• Journal of Sericultural and Entomological Science
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• v.29 no.1
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• pp.7-11
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• 1987

The influence of planting density, on the mulberry yield, had been studied for 5 years period since 1982. For this purpose, a hilly land (15$^{\circ}$) was selected and 5 planting density level (926, 1,667, 2,780 and 3,444 tree/10a) were used. Following results were obtained. 1. Vinyl mulching promoted 2 days earlier of green tip sprouting stage and 3 days earlier of shallow-bill stage, compared with the non-mulching. 2. It was shown that increase of the length of the branch with vinyl mulching and decrease of the mulching effect with the higher density of plants from, 2,780 tree/10a. 3. When the planting density was higher, length and width of leaf was decreased sharply, and chlorosis of the lower part of the branch was occured heavily. 4. With the higher planting density, number of branches per tree and average length of the branch was decreased. Number of shorter branch-normal branch ratio were increased. However, number of branches and total length of branch per area were shown opposite. 5. Yield of mulberry was increased for the peroid of 3 years after planting with the all the levels of planting density after that, yield increase was dully in 926 tree plot, and more dully in 1,677 trees plot, while decrease of the yield were showen with density of 2,780 and 3,444 trees plots. 6. The highest average yield for the 5 years were obtained from 2,780 trees plot, 46.6% higher than in 926 trees plot, followed 40% higher in 3,444 trees plot, and 29.9% higher in 1,667 trees plot. 7. Soil pH, organic matter, Ca and Mg decreased with cultivation, especially P2O5, pH, Ca and Mg in the density of more than 926 trees plot.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.1
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• pp.37-44
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• 2002

This study was conducted to investigate the effects of the application rate of cattle slury and urea N on productivity of corn and environmental pollution in com cultivation soil. The experiment was conformed in lysimeter which was constructed with 0.33m diameter and 1m height. This study was arranged in split plot design. Main plots were the application rate of mineral fertilizer, as urea, such as 0, 100 and 200kgN/ha and subplots were the application rate of cattle slurry, such as 0, 200 and 400kgN/ha. The results obtained were summarized as follows. 1. Dry matter yields of corn increased as the application rate of cattle slurry and urea increased. 2. Total nitrogen content of whole corn was increased as the application rate of cattle slurry and urea increased 3. The average nitrate content in leaching water by application rate of the slurry and urea N was 7.78$\mu\textrm{g}$/$m\ell$(ranged from 6.27 to 9.02$\mu\textrm{g}$/$m\ell$). Nitrate content was hardly influenced by application rates of the slurry and urea. However, nitrate content rises in proportion to a rise in precipitation.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.478-487
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• 2013

Onions were treated with different amounts of sulfur (S) during cultivation and examined for their physicochemical properties and flavor. Onions cultivated without S application were the control group; the treatment groups were grown in soil that had been pretreated with S and received additional S applications or four times before harvest. As the number of S applications increased, the levels of crude protein, quantified with total nitrogen; ash, approximating total amounts of minerals; and dietary fiber of the onions tended to increase. The mineral compositions also improved, with noticeable increases in the levels of Mg, K, Fe, and Zn. In particular, the reducing capacity of the onions increased appreciably (p<0.05), without increases in the levels of S-containing compounds such as thiosulfinate or S-containing amino acids. Nevertheless, the spicy hot taste and flavor, which is generated mainly from S-containing compounds, were perceived more strongly in the onions that had received more S applications.

• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.175-180
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• 2002

This study was conducted to examine the effect of row covering materials on the growth and yield of broccoli for early production in the open meld. Materials for plastic tunnel were row-covering (ventilating non-woven fabric), perforated film (2.3％ pore space) and P.E. film. The types of row covers were tunnel and covering period was one months after transplanting. The row cover and perforated film increased daily air and soil temperature by 3~4$^{\circ}C$ and 2~3$^{\circ}C$, respectively as compared to no covering. Also, relative humidities in those treatments were higher than those in P.E. and no covering. The row covering and perforated film enhanced plant growth. Broccoli grew best and abnormal head appeared the least with row covering treatment. Days taken for head formation, however, did not differ between treatments but the weight of curd was over 400 g in the treatment of row covering and perforated film covering. Marketable yield doubled under row covering as compared to no covering. The first harvest time was earlier by two weeks in row-covering. The results of this experiment indicated that covering row-cover film in spring cultivation was effective fer not only yield increase but also quality evaluation in early production of broccoli.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.295-302
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• 2005

