• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.35-39
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• 2001

It is important to accelerate rooting and establishment of seedlings after transplanting for higher dry matter production and tuber yield in sweet potato cultivation. Therefore, this study was conducted to obtain some information about the effects of vine-cutting holding on rooting and plant growth after transplanting. Vines were cut 20-25cm long and stored for 1, 3, 5, 7 or 9 days in a shade room at 20$\pm$0.5$^{\circ}C$, RH 68$\pm$,/TEX>1%. Peroxidase activity in the vine cuttings increased as the holding period increased and the highest catalase activity was detected in the 5-day holding. Length of main vine, number of branches and nodes on main vine also increased in the 5-day holding. There was little difference in the diameter of main vine among the various holding periods. The data obtained indicate that transplanting of vine cuttings after 5-day holding could promote rooting and vine growth.

• Journal of Biosystems Engineering
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• v.36 no.1
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• pp.9-14
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• 2011

This study was carried out to develop a vine crusher for harvesting sweet potato. The experimental two-row vine crusher attachable to agricultural tractor composed of vine crushing part with frail type vine crushing blades and vine lifting blades, power transmission part with chain and gear transmission mechanism, crushing height control part with two control wheels and manual levers, and implement frames, was designed and fabricated. And this vine crushing performance was also analyzed. From vine crushing tests, backward travel direction (i.e., rotational direction of the vine crushing blades) showed better vine crushing performance than forward travel direction. Crushing ratio of remained vine was increased, and length of remained vine and length of crushed vine were decreased as working speed was decreased and rotational speed of vine crushing blades was increased. At a working speed of 0.27 m/s and rotational speed of vine crushing blades of 800 rpm, crushing ratio of remained vine was 98%, length of remained vine was 104 mm, and length of crushed vine was 327 mm. But, when crushing vine on irregular ridges, vines and mulching vinyl were wound in the vine crushing part. Therefore, change of location of power transmission chain mechanism, and an automatic control device for controlling crushing height were needed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.267-267
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• 2017

In Korea, the average air temperature has been elevated twice faster than the average global warming. And the climate warming is characterized by the smaller rise of air temperature in summer and the greater rise of air temperature in spring and winter. Therefore, the number of frost-free days to determine the cultivation ability of crops has increased by more than 15 days in 10 years according to climate warming. This climate warming trend has extended and is projected to extend not only the sweet potato growing season but also the sweet potato early cultivating area to higher altitude and latitude region. This study was carried out to evaluate the possibility of sweet potato double cropping in the southern island area of Korea by assessing the growth and yield performance of sweet potato cultivated at extremely-early and -late time. We had performed at Yokji Island Yokji Island($E128^{\circ}$ 18' $N34^{\circ}$ 36'), a representative specified complex area of sweet potato cultivation in southern Korea. As the test varieties, the major cultivars of the this region, Shinyulmi and early hypertrophic cultivars, Dahomi were used. The prior cropping were planted with PE film mulching on March 30 and April 10, and harvested after 110 days. So the succeeding cropping were planted without PE film mulching on July 25 and August 5 according to the harvesting time of the prior sweet potato and harvested after 120 days. As a control, it was harvested on September 15, 120 days after planted on May 15. Each experimental plot had an area of 12 square meters consisting of 4 beds, and was planted one at a time at intervals of 25cm. We had investigated growth characteristics - main vine length, node number, branch number, total vine yield, and tuberous root characteristics - tuberous root number, average weight, starch value, and etc. After harvesting, we analyzed the economic effects by examining the postharvest quantity, the input labor, the management cost, and the income. The total yield of marketable products in prior and succeeding cropping was 46~70% higher than that of control. The average unit price of sweet potato was 36% higher than the conventional culture, and the gross income increased by 98%, but the operating cost increased by 83%, and the farm income increased by 103%. There are considerations such as the difficulty of enlargement of cultivation area due to lack of labor in limited space and the need for watering measures due to spring drought. However, if the area of application for sweet potatoes double system is increased by 10%, it can be used as a new cropping system.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.280-280
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• 2017

