Sweet potato [Ipomoea batatas (L.) lam] plant is known to have the relatively tolerance soil moisture deficit compared to other upland crops. However, recently, it has been causing plant growth inhibition and decrease storage quality due to the drought during the growing season of sweetpotato in Korea. The response of root elongation, leaf and shoot growth of sweet potato plantlets, cultivated under different water potential conditions were observed. Six varieties, such as yellow fleshed (Jinhongmi), dark-yellow fleshed (Daeyumi), dark-orange fleshed (Juhwangmi), light-orange fleshed (Dahomi, Pungwonmi), and purple fleshed (Sinjami) were used in this experiment. Using the follow water osmotic potential (WOP) levels were 0 (control), -0.05, -0.1, -0.2, -0.3, -0.4, -0.5 MPa by polyethylene glycol (PEG). In in vitro culture condition, ‘Jinhongmi’ has been inhibited rooting number and number of leaves less than 2, although slightly low WOP of–0.05 and –0.1 MPa, and at –0.2 MPa. shoot was not growing. ‘Daeyumi’, Dahomi, and Juwhangmi’ produced 2 roots as a low WOP of –0.3 MPa. and at –0.2 MPa., it appeared 2 or 3 leaves. ‘Pungwonmi’ produced similar to root number 3.9 at –0.1 MPa compared to control, but root weight decreased 75% at - 0.1 MPa more than control. Root did not grow at – 0.2 MPa for ‘Sinjami’. In nursery bed culture condition, roots fresh weight, number of leaves, and shoot length were inhibited according to the decreases of water osmotic potential. In the case of leaf area, ‘Jinhongmi’ and ‘Daeyumi’ was a significantly difference to 8.4, 22.6 cm3 at –0.2 MPa compared to control, respectively. No difference were obsered for ‘Dahomi’ at -0.1 and –0.2 MPa. ‘Pungwonmi’ was decreased 86% at -0.1 MPa compared to the control. ‘Juhwangmi’ and ‘Sinjami’ was a significantly difference to 15.5, 3.6 cm3 at –0.1 MPa compared to control of 22.9, 16.8 cm3, respectively.

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.

수확과정에서 버려지고 있는 고구마 잎을 이용한 기능성 식품소재로서 활용가능성을 검토하고자, 밀가루 중량 대비 고구마 잎 분말을 2, 3, 5, 7%의 비율로 첨가하여 식빵을 제조 하고, 반죽 및 제빵 특성, 생리활성 및 기능성분 등을 조사하 였다. 반죽의 수분흡수량은 7% 첨가 시 가장 높았고, 반죽시 간은 유의적인 차이를 보이지 않았으며, 반죽의 저항도는 2~3% 첨가할 때가 가장 안정적이었다. 식빵의 수분 함량은 첨가량이 증가하여도 큰 차이를 보이지 않았고, 식빵의 내부색은 첨가량이 증가할수록 L값과 a값은 감소하였으나, b값은 증가하였다. 식빵의 부피와 비용적 및 굽기 손실률은 첨가량 이 증가할수록 감소하였으나, 항산화 활성과 총 폴리페놀, 루 테인 및 베타카로틴 함량은 증가하였다. 관능평가의 결과, 고 구마 잎 분말의 2~3% 첨가 시 맛과 색깔, 조직감, 입안에서의 씹힘성과 종합적인 기호도에서 가장 우수한 값을 얻었다. 이 상의 결과에서 고구마 잎 분말의 2~3% 첨가 시, 제빵 적성과 기능성, 상품성이 우수한 식빵을 제조할 수 있었다.

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.

‘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).

The importance key to overcome crisis in rural society is to utilize multivaluedness of rurality. In order to comprehend and utilize a variety of multivaluedness of rurality, firstly it should be needed to investigate and analyze the rural resource. secondly it should be needed to make a plan reflected re-evaleted rural resources. This study aimed at setting up the analysis of all villages in Yeongdong-Gun, Chungcheongbuk-Do by 5 rural village types(Basic life-supporting, Agricultural promotion, Marketing/processing oriented, Urban-rural communication, Life-style choice types) differed in score of classified indicators. These results are expected to be helpful to make a rural development plan reflected villages’ characteristics based on rural resources.