The nitrogen (N) balance in Korea during 1985-1997 was calculated according to the surface balance method of the PARCOM guidelines and compared with Japanese N balance. The some differences were founded in the coefficients used on calculating N balance in two nations. Of the important parameters, which can make a big difference in balance, N input by organic fertilizers was not included in Korea different with Japanese, due to absence of reliable statistics and then made lower the input. Nitrogen destruction rate from livestock manure was adjusted differently with 15% in Korea but 28% in Japan. There was some difference in the conversion factors of livestock number into manure N quantity in two nations, but the gap was ignoble scale except beef cattle. Our manure N production rate of beef cattle might be evaluated to be so lower than Japanese. Biological N fixation by pulses was very higher in Korea than in Japan but scarcely affect the increase of total N input, due to small cultivation area. In contrast, N fixation rate by free-living organisms in Korean and Japanese wet paddies showed the big difference with 7.6 and $37.0kg\;ha^{-1}\;yr^{-1}$, respectively, and therefore $29.4kg\;ha^{-1}\;yr^{-1}$ of nitrogen was estimated to be more inputted in Japan. Although there are many points to be more specified and improved, still, Korean N balance was very high with $250-257kg\;ha^{-1}$ in the mid of 1990s, which was the second highest level in OECD countries and furthermore increased continuously during the investigation. In contrast in Japan, which has similar fanning system with Korea, N balance was lower with $130-158kg\;ha^{-1}$ and has decreased continuously since 1993. This high N balance was mainly due to a high usage of chemical fertilizers in our intensive fanning system and the fast increment of livestock feeding. Therefore, the more active action to decrease chemical fertilizer utilization and reduce livestock feeding density is required in the government and farmer sides.

• Korean Journal of Plant Resources
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• v.12 no.2
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• pp.107-119
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• 1999

In this study, the induction regeneration of callus from immature embryo in trifoliata orange (Poncirus trifoliata RAFIN.) were accomplished. The embryogenic calli were induced from the immature embryo derived from seed when the calli were irradiated for 16hr at about 2,000 Lux in $\frac{1}{2}$ MS medium supplemented with 3% sucrose, and 44.4$\mu$M BA. Regeneration to whole plants was the most successful in MS medium containing 5.0$\mu$M BA. The yellowish callus was developed at 2 to 3 weeks of culture and the callus was changed from yellow to green at 5 to 6 weeks culture. In vitro regeneration was directly induced from embryogenic callus in MS medium containing 3% sucrose and 5.0$\mu$M BA. Multishoot was formed at 16 weeks culture. Moreover, when the root-formed plantlet was transplanted to soil, they grew to a whole plant. The compact cultured-cells were observed by light microscope after 4 weeks of cultivation and the embryogenic clumps were formed about the 5 weeks. At the same time, the neighboring cells were liquefied. In addition, differentiation of leaf and stem from the callus was observed after 12 weeks. The developed oil sacs and the profacicular cambium of the immature leaf were observed after 18 weeks. Therefore, we can see the considerable changes of cell arrangements according to the developmental stages of calli from trifoliata orange.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.160-167
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• 2011

Shallot is a foreign crop introduced from France in 1995 as a new overwintering field crop with an aim to develop as an export crop. During the introductory cultivation trials, several problems were raised such as premature growth depression in early summer, sensitivity to summer moisture, and weakened vigor of the seed bulbs following successive propagations. This study was conducted to develop proper cultural methods based on annual productivity and adaptability of growing area to address and suggest solutions to some of these problems. Bulb weight was 18.7 g and bulb yield per 10a was 4,113 kg in 1995. In 1996, bulb weight increased to 25.8 g, while bulbs yield per 10a deceased to 2,013 kg. This trend continued in 1997 so that bulb weight increased, and yield per 10a decreased as compared to those in 1996. However, in 1998, both bulb weight (21.1 kg) and yield per 10a (1,246 kg) decreased significantly as compared to those of the previous years. Plant growth from planting to April in the coastal area was better than in other areas. However, the plant growth thereafter until early July was better in the semi-highland area. As a result, the bulb yield in the semi-highland area was 57% more than that in the lowland areas such as the coastal area.

