• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.316-338
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• 1988

To identify the physiological phenomena on the sudden wilting of japonica/indica crossed varieties, Pot experiment was carried out under the heavy N application with various levels of potassium in Japan. The results obtained are as follows. 1. Sudden wilting was occurred in both varieties used, Yushin and Milyang 23. The former showed a higher degree than the latter. 2. Sudden wilting was occurred into two types, one at early ripening stage and the other at late ripening stage. The former type was found in the field with low potassium supply and the latter was seemed to be related to varietal wilting tolerence. 3. By the investigation of concerning the effective tillering rate and the change of dry weight of each organ at the heading stage, it was inferred that the growth status from young panicle formation stage to heading stage were related to sudden wilting tolerence. 4. Manganese content at heading stage, ratio of Fe/Mn and Fe. Fe/Mn in stern at late ripening stage and $K_2$ O/N ratio of stem at harvesting stage were recognized as the specific factors in connection with sudden wilting. Mn content in the sudden wilting rice plant was already in creased remarkably at heading stage. In relation to root age and absoption characteristics of Mn, the senility of root before heading stage was inferred as the cause of increase the value of Fe/Mn or Fe. Fe/Mn. 5. The $K_2$ O/N ratio of culm at harvesting stage was lower in upper node than lower node in relation to sudden wilting. And it was well accordance with the fact that the symptoms of sudden wilting proceeded from upper leaf to lower leaf. These phenomenon was different from the usual one that the effect of potassium deficiency was more remarkable in lower node than upper node. 6. All varieties which have a condition of potassium deficiency have a high degree of nitrogen content of leaves at heading stage and the $K_2$ O/N ratio of each organ was low, Especialy, $K_2$ O/N ratio is much lower in sheath and culm than leaves.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.376-382
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• 2014

This work was conducted to investigate the variation of growth and yield among three generations ($TC_0$, $TC_1$, and $TC_2$) in the field cultivation of virus-free sweetpotato (Ipomoea batatas) plants. Virus-free generations of three cultivars ('Matnami', 'Shinhwangmi', and 'Yeonhwangmi') were cultivated with $75{\times}25cm$ planting density on May 20th, covered with black vinyl film. At 30 days after planting, vine growth in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant, and vine length in $TC_0$ showed the highest growth among treatments. At harvesting time after 120 days, vine diameter, number of node, and number of branch in $TC_0$, $TC_1$, and $TC_2$ were more increased than farmer's plant, but were not statistically significant. Fresh weight of shoot in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant, but was not statistically significant among generations or cultivars. Number of tuber per plant and mean weight of tuber in $TC_0$ and $TC_1$ showed significant increasement, but that in $TC_2$ did not show significant difference as compared to the farmer's plant. Weight of tuber per plant in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant. Marketable yield, percentage of marketable tuber, and percentage of small tuber (40 to 200g) in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant. The large tuber over 300g showed the lowest percentage in $TC_0$. Marketable yield in $TC_2$ was significantly decreased as compared to $TC_0$, and was not significantly different as compared to the farmer's plant. Marketable yield in 'Matnami' was highest among cultivars. From this results, Farmers are required to renew every three years to maintain the yield and quality of virus-free plants. However, the exchange period of virus-free plants is desirable to renew every 2 or 3 years according to the degree of virus reinfection.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.568-575
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• 1991

The morpho-anatomical characteristics of panicle in rice plant is generally correlated with the number of spikelets and grain weight per panicle. For the increase of grain yield potential in rice, a low -tillering plant type with large panicles has been suggested as an ideotype. This study was conducted to investigate the panicle morphology and peduncle anatomy of different tillers within a plant in low -and high-tillering cultivars and their relationships on the number of spikelets and grain weight per panicle. A low-tillering, large panicled IR25588 was compared with a high-tillering. small panicled IR58. IR25588 had more inner(IVB) and outer vascular bundles (OVB). bigger peduncle diameter and peduncle thickness just below the panicle neck node than IR58. The top six tillers(M. P1, P2, P3. P4 and S1P2) within a plant had more IVB and OVB. larger peduncle diameter and thickness than the rest of the tillers in both cultivars. Tillers that emerged earlier had more IVB and OVB than tillers that emerged Jater. The total number of primary and secondary rachis-branches of IR25588 was much higher than that of IR58. IR25588 had more number of spikelets per panicle than IR58. and the top six panicles showed more spikelets per panicle than the rest of the panicles in both cultivars. The peduncle diameter was more important than peduncle thickness on the spikelet differentiation and panicle weight. especially in low-tillering cultivars. The number of IVB and OVB were highly correlated with the number of rachis-branches. spikelets and grain weight per panicle. The number of spikelets per IVB and spikelets per primary branch were higher in IR25588 than IR58 indicating the higher sink strength in low -tillering with large panicled cultivars than in high-tillering with small panicled cultivars. Based on the morpho-anatomical characteristics of a low-tillering cultivar and the top six tillers within a plant. the present results could be support that 'a low-tillering sturdy culms with large panicles' is an ideo-type of rice plant for increasing grain yield potential.potential.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.273-282
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• 1988

