This study investigated the antioxidant characteristics of sweet potato according to different plant parts and drying methods. The sweet potato plant parts were divided into root tubers, stems, stalks, leaves, and tips, and the drying methods were freeze-drying and hot air drying. Total polyphenol and flavonoid contents and radical scavenging activity of the sweet potato plant parts were significantly different depending on the plant parts and drying methods. The total polyphenol content of freeze-dried sweet potato leaves and tips were 52.76 and 46.19 mg chlorogenic acid equivalents/g sample, and the total flavonoid contents were 222.47 and 214.12 mg quercetin equivalents/g sample, respectively, and decreased with hot air drying. DPPH radical scavenging activity was higher in freeze-drying than hot air drying and was significantly different depending on the plant parts. The ABTS radical scavenging activity of freeze-dried sweet potato leaves and tips were 43.48 and 44.68 mg Trolox equivalents/g sample, respectively, and decreased with hot air drying. Therefore, additional studies on the functionality of using by-products from sweet potato cultivation are needed.
This study examined the quality characteristics of Makgeolli to investigate the availability of Korean sweet potato cultivars as alcoholic beverages. The following sweet potato varieties were used: Gogunmi, Daeyumi, Shingunmi, Shinyulmi, Shincheonmi, Jinyulmi, Jinhongmi, Jeungmi and Pungwonmi; their alcohol contents ranged from 12.20% to 14.20%, with the lowest value in Makgeolli made with Jeungmi and the highest value in Makgeolli made with Jinhongmi. The DPPH radical scavenging activity was in the range of 37.51~77.02%, with the lowest value in Makgeolli made with rice (control) and the highest value in Makgeolli made with Gogunmi. As a result of analyzing the aroma component of sweet potato Makgeolli, 27 kinds of aroma components were detected, and six kinds of alcohols, 13 kinds of esters, four kinds of acids, and four kinds of other compounds were found. Regarding the number of aroma compounds, Makgeolli made with Shinyulmi showed the lowest number with 14 kinds, while Makgeolli made with Pungwonmi showed the highest number with 27 kinds.
This study examined the nutrient components and measured the physicochemical properties of 23 Korean sweet potato cultivars. The proximate composition, free sugars, organic acids, and dietary fiber of sweet potato were analyzed and the water binding capacity, oil absorption and pasting characteristics were measured. The proximate composition was the highest in Happymi and was higher in colored sweet potato than in general sweet potato (p<0.05). The sucrose content was the highest among the free sugars in the general cultivars and yellow/orange colored cultivar. The major organic acids were oxalic acid, citric acid, malic acid, succinic acid, fumaric acid, and acetic acid. Oxalic acid and citric acid were high in the purple colored cultivars and malic acid was high in yellow/orange colored cultivars. Each total dietary fiber content of the general and colored cultivars was 7.51-13.94 and 13.04-16.97%, respectively, but there was no significant difference. The water binding capacity and oil absorption of Juhwangmi was high in all cultivars (p<0.05). The peak viscosity of sweet potato powder showed highest a significant difference of 12.50-1342 cP (p<0.05). The breakdown of Sincheonmi was 512, which was the highest value (p<0.05). The setback of Geonpungmi was significantly low, 6.0 (p<0.05).
Spodoptera litura (Fabricius, 1775) is considered as a serious agricultural pest, which damaged to the many crops including sweet potato (Ipomoea batatas). We investigated weekly occurrence of the Spodoptera litura (Fabricius) using pheromone trap at six study fields of three regions, Jeonnam, Korea. A total of 41,895 individuals were collected from 18th July to 23th September in 2013; Yeongamgun was collected the highest individuals (17,519), and following the Muan-gun (12,709) and Haenamgun (11,667). The seasonal occurrence of S. Litura was increased from July to September, and peak occurrence timing was in late-September. There were a positive correlation between field area and number of individuals (P=0.02, r=0.89), and a negative correlation between field area and density (p=0.02, r=-0.89). As a PCA (principal component analysis) result, adults occurrence pattern were closely related to the temperature and relative humidity during larva stage.
