• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.69 no.2
• /
• pp.71-77
• /
• 2024

After the strongest El Niño since 2015 occurred in 2023, there has been a growing interest in understanding its impacts on rice yield in South Korea. We investigated the impact of El Niño during the rice-growing season on rice yield by analyzing the correlation between detrended rice yield data and ONI (Oceanic Niño Index) values exceeding 0.5. The results show a positive correlation between ONI intensities and detrended rice yields. Furthermore, we found that variations in sunshine duration, precipitation, and typhoon activity affect detrended yield values positively and negatively. This pattern was similar to the classification of El Niño into Cold Tongue El Niño and non-Cold Tongue El Niño, which showed positive and negative detrended rice yield values, respectively. This observation suggests that predicting yield based on ONI intensity during Cold Tongue El Niño years may be feasible to some extent.

• Korean journal of applied entomology
• /
• v.15 no.2 s.27
• /
• pp.57-60
• /
• 1976

Experiments were carried out to determine the effectiveness of a new systemic fungicide EL-291 (5-Methyl-1, 2,4-triazolo (3,4-b) benzothiazole) for the control of rice blast disease in greenhouse and paddy field. The efficiency of EL-291 was much greater when applied before inoculation than when applied after inoculation. Kasugamin and Benlate were most effective as eradicants. For control of leaf blast, effectiveness of EL-291 was not significantly different than either Kasugamin or Benlate. However, EL-291 was considered more economical and reliable than either Kasugamin or Benlate. EL-291 required only a single foliar application or a transplant root soak, whereas two applications of the other fungicides were required. EL-191 was also more effective against panicle blast when applied only once, compared with two applications of Kasugamin or Benlate. The highest riceyields were obtained in plots treated with EL-29l.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.51 no.spc1
• /
• pp.12-20
• /
• 2006

This study was carried out to investigate the relationship between each quality characteristics and changes of grain quality according to storage temperature and moisture contents of rough rice of Dongjin 1 and Siodongjinbyeo. Respiration rate of rough rice and fat acidity of brown rice were increased with moisture contents of rough rice and storage temperature. Germination rate of rough rice was the highest at $17{\sim}18%$ moisture contents of rough rice stored at low temperatures for 12 months. Germiation rate of the stored at low temperature after 16 months was up to 80% however the rate of $13{\sim}14%$ moisture contents of rough rice stored at room temperature was severely decreased to below the 10%. Gloss value of cooked rice was increased with moisture contents of rough rice and the lower storage temperature. Fat acidity of brown rice was lower in Sindongjinbyeo than Dongjin 1 at the lower storage temperature. Sensory score of cooked rice of Sindongjinbyeo which stored at low temperature for 16 months was better than Dongjin 1 and excllent at $17{\sim}18%$ moisture contents of rough rice. Correlations between sensory score of cooked rices and color b value of brown rice, gloss value of cooked rice and color L value of brown rice were significant 0.731**, 0.625*, and 0.615*, resectively, and were also positively significant correlated with break down, peak viscosity, pasting temperature, and fat acidity of brown rice -0.864**, -0.795**, -0.786**, and -0.779**, respectively.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.3
• /
• pp.143-150
• /
• 2016

In this study, we analyzed the relationship between rice yield and abnormal meteorological features for El $Ni{\tilde{n}}o$ years (with more than 1.0 Oceanic $Ni{\tilde{n}}o$ Index) since 1980 in South Korea. The national averaged rice yield of El $Ni{\tilde{n}}o$ years (n=14) was $4,663kg\;ha^{-1}$, which was less than that of non El $Ni{\tilde{n}}o$ years (n=16) by $102kg\;ha^{-1}$, but the difference was not significant statistically (t=1.215, p=0.234). The averaged rice yield of El $Ni{\tilde{n}}o$ end years ($4,558kg\;ha^{-1}$) was analyzed to be less than those of El $Ni{\tilde{n}}o$ start years and non El $Ni{\tilde{n}}o$ years by 209 and $206kg\;ha^{-1}$, respectively. But, the trend was not significant statistically (df=2, f=2.355, p=0.114). When meteorological anomalies were analyzed based on seasonal meteorological values, 18 meteorological events in total were observed for the past 30 years (1981-2010). In detail, abnormally much precipitation occurred 6 times, most often, followed by 5 times of abnormally low temperature during the past 30 years. Occurrence of meteorological anormalies of El $Ni{\tilde{n}}o$ end years was 0.71 events per year on average, which was higher than those of El $Ni{\tilde{n}}o$ start years ($0.43yr^{-1}$) and non El $Ni{\tilde{n}}o$ years ($0.63yr^{-1}$), even if the differences were not significant statistically (df=2, f=0.321, p=0.727).