The seventeen barnyardgrass [Echinochloa crus-galli (L.) Beauv.] accessions, which were collected national-widely in 1986 and selected two times through 1987, were experimented at 1988. To study the degree of ecological variations of the collected accessions of native barngardgrass species as a weed, the experiment was conducted with Wagner pots in size of 1/5000a and under P.E. film house. Among 57 characters, 100 grains weight, rate of tiller increase from transplanting to 30 days, the number of the maximum tillers and rate of dry weight increase from 15 DAS to 22 DAS were become intra-specific variarions as higher coefficient of varation than 30%, the size of the first leaf, fresh weight and dry 22 seedlings, rate of productive tiller, panicle number and tillering divergence made intra-specific variations as more and less C. V. than 25%, while the required days upto heading since seeding at June 6. rate of fresh/dry weight and plant height of 22 days old seedling made intra-specific variations as the coefficient of variation of about 50%. Among the attributes the color in leaf, leaf sheath, mid-ribs, node, spike, grain, and plant type, length of leaf marginal tooth, grain shape, purple bend on leaf were seemed useful to indentify the accessible specific.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.332-340
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• 2018

Supplemental lighting with artificial light sources is a practical method that enables normal growth and enhances the yield and quality of fruit vegetable in greenhouses. The objective of this study was to investigate the effect of sulfur plasma lamp (SP) and high-pressure sodium lamp (HPS) as supplemental lighting sources on the growth and yield of paprika. For investigating the effectiveness of SP and HPS lamps on paprika, the effects of primary lighting on plant growth were compared in growth chambers and those of supplemental lighting were also compared in greenhouses. In the growth chamber, plant height, leaf area, stem diameter, number of leaves, fresh weight, and dry weight were measured weekly at SP and HPS from 2 weeks after transplanting. In the greenhouse, no supplemental lighting (only sunlight) was considered as the control. The supplemental lights were turned on when outside radiation became below $100W{\cdot}m^{-2}$ from 07:00 to 21:00. From 3 weeks after supplemental lighting, the growth was measured weekly, while the number and weight of paprika fruits measured every two weeks. In the growth chamber, the growth of paprika at SP was better than at HPS due to the higher photosynthetic rate. In the greenhouse, the yield was higher under sunlight with either HPS or SP than sunlight only (control). No significant differences were observed in plant height, number of node, leaf length, and fresh and dry weights between SP and HPS. However, at harvest, the number of fruits rather than the weight of fruits were higher at SP due to the enhancement of fruiting numbers and photosynthesis. SP showed a light spectrum similar to sunlight, but higher PAR and photon flux sum of red and far-red wavelengths than HPS, which increased the photosynthesis and yield of paprika.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.67-74
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• 2015