The most common method of vegetative propagation of virus free plantlets is the use of shoots meristem culture in solid medium culture. This study was to investigate the effect on liquid medium culture for the growth of virus-free sweetpotato plantlets. Single-nodes derived from meristem culture of sweetpotato was examined in this experiment and three sweetpotato varieties ‘Singeonmi’, ‘Sinhwangmi’, and ‘Sinjami’ was used. The growth of plnatlets was greater in liquid medium culture than that of solid medium culture after longer incubation in 3 varieties. The total fresh weight of 5 week old plantlets after planting in solid culture were 2.17 g (‘Singeonmi’), 2.49 g (‘Sinhwangmi’), and 2.18 g (‘Sinjami’), but the fresh weight in liquid medium culture was 3.87, 3.88, and 3.35 g, respectively. Leaf number of ‘Singeonmi’ and ‘Sinjami’ plantlets after 5 weeks of liquid medium culture was 21.1 and 22.6, respectively and liquid medium culture showed 3 and 6.2 more leaf number than that of solid medium culture. Plant height of ‘Sinhwangmi’ and ‘Sinjami’ plantlets after 3 weeks of liquid medium culture was 4.1 cm and 3.4 cm, respectively, and liquid medium culture showed 1.1 cm longer stem length than solid medium. Overall, liquid medium culture of sweetpotato plantlets was more effective than solid medium in terms of leaf and stem growth.
The effect of transplanting and harvesting dates on growth, yield, and quality of sweetpotato varieties was studied. Three sweetpotato varieties, Yulmi, Singeonmi, and Dahomi, were transplanted on 23 Apr., 21 May, 5 June, 15 June, 25 June, 5 July, 15 July, and 25 July. Fresh vine weight and marketable storage root yield of the three varieties were the highest in transplanting plots on 23 April and 21 May, respectively, and those tended to decrease when transplanting dates were late after May. GDD (Growing Degree Days) and cumulative radiation seemed to be related to marketable storage root yield. Number of marketable storage root per plant, average weight of marketable storage root, and marketable storage root yield were significantly different according to transplanting dates. Marketable storage root yield showed significantly positive correlations with fresh vine weight, number of marketable storage roots, and average weight of marketable storage roots. Hardness and dry matter content of storage root showed significantly positive correlations with starch content and decreased with late transplanting dates in Yulmi and Singeonmi varieties. Pasting temperature showed significantly positive correlations with soluble solid content, dry matter content, and amylose content, but it showed significantly negative correlations with breakdown. Setback was significantly different among varieties, but it was not significantly different in transplanting dates.
본 연구에서는 2년간 수원 밭작물 시험포장에서 단옥수수 품종인 고당옥과 구슬옥을 파종시기에 따른 생육 및 이삭 특성을 검토한 결과이다.
1. 고당옥과 구슬옥 모두 파종시기가 늦어질수록 파종에서 출사기까지의 일수가 짧아졌고, 출사에서 수확기간은 증가하였다. 2011년의 출사일수는 43 ~ 53일, 2012년은 44 ~ 54일이었고, 출사에서 수확까지는 2011년은 22 ~ 36일, 2012년에는 20 ~ 34일이었다.
2. 파종에서 출사기까지 생장온도일수(GDD)는 출사 후부터 수확기까지는 약 213 ~ 353oC 범위로 비슷하였으나 파종에서 수확까지의 GDD는 2011년(약 916 ~ 1,067oC)과 2012년(약 911 ~ 1,055oC) 모두 큰 차이가 없었다. 특히 8월 5일 파종에서 등숙기 중의 생장온도일수가 다른 파종시기에 비하여 크게 낮았는데 이는 등숙기의 기온이 상대적으로 낮은 것이 원인으로 판단된다.
3. 파종시기에 따른 생육특성을 보면 간장과 착수고는 파종시기가 늦어질수록 짧아졌으며 7월 말 파종 재배에서 유의하게 짧았으며, 경태는 파종시기가 늦어질수록 유의하게 얇아지는 경향을 보였다. 이삭직경은 고당옥은 4.37mm, 구슬옥은 4.43mm로 차이가 없으나 6월, 8월 파종보다 7월 파종구에서 두꺼운 것으로 나타났다.
