sim}10.47$ MT per ha, and averaged ADF and NDF contents were $31.6\%\;and\;62.2\%$ respectively. Albori was the most promising variety among the barley). The growth of wheat was a little late compared to that of barley, but it seemed to be crop having higher forage yield md nutritive value. In milk to yellow stage, DM yield of wheat was $7.51{\sim}11.96$ MT per ha, and nutritive value of wheat was high(ADF $30.6\%$ and NDF $60.1\%$). Heading stage of rye was $25{\sim}27$ April, and it seemed to be suitable to harvest at heading to flowering stage because of heavy lodging after flowering. In flowering stage, DM yield of rye was 17.26 MT per ha, and nutritive value of rye was the lowest among 4 species(ADF $38.6\%$ and NDF $65.5\%$). Heading stage of early maturing IRG was 30 April and it seemed to be suitable for harvest at flowering stage of middle May in cropping system. In flowering stage, DM yield of early type IRG was 10.77 MT per ha, and averaged ADF and NDF contents were $31.6\%\;and\;59.2\%$, respectively. The results demonstrated that the promising forage crops for forage production in paddy field were rye, barley, early maturing IRG and wheat in Honam region. In Southern region, rye harvesting at early May was recommended when considered middle May of rice transplanting period, and barley(Albori) and early maturing IRG harvesting at middle May were recommended when considered late May of rice planting period. And also, wheat with high nutritive value and possibility for harvesting at late May were recommended in case of transplanting period at early June.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.2
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• pp.145-154
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• 2004

The objective of this experiment was to suggest the optimum cutting height for turf type mixtures{Kentucky bluegrass(Newport) 40％ + tall fescue(Rebell Jr) 20％ + perennial ryegrass (Palmer Ⅱ) 10% + redtop(Barricuda) 10％ + red fescue(Salem) 10% + creeping bentgrass(Crenshaw) IO%}. The fields trials were conducted from 1998 to 2001 at Chungnam National University in order to evaluate the dry matter yield and quality on the cutting heights(3, 4, and 5cm). With increasing the cutting height, the average DM yields of turf type mixtures over 3-year significantly increased, therefore the average total DM yields were obtained 11,158, 12,143 and 13,181㎏/ha at cutting height 3, 4 and 5cm(p<0.05), respectively. The CP content and OMO decreased(p<0.05), whereas the fiber contents slightly increased with increasing the cutting height. The average CPDM and DDM yields were obtained 2,012 and 8,621㎏, 2,097 and 9,461㎏, and 2,298 and 9,951㎏ at cutting height 3, 4, and 5㎝(p<0.05), respectively. The botanical compositions of Kentucky bluegrass and tall fescue were maintained high as 30 ∼ 36％, but that of perennial ryegrass was maintained low as 10-15%. Most of other species were low, but redtop and creeping bentgrass among the other species made up 8∼10％ and 7 ∼ 8% of botanical composition at the last 6th cutting time in 2001, respectively. In general, the level of cutting height of turf type mixtures was not more closely associated with botanical composition. The results of this experiment indicated that a 5㎝ of cutting height of turf type mixtures sown by extensive method would seemed adequate.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.1
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• pp.43-48
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• 1993

This experiment was carried out to determine the effects of application time of cattle slurry on grazing pasture on the grass growth, dry matter yield, nutritive value, animal preference, and efficiency of pasture utilization. Four different application times of slurry(right now after grazing, 5th day, 10th day, and 15th day after grazing), and a no-slurry(control) plot were designed, 1991∼1992. Annual application amount of slurry was 40 ㎥/ha, and slurry was applicated in spring(2 times), summer and autumn. Total NPK fertilizer applicated were same as 280, 200 and 240 kg/ha in all treatment, respectively. The pasture was grazed with growing beef cattle(initial body wt.; ca. 250 kg) at every 30∼35 cm of plant height. The grass height, dry matter yield, crude protein yield, and other nutritive value were not different among treatments. However, the animal preference and efficiency of pasture utilization showed significant difference by application time of slurry. The highest grazing preference (1: the worst∼9: the best). and utilization efficiency (0∼100%) were observed by application time of right now after grazing (7.8, 76%), which was same to control(7.8, 77%), and followed by 5th day after grazing(7.3, 74%) and l0th day after grazing(6.9, 71%). But the preference and pasture utilization were greatly decreased at application time of cattle slurry of 15th day alter grazing(5.5, 60%). From the above results, the optimum application time of cattle slurry on grazing pasture to enhance animal preference, and efficiency of pasture utilization was within 5 days after grazing (less than 13.6 cm of plant height), and within 10 days after grazing (less than 18.5 cm of plant height) at least.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.251-258
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• 1999

