• Journal of the Korean Society of Food Science and Nutrition
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• v.5 no.1
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• pp.19-24
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• 1976

A determination of proper maturity is a significant factor for a good quality and storage. This study is aimed at a determination of optimum harvest date related to a decisive measuring of maturity in Spur Golden Delicious. In this case, respiratory status and other characteristics are taken as a indicator for maturing determination. The results are as follows. 1. Respiratory rate has been decreased through a fruit development and come to its minimized point on Sep. 25. at last. On the contrary its tendency has been increased after Sep. 25. It is also estimated that the former is pre-climacteric, the latter climacteric rise based on dimacteric minimum Sep. 25. 2. A flesh hardness has maintained comparably high value until Sep. 18. But in the point of climacteric minimum, Sep. 25, curve of flesh firmness has rapidly been broken down, and after Sep. 25, tendency has slowly decreased at the sucessive date. 3. Pectin content, optimum acidity are remarkably decreased after Sep. 25, Oct. 2 respectively. 4. When water soluble sugar content shows to be swung from climacteric minimum, any resonable tendency are not found. 5. In this experiment, optimum harvest time is found by Oct. 2, in time of 145 days after flowering.

• Journal of Plant Biology
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• v.35 no.3
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• pp.185-190
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• 1992

Changes in activity of gibberellin $3{\beta}-hydroxylase$ which converts $[^3H]GA_{20}\;to\;GA_1$ were studied during seed maturation using partially purified enzyme preparations of two cultivars, Kentucky Wonder (normal) and Masterpiece (dwarf) of Phaseolus vulgaris. The specific activity of $3{\beta}-hydroxylase$ per seed reached maximum at 21 days after flowering and subsequently decreased during seed maturation in both cultivars. The ratios of conversion of $[17-^{13}C,\;^3H_2]GA_{20}\;to\;GA_1.\;GA_5,\;and\;GA_6$ by the same amount of $3{\beta}-hydroxylase$ were almost identical. Epoxidation of $GA_5\;to\;GA_6$ is also catalyzed by the partially purified $3{\beta}-hydroxylase$ preparation(Kobayashi et aI., 1991) and the conversion was inhibited by the substrates of $3{\beta}-hydroxylase$. These results suggest that the same enzyme might catalyze $3{\beta}-hydroxylase{\;}of{\;}GA_{20}\;to\;GA_1$ and epoxidation of $GA_5\;to\;GA_6$..

• Korean Journal of Medicinal Crop Science
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• v.6 no.3
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• pp.170-175
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• 1998

This study was conducted to determine the effect of seminal sections of tuber and staking methods on growth and yield of a chinese yam (Dioscorea batatas Decne). Tuber was divided into top head, head, median and tail which were used as seminal sections of tuber. The emergence of shoots was delayed in median and tail sections by 15 days as compared with top head and head sections. Sections from head and tail exhibited yield increase as high as 16 and 15%, respectively, compared to top head sections. Although flowering and bubil setting occurred almost at the same time in all staking methods, fresh weight of stem and leaves was higher in ${\wedge}-$, I-type stake supporting net than in the conventional stake. In the cultivar, 'Dan-ma', tuber yield didn't show a meaningful increase statistically by all staking methods. But ${\wedge}-$ and I-type stake supporting net increased the yield of the cultivar, 'Jang-ma', as high as 11 and 8%, respectively, compared to conventional stake. Also I-type stake was ideal supportor of net, considering the cost of management.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.365-370
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• 2017

The flowering season of jujube (Zizyphus jujuba var. inermis (Bunge) Rehder) is overlaps with the rainy season and the abnormal weather conditions in Korea, thereby affecting pollination, fertilization, and fruit setting. We studied the pollinating activities of Apis mellifera L. and Bombus terrestris L. in rain shelter houses and their effects on fruit setting, with the ultimate aim of stabilizing fruit setting in Z. jujuba. A. mellifera and B. terrestirs were used for pollination in jujube orchard in the rain shelter house for approximately 55 days from June 1, 2016, to July 25, 2016. The peak time of the rate of outgoing and incoming A. mellifera was recorded in the afternoon. However, the diurnal activity of B. terrestris was constant between 09:30 and 17:30 h. The rate of jujube fruit set on current shoots by A. mellifera and B. terrestirs was 10.2 and 8.9%, whereas that in plots with no pollinators was 5.5%. Therefore, using pollinator in the rain shelter house in jujube orchard is effective in promoting jujube fruit setting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.105-109
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• 2004

