• Korean Journal of Medicinal Crop Science
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• v.20 no.3
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• pp.190-194
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• 2012

Shoot tips of chinese yam (Dioscorea opposita Thunb.) were cultured on MS medium containing 0.5 mg/L BA to produce micro-tubers in vitro. To stimulate the formation of shoots and micro-tubers, and produce large micro-tubers, the sections of micro-tubers were cultured on MS media with BA and IAA. The shoot multiplication, and the micro-tuber formation and growth were very effective on the media containing 2.0 mg/L BA and 0.5~1.0 mg/L IAA. Sucrose added to MS medium with 2.0 mg/L BA and 0.5 mg/L IAA to stimulate more micro-tuber growth. The medium added 50 g/L sucrose was very effective in the increase of plant fresh weight and micro-tuber growth. After 4 weeks' culture of micro-tuber sections on the medium with 2.0 mg/L BA, 0.5 mg/L IAA and 50 g/L sucrose, the liquid media were added into the same vessels. The micro-tuber growth was stimulated remarkably by the addition of liquid medium. The addition of 25 $m{\ell}$ liquid medium containing 10 g/L activated charcoal, 3x MS salts and 250 g/L sucrose was the most effective in micro-tuber growth.

• Korean Journal of Medicinal Crop Science
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• v.8 no.2
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• pp.89-93
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• 2000

This experiment was conducted to investigate the effects of soil texture on agronomic characteristics and tuber yield in chinese yam (Dioscorea opposita Thunb). Tuber length and weight was greater and tuber shape was much better in sandy loam and loam soil than in sandy or clay loam soil. In loam and sandy loam soil, fresh tuber yield was increased by $21{\sim}27%$ in short-tuber type and 6% in long-tuber type, and large tubers yield (above 260g) was increased by $45{\sim}55%$ in short-tuber type and $20{\sim}22%$ in long-tuber type compared to those in sandy soil. There was no differences in large tuber yield at the 5% level of significance between loam and sandy loam soil. Malformation of tuber with bifurcation was extremely increased in sandy soil, and tuber diameter of long-tuber type was decreased in clay loam soil compared to those of the other soil texture.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.266-270
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• 2012

Stem canker and tuber rot symptoms were observed on yam grown in Andong and Jinju, Korea in 2011. A total of 20 isolates of Rhizoctonia and allied fungi were obtained from the symptomatic plants. Among the isolates, 8 isolates were identified as Rhizoctonia solani and 12 isolates as Ceratobasidium sp. based on rDNA-internal transcribed spacer (ITS) sequence similarity. In the cluster analysis of rDNA-ITS sequences, 7 isolates of R. solani belonged to AG 2-2IIIB and remaining one to AG 1-1A. In addition, among the 12 isolates of Ceratobasidium sp., 7 isolates belonged to AG-Fa, three isolates to AG-A and the other two isolates to AG-Fb and AG-O, respectively. Pathogenicity tests showed that all the R. solani AG 2-2IIIB isolates are pathogenic on stem and tuber of yam but R. solani AG 1-1A and all the Ceratobasidium isolates are non-pathogenic. The results indicate that R. solani AG 2-2IIIB is an important pathogen causing stem canker and tuber rot on yams grown in the study areas. This is the first report of R. solani AG 2-2IIIB causing stem canker and tuber rot of yam in Korea.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.245-252
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• 2018

Yam bean (Pachyrhizus erosus) is a subtropical plant belonging to the Fabaceae family, and is a tuberous vegetable used as various food material with a crisp and juicy taste. This study was conducted to seek optimum sowing time of yam bean in Korea. For this, we surveyed germination properties by the different temperatures and compared the accumulation temperature (AT) and dry matter production (DMP) on growth stages of yam bean by the different sowing times. Two types of varieties cultivated mainly in Korea, Thailand local variety (TLV) and Cheongunmanma cultivar (CGMM), was used. The germination rate of yam bean was 86.0~94.0% at above $18^{\circ}C$, and germination days was longer at lower temperature. The times for flowering and tuber formation of CGMM were later than those of TLV, and the AT required for flowering, tuber formation and hypertrophy of CGMM were higher than those of TLV by $293^{\circ}C$, $280^{\circ}C$ and $108^{\circ}C$, respectively. Also, DMP of shoot and tuber in CGMM were greater than those in TLV. In sowing at April 25, tuber formation was slower than sowing after that time, and harvest index (HI) was relatively low due to delayed formation and hypertrophy of tuber. In sowing after June 9, DMP of shoot was relatively greater in early growth, but tuber was not sufficient to enlarge due to lack of growth days by cold and frost in late October. In sowing May 10 and 25, DMP of tuber and HI were the highest, because the change of day length and temperature gave an advantage to vegetable growth and tuber development. All above suggest that it was suitable to sow seeds on May for increment of tuber productivity in Korea.

