• Title/Summary/Keyword: Plant temperature

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Studies on the Consumptine Use of Irrigated Water in Paddy Fields During the Growing of Rice Plants(III) (벼생유기간중의 논에서의 분석소비에 관한 연구(II))

  • 민병섭
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.11 no.4
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    • pp.1775-1782
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    • 1969
  • The results of the study on the consumptine use of irrigated water in paddy fields during the growing season of rice plants are summarized as follows. 1. Transpiration and evaporation from water surface. 1) Amount of transpiration of rice plant increases gradually after transplantation and suddenly increases in the head swelling period and reaches the peak between the end of the head swelling poriod and early period of heading and flowering. (the sixth period for early maturing variety, the seventh period for medium or late maturing varieties), then it decreases gradually after that, for early, medium and late maturing varieties. 2) In the transpiration of rice plants there is hardly any difference among varieties up to the fifth period, but the early maturing variety is the most vigorous in the sixth period, and the late maturing variety is more vigorous than others continuously after the seventh period. 3) The amount of transpiration of the sixth period for early maturing variety of the seventh period for medium and late maturing variety in which transpiration is the most vigorous, is 15% or 16% of the total amount of transpiration through all periods. 4) Transpiration of rice plants must be determined by using transpiration intensity as the standard coefficient of computation of amount of transpiration, because it originates in the physiological action.(Table 7) 5) Transpiration ratio of rice plants is approximately 450 to 480 6) Equations which are able to compute amount of transpiration of each variety up th the heading-flowering peried, in which the amount of transpiration of rice plants is the maximum in this study are as follows: Early maturing variety ; Y=0.658+1.088X Medium maturing variety ; Y=0.780+1.050X Late maturing variety ; Y=0.646+1.091X Y=amount of transpiration ; X=number of period. 7) As we know from figure 1 and 2, correlation between the amount evaporation from water surface in paddy fields and amount of transpiration shows high negative. 8) It is possible to calculate the amount of evaporation from the water surface in the paddy field for varieties used in this study on the base of ratio of it to amount of evaporation by atmometer(Table 11) and Table 10. Also the amount of evaporation from the water surface in the paddy field is to be computed by the following equations until the period in which it is the minimum quantity the sixth period for early maturing variety and the seventh period for medium or late maturing varieties. Early maturing variety ; Y=4.67-0.58X Medium maturing variety ; Y=4.70-0.59X Late maturing variety ; Y=4.71-0.59X Y=amount of evaporation from water surface in the paddy field X=number of period. 9) Changes in the amount of evapo-transpiration of each growing period have the same tendency as transpiration, and the maximum quantity of early maturing variety is in the sixth period and medium or late maturing varieties are in the seventh period. 10) The amount of evapo-transpiration can be calculated on the base of the evapo-transpiration intensity (Table 14) and Tablet 12, for varieties used in this study. Also, it is possible to compute it according to the following equations with in the period of maximum quantity. Early maturing variety ; Y=5.36+0.503X Medium maturing variety ; Y=5.41+0.456X Late maturing variety ; Y=5.80+0.494X Y=amount of evapo-transpiration. X=number of period. 11) Ratios of the total amount of evapo-transpiration to the total amount of evaporation by atmometer through all growing periods, are 1.23 for early maturing variety, 1.25 for medium maturing variety, 1.27 for late maturing variety, respectively. 12) Only air temperature shows high correlation in relation between amount of evapo-transpiration and climatic conditions from the viewpoint of Korean climatic conditions through all growing periods of rice plants. 2. Amount of percolation 1) The amount of percolation for computation of planning water requirment ought to depend on water holding dates. 3. Available rainfall 1) The available rainfall and its coefficient of each period during the growing season of paddy fields are shown in Table 8. 2) The ratio (available coefficient) of available rainfall to the amount of rainfall during the growing season of paddy fields seems to be from 65% to 75% as the standard in Korea. 3) Available rainfall during the growing season of paddy fields in the common year is estimated to be about 550 millimeters. 4. Effects to be influenced upon percolation by transpiration of rice plants. 1) The stronger absorbtive action is, the more the amount of percolation decreases, because absorbtive action of rice plant roots influence upon percolation(Table 21, Table 22) 2) In case of planting of rice plants, there are several entirely different changes in the amount of percolation in the forenoon, at night and in the afternoon during the growing season, that is, is the morning and at night, the amount of percolation increases gradually after transplantation to the peak in the end of July or the early part of August (wast or soil temperature is the highest), and it decreases gradually after that, neverthless, in the afternoon, it decreases gradually after transplantation to be at the minimum in the middle of August, and it increases gradually after that. 3) In spite of the increasing amount of transpiration, the amount of daytime percolation decreases gadually after transplantation and appears to suddenly decrease about head swelling dates or heading-flowering period, but it begins to increase suddenly at the end of August again. 4) Changs of amount of percolation during all growing periods show some variable phenomena, that is, amount of percolation decreases after the end of July, and it increases in end August again, also it decreases after that once more. This phenomena may be influenced complexly from water or soil temperature(night time and forenoon) as absorbtive action of rice plant roots. 5) Correlation between the amount of daytime percolation and the amount of transpiration shows high negative, amount of night percolation is influenced by water or soil temperature, but there is little no influence by transpiration. It is estimated that the amount of a daily percolation is more influenced by of other causes than transpiration. 6) Correlation between the amount of night percoe, lation and water or soil temp tureshows high positive, but there is not any correlation between the amount of forenoon percolation or afternoon percolation and water of soil temperature. 7) There is high positive correlation which is r=+0.8382 between the amount of daily percolation of planting pot of rice plant and amount and amount of daily percolation of non-planting pot. 8) The total amount of percolation through all growin. periods of rice plants may be influenced more from specific permeability of soil, water of soil temperature, and otheres than transpiration of rice plants.