In recent years, frequent itemset mining for considering the importance of each item has been intensively studied as one of important issues in the data mining field. According to strategies utilizing the item importance, itemset mining approaches for discovering itemsets based on the item importance are classified as follows: weighted frequent itemset mining, frequent itemset mining using transactional weights, and utility itemset mining. In this paper, we perform empirical analysis with respect to frequent itemset mining algorithms based on transactional weights. The mining algorithms compute transactional weights by utilizing the weight for each item in large databases. In addition, these algorithms discover weighted frequent itemsets on the basis of the item frequency and weight of each transaction. Consequently, we can see the importance of a certain transaction through the database analysis because the weight for the transaction has higher value if it contains many items with high values. We not only analyze the advantages and disadvantages but also compare the performance of the most famous algorithms in the frequent itemset mining field based on the transactional weights. As a representative of the frequent itemset mining using transactional weights, WIS introduces the concept and strategies of transactional weights. In addition, there are various other state-of-the-art algorithms, WIT-FWIs, WIT-FWIs-MODIFY, and WIT-FWIs-DIFF, for extracting itemsets with the weight information. To efficiently conduct processes for mining weighted frequent itemsets, three algorithms use the special Lattice-like data structure, called WIT-tree. The algorithms do not need to an additional database scanning operation after the construction of WIT-tree is finished since each node of WIT-tree has item information such as item and transaction IDs. In particular, the traditional algorithms conduct a number of database scanning operations to mine weighted itemsets, whereas the algorithms based on WIT-tree solve the overhead problem that can occur in the mining processes by reading databases only one time. Additionally, the algorithms use the technique for generating each new itemset of length N+1 on the basis of two different itemsets of length N. To discover new weighted itemsets, WIT-FWIs performs the itemset combination processes by using the information of transactions that contain all the itemsets. WIT-FWIs-MODIFY has a unique feature decreasing operations for calculating the frequency of the new itemset. WIT-FWIs-DIFF utilizes a technique using the difference of two itemsets. To compare and analyze the performance of the algorithms in various environments, we use real datasets of two types (i.e., dense and sparse) in terms of the runtime and maximum memory usage. Moreover, a scalability test is conducted to evaluate the stability for each algorithm when the size of a database is changed. As a result, WIT-FWIs and WIT-FWIs-MODIFY show the best performance in the dense dataset, and in sparse dataset, WIT-FWI-DIFF has mining efficiency better than the other algorithms. Compared to the algorithms using WIT-tree, WIS based on the Apriori technique has the worst efficiency because it requires a large number of computations more than the others on average.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.235-242
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• 2015

The objective of this study was to determine the effects of soluble potassium silicate by soil drenching application on watermelon growth, yield, and nutrient uptake. The potassium silicate rates were control (No potassium silicate), 1.63mM, 3.25mM, 6.50mM. The potassium silicate were treated 6 times (twice before fruit forming and 4 times after fruit forming per 7 day. Soil chemical properties, such as soil pH, EC, available phosphorus and silicate, exchangeable K, nitrate-N levels were increased after potassium silicate treatment, while the concentrations of soil organic matter, exchangeable Ca and Mg were similar to control. The growth characteristics of watermelon, such as stem diameter, fresh and dry weight of watermelon at harvest were thicker and heavier for increased potassium silicate treatment than the control, while number of node, and plant length were same for all treatments. With increased potassium silicate treatment, nutrient concentrations, such as P and K in the watermelon leaf at harvest were increased, N concentration in the leaf was decreased, and Ca and Mg concentrations in the leaf were same. Chlorophyll content was increased with increased potassium silicate application. The occurrence of powdery mildew was lower for the potassium silicate treatments than the control. Fresh watermelon weight for the potassium silicate treatments was 0.1 to 0.5kg per watermelon heavier than the control, sugar content was 0.5 to $0.6^{\circ}Brix$ higher than control, and merchantable watermelon was 2 to 4% increased compared to the control. These results suggest that potassium silicate application by soil drenching method in the greenhouse can improve watermelon nutrient uptake, merchantable watermelon and suppress the occurrence of powdery mildew.

• Journal of Sericultural and Entomological Science
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• no.11
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• pp.31-44
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• 1970

This experiment is conducted fer method cf bring to perfectly from defective cutting sapling 25 a production method of sapling which is to substitute for conventional graf ting. 1. In green wood cutting root comes out after 15 days of cutting with nearly straight development of root system; after 40 days of cutting, roots with total length of 1119 mms 43 roots, and 5.4 grs a root in total weight obtained. 2. Survival percentage of green wood cutting ranges between 56％ and 90％, average 73％ of that and it varies with natural characteristics of varietes. The results show variety of Gaeryang-Suban and Iljiroe with 80％ as a best ones in contrast with the variety of Shipyung. 3. The varietics or Gaeryang-Suban. Iljiroe, Suwon-Sang No.4, Rosang makes of much more roots than Yongchonchuwoo and Shipyung do. 4. Root ability made good number of roots commercially, when cutting is conducted soaking in 0.01 ％ NAA solution or 0.02％ NAA solution for 2 or 3 seconds as a chemical promoter. 5. Economical measures for increase of scion adapted 1) 2 scions from a green wood 50 cm long should be taken and basal pan of scion at its middle portion should be cut right under the node. 2) Scions below 50cm long may be used. Small scions or growthceased shoots h3ve also considerable root ability enough to be used. 3) Thus far, up 100,000 scions might be produced in 10 a. 6. We can find number of root increased, when cutting the opposite side in obliquity manner at 450. 7. When 110,000 saplings in 10 a. for the production of bring to perfectly from defective cutting sapling planted, quality of stocks does not go to bad condition without any obstacles in practical use. 8. Although the times or grafting delayed until middle of July, quality of sapling goes just a little down. Grafting may be conducted from early June to middle of July separately in several times, and the green wood of prunned mulberry in spring is available for a scion after end of June. 9. 10 grs weight of defective cutting sapling makes 95％ of complete sapling, otherwise 5 or 10 grs in weight of one becomes 80％ of complete sapling with its quality as similar as grafted one. 10. When the sapling planted, its branches should be cut, leaving 3 or 4 buds at the bottom of new branches. 11. In view of economical stand point, production cost of bring to perfectly from defective cutting sapling obtains 52％ of grafting cost.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.768-776
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• 2010