4. 이삭무게는 두 품종 모두 6월, 8월 파종구 보다 7월 파종구에서 높고, 7월 25일 파종구를 보면 고당옥은 201g, 구슬옥은 140g으로 높았다. 2년간 단위면적당 이삭수량은 고당옥은 715kg/10a이고, 구슬옥은 677kg/10a이었다.
5. 파종시기에 따른 단옥수수 재배는 파종기가 늦을수록 생육이 지연되고 이삭수량이 감소되는 경향이 있고, 단옥수수 만식재배에 따른 최적 파종시기는 7월 20일 ~ 25일로서, 두 품종 모두 7월 25일에 이삭 수량성이 높은 것으로 나타났다. 7월 20 ~ 25일 파종 시 생육이 지연되고 이삭수량이 감소되는 단점
이 있지만 6월 말에 재배한 단옥수수 보다 습해의 피해가 적고, 수확적기가 짧고 전분축적 시간의 지연으로 수확시기를 연장할 수 있다는 장점이 될 수 있을 것으로 판단되어진다. 따라서 추후 단옥수수 만식재배 시 수량과 상품성 향상을 위한 최적 수확적기, 저장방법에 대한 연구가 이루어져야 할 것이다.
Total of 36 sweet potato field soils were sampled to survey the occurrence of the root-knot nematodes (RKN). The 61% of sweet potato fields in Haenam, 40% in Iksan and 31% in Yeju were infested with RKN, respectively. Average population density of RKN was 324 juveniles per 300 g soil. The resistance screening of sweet potato cultivars against RKN was carried out by using clay pots in a greenhouse. Average temperature under ground 10 ㎝ in pot was 21.5℃ during the test. There was no difference in number of egg sacs among different inoculation methods, however the egg-inoculation method was easy for treatment and had stable for results. The multiplication ratio of Melioidogyne incognita differed from 6.3 times (Jeungmi) to 63.2 times (Yulmi) by sweet potato cultivars. There were no cultivars showing resistance to M. incognita, but Jinmi, Jeungmi and Borami had resistance to M. arenaria, M. hapla and M. javanica.
‘Pungwonmi’, a new sweetpotato variety, was developed for table use by Bioenergy Crop Research Institute, National Institute of Crop Science (NICS), RDA in 2014. This variety was derived from the cross between ‘Benisatsuma’ and ‘Luby3074’ in 2006. The seedling and line selections were performed from 2007 to 2009, and preliminary and advanced yield trials were carried out from 2010 to 2011. The regional yield trials were conducted at five locations from 2012 to 2014, and it was named as ‘Pungwonmi’. This variety has cordate leaf shape, and its leaves, stems, nodes, and petioles are green. Storage root of ‘Pungwonmi’ has an elliptical shape, red skin, and light orange flesh. ‘Pungwonmi’ was moderately resistant to fusarium wilt, and resistant to root-knot nematode. Dry matter content was 31.2%, and texture of steamed storage root was intermediate. Total sugar content of raw and steamed storage roots of ‘Pungwonmi’ was higher than that of ‘Yulmi’. β-carotene content of ‘Pungwonmi’ was 9.1 mg/100g DW. Yield of marketable storage root over 50 g of ‘Pungwonmi’ was 24.3 MT/ha under the early season culture, which was 46% higher than that of ‘Yulmi’. The number of marketable storage roots per plant was 2.8 and the average weight of marketable storage root was 156 g under the optimal and late season culture. Marketable storage root yield of ‘Pungwonmi’ was 24.1 MT/ha under the optimum and late season culture, which was 26% higher than that of ‘Yulmi’. (Registration No. 6428).
Geonpungmi is a new sweetpotato variety developed by Bioenergy Crop Research lnstitute in the National Institute of Crop Science (NICS) at RDA for table use in 2008. This variety was selected from the cross between Mokpo34 and Southern Queen. Two parents, Mokpo34 and Southern Queen, were crossed in 2002. Selection of elite line was performed for 2 years from 2003 to 2004. Preliminary and advanced yield trials were carried out from 2004 to 2005. The regional yield trials were conducted at six locations from 2006 to 2008. Geonpungmi has cordate leaf, greenish purple vine and petiole, elliptic storage root, dark purple skin and yellow flesh color of storage root. This variety is resistant to fusarium wilt and nematode. The starch value and total sugar content were 25.8% and 5.82%, respectively. Pasting temperature of starch in Geonpungmi was 74.7°C, and the retrogradation process is earlier than Yulmi. The average yield of storage root is 19.8 ton/ha in the regional yield trials, which is 3% lower than that of Yulmi. The number of marketable storage roots per plant was 2.6 and the average weight of one storage root was 154 g.
