• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.342-351
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• 1990

Experiments were conducted to find out the possibilities of producing good quality seed of summer type soybean at Chuncheon, 74m above sea level and Jinboo, 600m above sea level in 1987. Local variety, Cheonan Jaelae was used. Seeds were sown June 25 harvested five times from 35 days after flowering with five days interval to 55 days. Vegetative period was longer in the early planting and high cool area, Jinboo, which resulted longer stem length than the late planting and in the plain area, Chuncheon. Pod number and 100 grain weight were shown more and heavier in Jinboo. Earlier planting and later harvesting resulted more pod number and heaveier 100grain weight. Grain yield was heigher in Jinboo, and earlier plainting shown more grain yield and its difference was greater in Jinboo. Long grain filling duration resulted more grain yield. Unripened seeds were produced more by earlier planting with earlier harvesting and earlier planting with late harvesting showed the high rates of pod and stem blight (Diaporthe Phaseolorum). Seed With high moisture content by early harvesting showed more rotten seeds in all planting dates production was more advantageous in the high cool area, Jinboo. Optimum planting date was between May 15 and June 5. Harvesting was desirable about 45-50 days after flowering with heigher germination rate seed yield.

• Journal of Bio-Environment Control
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• v.8 no.2
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• pp.75-82
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• 1999

This study was carried out to examine the effect of day/nignt temperatures during seedling culture on the vegetative and reproductive growth of Lycopersicum esculentum ‘Seokwang’. The study was consisted of two culture stages, plug seedling production in the growth chamber and hydroponic culture of the plant in a glasshouse. Experiments were replicated over time. The germinated seedlings were raised for 33 days (experiment 1) and 35 days (experiment 2) in 4 growth chambers, each with day/night temperatures of either $25^{\circ}C$/$25^{\circ}C$, 16$^{\circ}C$/16$^{\circ}C$, 16$^{\circ}C$/$25^{\circ}C$ or $25^{\circ}C$/16$^{\circ}C$. Cool-white fluorescent lamps provided 140$\mu$mol.m$^{-2}$ .s$^{-1}$ light for 12h each day. In the second experiment, all chambers were supplied with 1000$\mu$mol.mol$^{-1}$ CO$_{2}$ during the photoperiod and had an air velocity of 0.3m.s$^{-1}$ and relative humidity of 80%. Plug seedlings raised were transplanted to rockwool slabs in a glasshouse and were grown hydroponically using the same nutrient solutions used for seedling culture for 37 days (experiment 1) and 35 days (experiment 2). Plant height was affected more by mean daily temperature than by interaction of day and night temperatures. Plant height was the highest in 16/16$^{\circ}C$ treatment. Leaf count was not affected by day and night temperatures, and the chlorophyll concentration was the highest in 16/$25^{\circ}C$ treatment. Fresh and dry weights of stem tended to be greater in treatments of constant day and night temperature. The number of node on which first and second flower clusters were set was significantly higher in 25/$25^{\circ}C$ treatment than in the other treatments. Days to flower of the first flower on the first flower cluster were the greatest in 25/$25^{\circ}C$ and the least in 16/$25^{\circ}C$ treatment. Vegetative and reproductive growth, such as height, fresh and dry weights, days to flower, and nodes of the 1st and 2nd flower cluster set were affected by day/night temperatures.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.91-91
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• 2017

Drought is the most serious abiotic stress limiting rice production. However, little progress has been made in the genetic analysis of drought tolerance, because it is a complex trait controlled by a number of genes and affected by various environmental factors. In here, we screened 218 rice genetic resources for drought tolerance at vegetative stage and selected 32 highly drought tolerant varieties in greenhouse. Under rain-fed conditions, Grain yield of Nagdong was decreased by 53.3% from 517 kg/10a to 241 kg/10a when compare to irrigation condition. By comparison, grain yield of Samgang was decreased by 23.6% from 550 kg/10a to 420 kg/10a. The variety Samgang exhibited strong drought tolerance and stable yield in rain-fed conditions and was selected for further study. To identify QTLs for drought tolerance, we examined visual drought tolerance (VDT) and relative water content (RWC) using a doubled haploid (DH) population consisted of 101 lines derived from a cross between Samgang (a drought tolerance variety) and Nagdong (a drought sensitive variety). Three QTLs for VDT were located on chromosomes 2, 6, and 11, respectively, and explained 41.8% of the total phenotypic variance. qVDT2, flanked by markers RM324 and S2016, explained 8.8% of the phenotypic variance with LOD score of 3.3 and an additive effect of -0.6. qVDT6 was flanked by S6022 and S6023 and explained 12.7% of the phenotypic variance with LOD score of 5.0 and an additive effect of -0.7. qVDT11, flanked by markers RM26765 and RM287, explained 19.9% of the phenotypic variance with LOD score of 7.1 and an additive effect of -1.0. qRWC11 was the only QTL for RWC to be identified; it was in the same locus as qVDT11. qRWC11 explained 19.6% of the phenotypic variance, with a LOD score of 4.0 and an additive effect of 9.7. To determine QTL effects on drought tolerance in rain-fed paddy conditions, seven DH lines were selected according to the number of QTLs they contained. Of the drought tolerance associated QTLs, qVDT2 and qVDT6 did not affect tiller formation, but qVDT11increased tiller number. Tiller formation was most stable when qVDT2 and qVDT11 were combined. DH lines with both of these drought tolerance associated QTLs exhibited the most stable tiller formation. These results suggest that qVDT11 is important for drought tolerance and stable tiller formation under drought stress condition in field.

