• Korean Journal of Food Science and Technology
• /
• v.13 no.4
• /
• pp.261-266
• /
• 1981

In order to clarify the removal of astringency in persimmon fruits (Diospyros koki L.) and its mechanism, a comparative histology of tannin cells in tile cultivars of astringent persimmon fruits (Sangju Dungsi. Daegu Bansi. Cheongdo Bansi) and a sweet persimmon fruit (Fuyu) was observed. Tannin cells were widespread in all fruits tissue expert for tissue of ovule before full blossom. The epidermal cells of ovary. flower and calyx consist of tannin cell. Arrangement of tannin cells has radiated type toward the upper directions in the calyx. The major part of seed coat consisted of tannin cells. The epidermal cells of persimmon fruits were consisted of small tannin cells, and the inner part of epicarp of the astringent persimmon was consisted of stone cells, but the sweet persimmon was consisted of parenchymatous cells. It was suggested that differantiation of tannin cell In persimmon fruits occured until about the middle of August. Some tannin cells of matured astringent persimmon fruits was coagulated and wall of tannin cell produced protuberance, and most of tannin cells of matured sweet persimmon fruits was coagulated or ruptured.

• Korean Journal of Medicinal Crop Science
• /
• v.5 no.2
• /
• pp.154-161
• /
• 1997

The germination inhibitory effects of American ginseng (Panax quinquefolium Linne) pulp were discussed. The germination inhibitory effects of pulp juice were decreased in a concentration dependent manner. When the pulp juice was diluted 0 (original juice), 1, 2, 5, 10, 20, 50 and 100 times, the radicle lengths of the assay plant, Chinese cabbage (Brassica chinensis Linne), showed 0, 0.32, 0.72, 3.13, 4.83, 16.07, 16.73 and 23.50 mm, respectively (CK=25.98 mm). The pulp evidently inhibited the embryo growth in natural fruit. The longer was the duration that the pulp stayed around the seed, the longer was the time course needed for embryo getting free from the inhibitory effects of pulp. When the depulping was performed on the day 0, 15, 30 and 60 after harvest, the time courses needed for embryo extricating the residual inhibitory effects from pulp were 30, 75, 135 and 135 days, respectively. Moreover, if the pulp stayed around the seed with time, that would make the seed rotten ratio increase. When the pulp stayed around the seed for 0, 15, 30, 60 and 270 days, the seed rotten ratios were 5.47, 5.71, 19.05, 27.14 and 33.33%, respectively. Therefore, we concluded that the pulp could be included in the inhibitory components which made American ginseng seed get into dormancy.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.4
• /
• pp.414-418
• /
• 2011

BACKGROUND: Plastic mulches widely used in raised-bed culture mainly to conserve water, control weeds and raise soil temperature. The most widely used plastic mulch colour is black. Reflective red and far-red light can affect on growth and yield of various vegetable crops. Objectives of this study were to investigate the characteristics of reflective light of black and red plastic mulches, and to evaluate the reflective red and far-red light on the quality characteristics and yield of the Oriental melon (Cucumis. Melo L.) and tomato (Lycopersicon esculentum L.). METHODS AND RESULTS: Oriental melon and tomato were cultivated over the reflective red and black plastic mulches in plastic house. Reflected red and far-red light over the red plastic mulch were 2.6 times higher than those of black plastic mulch. Red to F-Red ratio of black plastic mulch, red plastic mulch and sunlight were 1.14, 0.93 and 1.16 respectively. Intensity of reflected red and far-red light over red plastic mulch were highest at surface height of 30 cm. The higher the height of the surface decrease the intensity of far-red light. Accordingly, Red to F-Red ratio were increased. Reflective red plastic mulch increased the weight of fruit and content of sugar in Oriental melon and tomato. CONCLUSION(s): Yield of Oriental melon over reflective red plastic mulch was higher than that of black plastic mulch. These results suggested that reflected red and far-red light over the red plastic mulch affected allocation of photosynthate in growing Oriental melon.

