• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.37-44
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• 2024

This study was conducted to validate the growth and productivity of cucumber hydroponics using coir as the medium, different types of nutrient solutions and formal methods, in order to select the most efficient cultivation method. The nutrient solutions consisted of culture solution (S) and raw water (W), the planting methods were rockwool cube seedlings (RC), rockwool plug seedlings (RP), and slab directly seedlings (DS). The reference date was set the sowing date. The initial growth showed a significant increase in the culture solution treatment, the differences among treatments decreased as the growth period lengthened. There was no apparent correlation between the planting methods and growth, but different results were observed among the same planting methods depending on nutrient solution used. Similarly, productivity followed a similar trend, with significantly higher harvest in the culture solution treatment during the initial harvest period of 6-8 weeks after sowing, but the harvest gap among treatments were diminished in the after period. The cumulative harvest was significantly higher in the culture solution treatment due to the initial difference in harvest quantity. Plant growth and fruit productivity exhibited a similar trend, showing a linear relationship. There was no correlation among the planting methods, but direct seedling with the culture solution showed the highest initial growth and harvests due to stable nutrient and moisture supply in the initial root zone. Therefore, it is believed that direct seeding method on the culture solution medium would be most advantageous for plant growth and productivity. Additionally, it is expected to contribute to cost effectiveness from an economic perspective through simplification of the cultivation process, labor costs and production cost reduction

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.70-79
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• 1992

From the beginning of the chosun dynasty, an agriculture-first policy was imposed by being written farming books, for instance, Nongsajiksul, matched with real conditions of local agriculture, which provided the grounds of new, intensive farming technologies. This farming book was the collection of good fanning technologies that were experienced in rural farm areas at that time. According to Nongsajiksul, rice culture systems were divided into "Musarmi"(Water-Seeded rice), /"Kunsarmi"(dry-seeded rice), /transplanted rice and mountainous rice (upland rice) culture. The characteristics of these rice cultures with high technologies were based of scientific weeding methods, improved fertilization, and cultivation works using cattle power and manpower tools systematically. Reclamation of coastal swampy and barren land was possible in virtue of fire cultivation farming(火耕) and a weeding tool called "Yoonmok"(輪木). Also, there was an improved hoe to do weeding works as well as thinning and heaping-up of soil at seeding stages of rice. Direct-seeded rice culture in flat paddy fields were expanded by constructing the irrigation reservoirs and ponds, and the valley paddy fields was reclaimed by constructing "Boh(洑)". These were possible due to weed control by irrigation waters, keeping soil fertility by inorganic fertilization during irrigation, and increased productivity of rice fields by supplying good physiological conditions for rice. Also, labor-saving culture of rice was feasible by transplanting but in national-wide, rice should not basically be transplanted because of the restriction of water use. Thus, direct-seeded rice in dry soils was established, in which rice was direct-seeded and grown in dry soils by seedling stages and was grown in flooded fields when rained, as in the book "Nongsajiksul". During the middle of the dynasty(AD 1495-1725), the excellent labor-saving farmings include check-rowing transplanting because of weeding efficiency and availability in rice("Hanjongrok"), and, nurserybed techniques (early transplanting of rice) were emphasized on the basis of rice transplanting ["Nongajibsung"]. The techniques for deep plowing with cattle powers and for putting more fertilizers were to improve the productivity of labor and land, The matters advanced in "Sanlimkyungje" more than in "Nongajibsung" were, development of "drybed of rice nursery stock", like "upland rice nursery" today, transplanting, establishment of "winter barly on drained paddy field, and improvement of labor and land-productivity in rice". This resulted in the community of large-scale farming by changing the pattern of small-farming into the production system of rice management. Woo-hayoung(1741-1812) in his book "Chonilrok" tried to reform from large-scale farmings into intensive farmings, of which as eminent view was to divide the land use into transplanting (paddy) and groove-seeding methods(dry field). Especially as insisted by Seo-yugo ("Sanlimkyungjeji"), the advantages of transplanting were curtailment of weeding labors, good growth of rice because of soil fertility of both nurserybed and paddy field, and newly active growth because rice plants were pulled out and replanted. Of course, there were reestimation of transplanting, limitation of two croppings a year, restriction of "paddy-upland alternation", and a ban for large-scale farming. At that period, Lee-jiyum had written on rice farming technologies in dry upland with consider of the land, water physiology of rice, and convenience for weeding, and it was a creative cropping system to secure the farm income most safely. As a integrated considerations, the followings must be introduced to practice the improved farming methods ; namely, improvement of farming tools, putting more fertilizers, introduction of cultural technologies more rational and efficient, management of labor power, improvement of cropping system to enhance use of irrigation water and land, introduction of new crops and new varieties.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.274-282
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• 1984