Field studies were conducted in the southeastern Korea ($36^{\circ}$N) on a commerce silt loam soil at paddy field. Seed were manually planted on 16 July 2003. Plants were planted with plant densities of 70${\times}$10 cm (row width x plant spacing), 50 x 10 cm, and 30 ${\times}$10 cm. Two seedlings per hill were taken prior to V3 stage. Fertilizer was applied prior to plant at a rate of 30-30-34 kg (N-$\textrm{P}_2\textrm{O}_5$-$\textrm{K}_2\textrm{O}$) per ha. Experimental design was a randomized complete block in a split plot arrangement with three replications. Yield from different planting densities responded similarly in three soybean cultivars and increased when planting density increased. Somyeongkong showed the highest increasing rate of yield about 26% by 338 g $\textrm{m}^{-2}$ at 30 x l0 cm compared to yield of conventional planting density (70 x 10 cm). Also, the planting density significantly affected pod and seed number and seed weight, but not seed per pod. The tallest plant appeared at 30${\times}$10 cm. The change of leaf area according to days after emergence showed differently in soybean cultivars. The highest and lowest total dry matter production per square meter appeared at 30 x 10 cm and at 70 x 10 cm, respectively. Crop growth rate (CGR) showed greater at R3∼R4 stages compared with V7∼R2 or R2∼R3 growth stages and showed the greatest at 30 x 10 cm in three soybean cultivars. As late planted soybean, there was a significant relation between seed yield and CGR, and leaf area index (LAI) according to planting densities at before and after the flowering stage. Relationship between seed yield and CGR in three planting densities showed a highly significant positive relation ($\textrm{R}^2$=0.757) at R3 to R4 stages, and significant relations ($\textrm{R}^2$=0.505, 0.617) at V7 to R2 and V2 to V3. Also, there was a highly significant positive difference between seed yield and LAI during R3 to R4 and R2 to R3 stages.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.343-348
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• 2015

Soybean is one of the important food crop around the world. Especially in East Asia, it is the main ingredient for traditional food like soy sauce and soy paste. The double cropping system including soybean following onion, Chinese cabbage, and potato is widely adopted in Southern region of Korea. In this system, sowing date of second crop (soybean) can be delayed depending on first crops' growth period and weather condition. When planting date is delayed it is known that soybean yield is declined because of shorter vegetative growth period and earlier flowering induced by warm temperature and changes in photoperiod. The objective of this study was to determine soybean growth and yield responses as plant populations at late planting date. Field experiment was conducted at Department of Functional Crop, National Institute of Crop Science, RDA located in Miryang, Gyeongsangnam-Do for two years ('13-'14) in upland field with mid-late maturity cultivar Daewon. A split-plot block design was used with three replications. Main plots were three sowing dates from June 20 to July 20 with 15 days intervals, and subplots were 4 levels of planting densities. Data of maturity (R8) was recorded, yield components and yield were examined after harvesting. Experimental data were analyzed by using PROC GLM, and DMRT were used for mean comparison. Optimum planting population for maximizing soybean yield in late planting which compared with standard population. In mid-June planting, higher planting density causes increased plant height and decreased diameter which lead to higher risk of lodging, however, reduced growth period due to late planting alleviated this problem. Therefore higher seeding rates can provide protection against low seedling emergence caused by late planting in this region.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.106-112
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• 2012

