• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.392-400
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• 2024

This study was conducted to find the flowering and growth characteristics according to the different altitudes (plains and mid-mountain regions) and cultivation methods (field and plastic houses cultivation) of Elsholtzia splendens. Experimental regions located at 12 meters and 500 meters above sea level were selected for the plains and the mid-mountain, respectively, and the same method was applied for cultivation management by different altitudes and cultivation methods. In the mid-mountain region, flower bud emergence (2-3 days), flowering (9 days), and full bloom (6-7 days) stages of Elsholtzia splendens were earlier than in the plains, and field cultivation was earlier than plastic house cultivation. The plant height, the main stem diameter, and the number of branches tended to increase gradually after an initial rapid growth at 59 to 69 days after planting date. The days of duration of sunshine (less than 8 hours) from the rainy season (June 20) to the period when vegetative growth increases gradually (59 to 69 days after planting) was 22 to 29 days and 26 to 35 days in the plains and the mid-mountain regions respectively, and this period was estimated time of transition from vegetative growth to reproductive growth. The spikes growth of Elsholtzia splendens by cultivation altitudes was higher in the mid-mountain region than in the plains, and there were no statistically significant differences in growth characteristics except for the main stem diameter, the number of branches, and the dry matter. Also, the amount of flowering and growth was higher in the plastic house cultivation compared to the field cultivation. As a result, some differences in flowering amount were observed when cultivating Elsholtzia splendens for landscaping purposes, but it was considered possible to cultivate in both plains and mid-mountain regions. This study therefore provides ecological information for understanding the relationship between weather characteristics and growth of Elsholtzia splendens.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.3
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• pp.205-209
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• 2018

'Saemimyeon,' a Tongil-type rice variety (Indica x Japonica), containing high amylose content, is suitable for rice noodle production. Currently, the major parts of the rice processing industry that include products such as rice flour and noodles are expected to partially replace the wheat flour market. The volume of the rice noodle market is growing and can contribute to the rice surplus problems and farmer's income. This study was carried out to promote productivity of 'Saemimyeon' by finding the most suitable transplanting times in Youngnam Province. The transplanting times were May $10^{th}$, May $17^{th}$, May $24^{th}$, May $31^{th}$, June $7^{th}$, and June $14^{th}$ and the planting distance was $30{\times}12cm$. The field experiment was conducted in the Miryang region (southern plain region of Korea) from 2015 to 2017. Our results suggested that the optimum transplanting dates were from May $17^{th}$ to May $31^{th}$, which resulted in an average yield of 750 kg/10 a. The average grain filling rate before May $31^{th}$ was more than 83% and it declined to 75% after June $7^{th}$. The average temperature range from heading to harvesting time was $21{\sim}25^{\circ}C$ and the estimated optimal temperature was $24^{\circ}C$, which is similar to that of May $24^{th}$ by regression equation. It is suggested that low temperature at seed maturation time caused the lower grain filling rate, and therefore 'Saemimyeon' needed to be transplanted before May $31^{th}$ for higher productivity. Estimated optimal transplanting time based on temperature was 1 ~ 2 weeks earlier than the optimum transplanting time for common japonica rice cultivars in Youngnam Province.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.230-235
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• 2015

The experiment was conducted to elucidate the growth characteristics of sorghum in the different planting methods: direct sowing and transplanting (20 days after sowing, DAS). Weed weight was taken from three randomly chosen-2 plots 60 DAS (DAT). One time (20, 30 days after transplanting, DAT) and two times (10/20, 10/30, 20/30, 20/40 DAS) application of weeder machine (FRT 80E) were conducted for direct sowing and transplanting, respectively. In transplanting, the weed control efficacy of weeder machine at 90 DAT was about 67% (DAT 20), 57% (DAT 30) at one time and 87% at two times. The most effective application number was two times (20/40 DAT) followed by one time (20 DAT). However, when reviewing yield and economy, the frequency and times of using weeder machine were preferably one time and 20 DAT. Results with mechanical weed control have been particularly good in transplanted row crops such as sorghum. In direct sowing, the weed control efficacy of weeder machine 60 DAS was about 87% (10/20 DAS), 88% (10/30 DAS) and 82% (20/30 DAS) at two times, respectively. When reviewing yield and economy, the times and frequency of weeder machine were preferably two times, 10 and 30 DAS.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.54-63
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• 1994