‘Geonhwangmi’, a new sweetpotato variety, was developed for table use by Bioenergy Crop Research Institute, National Institute of Crop Science (NICS), and RDA in 2013. This variety was derived from the cross between ‘Singeonmi’ and ‘Mokpo34’ in 2005. The seedling and line selections were performed from 2006 to 2008, preliminary and advanced yield trials were carried out from 2009 to 2010. The regional yield trials were conducted at five locations from 2011 to 2013, and it was named as ‘Geonhwangmi’. This variety has five-lobed leaf, and its leaves, stems, and petioles are green. Storage root of ‘Geonhwangmi’ has an elliptical shape, red skin, and light orange flesh. ‘Geonhwangmi’ was moderately resistant to fusarium wilt, and resistant to root-knot nematode. Dry matter content was 29.4%, and texture of steamed storage root was intermediate. Sucrose content of steamed storage root of ‘Geonhwangmi’ was higher than that of ‘Yulmi’, and steamed storage root palatability of ‘Geonhwangmi’ was better than that of ‘Yulmi’. β-carotene content of ‘Geonhwangmi’ was 3.4 mg/100g DW, which was 7.8% of ‘Juhwangmi’. Yield of marketable storage root over 50 g of ‘Geonhwangmi’ was 23.0 MT/ha under the early seasonal cultivation, which was 39% higher than that of ‘Yulmi’. The number of marketable storage roots per plant was 2.6 and the average weight of marketable storage root was 151 g under the optimal and late seasonal cultivation. Marketable storage root yield of ‘Geonhwangmi’ was 24.2 MT/ha under the optimum and late seasonal cultivation, which was 45% higher than that of ‘Yulmi’. (Registration No. 5853).
최근 고구마의 연작, 병해충에 감수성인 품종의 재배면적 확대 및 이상기상 등으로 인해 고구마의 단위면적당 생산량이 ’00년 2,136kg/10a에서 ’13년 1,484kg/10a으로 30% 이상 감소하였다. 특히 고구마뿌리혹선충(Meloidogyne incognita)에 감염된 고구마는 뿌리에 혹이 발생하거나 괴근의 표피가 갈라지고 심하면 부패될 수도 있어 고구마의 수량과 상품성을 현저히 저하시킨다. 따라서 고구마의 생산성과 상품성을 향상시키기 위해서는 선충 등 병해충에 강하고 수량성이 높은 품종의 개발 및 보급이 필요하다. 2014년에 육성된 ‘풍원미’(Pungwonmi)는 육색이 담주황색이고 껍질색은 홍색이며 괴근의 모양은 방추형이다. ‘풍원미’는 ‘베니사쯔마’(IT232278)를 모본, ‘Luby3074’(IT232216)를 부본으로 하여 2006년에 교배하였으며 고구마뿌리혹선충에 강하고, 덩굴쪼김병(Fusarium oxysporum) 저항성도 ‘중’ 이상으로 주요 병해충에 저항성인 품종이다. 생산력검정시험에서 ‘풍원미’의 상품괴근수량은 표준품종인 ‘율미’ 대비 42%가 많았다(’10~’11). 지역적응시험 보통기재배 시 상품괴근수량이 24.1MT/ha으로 ‘율미’ 대비 26% 증수하였고, 주당상저수는 2.8개로 ‘율미’의 2.2개보다 유의적으로 많았다(’12~’14). 조기재배 시 ‘풍원미’의 상품괴근수량이 24.3MT/ha으로 ‘율미’ 대비 46%가 많아 조기재배용으로도 적합하였다. ‘풍원미’의 찐고구마 총유리당 함량과 감미도(sweetness)는 각각 31.6g/100g, 16.5로 ‘율미’의 26.1g/100g, 12.7보다 높아 단맛이 더 강하였다. 베타카로틴 함량은 9.1mg/100g으로 높은 편이었으며, 전분의 호화개시온도는 70.0℃로 ‘율미’의 75.3℃보다 5.3℃ 낮아 ‘풍원미’의 전분이 ‘율미’보다 낮은 온도에서 호화되는 것으로 나타났다. ‘풍원미’는 고구마뿌리혹선충과 덩굴쪼김병이 상습적으로 발생하는 포장에서 재배될 경우 수량 증대 및 상품성 향상으로 농가소득 증대에 기여할 수 있을 것으로 기대된다.