To obtain basic data on the effects of differences cultivation periods and methods on growth and development of sweet potato tuber. We investigated growth and development of six major cultivars showing different characteristics, such as dry type(Yulmi, YM; Jinhongmi, JHM), intermediate type(Pungwonmi, PWM; Hogammi, HGM), and purple type(Sinjami, SJM; Danjami, DJM). The average tuber weight of YM and JHM was 4.1 and 8.6 g respectively, 50 days after transplant. At 80 days, the weight of YM and JHM rapidly increased to 25.2 and 26.1 g, respectively. Finally, at 120 days, the weight of YM and JHM increased to 120.7 and 79.4 g, respectively. The average tuber weight of PWM and HGM was 13 and 3.3 g, respectively, 50 days after transplant. The development pattern of PWM showed a consistent increase in tuber weight during the cultivation period, an average weight of 104.2 g at 120 days. However, the tuber development pattern of HGM was different from that of PWM. The average tuber weight of HGM rapidly increased for 100 days after transplant and then showed no increase at 120 days. In case of purple type sweet potato, the average tuber weight of SJM consistently increased during the cultivation period, whereas DJM showed rapid increase in average tuber weight at 80 days after transplant. Korean consumers prefer small, round sweet potato approximately 100g in weight. Based on the results, YM, PWM and SJM are classified as early developing cultivars that can be harvested approximately 120 days after transplant. On the other hand, JHM, HGM, and DJM are classified as late developing cultivars that can be harvested approximately 130 days after transplant.

The purpose of the study was to investigate how the Cheongwon Organic Life Festival, a rural festival, affects the farmers of the local farms in Cheongju. Based on grounded theory, this study analyzed the objective using a qualitative research program, the Nvivo11 program. The data was collected through in depth interviews from 13 farmers who participated in the Cheongwon Organic Life Festival, and were also residents of Chungcheungbuk-do. The roles of the local festival expected by farmers, were the sale of local agricultural products, local public relations, regional revitalization, a sense of pride as a farmer, exchange of business ideas for sales of agricultural products, and a line of direct communication between farmers and consumers. The farmers who participated in the Cheongwon Organic Life Festival insisted that sales should rise. The results showed that the farmers who participated in the festival felt socially and psychologically stable while participating. The programs at the Cheongwon Organic Life Festival include a concert, hands on involvement, and agricultural sales, which have a direct influence on both sales and attracting visitors during the local festival. Farmers who participated in the Cheongwon Organic Life Festival asked for the improvement of the overall operation of the festival, including the problems with the admission tickets, parking, arrangement of facilities, festival venue, time, and etc. The suggested improvements for the Cheongwon Organic Life Festival focused on the quality certification system of agricultural products, as well as the organic farming of products, thereby to gain trust from the consumers.

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).

This study has been done to have a good grasp at the importance among the constituent elements of the rural healing tourism for working out the rural healing tourism planning. The above constituent elements were produced from the survey targeting the rural area-visiting visitors. For this study, 350 questionnaires were distributed to them and 306 out of them, valid, were collected. For the analysis of correlation among each item in the questionnaires, T-test, ANOVA were carried out. The results of the analysis of the questionnaires show that the consumers of the rural healing tourism have interest in the rural healing tourism regardless of their gender. The results also show that the consumers lay stress on the aspect of the infrastructure(H/W) more than contents-based aspect of the healing tourism(S/W). While especially, regarding healing tourism facilities or infrastructure, this study shows that there is significant difference in every item except gender item, regarding the contents and purpose of the rural healing tourism there is a significant difference among groups only in the item of age.