In Korea, the average air temperature has been elevated twice faster than the average global warming. And the climate warming is characterized by the smaller rise of air temperature in summer and the greater rise of air temperature in spring and winter. Therefore, the number of frost-free days to determine the cultivation ability of crops has increased by more than 15 days in 10 years according to climate warming. This climate warming trend has extended and is projected to extend not only the sweet potato growing season but also the sweet potato early cultivating area to higher altitude and latitude region. This study was carried out to evaluate the possibility of sweet potato double cropping in the southern island area of Korea by assessing the growth and yield performance of sweet potato cultivated at extremely-early and -late time. We had performed at Yokji Island Yokji Island($E128^{\circ}$ 18' $N34^{\circ}$ 36'), a representative specified complex area of sweet potato cultivation in southern Korea. As the test varieties, the major cultivars of the this region, Shinyulmi and early hypertrophic cultivars, Dahomi were used. The prior cropping were planted with PE film mulching on March 30 and April 10, and harvested after 110 days. So the succeeding cropping were planted without PE film mulching on July 25 and August 5 according to the harvesting time of the prior sweet potato and harvested after 120 days. As a control, it was harvested on September 15, 120 days after planted on May 15. Each experimental plot had an area of 12 square meters consisting of 4 beds, and was planted one at a time at intervals of 25cm. We had investigated growth characteristics - main vine length, node number, branch number, total vine yield, and tuberous root characteristics - tuberous root number, average weight, starch value, and etc. After harvesting, we analyzed the economic effects by examining the postharvest quantity, the input labor, the management cost, and the income. The total yield of marketable products in prior and succeeding cropping was 46~70% higher than that of control. The average unit price of sweet potato was 36% higher than the conventional culture, and the gross income increased by 98%, but the operating cost increased by 83%, and the farm income increased by 103%. There are considerations such as the difficulty of enlargement of cultivation area due to lack of labor in limited space and the need for watering measures due to spring drought. However, if the area of application for sweet potatoes double system is increased by 10%, it can be used as a new cropping system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.176-179
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• 2001

To obtain the basic information of high yielding ability for varietal improvement and cultural practice, reciprocal grafts were made analyzed among five sweet potato cultivars. Five cultivars were characterized with the different in whose source and sink capacities. Grafting decreased main vine length, number of tuberous roots per plant, but its effects were different among grafting combinations. The growth of vines was affected more by scion, while growth and yield of under-ground were influenced more by stock. Grafting effects, interactions between stock and scion for main vine length and number of tuberous roots were highly significant in diallel grafting. The percentage of marketable tuberous roots was higher in the order of stem cutting＞self grafting＞reciprocal grafting.

• Journal of Bio-Environment Control
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• v.19 no.3
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• pp.153-158
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• 2010

To obtain the basic information for late-cultivation of sweet potato [Ipomoea hatalas (L.) Lam. cv. 'Jinhongmi'], vine growth and storage root yield were investigated in variously cutting sizes (10, 20, and 30 cm) and planting depths (1~4 nodes in 30 cm vine) using black-film vinyl mulching cultivation ($75{\times}25\;cm$ planting density, June 20). At 30 days after planting, main vine length, number of node, and vine fresh weight were significantly affected by the cutting length, and these were significantly different 10 and 30 cm at 120 days. The vine elongation affected by planting depths showed the best growth in 2-nodes planting depth and the lowest growth in 4-nodes planting depth at 30 days, but the vine growth was not significantly different among planting depths at 120 days. Number of storage root per plant, weight of storage root per plant, mean weight of storage root and yield of storage root were increased in longer cutting length, and those in 10 cm cutting length were significantly reduced compared to the 20 and 30 cm cutting length. Number of storage root per plant in the deeper planting was much increased, but mean weight of storage root was much decreased. Yield of storage root per 10a was highest in 3-nodes planting depth. Therefore, planting methods by cutting length over 20 cm and planting depth of 2~3 nodes in late-cultivation of sweet potato will be more efficient to improve the vine growth and storage root yield.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.907-912
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• 1997

Physicochemical characteristics of kochujang prepared with various raw materials, were investigated during 90 days of fermentation to obtain information for the industrial production of traditional kochujang. Reducing sugar contents of kochujang increased until 60 days but slightly decreased thereafter, showing highest value for malt added group. Ethanol contents increased after 45 days and were highest in Chinese matrimony vine group, followed by purple sweet potato and malt added groups. Amino nitrogen contents increased until the 45 to 60 days of fermentation, but ammonia nitrogen contents did not change significantly during fermentation. Amino and ammonia nitrogen contents were higher in soy sauce and Chinese matrimony vine added groups. Water activities decreased slightly during fermentation and purple sweet potato added group was lowest among the groups. Consistency of kochujang decreased until the middle of the aging but after that it increased. Consistency of purple sweet potato and Chinese matrimony vine added groups were remarkably higher than that of the others. The color values tended to decrease slightly during fermentation. Purple sweet potato kochujang was low in the lightness, redness and yellowness. Results of sensory evaluation showed garlic and malt added kochujang were more acceptable than purple sweet potato added kochujang due to more desirable taste and color.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1205-1212
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• 2010

