• Current Research on Agriculture and Life Sciences
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• v.27
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• pp.1-6
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• 2009

Persimmon occupied the second largest cultivation area next to apple among the fruits in Korea. Since 70 % of its cultivating field is located at slope, the efficiency of its harvesting operation is very low. Also, the traditional persimmon harvest apparatus does not seem to be efficient to use due to a structural problem. In this paper, the author has analyzed the physical properties of persimmon friut-stem system and compared detachment force with developed persimmon harvest apparatus and traditional persimmon harvest apparatus in order to solve the problems mentioned above. The results of the research are summarized as follows : 1. The weight of the persimmon is shown as 157 g on average, the lengths of stem's major axis and minor axis is shown as 4.6 mm and 3.7 mm on average, respectively, sectional area of stem is shown as $13.9mm^2$ on average and the stem length is shown as 13.6 mm on average. 2 In case of the traditional persimmon harvest apparatus, the detachment force needed when a persimmon was detached from its stem was shown as 86.3 N on average. 3. In case of the developed persimmon harvest apparatus, detachment force needed when a persimmon was detached from its stem was shown as 72.6 N on average.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.328-333
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• 2006

This study was conducted to find the characteristics of photosynthesis, leaf and fruit by crown layers in Rubus coreanus Miq. Light compensation points were shown PPFD 33, 20 and $5{\mu}mol\;m^{-2}\;S^{-1}$ at upper, middle and lower layer, respectively. Light saturation points were appeared PPFD 1000, 500 and 200 and their net photosynthesis rate were 8.52, 5.25 and $3.60{\mu}mol\;CO_2\;m^{-2}S^{-1}$ at upper, middle and lower layer, respectively. Uiryeong 7 which was viny type showed higher net photosynthetic rate than others at upper layer. Songgye 6 which was upright type showed lower net photosynthetic rate than others at lower layer. Chlorophyll contents of middle layer had the highest value in the all layers and upper layer showed the lowest value. Most characteristics of leaf morphology were showed that middle and lower layer had higher value than upper layer. That trend was contrary to characteristics of photosynthesis by crown layers. However, dry weight per leaf area and most characteristics of fruit had the highest value at upper layer and that was similar to characteristics of photosynthesis by crown layers. Also, sugar contents of fruit showed the highest value at middle layer.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.105-111
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• 2006

The objectives of this study, an analysis of fruit and leaf morphological characteristics among the five Zizyphus cultivars could be used for the investigation of cultivars classification and could provide information to make out the UPOV TG(Test Guidelines). ANOVA tests showed that there were statistically significant differences in all fruit and leaf morphological characteristics among the five Zizyphus cultivars at 1% level. But, for kernel characteristics, differences were statistically non-significant among the cultivars. Approximately, the Wolchul and Boeun cultivars showed larger and smaller values in overall characteristics and cultivars, respectively. The results of principal component analysis(PCA) for the fruit and leaf morphological characteristics showed that the first for principal components(PC's) explained about 65.3% of the total variation. The first PC was correlated with those characteristics that were mainly related to the terminal leaf length(TLL), leaf length(LL), fruit length(FL), terminal leaf width(TLW), and leaf petiole length(LPL). The second and third PC was mainly correlated with the terminal leaf morphological index(TLMI). Therefore, these characteristics were important to analysis of the fruit and leaf morphological characteristics and classification among the five Zizyphus cultivars. Cluster analysis using UPGMA method based on principal components showed that five Zizyphus cultivars could be clustered into two groups. Group I comprises Mudung, Wolchul, and Bokjo and Geumsung cultivars, Group II is Boeun cultivar. These results well similar to that of principal component analysis.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.268-275
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• 2015