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Studies on the Characteristics of Volatile Fatty Acid Evolution from Fresh Animal Feces (축분의 휘발성 지방산 발현 양상 연구)

  • ;;;Hudson, Neale
    • Journal of Animal Environmental Science
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    • v.10 no.1
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    • pp.11-22
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    • 2004
  • This work was carried out to measure volatile fatty acids emissions from different manure (poultry, swine, cattle) incubated at $10^{\circ}C$, $25^{\circ}C$, and $37^{\circ}C$ for 6 days under anaerobic condition. Following are summary of these tests results. 1. Amounts of Acetic acid generated were 1,128.05mg/kg, 628.21mg/kg and 592.50mg/kg for swine, poultry, and cattle manure, respectively, during the period of incubation. In the case of swine and cattle manure, 83.87%(946.10mg/kg) and 57.49%(340.63mg/kg) from all the temperature treatments were produced in the $25^{\circ}C$, respectively. 83.57% in swine and 78.79% in cattle manure were intensively emerged from 3 day, 4 day and 5 day of the $25^{\circ}C$ treatment. In the case of poultry manure, 45.36%(284.93mg/kg) and 45.36%(284.93mg/kg) in the $25^{\circ}C$ and in the $37^{\circ}C$, respectively, were produced. Accordingly, acetic acid generated from poultry manure was characteristic of being mainly produced in more than $25^{\circ}C$. 2. Amounts of propionic acid generated were 238.56mg/kg, 162.14mg/kg and 155.49mg/kg for swine, poultry, and cattle manure, respectively, during the period of incubation. In the case of swine manure, 78.52%(187.32mg/kg) of propionate emitted from all the temperature treatments was produced in the $25^{\circ}C$ and 79.1% of them was intensively emerged from 3day, 4day and 5day of the $25^{\circ}C$ treatment. In the case of poultry manure, 35.12%(56.95mg/kg) and 45.89%(74.40mg/kg) of the propionate amounts were produced in the $25^{\circ}C$ and in the $37^{\circ}C$, respectively. In the case of cattle manure, 28.21% (43.86mg/kg) and 49.30% (76.66mg/kg) of the propionate amounts were produced in the $10^{\circ}C$ and in the $25^{\circ}C$, respectively. Accordingly, propionate evolved from poultry manure was characteristic of being mainly produced in more than $25^{\circ}C$ and from cattle manure, in less than $25^{\circ}C$, respectively. 3. Amount of butyric acid generated were 1,463.87mg/kg, 96.72mg/kg and 129.18mg/kg for swine, poultry, and cattle manure, respectively, during the period of incubation. The time intensively emerged from the period of incubation was differently generated from the incubation temperature and animal feces. 4. Amounts of iso-valeric acid generated were 6,885.99mg/kg, 399.28mg/kg and 307.47mg/kg for swine, cattle and poultry manure, respectively, during the period of incubation. In the case of swine and cattle manure, 28.22%(1,943.52mg/kg) and 48.56%(193.90mg/kg) in the $25^{\circ}C$, 68.76%(4,734.90mg/kg) and 46.93%(187.40mg/kg) in the $37^{\circ}C$, respectively, were occupied. Accordingly, iso-valeric acid evolved from swine and cattle manure was characteristic of being mainly produced in more than $25^{\circ}C$. In the case of poultry manure, 59.89%(184.13mg/kg) of iso-valeric acid generated from all the temperature treatments was produced in the $37^{\circ}C$ and 100% of them was intensively emerged from 2 day and 3 day of the $37^{\circ}C$ treatment.