In order to study the effect of seed-fertilizer vertical distance with soil moisture and fertilizer levels on the emergence and initial growth, barley cv. Olbori was seeded in the pots filled with sandy loam or loamy sand soils which were adjusted to 80-100% (higher soil moisture) or 50-60% (lower soil moisture) of soil moisture retention percent at 1/10 atmosphere tension. Prior to seeding of barley seed-fertilizer distance was appropriately controlled by adding soils after dressing fertilizer at three levels-normal application ($N:P_2O_5:K_2O=6-9-7kg/10a$), 50% increase of normal dose and double application. In addition, germination experiment was conducted in the various concentrations of fertilizer solutions under room temperature. The results are summarized as follows; 1. Seed-fertilizer vertical distance must be more than three centimeters to avoid from the decrease and retardation of emergence and poor initial growth of bareley by fertilizer application. 2. Emergence of barley more decreased and retarded in sandy soils than loamy soils and was decelerated with increase of application rate in fertilizer and decrease of soil moisture content. 3. Germination rate remarkably decrease from 0.4 percent of nitrogen solution and 0.5 percent of potassium solution and reached zero at 2.3 and 2.4 percent of nitrogen and potassium solutions, respectively. 4. Germination of seeds affected by concentrated fertilizer solutions was remarkably recovered with dilution degree of fertilizer solution.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.207-212
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• 2012

The objective of the present study is to identify the physico-chemical characteristics of used plug media (UPM) and its effect on growth response of tomato and cucumber seedlings. The UPM from commercial media Mix#5 (Sungro co., Ltd.) was used in this study. This media was sterilized by sterilizer at $120^{\circ}C$ in 30 minutes at 1.5 atm. Physicochemical properties of UPM was compared with new plug media (NPM). Physical properties such as air volume, particle density, solid volume, bulk density were investigated by three phase device (DIK-1130, Japan). And chemical characteristics such as $NO_3$-N, $P_2O_5$, K, Mg, Ca, $SiO_2$, CEC, OM were investigated by soil spectrophotometer (PTIZEN 1412SA, Mecasys Co., Ltd). The result indicates that air volume and water holding capacity of UPM are lower than NPM (25%, 15%, respectively). Bulk density and soil weight are more than two times higher than NPM per unit volume. Compared to NPM, there were no significant different for pH and EC. But CEC of UPM is lower than NPM 40%. In order to compare growth response and ability absorption of inorganic elements by plants, cucumber and tomato seedlings were used and chemical characteristics after growing of mediums were determined. The result indicated that seeding quality of tomato and cucumber in UPM is less than in NPM and almost inorganic ions of UPM are lower than NPM. So it is necessary to improve physicochemical properties of UPM.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.220-227
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• 2012

This study was conducted to analyze the seeding quality of paprika and the growth and early yield after transplanting of paprika nursed under artificial light and natural light. In this study, blue LED, red LED, and white fluorescent lamps (FL) were used as artificial lighting sources. Photoperiod, average photosynthetic photon flux, air temperature, and relative humidity in a closed transplants production system (CTPS) were maintained at 16/8 h, $204{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 26/$20^{\circ}C$, and 70%, respectively. Leaf length, leaf width, leaf area, top fresh weight and dry weight of paprika seedlings, and chlorophyll content in paprika leaves nursed under LED and fluorescent lamps for 21 days after experiment were significantly affected by light treatments. As compared with the control (white FL), leaf area of paprika grown under blue LED, red LED, and natural light was decreased by 63%, 63%, and 28%, respectively. Top dry weight of paprika grown under blue LED, red LED, and natural light was 64%, 50%, and 22%, respectively, compared with the control. Number of leaves on 18 days after transplanting showed with red LED, blue LED, and natural light by 86%, 84%, and 48%, respectively, compared with the control. On 114 days after transplanting, paprika nursed under blue LED and red LED had relatively short plant height. This result might be caused that the elongation of its internodes was suppressed by the illumination of sole blue or red light. Average number of fruits per plant harvested during 4 weeks after first harvest was 3.5 with red LED, 3.3 with blue LED, 1.0 with natural light, and 2.2 with control, respectively. Early yield of paprika nursed under red LED, blue LED, natural light, and control were 453 g/plant, 403 g/plant, 101 g/plant, and 273 g/plant, respectively. Larger fruit of 136 g was harvested with red LED treatment. Even though the early yield of paprika was greatly increased with artificial lighting, but total yield was almost similar as the harvest period after transplanting in greenhouses was lengthened. From the above results, we could understand that paprika nursed under white FL, blue LED, and red LED showed good growth after transplanting and was early harvested by a week as compared to the natural light. Therefore, the white FL, blue LED, and red LED as the artificial lighting sources in CTPS could be strategically used to enhance the seedling quality, to shorten the harvest time, and to increase the yield of paprika.