In order to understand the growth and ecophy -siological response of ginseng to global warming condition, we cultivated one and two year ginseng seedlings in control (ambient $CO_2$ + ambient temperature) and global warming treatment (elevated $CO_2$ + elevated temperature) from March 2010 to July 2011. Shoot appearance and initiation of flowering were advanced by 3-4 days in global warming treatment than in control. However, timing of fruit setting and seed ripeness was similar in both control and global warming treatment. Shoot length was longer in global warming treatment than in control, and also the number of leaves was much in global warming treatment. Fresh root weight was not different between control and global warming treatment. Photosynthetic rate was higher in global warming treatment than at control. Photosynthetic rate and transpiration rate were higher in two year seedlings than in one year seedlings at control, but was not different between seedling age of ginseng in global warming treatment. Water use efficiency was higher in one year seedlings than two year seedlings at control and global warming treatment. These results demonstrated that Korean ginseng more or less positively responds to global warming situation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.1
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• pp.6-13
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• 2024

This study was conducted to determine the optimal spring seeding dates for alfalfa yield and feed value. The experiment was conducted annually for three years (2021~2023) at the field in the Department of Animal Resources Development, NIAS, located in Cheonan. The treatments involved six seeding dates ranging from February 24 to April 14, with 10days intervals. Alfalfa was harvested four times a year at the early flowering stage. Dry matter yield showed a tendency to decrease with delayed the seeding date. However, depending on the climatidc condisions in the seeding year, the dry matter yield on March 14 or 24 was comparable to that on February 24. Annual dry matter yield varied, influenced by the daylight conditions each year. The average feed value did not significantly differ within in the same year with delayed seeding dates (p>0.05). Therefore, the most stable period for alfalfa spring seeding in the central area of South Korea is considered to be from February 24 to April 4, with February 24 indentified as the optimal date.

• Korean Journal of Environmental Biology
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• v.42 no.1
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• pp.62-79
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• 2024

Garlic mustard (Alliaria petiolata) is a species that has devastated the United States and Canada. It is known to play a role in destroying the ecosystem. In this study, the domestic distribution of garlic mustard was confirmed and a detailed distribution map was created for the Samcheok region, where the largest population has been established in South Korea. This study investigated the growth environment, life cycle, and population dynamics of the species in the Samcheok region. Garlic mustard was found in a total of 301 locations in Samcheok, with a total distribution area of 2,957 square meters. Annual plants germinated in mid-April, overwintered in rosette form, underwent vegetative growth from April 10 to April 24 the following year, and flowered from April 24 to May 7. Individuals producing seeds began to die off from June. Both annual and biennial individuals showed a trend of increasing and then decreasing in number around April 27 (118 days). Garlic mustard grew well under favorable light conditions in early spring. They showed less growth on leaf litter, short distance from roads, lower altitude, deciduous broad-leaved forest of middle and lower parts of the slope and forest edge. Without proper control measures in the Samcheok region, it is likely to spread more rapidly in deciduous broad-leaved forests along hiking trails in the Galyasan Mountains. In particular, it is more likely to extend to oak community where light enters the site during flowering than to pine community where there is less light in the site.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.185-193
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• 2004

Gibberellin (GA) treatment on fruit stalk was effective in fruit growth but reduced the shelf life of fruit. This study was carried out to improve the shelf life of GA treated fruit. Fruit characteristics were surveyed according to the treatment part and concentration of polyamine in 'Whangkeumbae', 'Yeongsanbae', and 'Chuwhangbae'. GA was treated on fruit stalk at 30 days after flowering and 100, 200, and 300 ppm of polyamine were sprayed on leaves of fruit cluster and canopy at 7 day before harvest. In GA treated fruit, fruit weight was heavier as $10\%$ and fruit hardness was lower as $0.3\~0.5\;kg$ than control in all cultivar, but sugar content and palatability were no difference in each treatment. In morphological characteristics, the distance from pith to epidermis of GA treated fruit was faraway as $42.0\%$. Fruit hardness and palatability of 'Whangkeumbae' was good in the leaves spray on the fruit stalk with 200 ppm and the leaves spray on the canopy with 500 ppm at 30 day after harvest. 'Yeongsanbae' and 'Chuwhangbae' showed the same to the result. So we knew that the effective treatment to improve the storagibility after GA treatment on fruit stalk was the fruit stalk leaves spray with 200 ppm because it needed small amount of polyamine.