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Bioacoustics and Habitat Environment Analysis of Cicadas in Taebaeksan National Park (태백산국립공원에 서식하는 매미류의 생물음향 및 서식환경 분석)

  • Kim, Yoon-Jae;Jung, Tae-Jun;Ki, Kyong-Seok
    • Korean Journal of Environment and Ecology
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    • v.33 no.6
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    • pp.664-676
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    • 2019
  • This study aimed to analyze the bioacoustics and habitat environment of the cicadas inhabiting Taebaeksan National Park, an sub-alpine region in Korea. The mating calls of the cicadas were recorded for approximately 3 months, between July and September of 2018. The recording devices were installed in Daedeoksan valley and Baekcheon valley, inside Taebaeksan National Park, and the sounds were recorded 24 hours a day. In order to obtain the habitat distribution data of the cicadas, the sounds were recorded from 111 spots located in the Taebaeksan National Park trail in August 2018. The daily weather data was obtained from the Taebaek city weather center. The results of the study demonstrated that 5 species of cicadas inhabit Taebaeksan National Park, namely, Leptosemia takanonis, Lyristes intermedius, Kosemia yezoensis, Hyalessa fuscata, and Meimuna opalifera. The time of appearance for L. takanonis was early July to mid-July, and that for L. intermedius, K. yezoensis, H. fuscata, and M. opalifera was mid-July to early September. Analysis of the circadian rhythm revealed that L. intermedius, K. yezoensis, and H. fuscata started producing mating calls between 6:00 and 7:00, which ended at around 19:00 for all the three species. The peak time for producing mating calls was 11:00 for L. intermedius, 12:00 for H. fuscata, and around 13:00 to 14:00 for K. yezoensis. The environmental factors influencing the mating calls of the cicadas inhabiting Taebaeksan National Park were analyzed by logistic regression. The results showed that the probability of producing mating calls increased by 1.192 and 1.279 times in L. intermedius and K. yezoensis, respectively, when the average temperature increased by one degree. When the duration of sunlight increased by one hour, the probability of producing mating calls increased by 4.366 and 2.624 times in L. intermedius and H. fuscata, respectively. Analysis of the interspecific effects revealed that when H. fuscata produced a single mating call, the probability of producing mating calls increased by 14.620 and 2.784 times in L. intermedius and K. yezoensis, respectively. When K. yezoensis and L. intermedius produced mating calls, the probability of producing mating calls in H. fuscata increased by 11.301 and 2.474 times, respectively. L. intermedius and K. yezoensis did not have any effects on each other with respect to the production of mating calls. Analysis of the habitat environment of each species revealed that their habitats were located at altitudes of 1,046 m (780~1,315 m) for L. intermedius, 1,072 m (762~1,361 m) for K. yezoensis, and 976 m (686~1,245 m) for H. fuscata. Unlike H. fuscata, which was found at a low altitude, K. yezoensis and L. intermedius were not found at altitudes lower than 700 m. Analysis of the average aspect of the habitats of each of the cicada species revealed that L. intermedius was found at 166° (125~207°), K. yezoensis was found at 100° (72~128°), and H. fuscata was found at 173° (118~228°). Examination of the distribution of each of the cicada species revealed that they were predominantly distributed in the ridges and slopes located in the southeastern region of Munsubong in Taebaeksan. In summary, L. intermedius and K. yezoensis was found to inhabit higher altitudes in Taebacksan National Park than H. fuscata, which was found throughout the Korean peninsula. Additionally, the main aspect of the cicada habitat was found to be the southeastern region (100~173°), which has good access to daylight.