• Mycobiology
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• v.36 no.4
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• pp.217-221
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• 2008

During 2007 survey of post-harvest diseases of yam performed in May and June, severe tuber loss caused by blue mold was observed in Iksan, Cheonbuk Province. Two species of Penicillium were isolated from the infected tubers. Based on $\beta$-tubulin gene sequence analysis, and cultural and morphological characteristics, the isolates were identified as Penicillium sclerotigenum and P. polonicum. P. sclerotigenum, which is a novel to Korea, is presently described and illustrated.

• Korean Journal of Plant Resources
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• v.22 no.6
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• pp.546-551
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• 2009

We examined the growth characteristics, fresh tuber yield, rotenone content of two yam beans (Pachyrhizus erosus and P. ahipa) introduced from Mexico. P. erosus species showed better adaptable ability than P. ahipa species in seed productivity and tuber yield. Rotenone content in the P. erosus species extracted with chloroform was 3.6 folds much more extracted than ethanol extraction. The order of rotenone content found in crude extract obtained by different solvent extraction from the highest to the lowest was mature seed (484.7 ${\mu}g$) and leaves (17.2 ${\mu}g$) of the P. erosus species, respectively.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2005.11a
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• pp.136-136
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• 2005

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.1
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• pp.8-14
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• 2011

The effect of flooding and soil salinity on the growth of yam (Dioscorea batatas) were studied on the experimantal site temporally established in the south-eastern part of Saemangeum Reclaimed Tidal Land (near Gwanghwal myun, Gimjae-gun, Jellabukdo, Korea). Yam seedlings planted by using aerial bulblet as alternative of sliced tubers, were grown for 20-days and transplanted in black-vinyl mulched ridges (about 20 cm in height) at 70cm interval by $20{\times}60cm$ spacing in the $4^{th}$ of May, 2010. Soil salinity was maintained at lower than 1.2 ds $m^{-1}$ during the growing period and did not result to salt injury in all plants. However, flooding injury very seriously led to plant death and plant mortality rates at $67{\pm}21$ and $82{\pm}9%$ of yam plants in the compost and no compost treatment, respectively, died by heavy flooding during the rainy summer season. The main reasons of the flooding injury included the decreased rainfall acceptable capacity (RAC) after the rising of water table and a slowdown of water infiltration rate after the formation of an impermeable soil crust in the furrow bottom with continuous and heavy downpour during the rainy summer season. The effect of compost treatment was not statistically observed because of the severe spatial difference caused by wet injury, although yam tuber yield was higher at 30 kg $10^{-1}$ in the compost treatment than in the no-compost treatment at 20 kg $10^{-1}$. However, the size of tuber ranged at 1.23 to 1.60 cm in diameter and 3.7 to 5.0 cm in length in all both treatment, which means they are still reproducible for the next cropping season. Conclusively, proper counter-flooding measure and soil salinity control critically important for successful yam production in Saemangeum Reclaimed Tidal Land.

• Korean Journal of Medicinal Crop Science
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• v.8 no.4
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• pp.362-372
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• 2000

This study was conducted to obtain the basic information on the production of high yield and qualitied yam in Andong, major yam-producing district, in Kyongbuk province, using three major Yam cultivars, such as Danma, Jangma and Alata (round type). Alata showed the longest tuber width while Jangma showed the longest tube length. Danma showed the highest tube yield at 2,123 kg/10a. Tubes of Alata had higher dry ratio than those of other cultivars, suggesting that Alata could be used as good processing materials. Characteristics of top parts, such as vine length, leaf number, and lateral vine number showed typical sigmoid curves. Tuber characteristics such as length, width and fresh weight of tuber were linearly increased as the growth period was progressed. Relative growth rate (RGR) for new tuber and stem reached the highest value at 86 DAT (days after transplanting). There were similar tendencies among the cultivars in net assimilation rate (NAR). The highest crop growth rate (CGR) was appeared at 156 DAT regardless of cultivars. In the changes of leaf area ratio (LAR), there were significant differences among three cultivars. LAR were decreased at 86, 106 and 136 DAT for Alata, Danma and Jangma, respectively. However, specific leaf weight (SLW) was greatly increased at 176 DAT, and leaf area index (LAI) was decreased at 156 DAT in all cultivars.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.64-73
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• 2005

This study was done to determine the regional adaptability of Dioscorea opposita in Korea. Suwon, Chunchon, Kangneung, Yonchon and Taean had soil pH of 6.62, 5.65, 5.9, 5.9 and 5.82, respectively, being at more unfavorable conditions than a standard soil condition for yam with pH 6.2. The amounts of organic matter in Suwon, Chunchon, Taean, and Yonchon were 1.96%, 4.51%, 3.76%, 1.89% and 1.12%, respectively, being at more favorable conditions than a standard organic matter in soil for yam with 2.0~3.0%. As the results from cultivating of large plantings in different regions, Suwon showed the largest the tuber dry weight of 135g. In comparison of general component between round yam and short yam in the area of Kangneung, protein of round yam(3.30%) was higher than that of short yam(1.40%). Dryness in round yam(36.5%) was lower than that of short yam(28.9%), indicating a higher dry weight ratio of round yam. In tuber extracts analysis, saponins content was respectively 23.7mg/g in round yam and 10.4mg/g in short yam.