‘다호미’는 국립식량과학원 바이오에너지작물연구소에서 2012년에 육성한 식용 고구마 품종으로 2005년에 ‘무안4호’를 모본으로, ‘진홍미’를 부본으로 하여 인공교배 하였다. 2007년부터 2008년까지 계통선발시험과 2009년부터 2010년까지 생산력검정시험을 실시하여 괴근 수량성, 상품성, 식미가 우수한 MI2005-05-04 계통을 ‘목포80호’로 계통명을 부여하였다. 2011년부터 2012년까지 2년간 지역적응시험을 수행한 결과, 괴근의 수량성, 상품성이 우수하고 식미가 양호하여 2012년 12월 농촌진흥청 농작물직무육성신품종선정심의회에서 신품종으로 선정되어 ‘다호미’라 명명하였다. ‘다호미’는 잎의 결각이 3개 내지 5개이고, 결각의 깊이는 보통이며 엽색, 잎자루색, 줄기색은 녹색이다. 괴근의 껍질색은 홍색, 육색은 담주황색이며 괴근 모양이 방추형으로 균일하여 상품성이 우수하다. ‘다호미’는 덩굴쪼김병에 강한 편이나 뿌리혹선충에는 저항성이 없다. ‘다호미’는 육질이 중간질이고 전분가는 20.9%으로 낮은 편이며 당도는 24.8 Brix°이고 총유리당은 생고구마가 9.7, 찐고구마가 32.0 g/100g (D.W.)으로 ‘율미’보다 높다. ‘다호미’는 조기재배시 상품괴근수량이 26.3 MT/ha으로 ‘율미’의 17.3 MT/ha보다 52% 증수되었다. 적기 및 만기재배시 상품괴근수량은 21.9 MT/ha으로 ‘율미’보다 35% 증수되었으며 주당상품괴근수는 2.8개/주, 상품괴근평균중은 138 g이다.

고구마는 주로 괴근(덩이뿌리)을 식용으로 이용하지만 최근 고구마 지상부에 대한 영양성분 및 기능성이 밝혀지면서 다양한 식품소재로 이용되고 있다. 고구마 줄기에는 탄수화물, 당류, 단백질 등의 에너지원과 칼슘, 철 등의 여러 무기질이 함유되어 있으며, 비타민 함량은 괴근보다 더 많다고 알려져 있다. 현재 농가에서 주로 재배하고 있는 잎자루 채소용 고구마 품종은 국립식량과학원에서 육성한 ‘신미’ 품종으로, 그 이외에 잎자루 채소용 고구마의 품종 육성은 미흡한 실정이다. 따라서 본 시험은 수량이 많고 껍질 벗김성이 뛰어난 우수 계통을 선발하여 품종으로 개발하고자 수행하게 되었다. 고구마는 ‘신미’(잎자루색 녹색)와 ‘하얀미’(자주색+녹색)를 대조품종으로 하여 ‘MI2011-31-09’, ‘MI2010-05-03’는 2014년 3월 중순에 유리온실에 파종(주간 0.5m, 조간 0.5m)하고 파종 후 60일부터 15~20일 간격으로 9차례 수확 한 후 생육 및 품질특성을 조사하였다. ‘MI2011-31-09’는 ‘신미’에 비하여 10a당 잎자루 평균수량이 47% 증수 되었으며, 잎자루 길이는 평균 6cm 정도 길었다. 또한 잎자루 두께도 평균 1.3mm 더 두꺼우며 껍질 벗김성은 ‘신미’ 5에 비하여 7.3으로 용이하였다. 잎자루를 삶았을 때 경도는 ‘신미’의 0.54kg 보다 낮은 0.45kg으로 삶는 시간이 절약되며 총폴리페놀 함량도 신미 949mg/100g보다 985mg/100g으로 더 높았다. ‘MI2010-05-03’은 ‘신미’에 비하여 10a당 평균수량이 61%, 잎자루 개수는 50% 증수되었고, 잎자루 길이는 평균 2.5cm 더 길었다. 껍질벗김성은 ‘신미’ 5에 비하여 7.0으로 쉽게 벗길 수 있었고 생잎자루의 경도와 삶았을 때의 경도는 각각 0.86kg, 0.48kg으로 신미 1.05kg, 0.54kg보다 낮아 삶는 시간이 절약되며 총폴리페놀 함량도 ‘신미’ 949mg/100g보다 1,078mg/100g로 더 높음을 알 수 있었다.

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.