• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.58 no.3
• /
• pp.253-259
• /
• 2013

This study was conducted to investigate proper mixed cultivation system of potato and succeeding crops (Chinese cabbage and Radish) in 2009. Potato varieties, 'Superior' a middle maturing variety and 'Haryeong' a late maturing variety were used. After potato harvest, succeeding crops of Radish and Chinese cabbage were planted on July 22th in 'Superior' variety plot and Aug. 3rd in 'Haryeong' variety plot. Potato crop was harvested in proper time, after 15, 30, 45 and 60 days. and a suitable potato variety for succeeding crops among 'Superior' and 'Haryeong' was checked. 'Superior' variety was observed to be low rotting, deformity and greening at Chinese cabbage and Radish treatment plot than non-treatment plot. In addition, high yields of potato was maintained in succeeding crop treatments.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.62 no.1
• /
• pp.51-59
• /
• 2017

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.

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.3
• /
• pp.181-188
• /
• 1993

The effects of paddy-upland rotation and cropping system on the mineralization of soil organic nitrigen, on the change of organic matter and available phosphorus content in the soil, and on the rice yield and nutrients absorption were studied in Seokcheon fine-sandy loam soil. 1. In the incubation test mineralzed soil nitrogen and the nitrogen extracted by pH 7 phosphate buffer solutions were higher in the soils from every and two year rotation systems than continuous rice cultivation. In terms of cropping system potato-chiness cabbage-rice increased them more than soybean-rice system. 2. The change of soil organic matter and available phosphorus contents were not much in continuous rice cultivation, while in rotation system they decreased as the paddy-upland rotation frequency decreased. In terms of cropping system they decresed more in potato-Chinese cabbage-rice system compared with soybean-rice systems. 3. The rice yield was higher in the paddy-upland rotation system than that of continuous rice cultivation. However, the effects were decreased gradually every year, as shown by 26~20, 17~5, and 5~4% yield increase for first, second, and third year, respectively, in potato-Chinese cabbage-rice and soybean-rice system compared with continuous rice cultivation. 4. All the absorbed nutrient contents increased in every and two year rotation system compared with continuous rice cultivation. In terms of cropping system potato-Chiness cabbage-rice system increased them more compared with soybean-rice system.

• The Plant Pathology Journal
• /
• v.37 no.6
• /
• pp.580-595
• /
• 2021

Although late blight is an important disease in ecofriendly potato cultivation in Korea, it is highly dependent on the use of eco-friendly agricultural materials and the development of biological control technology is low. It is a necessary to develop an effective biocontrol agent to inactivate late blight in the field. AFB2-2 strain is a gram-positive with peritrichous flagella. It can utilize 20 types of carbon sources, like L-arabinose, and D-trehalose at 35℃. The optimal growth temperature of the strain is 37℃. It can survive at 20-50℃ in tryptic soy broth. The maximum salt concentration tolerated by AFB2-2 strain is 7.5% NaCl. AFB2-2 strain inhibited the mycelial growth of seven plant pathogens by an average inhibitory zone of 10.2 mm or more. Among the concentrations of AFB2-2, 10⁷ cfu/ml showed the highest control value of 85.7% in the greenhouse. Among the three concentrations of AFB2-2, the disease incidence and severity of potato late blight at 10⁷ cfu/ml was lowest at 0.07 and 6.7, respectively. The nucleotide sequences of AFB2-2 strain were searched in the NCBI GenBank; Bacillus siamensis strain KCTC 13613, Bacillus velezensis strain CR-502, and Bacillus amyloliquefaciens strain DSM7 were found to have a genetic similarity of 99.7%, 99.7%, and 99.5%, respectively. The AFB2-2 strain was found to harbor the biosynthetic genes for bacillomycin D, iturin, and surfactin. Obtained data recommended that the B. velezensis AFB2-2 strain could be considered as a promising biocontrol agent for P. infestans in the field.