• Korean Journal of Organic Agriculture
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• v.25 no.3
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• pp.587-602
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• 2017

Correlations of soil and leaf nutrients and growth of young 'Enterprise' apple (Malus ${\times}$ domestica Borkh.) trees were analyzed with tree damage, such as Japanese beetle (JB; Popillia japonica Newman)-damaged leaves, vole damage to trunk, tree mortality, and weed density in a certified organic orchard in warm and humid environment of Southern USA. Interaction treatments of four mulch and three fertilizers were applied around trees as follows: mow-and-blow (MB), shredded paper (SP), wood chips (WC), and green compost (GC) as a mulch, with no fertilizer (NF), poultry litter (PL), and commercial organic fertilizer (CF) as a fertilizer applied in April. Vole damage to trunk and weed density were little correlated with mineral nutrients and tree growth. JB-damaged leaves were highly stimulated to 26.5% in GC-treated plots while tree mortality were increased by MB treatments. Biomass production per tree was approximately 3,700 g on the WC- and GC-treated plots, which was two times higher than those values observed on the other two mulch plots. JB-damaged leaves tended to get worse when nutrients in soil and leaf increased through the correlation analysis, with a strong positive relationship ($r^2=0.585$) observed between JB-damaged leaves and trunk cross sectional area, a vegetative indicator. Tree mortality was more negatively associated with nutrient contents and growth of trees than those of soil nutrients. Wood chips was considered for a local organic mulch materials to increase organic matter contents and to produce healthy young trees in Southern USA, with control insect, such as beetle, and vole density in an orchard habitat.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.492-501
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• 2009

This study was carried out to investigate influence of tree height on vegetable growth, productivity, and labor input in 5 year old slender spindle 'Fuji'/M.9 apple trees planted with the tree space of $3.2{\times}1.2m$ and trained to the tree height of 2.5m in the apple orchard of Apple Research Station, NIHHS, RDA in Gunwi County, Korea. Tree height was extended to the tree height of 4.0m for two years. And then, the tree height was restricted to 2.5 (control), 3.0, 3.5, and 4.0m in 8th year. Yield per 10a was 46, 25, and 4% higher at the tree height of 4.0, 3.5, and 3.0m than at the tree height of 2.5m respectively in first year and 17, 12, and 10% higher respectively, indicating the taller tree, the higher yield. Soluble solid contents was highest in the height of 2.5m than in any other treatments for 2 years, but fruit skin color was not clear. Labor input was increased parallel with the increase of tree height, but yield per labor input was decreased. Gross income and net income per 10a were increased parallel with the increase of tree height in first year, but not increased in second year. In considering production, labor input, and economic efficiency, the optimum tree height of slender spindle 'Fuji'/M.9 apple planted with the tree space of $3.2{\times}1.2m$ was presumed to be 3.0~3.5m.

• Research in Plant Disease
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• v.8 no.3
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• pp.184-188
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• 2002

An antagonistic bacteria, Bacillus licheniformis Nl strain which effectively inhibited mycelial growth of gray mold rot pathogen, Botrytis cinerea was isolated from the rhizosphere of perilla crop. Powder soy formulation by B. lichentfomis Nl strain as a biocontrol agent was developed far the first time and estimated its control effect on perilla leaves in this study. First of all, far the mass production of antifungal metabolites of B. lichentfomis Nl strain in flask liquid culture, the most effective carbon and nitrogen source were selected as glucose and tryp-tone, respectively, For the formulation, vegetative biomass of B. licheniformis Nl strain from 5-day-old liquid culture in nutrient broth added glucose and tryptone was mixed with soy flour, rice flour glucose, FeSo$_4$~7$H_2O$, and MnCl$_2$. 4$H_2O$, and dried and pulverized. In plastic house test, powder soy formulation effectually controlled gray mold rot as the control value of 93.1 %, was more effective than chemical fungicide, benomyl showing the control value of 86.1%. Thus, development of powder soy formulation of B. lichentfomis Nl will aid large-scale application of biological control in field trials.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.371-379
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• 2017

