• Journal of Forest and Environmental Science
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• v.26 no.2
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• pp.95-102
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• 2010

Jatropha curcas is an oil bearing species with multiple uses and considerable economic potential as a biofuel plant. Plant flowering and breeding characteristics are important for us to understand the reproduction of plant populations. The present study describes the floral biology and flowering phenology of J. curcas which is a prerequisite for hybridization program for genetic improvement through conventional breeding. The plant produces flowers in dichasial inflorescences. Normally, the flowers are unisexual, and male and female flowers are produced in the same inflorescence. Only a few male flowers are produced in an inflorescence, and fruits are produced only through pollination between different flowers from the same or different plants. This study includes a description of the inflorescence, flower anatomy of both male and female flowers, female : male ratio, pollen : ovule ratio, flowering phenology, pollen viability, stigma receptivity, comparison of selfing methods and a comparison of geitonogamy and xenogamy. This information may be useful in J. curcas breeding programmes.

• The Korean Journal of Ecology
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• v.1 no.1
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• pp.17-23
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• 1977

Flowering dates of 389 plant species in the Hongneung Arboretum, Seoul, had been recorded from 1968 through 1975. The thermal analysis on the air temperature as the key factor determining the first flowering date, with climatological data obtained in the Arboretum, were undertaken by Nuttonson's Index (1948) and Lindsey & Newman's Index (1956). The results and conclusion in this study are as follow; Peak in the bell shape distribution curve of the species and first flowering dates, largely, was early May. Flower spans of most species were 10 to 20 days, neverthless, some species flower only a few days while others may stay flowering a hundred days even more. Increase-curves of summation temperature from early spring through late-summer showed almost the same mode in both Nuttonson;s Index (Tn) and Lindsey & Newman's Index (T1). These Indices manifested the exponential curve, increasing slowly at the beginning of spring chiefly but rapidly from the middle part of April. The equation of the linear relationahip between Tn and Tl as far as in thisstudy is as follow. Tl=230Tn It appears that the distribution of summation temperature, below Tn=400°C·day, affects the first flowering, even though it could be modified somehow by the distribution of precipitation, day length and others. Nuttonson's Index (Tn.f) and Lindsey & Newman's Index (Tl.f) upon the thermal amount first flowering dates have been respectively simulated as follow. Tn.f=θa + C Tl.f=230θa + 230C where θ is air temperature 10°C, a and C are a constant.

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.163-168
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• 2001

This study was conducted to obtain basic information on cross breeding for developing bolting resistant variety of Angelica gigas NAKAI which has been subjected to severe yield reduction resulted from flower-stalk initiation during the growth. Compatibility of selfing and/or crossing pollination among 5 local cultivars were tested. Results obtained are summarized as follows. In case of three year old plant, all cultivars emerged March 14 and bolted from May 12 to May 13. Ponghwa cultivar was flowered 3 to 5 days earlier than other cultivars. Flower duration continued 41 to 43 days. Interval of flowering date from main stem to first primary branch, from first to second or second to third primary branch was 9 to 13 days. Emergency of stamen proceeded 4~8 days of pistil initiation demonstrating that Angelica gigas NAKAI is protandrous plant. Furthermore initiation of first pistil was 1~4days later than formation of last stamen in the same flower cluster. Percent pollination of Angelica gigas NAKAI was 52% under natural condition, so called open-pollination, but bagging by enveloping flowers was as low as 0.4~2.4%. In the result of compatibility test, all local cultivars tend to show both of self-and cross-compatibility. Inpollination, ‘Muju’$\times$‘Muju’combination showed highest fertility up to 40.8% whereases cross pollination, ‘Pyeongchang’$\times$‘Inje’combination, showed 67.0% fertility.

• FLOWER RESEARCH JOURNAL
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• v.17 no.2
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• pp.88-92
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• 2009

This experiment was conducted to find out the effects of pinching on shoot growth, flowering and covering of Lonicera sempervirens growth in containers. 180 cm high pinching of plants increased shoot length compared to 60 cm low pinching and decreased lateral shoot numbers, but there was no difference in branch numbers by the pinching methods. Covering rates of the pergola were 85% with 60 cm low pinching, 74% with 120 cm middle pinching, and 62% with 180 cm high pinching. The pinched plants continued to flower from the middle of May to the middle of September. The first flowering time was in the middle of May in low pinching and in the early of June in middle and high pinching. The lower pinching height and the earlier pinching time induced earlier flowering time, and the peak flowering of pinched plants was in mid-August. To cover over 85% of the pergola screen with 3.0 m wide and 2.2 m high, two plants per 1 m needed to grow and to pinch at 60 cm height.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.379-386
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• 2013