To analysis of virus free sweetpotato effect, 5 virus free sweetpotato and virus normal sweetpotato varieties were planted in 5 different regions at 2010 year. The average yields of virus free sweetpotato are showed different results according to regions. Sinjami which cultivated at Iksan were increased maximum 68% compare to normal. However, Sinjami which cultivated in Hamyang were decreased yield 11% compare to normal. Analysis of tuber formation ratio of Sinjami, Yenhwangmi, Singeonmi which cultivated in Nonsan were decreased tuber number compare to normal. However, 3 varieties were all increased on Average storage root weight and yield of marketable storage root. In the results of analysis of marketable storage root according to cultivated regions and varieties, all varieties except Sinjami which cultivated in Hamyang were increased yield. Also, quality of virus free sweetpotato were enhanced 7 to 9 compare to virus infected sweet potato which showing average 3. Contents of starch between virus free and virus infected sweetpotato were not affected by virus. Virus free sweetpotato were more increased starch products according to increased total production yield. Also, Brix° (%) was not showing difference between virus free and virus infected sweetpotatoes. In this experiment, Virus free sweetpotato are enhanced production yields and quality. Therefore, we suggested that virus free sweetpotato is one of the methods to reduce damage by sweetpotato virus.
Storage root yield of sweetpotato was decreasing owing to continuous sweetpotato cropping, debasement of soil physical properties, increasing incidence of pest and disease. This study was conducted to evaluate the changes in physicochemical properties of the soil owing to subsoiling (subsoiling to 50 cm depth), and the effect on growth and yield of sweetpotato. The subsoiling treatments included subsoiling treated every year for two years, subsoiling in the first year, and no subsoiling control. The soil physical properties measured were bulk density, hardness, porosity, three phase. Bulk density, porosity, soild (%) of three phase were improved by subsoiling in topsoil and subsoil. Main vine length and vine yield in subsoiling soil were higher than those in no subsoiling soil, but those were not significantly different. Yield of marketable storage root in subsoiling soils treated every year for two years and treated in the first year was more increased 17% and 20% than no subsoiling soil, respectively. The number of marketable storage root per plant was also higher in subsoiling soils than no subsoiling soil, but it was not significantly different. Soluble solid contents and total free sugar contents of storage root of sweetpotato were not significantly different among the treatments. These results show that improving soil physical properties by subsoiling could promote high yield of marketable storage root in continuous sweetpotato cropping field.
고구마의 단위면적당 수량은 연작, 병 감수성 품종의 재배면적 증가, 이상기상 등으로 인해 ’00년 21.4MT/ha에서 ’12년에는 14.9MT/ha까지 꾸준히 감소하였다. 특히 고구마 주산지에서 덩굴쪼김병 피해가 증가하고 있어 덩굴쪼 김병 저항성 품종의 개발이 필요하다. 최근에 육성된 ‘예스미’는 덩굴쪼김병 저항성이 강한 품종으로서 육색이 담 주황색이고 껍질색은 붉은색이며 괴근의 모양은 장방추형이다. ‘예스미’는 목포34호(IT232329)를 모본, 덩굴쪼김 병 저항성 품종인 신건미(IT258213)를 부본으로 하여 2005년에 교배하였으며, 2009년부터 2010년까지 생산력 검 정시험, 2011년부터 2013년까지 전남 무안 등 5개 지역에서 지역적응시험을 수행하였다. 생산력검정시험 결과, ‘예스미’의 상품괴근수량은 ha당 45.9MT으로 ‘율미’의 15.5MT/ha 대비 196% 높았다. 지역적응시험 보통기재배 결과, 상품괴근수량이 ha당 23.9MT, 주당괴근수는 2.8개, 괴근평균중은 개당 143g이었다. 전남 무안에서 수행한 지역적응시험 조기재배 결과, 상품괴근수량이 32.5MT/ha, 주당괴근수는 4.2개로 많아 조기재배용으로도 적합하 였으며, 괴근평균중은 개당 117g으로 율미의 135g 보다 낮았다. 또한 ‘예스미’는 보통기재배 시 베타카로틴 함량이 15.7mg/100g으로 높았으며, 총유리당 함량과 감미도 역시 각각 30.3g/100g d.w.과 16.9로 ‘율미’ 보다 높았다. ‘예스 미’는 덩굴쪼김병이 상습적으로 발생하는 포장에서 재배될 경우 수량 증대로 인한 농가소득 향상에 기여할 수 있 을 것으로 보이며, 베타카로틴 함량이 높아 기능성 식품 등 가공 제품으로의 이용도 기대된다.