Runner-derived(Expt.1) and tissue culture-derived strawbeery plantlets(Expt. 2) were grown in pots under greenhouse condition and inoculated with inocula of the vesicular-arbuscular mycorrhizal(VAM) fungi isolated from a field strawberry plants. Total biomass of mycorrhizal strawberry plants was significantly increased. There was a similar tendency in the number of cluster and flower at 20 weeks after inoculation, and VAM fungi inoculation positively influenced the leaf number, leaf length, leaf width and petiole length of strawberry plants in all investigated times. However, no difference was in the flowering time of strawberry plants. Leaf margin of non-inoculated strawberry plantlets turned into raddish brown(7.5R 4/8) from around 4 weeks after habituation. Inoculation of VAM fungi at the time of habituation was much more effective in stimulating plant growth. VA mycorrhizal dependency were 162.7 % in the runner-derived strawberry plants, Dependency with pre-and post-habituated incoulation in tissue culture-derived plants was respective 116.4% and 106.0%. The levels of mycorrhizal colonization were increased with plant growth and infection rates by endophytes at harvest time were 47.5% in Expt. 1, 56.4% in Expt. 2, respectively. Contents of phosphorus, potassium and calcium in mycorrhizal strawberry plants at harvest time were higher than non-mycorrhizal ones however, magnesium concentration was decreased. These experiments demonstrated that VAM fungi could be introduced into nursery stages of strawberry plantlets including the temporary planting period to improve growth and plant nutrients uptake by mycorrhizal plants.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.4
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• pp.84-94
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• 2013

This study scrutinizes the titles of serial poems on Japanese Apricot, which have lucid characters on season and time changes, having been appreciated and recited by the scholars in the Choseon Dynasty era and analyses the records of Zhang zi(1153~1235), a writer in Song(宋) Dynasty in China, having presented the objects harmonizing perfectly with Japanese Apricot. The results of this study categorizes the objects of Japanese Apricot appreciation and establishes the landscape characteristics on Japanese Apricot appreciation affiliated with as follows. First, the objects of Japanese Apricot appreciation are categorized into 'form of blossoms', 'natural feature(景物)', 'place of tree planting', 'the picturesque scene(景色)' and 'behavior'. Second, the scholars regarded the single trees whose branches are grotesque as the objects of appreciation and enjoyed them. They preferred white and single petal Japanese Apricot and admired red Japanese Apricot which has Taoism images. Third, they admired pines and camelias which represent fidelity and strength and valued Japanese Apricot with cranes which remind themselves of solitary scholars. Fourth, they appreciated the images of Japanese Apricot reflected on the water, and the poetically inspiring atmosphere where the trees are planted by the window. Fifth, the moon and snow were crucial weather conditions for appreciating. cold weather and time from night to dawn were ideally suited for enjoying. Sixth, they enjoyed blossoms in various fashions like bottling(甁梅), potting(盆梅), green-housing(龕梅), searching(龕梅) and black-and-white painting(墨梅) with a view to seeing blossoms earlier than the usual flowering time. Moreover, they used paper drapes, bead curtains, mirrors and ice lamps for active appreciation. They also listened to the sound of Piri(wind) and Geomungo(string), played go and drew tea with noble and elegant beauties when they enjoyed Japanese Apricot. The scholars influenced by the neo-Confucianism, which contemplates the objects, attached the specific sentiments like memories, grieves, dreams and farewells to Japanese Apricot and appreciated them. As stated above the scholars enjoyed the landscape including the picturesque scene like climate-weather, time-season and human behaviors not to mention the physical beauty of Japanese Apricot themselves and objects in company with Japanese Apricot including animals and plants.

• Korean Journal of Agricultural Science
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• v.36 no.2
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• pp.123-127
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• 2009

This study was carried out to gain the informations about seedling transplanting cultivation of Daehakchal Gold 1 which was developed at the Corn Breed. and Genetics Lab., Coll. of Life and Sci., Chungnam Nat'l Univ. in 2009. This hybrid and Check were sowed over four times at intervals of 10 days from 15th April(1st) to 30th May(last) and transplanted at CNU Corn Breed. Farm the 20th seedling cultivated after sowing, respectively. Results obtained from this experiment were as follows; stem height of this hybrid were variable regardless of sowing and transplanting times, while ear height was gradually increased according to delay of sowing times. Ear size and sharp of fresh corn as one of important traits was good at 2nd harvest times, while tip filling of ear harvested at 1st time was not good and also it's size decreased according to delay of transplanting stage. Stability of this hybrid expressed as ratio of stem height to ear height was very good as 50% below. Accordingly, the proper sowing and transplanting times of Daehackchal Gold 1 considered the late in April to early in May as harvesting proper period.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.437-448
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• 2013