We evaluated the effect of mixed liquid fertilizer (MLF) on growth responses of plants and soil chemical properties. To do so, a pot experiment with cherry tomatoes (Lycopersicon esculentum var. cerasiforme) using loam soil was conducted for 81 days in a temperature-controlled glasshouse, and four N fertilization treatments were laid out in a completely randomized design with three replicates: control (C), chemical fertilizer treatment (CF), and two rates (MLF-0.5 and MLF-1.0) of MLF treatment. Soils were periodically sampled and analyzed for pH, EC, total N, inorganic N and total C, and growth characteristics of cherry tomatoes were measured. During the experimental periods, the pH of MLF soils was higher than that of CF soils. Soil total-N content increased right after CF-application and ultimately decreased to the level of the control (C) soil, while MLF-application slightly increased the level of soil total-N and this level remained unchanged throughout the experiment. The levels of soil inorganic N content increased after application of CF or MLF, but the initial increase disappeared in 56 days after transplanting (DAT). The dry weight of shoots and roots increased in CF or MLF plants, while the number of fruit increased only in MLF plants. Whereas soluble solid contents were higher in MLF plants than in the other (C and CF) plants, the titratable acidity was not different among treatments. However, no consistent effect of N treatments on major elements of the organs of cherry tomatoes was found. The amounts of N taken up by plants were 0.91 g for CF, 0.61 g for MLF-1.0, 0.43 g for MLF-0.5, and 0.25 g for control treatments, resulting in greater N efficiency for CF than for MLF.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.306-312
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• 2007

To investigate the effect of N fertigation on the growth, yield, and water and nitrogen use efficiencies during tomato cultivation, seedlings were transplanted in a sandy loam soil under plastic film house condition. 0, 88, 132, 176, $220\;kg\;ha^{-1}$ N rates, which correspond to 0 (NF0), 40 (NF40), 60 (NF60), 80 (NF80), 100% (NF100) N level of soil test-based N fertilization, were injected weekly through drip irrigation system for 15 weeks in N fertigation system, and the control (conventional N treatment) was installed for comparison. Herein, nitrogen was applied by top-dressing with 60% as a basal and 40% as additional fertilizer. There was little different in stem diameter growth among N fertigation treatments, but plant height and dry matter increased with increasing N fertigation rates as well as in N conventional treatment. Tomato yield was increased with increasing the number of marketable fruits in N fertigation treatments, and the fruit yield was maximized in NF 80 treatment ($176\;kg\;ha^{-1}$ N supply or $96.6\;mg\;L^{-1}$ N injection). Dry matter productivity and nitrogen uptake amount were significantly increased with increasing N fertigation rates. The ratio of fruits to the dry weight of whole plant was decreased with increasing N fertigation rates, but this ratio was $2.6{\sim}5.3%$ higher in N fertigation treatments than in the control. In addition, the ratios of nitrogen distributed toward fruits in N fertigation treatments were $3.7{\sim}21.7%$ higher than that of control. The apparent N recovery percentages showed significantly higher values as $71.8{\sim}102.3%$ in N fertigation treatments, compared to 45% in N conventional treatment. Water use efficiency was significantly increased by fertigation system with the maximum $361\;kg/ha\;cm^{-1}$ in NF 80, which is comparable to $324\;kg/ha\;cm^{-1}$ of the conventional treatment. Conclusively, N fertigation system was effective on increasing tomato productivity and nutrient efficiency as well as 20% reduction of N fertilization level.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.126-131
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• 1992

For the development of kiwifruit storage method applicable to farm level, several quality indicator of kiwifruit(Actinidia chinensis Planch.) were measured during storage at modified atmosphere(MA) conditions(0.04, 0.06, 0.08 and 0.10 mm PE Film). The results obtained from the experiment were as follows. The highest firmness was marked by the kiwifruit kept in 0.06 mm thick film bag and the lowest weight loss was shown in 0.10 mm thick film bag. The largest production of respiratory rate was occured after storage for 30 days. The concentration of $O_2\;and\;CO_2$ in 0.06 mm thick film bag was 2.6% and 3.2% after storage for 60 days, respectively. It could be concluded that the optimum PE film thickness for MA storage of kiwifruit was 0.06 mm.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.603-609
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• 1992

