• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.699-704
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• 2007

This experiment was conducted to investigate growth and flowering characteristics of Iris koreana and Iris minutoaurea Makino native to Korea for potting plant of early spring treated by forcing date and temperature. As forcing date delayed from November 1 to December 1, the plant height and number of leaves were increased, however no difference in the number of flower and date of flowering. In Iris koreana, the plant was not flowering in forcing on November 1, flowering 30% on November and 100% on December 1. However all the forcing plant flowered in Iris minutoaurea Makino. As forcing temperature increased from $7^{\circ}C$ to $15^{\circ}C$, the plant height and number of leaves were decreased, however the number of flower in $7^{\circ}C$ was increased and date of flowering was earlier than ones of higher temperature. In Iris koreana, the plant was not flowered in forcing $12^{\circ}C$ and $15^{\circ}C$, all flowered in forcing $7^{\circ}C$. Iris minutoaurea Makino was flowered 30% forcing in $12^{\circ}C$ and all flowered forcing in $7^{\circ}C$.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.105-111
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• 1999

The objectives of this research were to determine growth characteristics of commercial cultivars of strawberry grown in Korea, then to differentiate each cuitivar into cropping system based on degree and duration of domancy and to determine starting date of greenhouse heating as forced culture. The date of floral differentiation on cuitivars such as 'Chodong' 'Shuko' 'Nyoho' was from Sep. 20 to 22. However those of 'Toyonoka', 'Reiko', 'Hokowase' etc. were Sep. 26 to 30 and that of 'Morioka(No. 16)' was Oct. 19. It indicated that the cultivars with short dormancy period 'Nyoho', 'Reiko', 'Toyonoka' etc. were suitable for forcing culture, cultivar with ordinary dormancy period such as 'Suhong' was for nearly forcing culture, cultivar with long dormancy period such as 'Hokowase' was for semi-forcing culture, and cultivar with extreamly long dormancy period such as 'Morioka (No. 16)' was for retarding culture.

• FLOWER RESEARCH JOURNAL
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• v.16 no.4
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• pp.260-265
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• 2008

Studies were carried out to elucidate the effect of temperature, glasshouse forcing date and $GA_3$ on the growth and flowering of pot Hydrangea macrophylla Ser. The plant height was elongated in the $5^{\circ}C$ treatments as 38 cm compared with $20^{\circ}C$ treatment as 6.7 cm, and stem length showed the similar results. The leaf length and width was broadened in the lower temperature, and stem diameter showed the same tendency. The first flowering date in the $15^{\circ}C$ and $20^{\circ}C$ treatment shortened markedly than $5^{\circ}C$ treatment. Days to flowering date of $5^{\circ}C$ was 161 day, while it shortened as 88 day in the $15^{\circ}C$ treatment. The flowering rate was 75.8~90.7% in the temperature. The plant height was elongated in the late glasshouse forcing date, and the leaf length and width showed the similar tendency. The plant height increased in the higher concentration of $GA_3$ compared to the control, and leaf length and width showed the similar results. The first flowering day was advanced by 7 days in the $GA_3$ $50mg{\cdot}L^{-1}$ treatment which had been transferred to greenhouse on Dec. 30 compared with the control of which first flowering day was March 17, and the days to first flowering was conspicuously shortened in the late glasshouse forcing treatment. The width of flower cluster was increased in the $GA_3$ at Dec. 30 glasshouse forcing treatment. The flowering rate was markedly decreased as 62.3% in the control of Nov. 15 treatment, but was increased as 97.9% of $GA_3$ $50mg{\cdot}L^{-1}$ of Jan. 15 treatment.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.123-126
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• 1999