This study was conducted to predict number and fresh weight of leaves, and total leaf area of a single-stemmed rose 'Vital' based on the accumulated thermal units, and to develop a model of shoot development for the prediction of the time when the flowering shoot reaches a phenological stage in a plant factory system. The base temperature ($T_b$), optimum temperature ($T_{opt}$), and maximum temperature ($T_{max}$) were estimated by regressing the rate of shoot development against the temperature gradient. The rate of shoot development ($R$, $d^{-1}$) for the phase from cutting to bud break (CT-BB) was best described by a linear model $R_b$ ($d^{-1}$) = -0.0089 + $0.0016{\cdot}temp$. The rate of shoot development for the phase from bud break to harvest (BB-HV) was fitted to the parabolic model $R_h$ ($d^{-1}$) = $-0.0001{\cdot}temp^2$ + $0.0054{\cdot}temp$ - 0.0484. The $T_b$, $T_{opt}$, and $T_{max}$ values were 5.56, 27.0, and $42.7^{\circ}C$, respectively. The $T_b$ value was used in the thermal unit computations for the shoot development. Number of leaves, leaf area (LA), and leaf fresh weight showed sigmoidal curves regardless of the cut time. The shoot development and leaf area model was described as a sigmoidal function using thermal units. Leaf area was described as LA = 578.7 $[1+(thermal units/956.1)^{-8.54}]^{-1}$. Estimated and observed shoot length and leaf fresh weight showed a reasonably good fit with 1.060 ($R^2=0.976^{***}$) and 1.043 ($R^2=0.955^{***}$), respectively. The average thermal units required from cutting to transplant and from transplant to harvest stages were $426{\pm}42^{\circ}C{\cdot}d$ and $783{\pm}24^{\circ}C{\cdot}d$, respectively.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.188-195
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• 2021

This study was conducted to investigate the growth and quality characteristics of melon (Cucumis melo L.) cultivars and the irrigation requirements for cultivars. In our previous study in 2019, twelve melon cultivars including 'Dalgona' were examined for their cultivar characteristics under the same irrigation condition for all cultivars, and sorted into several groups based on different growth condition; for the internode length (from 0 to 20th node), leaf area, and fruit weight, 'Kingstar' belonged to the largest group, 'Worldstar' the middle group, and 'Dalgona' the smallest group. After analyzing the results of the previous experiment, 'Dalgona', 'Worldstar', 'Kingstar', and 'Rubyball' were selected as test cultivars for the growth group in 2020, and irrigated according to different irrigation levels for each cultivar. The control of the irrigation volume for each melon cultivar by monitoring the drainage rate during the cultivation periods showed that all four cultivars required a similar amount of irrigation in the 'early growth' stage where crops grew at about the same rate. From 'flowering time', however, the change in irrigation requirements showed a similar tendency for 'Worldstar' and 'Kingstar' and for 'Rubyball' and 'Dalgona' respectively. A sudden change in each irrigation volume was observed from the fruit set; 'Dalgona' began first to decline and 'Rubyball' was second, followed by 'Worldstar' and 'Kingstar'. In conclusion, the irrigation volume was the largest in 'Kingstar', followed by 'Worldstar', 'Rubyball', and 'Dalgona' in the same order as the growing amount of plant length, leaf area, and fruit weight. Therefore, it is necessary to control exactly the irrigation volume by reflecting the unique growth characteristics of each cultivar for the production of high-quality fruit in melon hydroponics, and especially to use great care when different cultivars are cultivated together.