The aim of the present study was to evaluate the effects of replacing 70% of the protein from fish meal by protein from ensiled or dry cassava leaves and sweet potato vines on the performance and carcass characters of growing F1 (Large White${\times}$Mong Cai) pigs in Central Vietnam. Twenty-five crossbred pigs (Large White${\times}$Mong Cai) with an initial weight of 19.7 kg (SD = 0.84) were allocated randomly to five treatment groups with 5 animals per group (3 males and 2 females). Pigs were kept individually in pens ($2.0{\times}0.8\;m$) and fed one of five diets over 90 days. The control diet was formulated with fish meal (FM) as the protein source while the other four diets were formulated by replacing 70% of fish meal protein by protein from ensiled cassava leaves (ECL), dry cassava leaves (DCL), dry sweet potato vines (DSPV) or ensiled sweet potato vines (ESPV). Animals were fed their diets at 4% of BW. Results showed that final BW, ADG, DMI and feed conversion ratio (FCR) among the experimental treatments were not significantly different (p>0.05). ECL or DCL and ESPV reduced feed cost per unit gain by 8-17.5% compared to the fish meal diet. There were no significant differences in carcass characters among the diets (p>0.05). Lean meat percentages and protein deposition ranged 41.5-45.8% and 40.2-52.9 g/d, respectively. Using ensiled or dry cassava leaves and sweet potato vine can replace at least 70% of the protein from fish meal (or 35% of total diet CP) without significant effects on performance and carcass traits of growing (20-65 kg) pigs. Including cassava leaves and sweet potato vines could improve feed cost and therefore has economic benefits.

• Horticultural Science & Technology
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• v.35 no.4
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• pp.490-498
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• 2017

The in vitro growth of virus-free sweet potato [Ipomoea batatas (L.) Lam.] plantlets was investigated under different light sources: fluorescent lamp (control); red (660 nm), blue (460 nm), white light-emitting diodes (LED), and two mixtures of blue and red LED (R:B = 8:2, and 7:3). Single node explants (10 mm) of three cultivars ('Matnami', 'Shincheonmi', and 'Yeonhwangmi') were cultured on Murashige and Skoog medium supplemented with $0.2mg{\cdot}L^{-1}$ 6-benzyladenine for 4 weeks. Explants were exposed to $150{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux at a distance of 20 cm, constant temperature of $25^{\circ}C$, and under 16/8-h (day/night) photoperiod. Using the same method, the in vitro growth of 10 cultivars under red LED was also compared. After 3 weeks, vine length was highest in plantlets cultured under red LED, and lowest in plantlets cultured under blue LED. Fresh and dry weights were also greatest in plantlets cultured under red LED. Compared to the control, vine thickness was significantly higher in plantlets grown under white LED and the 7:3 R:B LED mixture. Significant differences were observed among the 10 cultivars grown under red LED. 'Matnami', 'Shincheonmi', and 'Shinhwangmi' all had excellent vine lengths, and fresh and dry weights. Compared to the control, vine elongation of sweet potato plantlets was most effective under red LED, and culture duration was about 1 week shorter.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.1-8
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• 2020

The influence of growth regulators (NAA and BA) and sucrose concentrations (0, 3, 5, 7, 9%) on in vitro rapid-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] was investigated with single-node or shoot-tip culture of two cultivars ('Matnami' and 'Shinhwangmi'). The survival rate and growth of shoot-tip explant was also investigated under the presence or absence of light (blue and red LED = 7:3, 150±5 μmol·m^-2·s^-1 PPFD) during minimal-growth in vitro conservation at 15℃. Vine length, vine diameter, fresh weight and dry weight were enhanced without callusing of explant in the MS medium supplemented with 0.2-0.5 mg·L^-1 BA. The growth of single-node and shoot-tip explants were significantly enhanced with the increase of vine length, number of leaf, number of root, fresh weight, and dry weight in the solid medium containing 5% sucrose and 0.2 mg·L^-1 BA. Vine elongation of shoot-tip explants were highest in the liquid medium containing 3% sucrose than the solid medium. The survival rate of minimal-growth in vitro conservation was 100% in 5 months under the presence of light (LED, 150±5 μmol·m^-2·s^-1 PPFD) at 15℃, but the explants in dark condition died in 3 months. The light was absolutely necessary for the in vitro conservation under minimal-growth conditions of virus-free sweet potato plantlets at 15℃, and the high density of explants (10 plantlets per Petri Dish) was increased the efficiency of mass conservation.