Effects of garlic juice (GJ), ethanol- (GJAE) and ethyl ether extract of garlic juice (GJEE), onion juice (OJ) and ethanol extract of onion juice (OJAE), garlic juice+Merit Blue (GJ+MB), ethanol extract of garlic juice+Merit Blue (GJAE+MB), onion juice+Merit Blue (OJ+MB), ethanol extract of onion juice+Merit Blue (OJAE+MB), and Merit Blue (MB) on budbreak, flowering, and maturity of plastic house-grown 'Daebong' grapes (Vitis labruscana B.) were studied. MB alone and in combination with other formulae hastened the budbreak, and double application was more effective than single one. Most of the buds sprouted in early forcing, but percent budbreak in late forcing was very poor except for MB application. In early forcing, single application of MB in combination with other formulae was most effective for hastening flowering while the response to double application was not consistent, and even delayed the flowering except for OJAE, MB, and OJ+MB. In late forcing, single application of all dormancy-breaking agents, especially MB in combination with other formulae, hastened the flowering while flowering response to double application was inconsistent, and even delayed the flowering except for OJAE+MB and OJ. Although there were no significant differences in harvest date among treatments and the number of application in early forcing, single and double application of MB alone and in combination with other formulae, especially double application of OJAE+MB hastened the harvest date for 12 days in late forcing culture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.184-187
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• 2004

In case of a semi-forcing culture for vegetable perilla, the following research results on the effect of black polyethylene mulching, the optimum sowing season, and the seedling stand improvement method were drawn. Soil temperature was higher and the emergence was faster in a black polyethylene mulching culture than in a non-mulching culture. However, the mature was late, the main stem were larger, and the seed yield, as well as the leaf yield, was greater in a mulching culture than in a non-mulching culture. Considering growth and chilling injury, the stable sowing season of vegetable perilla was judged to be the early in January. The covering materials for improvement of the seedling stand can be a non-woven fabric and hyaline polyethylene. However, the non-woven fabric seemed to be quite suitable in view of the stability and convenience of control after the emergence of perilla.

• The Journal of Natural Sciences
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• v.8 no.1
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• pp.71-80
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• 1995

This experiment was conducted to investigate the effect of raising seedling methods of cold water, low night temperature, and abandoned mine on forcing culture of strawberry. The results were as follows ;1. $17^{\circ}C$ cold water alone and cold water plus 8-hour short day treatments significantly accelerated the flower bud differentiation of Nyoho cultivar to 11 and 15 days, respectively, comparing to common soil raising seedling.2. The date of flower bud differentiation of Nyoho cultivar as influenced by cold water treatment the 17th, the 13th and the 10th of September, respectively, when the seedlings were treated on the 10th of September and on the 25th and the 10th of August in 1991. In 1992, data showed that the flower bud differentiation dates were the 4th and the 2nd of September and the 29th of August when cold water treatment was done on the 10th of August and on the 25th and the 10th of July.3. The first harvest date when Nyoho cultivar was treated by cold water for 30days from Jul. 25 was Nov. 10, this implying that the harvesting day could advanced to 19 days comparing to that by the common soil raising seedling method. The resulting yield was recorded to 21.94 ton per hectare.4. Regardless of the starting date of the treatment, $13^{\circ}C$ low night temperature plus 8-plus short day treatments for 20 days required 17 days to differentiate the flower bud of Nyoho cultivar. Harvesting day could be advanced to 59 days comparing to that by the common raising seedling method when the seedling was treated on July 25, this resulting in increasing the total yield obtained by April 14 of following year to 8.25 ton per hectare.5. When the seedlings of both Nyoho and Hokowase cultivars were raised under the condition of abandoned mine, flowering and harvest date were earlier by the treatment for 20 days than that for 30 days or 40 days. The highest yiesd obtained was recorded in Nyoho cultivar or 1.88 ton per hectare.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.111-114
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• 1999

Experiments were conducted to select the optimum cultivars which are adaptable to South Korea through estimating the differences in daughter plant production and growth response among seven strawberry cultivars. In the vegetative stage, Nyoho, Akihime and Suhong produced more daughter plants than other cultivars whereas Akaneko and Tochinomine, which developed less runners, showed better condition in runner vigorness. The quality of daughter plants derived from forcing cultivars was uniform in general. Even though there was no significant differences in rooting among cultivars, runners from Akaneko and Tochinomine developed more roots and fresh weight of roots than other cultivars. In the forcing cultivars, Akihime showed the most excellent plant vigorness, yield and highest sugar content of fruits and also was 5 days faster than Nyoho in flowering date. However, the fruit tended to be softened. In the semi-forcing cultivars, Tochinomine was excellent in vigorness, firmness, sugar content of fruits and the average of fruit weight but low in flower numbers per cluster and late in the emergency of second flower cluster. Although Akaneko showed highest in sugar/acid ratio and rich in flavour, lighting treatment was recommended to this cultivar for early harvest because of softness of fruits.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.2
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• pp.148-155
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• 2005