• The Korean Journal of Zoology
• /
• v.34 no.2
• /
• pp.142-147
• /
• 1991

Angiotensin I-converting enzyme (ACE) activity has been characterized in the rice eel, Monopterus albus. Peak activity of ACE in plasma from the rice eel was shown at around pH 10, which was more alkaline compared to that of mammals. Chloride requirements for the optimal ACE activity were different from species to spedes. ACE inhibitors, EDTA, teprotide (SQ 20, 881), and captopril (SQ 14, 225) showed dose-dependent inhibitions of ACE activity in plasma from the rice eel as well as mammals. ACE activity in the rice eel was increased by CoCI2, and the enzyme activity was more unstable at high temperature as compared to mammals The highest activity of ACE among the various tissues in the rice eel was found in the brain.

• Carbon letters
• /
• v.13 no.2
• /
• pp.61-72
• /
• 2012

Dye removal from waste water via adsorption by activated carbons (ACs) developed from agricultural wastes represents an ideal alternative to other expensive treatment options. Physical and chemical ACs were prepared from rice husks. The textural properties of the ACs were characterized by Brunauer-Emmett-Teller-$N_2$ adsorption and scanning electron microscopy. The chemistry of the carbon surface was investigated by Fourier transform infrared spectroscopy, base and acid neutralization capacities, pH of the active carbon slurry, and $pH_{pzc}$. The adsorption capacities of the ACs for the basic dye (methylene blue) and acid dye (acid green 25) were determined using parameters such as contact time, pH, and temperature. NaOH-ACs showed the highest surface area and total pore volume, whereas steam-ACs showed the lowest ones.

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.386.1-386.1
• /
• 2002

The H2O and 50% extracts of herbal medicines(HM) combinations which were consisted of Acanthopanacis Cortex. Phragmitis Rhizoma. Chaenomelis Fructus. Pruni pseudocerasi Semen and rice bran were prepared and administered orally before 40% ethanol administration in the males S.D rats. The 50% ethanol extract of HM (HM50E) showed blood alcohol decreasing activity and was fractionated again into HM50El and E2 by Sephadex LH-20 gel column chromatography. HM50E2 showed more effective blood ethanol decreasing activity than HM50El. (omitted)

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.6
• /
• pp.487-493
• /
• 2013

The effects of long-term fertilization on soil biological properties and microbial community structure in the plough layer in a rice paddy soil in southern Korea were investigated in relation to the continuous application of chemical fertilizers (NPK), straw based compost (Compost), combination these two (NPK + Compost) for last 40 years. No fertilization plot (Control) was installed for comparison. Though fertilization significantly improved rice productivity over control, the long-term fertilization of NPK and compost combination was more effective on increasing rice productivity and soil nutrient status than single application of compost or chemical fertilizer. All fertilization treatments had shown significant improvement in soil microbial properties, however, continuous compost fertilization markedly increased soil enzyme and microbial activities as compared to sole chemical fertilization. Results of microbial community structure, evaluated by EL-FAME (ester-linked fatty acid methyl esters) method, revealed big difference among Control, NPK, and Compost. However, both Compost and Compost+NPK treatments belonged to the same cluster after statistical analysis. The combined application of chemical fertilizer and organic amendments could be more rational strategy to improve soil nutrient status and promote soil microbial communities than the single chemical fertilizer or compost application.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2016.09a
• /
• pp.20-24
• /
• 2016

• Journal of Microbiology and Biotechnology
• /
• v.19 no.5
• /
• pp.468-473
• /
• 2009

The antibiotic meroparamycin was produced in the free culture system of Streptomyces sp. strain MAR01. Five solid substrates (rice, wheat bran, Quaker, bread, and ground corn) were screened for their ability to support meroparamycin production in solid-state fermentation. In batch culture, wheat bran recorded the highest antibacterial activity with the lowest residual substrate values. The highest residual substrate values were recorded for both ground corn and Quaker. On the other hand, no antibacterial activity was detected for rice as a solid substrate. The use of the original strength of starch-nitrate medium in the solid-state fermentation gave a lower antibacterial activity compared with the free culture system. Doubling the strength of this medium resulted in the increase in the activity to be equivalent to the free culture. The initial pH (7.0) of the culture medium and 2 ml of spore suspension (1 ml contains $5{\times}10^{9}spores/ml$) were the optima for antibiotic production. The water was the best eluent for the extraction of the antibiotic from the solid-state culture. Ten min was enough time to extract the antibiotic using a mixer, whereas, 60 min was required when shaking was applied. Semicontinuous production of meroparamycin using a percolation method demonstrated a more or less constant antibacterial activity over 4 runs ($450-480{\mu}g/ml$). The semicontinuous production of the antibiotic was monitored in a fixed-bed bioreactor and the maximum activity was attained after the fourth run ($510{\mu}g/ml$) and the overall process continued for 85 days.