‘전미’는 2009년에 농촌진흥청 바이오에너지작물센터에서 전분용 고구마로 개발되었다. 이 품종은 ‘진홍미’를 모본으로 하고, 99IT55-2를 부본으로 하여 선발되었다. 2001부터 2003 년까지 계통선발시험과 2004년부터 2005년까지 2년 동안 생 산력검정시험을 수행하였고, 2006, 2008, 2009년 3년간 무안 등 전국 6개 도에서 지역적응시험을 수행하였다. ‘전미’의 엽 형은 심장형이고, 줄기 및 잎자루색은 녹색이다. 고구마 모양 은 방추형으로 표피색은 자색, 육색은 담황색이다. 선충 및 덩 굴쪼김병 저항성은 ‘중강’이며, 검은썩음병과 연부병도 ‘중강’ 이다. 전분가는 25.6%로 ‘율미’보다 높고, 전분수량은 6.8 t/ha 으로 ‘율미’ 보다 26% 높다. 총당 함량은 ‘전미’가 3.59 g/100 g, dry weight으로 ‘율미’에 비하여 20%가 높다. 당 종류별로 는 sucrose가 2.53 g/100g, dry weight으로 가장 많이 함유되 어 있다. ‘전미’의 조기재배 수량은 3개년 평균 26.1 t/ha으로 ‘율미’에 비하여 147%로 수량이 증수되었고, 만기 및 적기재 배는 26.2 t/ha으로 ‘율미’ 대비 139%로 수량이 높다. 조기재 배의 경우 주당 상품괴근수는 ‘전미’가 3.0개/주로 ‘율미’와 동일하였고, 상품괴근평균중은 151 g/개로 ‘율미’보다 12% 높다. 또한 만기 및 적기재배의 경우 주당 상품괴근수는 평균 3.0개/주로 ‘율미’ 2.3개/주개보다 많고, 상품괴근평균중은 178 g/개로 ‘율미’ 보다 높다.
재배지역에 따라서 동일한 고구마 품종이 나타내는 생육특성과 괴근특성을 구명하고 보다 우수한 품질의 고구마를 생산하기 위한 기초자료를 얻고자 수행된 결과는 다음과 같다. 1. 지역별 재배 토양의 토성은 논산시험구가 식양토, 함양이 양토였으며, 무안, 익산, 보령은 사질양토였다. 또한 보령시험구는 강우량이 많아 일조시간이 짧았으며 적산온도는 익산시험구가 높게 나타났다. 2. 전기전도도는 무안시험구가 다른 지역 시험구에 비해 높았고, 유기물 함량 및 유효인산, 양이온치환용량은 보령이 높아 토양 비옥도가 높게 나타났다. 3. 덩굴무게는 보령시험구에서 많았으며 수량과 당도는 무안과 익산에서 높았다. 4. 고구마의 형태는 익산시험구는 단방추형이었고, 함양은 장방추형으로 길쭉한 경향이었으며, 육색은 익산과 무안시험구의 색도가 낮아 어두운 색을 보였다. 5. 전분가 및 당도는 무안과 익산시험구가 높았고 함양은 낮은 경향이었다.