An accurate prediction of blooming date is crucial for many authorities to schedule and organize successful spring flower festivals in Korea. The Korea Meteorological Administration (KMA) has been using regression models combined with a subjective correction by forecasters to issue blooming date forecasts for major cities. Using mean monthly temperature data for February (observed) and March (predicted), they issue blooming date forecasts in late February to early March each year. The method has been proved accurate enough for the purpose of scheduling spring festivals in the relevant cities, but cannot be used in areas where no official climate and phenology data are available. We suggest a thermal time-based two-step phenological model for predicting the blooming dates of spring flowers, which can be applied to any geographic location regardless of data availability. The model consists of two sequential periods: the rest period described by chilling requirement and the forcing period described by heating requirement. It requires daily maximum and minimum temperature as an input and calculates daily chill units until a pre-determined chilling requirement for rest release. After the projected rest release date, it accumulates daily heat units (growing degree days) until a pre- determined heating requirement for flowering. Model parameters were derived from the observed bud-burst and flowering dates of cherry tree (Prunus serrulata var. spontanea) at KMA Seoul station along with daily temperature data for 1923-1950. The model was applied to the 1955-2004 daily temperature data to estimate the cherry blooming dates and the deviations from the observed dates were compared with those predicted by the KMA method. Our model performed better than the KMA method in predicting the cherry blooming dates during the last 50 years (MAE = 2.31 vs. 1.58, RMSE = 2.96 vs. 2.09), showing a strong feasibility of operational application.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.540-544
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• 2010

The nursery plant quality and flower bud induction of new strawberry cultivars, 'Maehyang' and 'Seolhyang' in forcing culture were evaluated in the highland and lowland region. In order to produce daughter plants, the new cultivars were grown in the open field located at both highland (Daekwallyung, above 800 m sea level) and lowland (Gangneung, above 20 m sea level) region, respectively. The average air temperature at highland during nursery plant propagation period was $5.3^{\circ}C$ lower than those at lowland. The number of daughter plants produced at lowland was 2 times as high as those of highland, presumably due to the higher air temperature. Anthracnose incidence rates of runner plants produced at lowland were 4 to 7% as high as those in highland. Mean temperature in the highland ($23.5^{\circ}C$) during flower bud differentiation treatment was $5.1^{\circ}C$ lower than that in the lowland ($28.6^{\circ}C$). Seedlings produced in highland showed higher C/N ratio and lower T/R ratio compared to those produced in lowland. The average flower bud formation date of the daughter plants grown in highland were advanced by 30 days compared to the date in lowland. Accordingly, highland was supposed to be appropriate region for raising seedlings in forcing culture of the new strawberry cultivars of 'Maehyang' and 'Seolhyang'.

• Journal of Bio-Environment Control
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• v.19 no.1
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• pp.6-11
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• 2010

This experiment was conducted to investigate the effect of greenhouse orientation on the greenhouse environment and the growth and yield of tomato cv 'Momotaro-Yoku' in forcing culture. The photosynthetic phpton flux density (PPFD) of a.m was higher in north-south orientation than that in east-west orientation and it was opposed in the p.m. Mean PPFD of a day was higher in east-west orientation than that in north-south orientation because the light transmitting area became larger in east-west orientation with decrease of incidence angle. The PPFD at 60 cm point above ground of all furrows was poor due to shadows near plants and it was higher in north-south orientation than that in east-west orientation. The air temperature in the greenhouse was higher in east-west orientation than that in north-south orientation but there was no significant difference since mid February as solar altitude goes up. The soil temperature was some higher in east-west orientation than that in north-south orientation and there was not significant difference among ridges. In east-west orientation, as ripening was promoted, high early yield of tomato were obtained. So total yield was greater about 8% in east-west orientation than that in north-south orientation. Therefore, it was considered that east-west orientation is more advantageous than north-south orientation for forcing culture of tomato.