• Korean Journal of Food Science and Technology
• /
• v.45 no.3
• /
• pp.305-311
• /
• 2013

Effects of cultivation methods on quality characteristics, pasting characteristics, chemical components, and antioxidant activities of sweet potatoes (Ipomoea batatas (L.) Lam) were determined. The Brix degree, hunter color value, pasting characteristics, moisture, protein, and mineral contents of the sweet potatoes showed significant differences from cultivation methods. The total polyphenol and flavonoid contents of the methanolic extracts of the sweet potato's pericarp were higher than sweet potato's sarcocarp. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the sweet potato's pericarp on the conventional culture and successful cropped hairy vetch culture was 776.38 and 715.20 mg TE/100 g sample. The 2,2'-azino-bis-3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS) radical scavenging activity of the sweet potato's pericarp on the conventional culture and successful cropped hairy vetch culture was 708.03 and 708.58 mg TE/100 g sample. Generally, there was a difference in antioxidant compound content and radical scavenging activity on the methanolic extract of sweet potato with cultivation methods.

• Korean Journal of Plant Resources
• /
• v.37 no.2
• /
• pp.149-160
• /
• 2024

In Korea, potatoes have served as a side dish, but their role as snacks, such as chips or French fries, has recently gained traction. While there is a high demand for processing potatoes, there remains a dearth of research on the impact of double cropping, particularly during autumn, on processing quality. Therefore, this study was conducted to determine the effects of different spring potato cultivation periods on growth, yield, and processing quality during autumn cultivation. Following spring planting, harvest was carried out four times: 70 days, 80 days, 90 days, and 100 days. Subsequently, autumn cultivation was carried out in Gangneung and Seocheon regions using these seed potatoes. Results showed an increase in above-ground emergence rate with shorter spring growing period. When seed potatoes with a spring cultivation period of 80 and 90 days were grown in the autumn in the Gangneung region, the stem length was 47.2 to 48.9, which was greater than that of other treatments. However, stem number and leaf color (SPAD) showed no significant differences across cultivation periods. The number of tubers, tuber weight, yield, and marketable yield did not vary significantly with cultivation periods but described clear cultivar dependent differences. The tuber weight of the Saebong cultivar in Gangneung and the Eunseon cultivar in Seocheon was superior. The starch content peaked at 7.9% when seed potatoes grown for 80 days in the spring were harvested after autumn cultivation in the Gangneung region, but there was no significant differences in the Seocheon region. Glucose content showed a clear difference depending on the cultivation period, increasing with longer spring cultivation period during autumn cultivation. In conclusion, as a result of the effect of the spring potato cultivation period on the growth, yield, and processing quality of tubers when cultivating potatoes in double-cropping, the differences depending on the cultivation period were insignificant, while cultivar-based disparities were pronounced. The Eunseon cultivar exhibited robust above-ground growth and yield, while the Saebong cultivar demonstrated excellent processing quality.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.4
• /
• pp.544-550
• /
• 2012

This study was conducted to investigate the characteristic factors which have been influenced on nitrous oxide ($N_2O$) emissions related to the environment change of nitrogen application level, rainfall and temperature during the potato cultivation at black volcanic ash soil from 2010 to 2011. During the potato cultivation, the more amount of nitrogen fertilizer applied, $N_2O$ emissions amounts were released much. $N_2O$ emissions with the cultivation time were released much at the first and middle of cultivation with heavy rainfall, but it was released very low until the end of cultivation and drought season. $N_2O$ emissions mainly were influenced by the rainfall and soil water content. The correlation (r) with $N_2O$ emissions, soil wate, soil temperature in 2010 were very significant at $0.6251^{**}$ and $0.6082^{**}$ respectively, but soil EC was not significant to 0.10824. In 2011, soil temperature was very significant at $0.4879^{**}$, but soil water and soil EC were not significant at 0.0468 and 0.0400 respectively. Also, $NH_4$-N was very significant at $0.7476^{**}$, but $NO_3$-N and soil nitrogen ($NO_3-N+NH_4-N$) were not significant at 0.0843 and 0.1797, respectively. During the potato cultivation period, the average emissions factor of 2 years released by the nitrogen fertilizer application was presumed to be 0.0040 ($N_2O-N\;kg\;N^{-1}\;kg^{-1}$). This factor was lower about 2.5 times than the IPCC guideline default value (0.0100 $N_2O-N\;kg\;N^{-1}\;kg^{-1}$).