• Korean journal of applied entomology
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• v.47 no.3
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• pp.273-286
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• 2008

Road-map for the environmental friendly integrated pest management(IPM) of insect pests was drawn up on the strawberry vinyl-houses of farmer's field. Major insect pests were occurred Tetranychus urticae and Aphis gossypii during the strawberry plant seeding in the vinyl house and open field. Also, same insect pests were occurred in the vinyl house during harvesting season of strawberry. For the control of T. urticae and A. gossypii, Phytoseiulus persimilis and Aphidius colemani as natural enemies were input to the vinyl house, respectively. However, because these natural enemies could not control insect pest populations, acaricide and insecticide were sprayed. Then natural enemies were input again in the vinyl house. Natural enemies could not endure the intense cold and differences of temperature and relative humidity between day and night during strawberry harvesting season. So, their behavior and control activity of pests were more decrease than pests. Firstly, natural enemies are input in the vinyl house during the early breeding season of strawberry, secondly, acaricides and insecticide are sprayed for the control of mites and aphids, respectively, during the middle breeding season in the hard winter. Finally, natural enemies are re-input in the vinyl house during the middle and late breeding season.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.485-491
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• 2017

This study examined the germination characteristics by collecting fruits and pretreatment of the diaspore from April 2014 to June 2015 to investigate the diaspore characteristics, seed dispersion, and seed germination characteristics of two myrmecochorous spring ephemerals (MCSE): -Jeffersonia dubia (Jb) and Corydalis remota (Cr)-. The diaspore of Jb was about 5mm-long yellow-dark brown, oblong seeds with the attached amorphous white elaiosome. The mean weights of diaspore, seed, and elaiosome were 15.86mg, 13.46mg, and 2.40mg, respectively, and the elaiosome ratio was 15.13%. The diaspore of Cr was about 1.2mm diameter and glossy black ovoid seeds with the attached white spatula-shaped elaiosome. The mean weights of diaspore, seed, and elaisome were 2.58mg, 2.05mg, and 0.53mg, respectively, and the elaiosome ratio was 20.54%. Camponotus niponensis and Formica japonica transported the diaspore of Jb while Formica japonica and Lasius japonicus transported the diaspore of Cr. The germination percentage of Jb seeds was statistically significant and had the significance level of 1% with the pretreatment and date of sowing. However, it was independent of attachment of elaiosome. The mean germination percentages of Jb seeds was 65.0% during sowing on June 20, 17.5% during sowing on August 19, and 0% during sowing on October 20. The germination percentage of Cr was statistically significant and had the significance level of 5% and 1% with the attachment of elaisome and date of sowing, respectively. The mean germination rates were 54.17% and 35.0% in the non-treatment section and the treatment section with elaisome detached, respectively. The mean germination percentages of Cr seeds was 75.0% during sowing on June 20, 53.75% during sowing on August 19, and 5.0% during sowing on October 20. Considering the fact that the ants transported the diaspores to the ant house when the fruits of MCSE were ripened and dropped the seeds, the direct seeding right after collecting may be most suitable to the characteristics of the evolution of these plant species and may be the best method to obtain the highest germination percentages. Since the ants distribute their seeds, the MCSE produces and attaches the elaiosome to the seed to maintain the symbiotic relationship with ants. The ants then transport the seed to the ant house where the environment is controlled for suitable temperature and humidity, and then the MCSE succeeds in germination after the embryo grows sufficiently in the next spring.