• Research in Plant Disease
• /
• v.14 no.1
• /
• pp.57-60
• /
• 2008

A rhizopus soft rot caused by Rhizopus stolonifer occurred sporadically on apple fruits (Malus pumila var. dulcissima Koidz.) at a wholesale market of agricultural products in Jinju, Korea in 2006 and 2007. Infected fruits were rapidly water-soaked, softened and rotted. The symptoms were initiated mainly from wounds or cracks occurred at harvest time. Sporangiophores were $950{\sim}1,900\;{\mu}m$ in length and $12{\sim}22\;{\mu}m$ in width. Sporangia were globose or hemispheric and $82{\sim}185\;{\mu}m$ in size. The color of sporangia was white and cottony at first and gradually turned to brownish black, bearing abundant spores when matured. Columella were hemispheric and $70{\sim}85\;{\mu}m$ in size. Sporangiospores were irregular round or oval, brownish-black streaked and $8{\sim}18{\times}7{\sim}8\;{\mu}m$ in size. Optimum temperature for mycelial growth of the fungus on PDA was $25^{\circ}C$. On the basis of mycological characteristics and pathogenicity to apple the causal fungus was identified as Rhizopus stolonifer (Ehrenb.) Vuill. This is the first report of Rhizopus soft rot by R. stolonifer on Fuji apple in Korea.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.1
• /
• pp.8-14
• /
• 2000

Long term cultivation crops like tomato, capsicum, melon etc. demand much amount of continuous supplying of nutrition during the whole growing periods. It is not easy to cover satisfactorily the nutritional demands for them by splitted top dressings, slow release fertilizer applications and fertigation systems. To overcome these problems, the "CULTAN" (Controlled Uptake Long Term Ammonium Nutrition) Beaker Deposit techniques have been developed and it was put into PVC beaker with the combined nitrogen fertilizer type mixed with the ratio of one-third of ammonium sulfate-N and two-thirds of urea-N, in which nitrogen was loaded on the demanding amount of a tomato plant during the growing period. Gypsum was mixed as a binder, and loamy soil and compost were used as a diffusion regulator. It was placed upside down into root zone of tomato at the transplanting. Tomato roots were spreaded into the Deposit beaker by ammonium ions which attract root growth. The tomato fruit yield and nitrogen uptake by plant were increased by application of $NH_4$-Beaker deposit fertilizer rather than those of common fertilizer treatment. In conclusion, it was able to improve economic and ecological benefits through CULTAN system compared with common fertilization systems. CULTAN system was estimated as a prospective alternative to enhance productivity and minimize nutrient lose. In addition, it shows further developing possibility of CULTAN system by the supplement of micro-nutrients and pesticides in the macro-nutrient beaker deposits.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.2
• /
• pp.99-104
• /
• 2013

Vegetables production in greenhouse are typically intensely managed with high inputs of fertilizers and irrigation water, which increases the risk of ground-water nitrate contamination. In 2010 and 2011, a study was conducted to determine the appropriate depth of soil moisture sensor for automatic irrigation control to use water and nitrogen efficiently under subsurface drip irrigation (SDI) systems. The irrigation line for SDI placed 30 cm below soil surface and tensiometer was used as soil moisture sensor. Three tensiometer treatments placed at 10 (SDI-T10), 20 (SDI-T20) and 30 cm (SDI-T30) depths below soil surface under SDI. These are also compared to SUR-T20 treatment where tensiometer placed at 20 cm below soil surface under surface drip irrigation (SUR) systems. The growth of cucumber was not statistically different between SUR and SDI without SDI-T30 treatment. Fruit yields (Mg/ha) were 57.0 and 56.9 (SDI-T10), 56.0 and 60.5 (SDI-T20), 40.9 and 41.2 (SDI-T30) and 56.6 and 54.3 (SUR-T20) for 2010 and 2011, respectively. Slightly higher total yield was observed in tensiometer placed 20 cm below the soil surface, although no significant differences were found between SDI-T10 and SDI-T20 under SDI treatments. In addition, nitrogen application rates and daily irrigation rates were lowest in SDI-T20 compared with other SDIs and SUR treatments. Nitrogen and daily irrigation application under SDI-T20 was lower than that under SUR-T20 by 6.0%. These findings suggested tensiometer 20 cm depth under SDI systems was best for cucumber production in greenhouse.