Aphidius colemani and Orius laevigatus aree natural enemies of the control cotton aphid and western flower thrips, which are the major pests of cucumber plants. We evaluated the low toxicity of 47 fungicides against A. colemani and O. laevigatus, and we investigated the simultaneous effect of the natural enemies with fungicide of low toxicity on the pests. The toxicity of DBEDC, hexaconazole, pyraclostrobin, tribasic copper sulfate, triflumizole, chlorothalonil, flusilazole, folpet, carbendazim+diethofencarb, cymoxanil+fenamidone and trifloxystrobin to A. colemani mummies was more than 50% and to O. laevigatus was low toxic. Among the fungicides with low toxicity, azoxystrobin 20% WP was selected because it could be used simultaneously with A. colemani and O. laevigatus and as a fungicide to control powdery mildew and downy mildew. In 2011, the densities of western flower thrips and cotton aphid increased rapidly in early-May in Gongju and Cheonan, Chungnam Province. When azoxystrobin was used at an interval of 10 days in spring, A. colemani and O. laevigatus were released at an interval of 7 days at the early occurrence of the pests. The natural enemies decreased the densities of the pests; the maximum number of A. colemani mummies was 18 per lower leaf, and the maximum number of O. laevigatus was 0.5 per flower. Azoxystrobin did not influence the densities of A. colemani and O. laevigatus. The results show that the selected fungicides can be used with A. colemani and O. laevigatus for the intergrated pest management of cotton aphid and western flower thrips in cucumber polyvinyl house cultivation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.222-229
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• 2016

Corni fructus is often distributed or processed in the form of dried fruit. However, Corni fructus is hard to develop due to its distinctive sour, bitter, and astringent taste. The aim of this study was to develop a puree to broaden the utilization of fresh Corni fructus. Manufacturing and quality characteristics of Sansuyu jam made from puree were investigated. Seeded Corni fructus pulp consisted of 20 to 26% whole fruit. The moisture and sugar contents of pulp were 52~63% and $15{\sim}31^{\circ}Brix$, respectively. Sterilized distilled water was added to seeded pulp to achieve a constant solids content in the puree. As the pectin content was low as $0.14{\pm}0.01%$, gelling agent was added to produce jam. The moisture content of the puree increased to 83~88%. The sugar content was reduced to $10^{\circ}Brix$. There was no significant difference in pH. DPPH radical scavenging activities of the puree according to ripening rate at a concentration of 100 ppm were 47.92% and 50.96%, respectively. The preference degree was $5.03{\pm}0.97$ at a ripening ratio of 50:50, 2% pectin, and 0.2% carrageenan. These results imply that Corni fructus pulp puree may be appropriate for development as a natural food product.

• Korean journal of applied entomology
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• v.56 no.3
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• pp.309-314
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• 2017

Sampling plan using yellow sticky traps for the major strawberry flying pests - western flower thrips Frankliniella occidentalis adults, cotton aphid Aphis gossypii alate and greenhouse whitefly Trialeurodes vaporarium adults was developed to determine the initial occurrence time. The analyzed trap data were obtained from three commercial strawberry greenhouses for the whole growing season (September to May of the following year) during 2013 to 2017 in Jeju province. Three flying pests showed the aggregated distribution patterns resulted from commonly used regression techniques - Taylor's power law and Iwao's patchiness regression. Taylor's power law was better description of mean-variance relationship of the western flower thrips and the cotton aphid than Iwao's patchiness regression, otherwise greenhouse whitefly was better described by Iwao's patchiness regression. There were highly significant correlated among mean density per trap, maximum density and proportion of traps with more than 10 individuals. To estimate 4.0 heads of mean density per trap, the minimum number of traps were required 13 traps for western flower thrips, 11 traps for cotton aphid and 10 traps for greenhouse whitefly. The sequential sampling plans at the fixed precision level 0.25 were developed using parameters of Taylor's power law for western flower thrips and cotton aphid, and of Iwao's patchiness regression for greenhouse whitefly.

• Journal of Korean Society of Forest Science
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• v.33 no.1
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• pp.59-67
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• 1977

Seasonal changes in free arginine concentration in Pinus radiata buds were studied in four clones from May, 1974 to June, 1975. The buds were from the tips of first order branches which had flowered the previous year, and the significant findings were as follows: (1) In general, arginine concentration in the buds of the four clones showed the highest peaks from December to March, a period spanning the time of flower initiation, and the lowest levels in Angust and September. (2) The timing of individual arginine peaks during the period of flower initiation matched roughly the timing of initiation of several female cone clusters, as determined from Clone 7 which characteristically initiates three cycles of female cones on its leading shoot. (3) The heavy-flowering clones showed higher arginine concentration than ther poorer flowering ones, especially at the time of flower initiation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.362-368
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• 2020