A field experiment was carried out to determine the effects of chemical /mechanical treatments at mowing on the field drying rate and hay quality of rye (Secale cereale L.). The chemical drying agent/mower conditioner ($K_2CO_3$ 2%, conditioning, $K_2CO_3$ 2% + conditioning and control) were treated at different harvest stage (late boot, heading and bloom stage) for hastening hay-making in the spring of 1996. After field dry, square bales were made by hay baler, and the dry matter(DM) loss, visual estimation and nutritive value of rye hay were evaluated after storing two months. The field drying rate of rye was higher with delayed stage of harvest, and mechanical and chemical + mechanical treatment, but the effectiveness of chemical alone was very low. With mower conditioning, the duration of field dry was shortened by 1.5 to 2 days compared with control. The DM loss of rye hay was reduced by late harvest and mechanical, and chemical + mechanical combined treatment, but the efficiency by chemical alone was very low. The visual score (Ieafiness, green color, odor and softness) of hay after storing was high in mechanical and chemical + mechanical, but the score by chemical alone was very low. The nutritive value (ADF, NDF, digestibility, and relative feed value) of hay was also high with treatment of mechanical and chemical + mechanical, but the quality by chemical alone was similar compared with control. The quality of hay was very low when harvested at bloom stage. In conclusion, mower conditioning can enhance the field drying rate of rye, but the drying effectiveness of chemical drying agent was very low. The effect of chemical/mechanical combined treatment was very similar when compared with mechanical alone. Harvest at early heading to heading stage was recommended for high quality rye hay.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.495-503
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• 2011

We evaluated the quality characteristics of fresh-cut produce (potato, sweet potato, carrot, radish, zucchini, cucumber, and green bell pepper) washed with sodium hypochlorite, which were vacuum packaged, and stored at 4 and 10$^{\circ}C$. The L-values of the fresh-cut potato and sweet potato decreased during storage. Lower PPO activities of potato and sweet potato were observed at 4$^{\circ}C$ than those at 10$^{\circ}C$ and development of potato and sweet potato browning was delayed at 4$^{\circ}C$. Total aerobic count and coliform increased continuously at 10$^{\circ}C$ during storage. Diced zucchini and shredded sweet potato had the greatest reduction in hardness among the fresh-cut produce during storage. Differences in the rate of quality change were observed according to the kinds and cut types of produce. Thus, a quality maintenance period for each type of fresh-cut produce must be determined, which will lead to the safe use of fresh cut produce in foodservice establishments.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.463-470
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• 2012

As the advanced seeding technology through use of plug tray for good cultivation of seeds was propagated along with the expansion and development of horticultural industry, the use of bed soils as growing medium has recently been increased. In this study, the effects of the four clay minerals such as illite, phyllite, zeolite, and bentonite on the early growth of red pepper in the bed soil were investigated. Furthermore, proteome analysis for the leaf and stem samples of red pepper treated with only illite was performed. Of the seedling cultured, the healthy and regular size seeds were selected and cultivated in the pots, after they were treated with four clay minerals. The experiment was performed during the whole six weeks in the glasshouse of the Chungbuk National University. The growth lengths, fresh and dry weights of red pepper were significantly higher in the treatments of illite, phyllite, zeolite, and bentonite than in the control. In addition, the uptake of $K^+$, $Ca^{2+}$, and $Mg^{2+}$ were higher in the treatment of illite, phyllite, zeolite, and bentonite than in the control. The 2-DE patterns for the red pepper by the applications of illite, phyllite, zeolite, and bentonite were similar to each other. Therefore, compared to the samples of control, the proteome analysis for the samples of red pepper treated by only illite were performed. Proteome analysis for red pepper showed that plastid fructose-1, 6-bisphosphate aldolase class 1, aldolase, and glyceraldehydes 3-phosphate dehydrogenase, all of which were involved in the energy metabolism, were highly expressed in leaf tissue by illite treatment. In stem tissue, NAD-dependent formate dehydrogenase involved in energy metabolism, potassium transport protein, and GIA/RGA-like gibberellins response modulator were highly expressed. Based on the results obtained from the proteome analysis, it appears that the proteins specifically and differentially expressed on the illite treatment may be involved in the enhanced growth of red pepper. The identification of some proteins involved in the response of vegetable crops to the treatment of clay mineral can provide new insights that can lead to a better elucidation and understanding of mechanism on their molecular basis.