• Korean Journal of Plant Resources
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• v.29 no.4
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• pp.511-518
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• 2016

The subject of this experiment is to supply basic data to inhibit non-productive tillers which are uneconomical for mechanical harvesting and to evaluate optimum planting density and sowing date in central district. Total number of tillers and effective first and second of tillers according to different planting density was higher in 80 ㎝ ridge than 60 ㎝ ridge in proso millet. The wider between plant distance on the ridge, the more increased total number of tillers and effective first and second of tillers. The highest effective tillers (91.7 %) in the first tillers was obtained from the second sowing date (23 May) among different sowing date and next is in the order of 3^rd(13 June, 89.8%) > 1^st(2 May, 85.6%) > 4^th(4 July, 85.2%). The percentage of effective tillers in the second tillers was decreased in the order of 2 May (53.7%), 23 May (40.7%), 13 June (22.2%), 4 July (0%) as the sowing date was delayed. There was no significant difference in days to heading and days to ripening according to different planting density. Although culm length was increased as planting density was increased, whereas number of tillers, stem diameter, ear length, grains per ear and 1000 grain weight was decreased. In the growth and yield characteristics of proso millet according to different sowing date, days to heading and days to ripening, culm length, stem diameter, ear length, grains per ear and yield per 10a were decreased. After the sowing date of 13 June, the reduction of growth and yield characteristics were higher because of excess-moisture injury.

• Korean Journal of Plant Resources
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• v.29 no.4
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• pp.479-494
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• 2016

The aim of this study is to select the superior resources of high yield, high content of functional material optimal to mechanical harvesting by the evaluation of crop growth and yield characteristics in sorghum germplasm. One hundred accessions of sorghum germplasm were used in this experiment. Days from seeding to heading date showed the range from 68 to 94 days with the highest frequency proportion was the group from 80 to 85 days, which occupied 34% (34 plant resources) of 100 germplasm. Ear types of 100 sorghum germplasm could be classified as 7 types of broom-tillering, half broom-tillering, extreme open-loose type, open-loose type, intermediate type, compact type, extreme-compact type of which intermediate type was the highest ratio of 28% (28 plant resources) of 100 germplasm. Yield showed the range from 106 to 365 ㎏/10a with the highest frequency proportion of it was the group from 150 to 200 ㎏/10a, which occupied 44% (44 plant resources) of 100 germplasm. Among 100 sorghum germplasm, 18 ideal resources of high yield and short plant height appropriate for mechanical harvesting were selected. In order to evaluate high content of functional substance, selected 18 resources were analyzed for total polyphenol content, DPPH radical scavenging activity and total anthocyanin content. Finally, we selected 5 resources of short plant height, high yield, high content of total polyphenol and high DPPH radical scavenging activity among 18 genetic resources.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.316-326
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• 2014

Determination of the late marginal heading date (LMHD), which would allow estimation of the late marginal seeding date and the late marginal transplanting date, would help identification of potential double cropping areas and, as a result, establishment of cropping systems. The objective of this study was to determine the LMHD at 51 sites in Korea. For these sites, weather data were obtained from 1971 to 2000 and from 1981 to 2010, which represent past and current normal climate conditions, respectively. To examine crop productivity on the LMHD, climatic yield potential (CYP) was determined to represent the potential yield under a given climate condition. The LMHD was calculated using accumulated temperature for 40 days with threshold values of $760^{\circ}C$, $800^{\circ}C$, $840^{\circ}C$ and $880^{\circ}C$. The value of CYP on a given LMHD was determined using mean temperature and sunshine duration for 40 days from the LMHD. The value of CYP on the LMHD was divided by the maximum value of CYP (CYPmax) in a season to represent the relative yield on the LMHD compared with the potential yield in the season. Our results indicated that the LMHD was delayed at most sites under current normal conditions compared with past conditions. Spatial variation of the LMHD differed by the threshold temperature. Overall, the minimum value of CYP/CYPmax was 81.8% under all of given conditions. In most cases, the value of CYP/CYPmax was >90%, which suggested that yield could be comparable to the potential yield even though heading would have occurred on the LMHD. When the LMHD could be scheduled later without considerable reduction in yield, the late marginal transplanting date could also be delayed accordingly, which would facilitate doublecropping in many areas in Korea. Yield could be affected by sudden change of temperature during a grain filling period. Yet, CYP was calculated using mean temperature and sunshine duration for 40 days after heading. Thus, the value of CYP/CYPmax may not represent actual yield potential due to change of the LMHD, which suggested that further study would be merited to take into account the effect of weather events during grain filling periods on yield using crop growth model and field experiments.