This study was aimed to investigate the contribution of tree plantation, tree breeding and soil erosion control techniques developed during Saemaul Undong periods to the successful forest rehabilitation in the Republic of Korea. We surveyed a various literature of forest journals and had deep interview with forest experts who were actively involved in the forest rehabilitation projects. In the Republic of Korea, the forest rehabilitation was started with Saemaul Undong in 1970s and carried out to make the country green and to restore degraded forest lands by supports of tree plantation, tree breeding and soil erosion control techniques. Various techniques such as seed storage, seedling production, mass vegetative propagation (grafting and cutting) and special planting at denuded land or slash and burn site were developed for tree plantation. All techniques developed for the forest rehabilitation were connected with Saemaul Undong which caused active participation of local community people. Therefore, the development of tree plantation, tree breeding and soil erosion control skills had great impact on the job creation and income sources of local dwellers. It would be an applicable case to developing countries suffering with deforestation and forest degradation if the Korean skills developed for forest rehabilitation could be transferred.

• Journal of Bio-Environment Control
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• v.7 no.3
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• pp.191-205
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• 1998

Among cauliflower, ‘Snow king’ and ‘Snow crown’, which are early maturing cultivars, showed active early vegetative growth. However, ‘Snow dress’ showed good curd characteristics and in marketability, ‘Green beauty’was superior and can also be grown in Cheju. All the cauliflower and broccoli Plots transplanted on Sep. 3 and on Sep. 17 had fewer number of days from the planting date to the harvesting date than did the plots transplanted on Oct. 1. h the case of broccoli, those transplanted on Oct. 1 had the highest marketability. In the case of cauliflower cultivars, ‘Snow dress’a late maturing cultivar, demonstrated the greatest reduction in growing stage when cultivated in an unheated plastic film houses and broccoli, growing stage is similar between those grown in an open field and those grown in unheated plastic film houses. For all the cauliflower and broccoli, the contents of vitamin A and C showed no significant difference between those grown in an open field and those grown in unheated plastic film houses.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.1-6
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• 1986

The growth, development, and morphological characteristics of Echinochtoa colons (L.) Link were determined through one life cycle. E. colons emerged 2 to 3 days after seeding (DAS) and reached the two leaf stage by 8 DAS. During the early growth stages, root length was greater than plant height, but the relationship was reversed from 4 weeks after seeding (WAS). Tillering started from the third leaf of the main culm as the sixth leaf on the main calm emerged. The unfolding of the leaves and tillering followed a regular pattern during the vegetative growth period. This resulted in the production of 19 tillers (5 primary, 12 secondary, 1 tertiary, and I nodal) at the 14-leaf stage. Shoot-root weight ratio was highest just before panicle initiation. The second spike from the top of the panicle was the shortest and produced the fewest seeds. Thereafter, spike length and the number of seeds per spike generally increased, the lower the position of the spike on the panicle. Seeds on the lower spikes weighed less and had lower germination ability than those from the upper spikes. Adventitious roots arose from the leaf sheath bases of a flowering stalk. The ability to produce adventitious roots was greater in a younger stalls than in an older stalk.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.288-292
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• 2014

This study was performed to investigate the possibility of water cutting by vegetative propagation method from July to August of Clematis. To find out proper cutting length and rooting growth regulator for water cuttings production, cutting lengths of C. 'Honora' made 1 node and 2 nodes length cutting, which were soaked in NAA $0.1mg{\cdot}L^{-1}$. Rooting rate of cuttings treated by NAA $0.1mg{\cdot}L^{-1}$ was 100% irrespective of root lengths, but that of 1 node and 2 nodes untreated by NAA $0.1mg{\cdot}L^{-1}$ were very low about 30% and 19% respectively. Number of roots and roots length were also highest in NAA $0.1mg{\cdot}L^{-1}$, effects of NAA $0.1mg{\cdot}L^{-1}$ treatment were greater at 1 node cutting. Based on the results, rooting rate for I node cutting of C. 'Pairu' according to NAA (0, 0.1, 0.5, $1.0mg{\cdot}L^{-1}$) concentrations was investigated. Days to rooting were 70-74 days (about 10 weeks), which was not significantly different among the NAA concentrations. Rooting rate increased by NAA concentration. it was about 90% usually and was improved with more than NAA $0.5mg{\cdot}L^{-1}$.