In this study, the gallic acid content of various varieties of chestnuts (Daebo, Okgwang, Chukpa, Samjosaeng) was investigated during the period between May 2018 to July 2019. A quantitative analysis was performed by HPLC using extracts of chestnut, inner skin, outer skin, branches, chestnut, male flower, and the male flower for each type of chestnut tree. Gallic acid was identified by dissolving standard gallic acid in water and analyzed three times in the concentration range of 100, 200, 250, and 500ppm. Linearity was confirmed by the peak area ratio at each concentration. Among the different chestnut varieties, the gallic acid content was highest at 0.0863% in Chukpa, followed by Daebo, Okgwang, and Samjosaeng. While comparing the average gallic acid content of each part of the chestnut tree, it was observed that the falling male flower had the highest content at 1.2100%, followed by chestnut leaves, chestnut pines, and branches. In a comparison of the inner skins, the Daebo variety had the highest gallic acid content at 0.7463% followed by Chukpa, Okgwang, and Samjosaeng. The outer skin of Samjosaeng had the highest content at 0.4918%, followed by Chukpa, Daebo, and Okgwang. The pines of the Samjosaeng chestnut had the highest content at 1.3035%, followed by Daebo, Chukpa, and Okgwang.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.69-89
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• 1981

Stevia (Stevia rebaudiana Bertoni) is a perennial herb widely distributed in the mountainous area of Paraguay. It belongs to the family Compositae and contains 6 to 12 percent stevioside in the leaves. Stevioside is a glucoside having similar sweetening character to surgar and the degree of sweetness is approximately 300 times of sugar. Since Korea does not produce any sugar crops, and the synthetic sweetenings are potentially hazardous for health, it is rather urgent to develop an economical new sweetener. Consequently, the current experiments are conducted to establish cultural practices of stevia, a new sweetening herbs, introduced into Korea in 1973 and the results are summarized as followings: 1. Days from transplanting of cuttings to the flower bud formation of 6 stevia lines were similar among daylengths of 8, 10 and 12 hours, but it was much greater at daylengths of 14 or 24 hour and varietal differences were noticable. All lines were photosensitive, but a line, 77013, was the most sensitive and 77067 and Suweon 2 were less sensitive to daylength. 2. Critical daylength of all lines seemed to be approximately 12 hours. Growth of plants was severely retarded at daylengths less than 12 hours. 3. Cutting were responded to short daylength before rooting. Number of days from transplanting to flower bud formation of 40-day old cuttings in the nursery bed was 20 days and it was delayed as duration of nursery were shorter. 4. Number of days from emergence to flower bud formation was shortest at short day treatment from 20 days after emergence. It was became longer as initiation of short day treatment was earlier or later than 20 days. 5. Plant height, number of branches, and top dry weight of stevia were reduced as cutting date was delayed from March 20 to May 20. The highest yield of dry leaf was obtained at nursery duration of 40-50 days in march 20 cutting, 30-40 days in April 20 cutting, and 30 days in May 20 cutting. 6. An asymptotic relationship was observed between plant population and leaf dry weight. Yield of dry leaf increased rapidly as plant population increased from 5,000 to 10,000 plants/10a with a reduced increasing rate from 10,000 to 20,000 plants/l0a, and levelled off at the plant population higher than 20,000 plants/l0a. 7. Stevia was adaptable in Suweon, Chengju, Mokpo and Jeju and drought was one of the main factors reducing yield of dry leaf. Yield of dry leaf was reduced significantly (approximately 30%) at June 20 transplanting compared to optimum transplanting. 8. Yield of dry leaf was higher in a vinyl house compared to unprotected control at long daylength or natural daylength except at short day treatment at March 20. Higher temperature ill a vinyl house does not have benefital effects at April 20 transplanting. 9. The highest content of stevioside was noted at the upper leaves of the plant but the lowest was measured at the plant parts of 20cm above ground. Leaf dry weight and stevioside yield was mainly contributed by the plant parts of 60 to 120cm above ground but the varietal differences were also significant. 10. Delayed harvest by the time of flower bud formation increased leaf dry weight remarkably. However, there were insignificant changes of yield as harvests were made at any time after flower bud formation. Content of stevioside was highest at the time of flower bud formation and earlier or later harvest than this time was low in its content. The optimum harvesting time determined by leaf dry weight and stevioside content was the periods from flower bud formation to right before flowering that would be the period from September 10 to September 15 in Suweon area. 11. Stevioside and rebaudioside content in the leaves of Stevia varieties were ranged from 5.4% to 14.3% and 1.5% to 8.3% respectively. However, no definit relationships between stevioside and rebaudioside were observed in these particular experiments.