• The Korean Journal of Mycology
• /
• v.23 no.1 s.72
• /
• pp.61-70
• /
• 1995

The genus Armillaria is important because they produce Gastrodia tubers. Seventy two isolates of Armillaria were obtained from fruit bodies grown on decayed wood in Korea. Twenty four isolates from Pinus koraiensis were identified as A. ostoyae. Two isolates from G. elata growing in the field were identified as A. mellea. Seven isolates from Acer ginnala and Quercus spp. were identified as A. tabescens. Thirty nine isolates were identified as A. gallica. Armillaria gallica was isolated from Quercus spp., Ainus japonica, Vitis amurensis and Prunus sargentii. Armillaria spp. isolates were divided into four groups based on the cultural characteristics. Group II (A. gallica KNU-A110) was better than the other groups for mycelial growth and rhizomorph formation. Isolate KNU-A110 proved to be good for production of G. elata tubers. This fungus forms mycelial fan in the plant tissue and rhizomorphs in contact with G. elata tubers. Gastrodia spp. was found in thirteen sites in Kangweon province in Korea. The plants were divided into three different kinds based on stem color. Plants with stems of brownish orange and greyish yellow were identified as G. elata, and those with greyish green colored stems were identified as G. gracilis. Gastrodia was collected mainly from humus soils rich in leaf debris, and slopes facing south from mid-May to mid-July. Once the new tubers are formed from the ancestry tuber, the ancestry tuber begins to decay. The offspring tuber, apparently gaining nutrients through rhizomorphs, begins to grow in length and slowly to enlarge. It takes three years for the offspring tuber to become ancestry tuber.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.6
• /
• pp.383-387
• /
• 2004

Effects of oyster shell powder as a liming material were investigated in an apple orchard. Soil texture of the apple orchard was silty clay loam (Upyeong series with 7% of slope) and topsoil pH was 5.6. Treatments of 1,590 kg oyster shell powder $ha^{-1}$ and calcium-magnesium carbonate as much as oyster shell powder were included in the experiment. With treatments of oyster shell powder and calcium-magnesium carbonate, the length, number and diameter of new branches and the diameter of main, secondary and side branches increased in comparison with control. With oyster shell powder application, soil pH increased from 5.6 to 6.8 at the harvest. In addition, it increased exchangeable Ca from 2.6 to $4.2cmol_c\;kg^{-1}$. But it didn't make any difference in chlorophyll, sugar and malic acid contents. The apple weight per fruit of oyster shell powder application was 9 g more than that of control. Apple yield was highest ($37,000kg\;ha^{-1}$) in the oyster shell powder treatment, and the yield increase was significantly different at 5% level LSD. We concluded that the oyster shell powder can be an alternative of lime and effective to restore soil nutrient balance in apple orchard soil.

• Korean Journal of Organic Agriculture
• /
• v.7 no.1
• /
• pp.35-48
• /
• 1998

The total amount of dry matter for the green manure crops was great wheat> rye> barley> Italian ryegrass in that order. The green manure crope were verified to have the reducing effect of injury of successive croppingin peper, mainly reducing the occurance of the most important pepper disease, Phytophthora capsisi, and enhancing the pepper quality in the fruit length and diameter. The direct seeding using current commercial pepper variety was proved as not economical one. In the first year of compost application, the growth and yield of red pepper were rather somewhat decreasing compared with those of check plot applied with organic fertilizers. compst application increased the content of organic matter in soil, which suggested compost could be applied for the sustainable purposes. In preference analysis about taking the new technique, the smaller farmer's cultivation area the more they wanted to accept the LISA farming, compared with the conventional one, could be possible to save 12% in the inorganic fertilizer expenses but wasted 412% ant 163% in both organic fertilizer and operator labor expenses, respectively. At the same time, the LISA decreased 15% in production cost but increased 225% and 139% in organic fertilizer quantity and operator labor hours. Since there was a great deal of difference in technological and economic factors from two farming methods, LISA multi-goal decision modeling is further required.

• Korean Journal of Organic Agriculture
• /
• v.22 no.4
• /
• pp.855-868
• /
• 2014

Synthetic agro-chemicals have been widely used to control diseases on paprika but these days negative attention has been increasing to use of them because of several adverse effects. This research was conducted to isolate and to characterize the antagonistic microorganism to control major paprika diseases, gray mold rot, fruit and stem rot, phytophthora blight, sclerotium rot, and wilt disease. Analysis of the fatty acid and analysis of the 16S rDNA gene sequence revealed that YKJ1 isolated in this research belongs to a group of Serratia marcescens. Specially, 16S rDNA gene sequence of YKJ1 showed 99% of sequence similarity with S. marcescens. Observation through the optical microscope revealed that YKJ1 suppressed the spore germination and the hyphal growth of pathogens. YKJ1 treatment on pathogens induced marked morphological changes like hyphal swelling and degradation of cell wall. In the case of phytophthora blight, the zoosporangium formation was restrained. S. marcescens found in this study call as S. marcescens-YKJ1 and it may be valuable as one of biological control agents against major diseases of paprika in the future even though it is require to be tested with more study on field test.