• Korean Journal of Weed Science
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• v.17 no.4
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• pp.390-399
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• 1997

This experiment was conducted to introduce PAT (phosphinothricin acetyltransferase, non-selective herbicide bialaphos resistant gene) gene into potato (Solanum tuberosum. cv. Desiree). Optimal shoot regeneration from leaf discs and stem segments was obtained in MS medium supplemented with 0.1 mg/L IBA and 0.5 mg/L BA, and the frequency of shoot regeneration was 54% in left discs and 46% in stem segments. In this condition, leaf discs and stem segments of potato were co-cultivated with A. tumefaciens MP90 which contained binary vector with GUS: :NPTII gene and PAT gene. Transgenic shoots were regenerated from leaf and stem-derived calli on selection medium with 100mg/L kanamycin. The 100${\mu}M$ acetosyringone treatment during the co-cultivation highly enhanced(4 times than the control) the shoot regeneration on selection medium. When the putative transgenic plants were transferred to medium with 10mg/L basta, all of them were survived. After PCR. GUS test, and Southern blot analysis of the survived plant, we confirmed that the gene was stably integrated into the potato genome and expressed. After the transgenic plants were transplanted in soil, and the transgenic plants were sprayed with the herbicide basta (300ml/10a), the transgenic plants remained green but control plants were died.

• Journal of Life Science
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• v.20 no.3
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• pp.403-410
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• 2010

In order to produce high-quality fermenting composts, a microorganism was isolated from the natural world. The bacterium has not only in high enzyme activities but also had good antimicrobial activities against phytopathogenic microorganisms. Its cultivating characteristics were then investigated. Bacterium KJ-9, which contains high CMCase, protease and chitinase activities and excellent antimicrobial activities against phytopathogenic microorganisms, was separated from leaf mold and identified as Bacillus licheniformis by two methods: Bergey's Manual of Systematic Bacteriology and API 50 CHL Carbohydrate Test Kit (Bio Merieux, France) using an ATB (Automated Identification) computer system (Bio Merieux, France). Optimal medium for cultivation of B. licheniformis was 2% soluble starch as a carbon source, 0.5% yeast extract as a nitrogen source and 0.05% $MgSO_4{\cdot}7H_2O$. Optimal growth conditions of pH, temperature and shake speed were pH 7.0, $50^{\circ}C$ and 180 rpm, respectively. Culture broth of B. licheniformis KJ-9 cultured for 36~60 hr was effective in fungicidal activities against plant pathogens including Botrytis cinerea, Corynespora cassicola, Fusarium oxysporum, and Rhizoctonia solani.

• Korean Journal of Medicinal Crop Science
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• v.23 no.3
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• pp.198-206
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• 2015

This study was conducted to investigate the effects of sowing density, number of seeds sown per hole, and thinning treatment on growth characteristics and disease occurrence in Panax ginseng under direct sowing cultivation in a blue plastic greenhouse. Seedling were grown from 2 or 3 seeds sown, and the healthiest was only retained, while the rest were thinned out at the foliation stage. $NO_3$-N, $P_2O_5$, and organic matter content differed significantly between growth conditions in the plastic greenhouse and in conventional shade in the soil. Disease also tended to be higher in the conventional shade than in the plastic greenhouse. Plant height and stem length showed an increasing trend with increasing sowing density and number of seeds sown per hole. However, these measures noticeably decreased when thinning treatment was conducted. Growth of the subterranean part of ginseng was not markedly influenced by sowing density, the number of seeds sown per hole, or thinning treatment. Root weight, which is an important factor in yield, was significantly affected by the number of seeds sown and thinning treatment. Interestingly, root weight tended to be higher in the thinning treatment plot than the untreated control plot. Damping-off and root rot increased noticeably as the number of seeds sown increased. Disease also tended to be substantially higher in the thinning treatment plot than the untreated control. However, physiological disorder of the plants did not vary with sowing density, the number of seeds sown, or thinning treatment.