To investigate the effect of polyethylene film packaging and $CO_2$ treatment on tomatoes during storage, the gas composition in film, weight loss, the changes of color, hardness and several components were measured. The concentrations of $CO_2$ and $O_2$ in film were changed rapidly in early stage, but it kept a constant level after 7 days of storage. In 0.06 mm polyethylene film, $CO_2$ and $O_2$ concentration was kept a level of $4{\sim}6%$ respectively. The increase in $C_2H_2$ concentration was delayed in thick and $CO_2$ treated film. The rate of weight loss was 4% in non-packed tomatoes, but it recorded about 1% in 0.06 mm polyethylene film. Titratable acidity, pH and soluble solids were changed slightly, but the obvious differents were not observed according to film thickness and $CO_2$ treatment. The value of tomatoes was increased but L and b values were not changed greatly during storage. These color changes were restricted by 0.06 mm film and $CO_2$ treatment. The firmness and content of ascorbic acid were reduced during storage but it restrained by $CO_2$ treatment and film packaging. Sugar of tomatoes were composed of glucose, fructose and a very small amount of sucrose, and they were changed little during storage.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.865-870
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• 2003

The effects of storage atmosphere on the physicochemical and organoleptic properties of Asian pears (Pyrus pyrifolia Nakai cv. Niitaka) were investigated. The pears were stored at $0^{\circ}C$ for up to 8 months under CA conditions (3 kPa $O_2$＋1 kPa $CO_2$, 1 kPa $O_2$+5 kPa $CO_2$, 1 kPa $O_2$+1 kPa $CO_2$) controlled by a static system or air (21 kPa $O_2$+0 kPa $CO_2$). CA conditions retarded the loss of weight, flesh firmness, organoleptic properties (appearance, aroma, sweetness, texture), and the development of injuries in the fruits during storage. Low $O_2$ plus high $CO_2$ conditions maintained the highest flesh firmness. In addition, low $O_2$ reduced injuries more than the other conditions. Skin color (lightness, chroma, hue), soluble solids, titratable acidity, pH and vitamin C were unaffected by storage atmosphere.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.445-451
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• 2012

The thinning effects of lime sulfur either alone or combined with fish oil on two apple cultivars 'Fuji'/M.9 and 'Hongro'/M.9 were investigated during two consecutive seasons. Either 1% or 2% lime sulfur at full bloom decreased the amounts of both terminal and axillary fruits compared with unsprayed 'Fuji' control trees in the first year. However, 1% or 2% lime sulfur did not decrease terminal fruit set in the second year. Only, triple applications of 1% lime sulfur significantly reduced the number of terminal and axillary fruits in both years. Multiple application of 1% lime sulfur was the most effective in thinning of 'Hongro'. In the first year, double or triple applications of 1% lime sulfur was effective in thinning terminal or axillary fruit, but one time applications of 1% or 2% lime sulfur was not reduced axillary fruit in 'Hongro' apple trees. In the second season, all treatments reduced terminal or axillary fruit in 'Hongro' clusters, except single application of 1% lime sulfur. Fish oil did not always improve the thinning effects of lime sulfur in 'Fuji' or 'Hongro' apple trees. None of treatments caused significant russeting in the harvested fruits. Most of thinning treatments had little effect on 'Fuji' or 'Hongro' fruit quality in terms of fruit weight, firmness, soluble solids concentration or titratable acidity.

• Applied Biological Chemistry
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• v.11
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• pp.67-76
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• 1969

The reduced pressure storage of apple, American Summer Pairman, was investigated comparing with the other storage methods and the following results were obtained. 1. The reduced pressure storage was better to extend the storage life and freshness of apples than the controlled atomoshere storage. 2. Decreasing the pressure of chamber atmosphere to about 20 cmHg showed the best result among several pressure conditions. 3. As for the surface treatment of the apples, poly-ethylene film wrapping showed to be the most favorable method in a short-term experiment. In a long-term experiment, however, poly-ethylene film wrapping seemed to cause apples rot. Poly-vinyl acetate coating seemed to keep the apples from color changing, but it caused an unpleasant odor and a peculiar taste. No significant effect was observed in Gibberellin. 4. Total sugar and reduced sugar of apples were decreased after a certain period of increasing. Acid and Vitamin C, however, gradually decreased from the beginning of storage.