Hemipteran bugs, which were previously considered as secondary pests, have currently become important pests of numerous crops. Among them, Riptortus pedestris (Fabricius) is a major species that occurs in Korea, Japan, China, and South Asian countries. Riptortus pedestris infests leguminous crops like soybean, vetches, and red clover; fruit trees like persimmon and yuju; and grains like barley, foxtail millet, broomcorn, and sorghum. Riptortus pedestris causes the greatest damage to soybean, as it is the most suitable host for the bug. Feeding damage during pod formation significantly reduces the yield of soybean. Currently, 17 insecticides, including diazinon and etofenprox, are registered for the control of hemipteran bugs in Korea, and growers apply insecticides two to three times on a regular basis. Aggregation pheromone traps are widely used as a monitoring tool and partial control measure. The aggregation pheromone of R. pedestris attracts conspecific adults and nymphs and is used for food exploitation rather than sexual attraction. In addition, the pheromone serves as a kairomone for egg parasitoids such as Gryon japonicum (Ashmead) and Ooencyrtus nezarae Ishii. As a new method of pest management, nonviable host eggs were included in the pheromone trap to catch R. pedestris and propagate parasitoids. As a part of cultural practices, resistant soybean varieties with specific color and size of pod and control of flowering time through the alteration of planting date can be used. For the effective management of R. pedestris in the near future, development of cultural practices that can support natural control factors and the use of multiple control tactics are needed.

• Korean journal of applied entomology
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• v.16 no.1 s.30
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• pp.41-45
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• 1977

The systemic insecticides carbofuran $(Curaterr\; 3\%\; G)$ mephosfolan $(Cytrolane\; 2\%\; G)$ and disulfoton$(Disyston\; 5\%\; G)$ were evaluated in the field for conrol of some insects on soybeans when the insecticides were applied in seeding-pits at the rates of 4.6, 9.2 and 13.8 mg(a.i)/pit at the planting time. Control of the soybean aphid (Aphis glycines Matsumura) and the two-spotted spider mite (Tetranychus telarius(L.)) on soybeans was obtained for about 2 to 3 months, but their treatments were ineffective against the soybean moth (Grapholitha glycinivorella Matsumura). For the control of aphids and mites, disulfoton was better than carbofuran and mephosfolan. The insecticides slightly reduced the soybean stands, while the low-dose treatments of carbofuran slightly increased the stands. Carbofuran and mephosfolan caused severe phytotoxicity at the early stages, but disulfoton showed slight or negligible phytotoxicity. The phytotoxic symptoms in carbofuran and mephosfolan treatments were shelving the large number of brown or black-brown spots on the cotyledon and the first-leaves, and in addition to that showing necrosis along the leaf-margin. The symptoms in disulfoton treatments were slight withering along the leaf-margin of the first-leaves. In spite of good control of aphids and mites, there were no differences in soybean yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.2
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• pp.91-98
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• 2018

This study was conducted in 2014 in the Gangjin area of Jeonnam province for the purpose of confirming the potential of Kenaf as an alternative feed crop of rice. The weather and soil conditions were favorable and there was no adverse effect on the growth of Kenaf. The amount of seeding was given at 10 kg, 15 kg and 20 kg. As the seeding volume increased, plant height and dry matter yield increased, and stem diameter and number of nodes decreased. The highest growth rate was observed between 75 and 90 days from the date of planting(p<0.05). As the growth progressed, stem rate increased and leaf rate decreased(p<0.05). Increased amount of seeding and growth resulted in decreased CP and TDN and increased ADF and NDF, which resulted in the decreased economic value of Kenaf as a feed crop. The result of increasing the use of organic fertilizer to 20 kg and 30 kg was similar to increasing the amount of seeding. As organic fertilizer usage increased, dry matter yield and growth rate improved(p<0.05).

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.184-190
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• 1997

Lesion enlargement of ginger rhizome rot was most rapid at 35~40 C, but delayed greatly as temperature decreased. Time needed for a killing a ginger plant, 22~25 cm long, was about 5 days at 35~40 C, but was 15 days at 15 C in a growth chamber test. Higher RH above 90%, higher soil moisture level above 80% of maximum soil moisture capacity, and deeper planting below 4cm enhanced the lesion development on ginger stems and rhizomes. Pythium myriotylum existed in field soil as forms of hyphal portion, hyphal swelling body, or oospore- or zoospore-like bodies, and served as the origin of its colonization. Inocula of P. myriotylum was randomly distributed in soil surface around ginger plants, but its density was decreased as increasing soil depth with the highest density at 0~10 cm soil depth. Population density of P. myriotylum did not vary significantly between the rhizoplane and the rhizosphere soil of a ginger plant, but differed greatly between the disessed and healthy plants with several to several hundreds times higher population in the diseased plants. A positive curvilinear relationship was found between P. myriotylum density and ginger rhizome rot severity.