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.39-39
• /
• 2017

In Asia, sweet potato (Ipomoea batatas) is a very important crop for starch production. Approximately 74.3% of the total sweet potato production quantity is produced in Asia (FAO, 2014) and China is the largest producer of sweet potato. Post-harvest management is particularly important because it is difficult to maintain the quality as well as quantity of sweet potatoes. Despite the importance of post-harvest management, researches on sweet potato have been focused on production-related study such as breeding of new variety, improved techniques of cultivation, so there is limited research on storage after harvest. Curing is a normal practice after sweet potato harvest to promote wound healing and extend postharvest storage life. In Korea, harvested sweet potatoes are usually cured for 4 to 7 days at $30-33^{\circ}C$ and 80-95% relative humidity within one week. Since the optimum storage temperature of sweet potato is regarded as $15-20^{\circ}C$, additional facilities and costs are required to raise the temperature for curing. However, the majority of small farmers do not have the capacity to provide additional facilities and costs. This study was initiated to suggest a new curing method to accelerate the wound healing by applying chemical oxidation to the wound surface of sweet potato. Oxidative stress is known to play an important role in the synthesis of secondary metabolites including lignin. In addition, chemical oxidation can be applied to prevent spoilage caused by microorganisms. Powerful gaseous oxidant with excellent penetration ability and superior sterilization effect was selected for this study. Lignification, weight loss, and spoilage rate of artificially wounded sweet potatoes were investigated after oxidant fumigation. There were clear differences in morphological analysis such as lignification pattern, lignin deposition color, and continuity of lignified cell layers between oxidant-fumigated sweet potatoes and control. These results show that gaseous oxidant can be used to supplement or replace the curing practice, to improve shelf-life as well as curing cost reduction.

• Korean Journal of Environmental Agriculture
• /
• v.26 no.4
• /
• pp.300-305
• /
• 2007

Soil erosion is one of the most serious problems in alpine upland in Korea. Soil fertility has continuously decreased due to serious soil erosion. To increase soil fertility, new sources of organic matter should be inputted. Therefore, the objectives of this research were to select winter cover crop as new sources of organic matter and to investigate the effect of winter cover crop on soil property changes, major crop productivity (Chinese cabbage, potato) production in highland, and disease occurrence with different cropping systems. Among 17 candidates for winter coverage crop, rye was most suitable due to it's soil covering rate, and over-wintering rate. The optimum sowing period for rye ranged from late August to late September. Soil porosity and organic matter content increased with rye cultivation. Rye cultivation during winter increased amounts of crop (both Chinese cabbage and potato) productivity up to 8%. There was little difference on amount of crop productivity depending on cropping systems such as monoculture (Chinese cabbage or potato) and Chinese cabbage-potato rotation.

• Korean Journal of Organic Agriculture
• /
• v.7 no.1
• /
• pp.79-90
• /
• 1998

This study was conducted to effect promotion of fall potato growth in the place which green manual crops had been previously cultivated, crushed and tilled and polyethylene transparent vinyl had been mulched from Aug. 5 to Aug. 29 in 1997. The maximum temperature of below-ground at the depth of 10cm was $42^{\circ}C$ during the mulching period, and the pH and the organic compound content of soil was very increased by the cultivation of green manual crops and the mulching of polyethylene transparent vinyl. The total yields of green manual crops which had been previously cultivated were as the following orders; the hybrid of sudan grass, soybean, alfalfa, otherwise, fresh weight of stems and the tuber yield of fall potato were significantly affected in the plot of soybean + fall potato after the soil solarization with the mulching. As these results, it was possible to improve crops growth and to sterilize soil by the mulching treatment of polyethylene vinyl after cultivation of green manual crops during the high temperature of the summer season.