Potassium Physiology of Upland Crops (밭 작물(作物)의 가리(加里) 생리(生理))

  • Park, Hoon
    • Korean Journal of Soil Science and Fertilizer
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    • v.10 no.3
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    • pp.103-134
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    • 1977
  • The physiological and biochemical role of potassium for upland crops according to recent research reports and the nutritional status of potassium in Korea were reviewed. Since physical and chemical characteristics of potassium ion are different from those of sodium, potassium can not completely be replaced by sodium and replacement must be limited to minimum possible functional area. Specific roles of potassium seem to keep fine structure of biological membranes such as thylacoid membrane of chloroplast in the most efficient form and to be allosteric effector and conformation controller of various enzymes principally in carbohydrate and protein metabolism. Potassium is essential to improve the efficiency of phoro- and oxidative- phosphorylation and involve deeply in all energy required metabolisms especially synthesis of organic matter and their translocation. Potassium has many important, physiological functions such as maintenance of osmotic pressure and optimum hydration of cell colloids, consequently uptake and translocation of water resulting in higher water use efficiency and of better subcellular environment for various physiological and biochemical activities. Potassium affects uptake and translocation of mineral nutrients and quality of products. potassium itself in products may become a quality criteria due to potassium essentiality for human beings. Potassium uptake is greatly decreased by low temperature and controlled by unknown feed back mechanism of potassium in plants. Thus the luxury absorption should be reconsidered. Total potassium content of upland soil in Korea is about 3% but the exchangeable one is about 0.3 me/100g soil. All upland crops require much potassium probably due to freezing and cold weather and also due to wet damage and drought caused by uneven rainfall pattern. In barley, potassium should be high at just before freezing and just after thawing and move into grain from heading for higher yield. Use efficiency of potassium was 27% for barley and 58% in old uplands, 46% in newly opened hilly lands for soybean. Soybean plant showed potassium deficiency symptom in various fields especially in newly opened hilly lands. Potassium criteria for normal growth appear 2% $K_2O$ and 1.0 K/(Ca+Mg) (content ratio) at flower bud initiation stage for soybean. Potassium requirement in plant was high in carrot, egg plant, chinese cabbage, red pepper, raddish and tomato. Potassium content in leaves was significantly correlated with yield in chinese cabbage. Sweet potato. greatly absorbed potassium subsequently affected potassium nutrition of the following crop. In the case of potassium deficiency, root showed the greatest difference in potassium content from that of normal indicating that deficiency damages root first. Potatoes and corn showed much higher potassium content in comparison with calcium and magnesium. Forage crops from ranges showed relatively high potassium content which was significantly and positively correlated with nitrogen, phosphorus and calcium content. Percentage of orchards (apple, pear, peach, grape, and orange) insufficient in potassium ranged from 16 to 25. The leaves and soils from the good apple and pear orchards showed higher potassium content than those from the poor ones. Critical ratio of $K_2O/(CaO+MgO)$ in mulberry leaves to escape from winter death of branch tip was 0.95. In the multiple croping system, exchangeable potassium in soils after one crop was affected by the previous crops and potassium uptake seemed to be related with soil organic matter providing soil moisture and aeration. Thus, the long term and quantitative investigation of various forms of potassium including total one are needed in relation to soil, weather and croping system. Potassium uptake and efficiency may be increased by topdressing, deep placement, slow-releasing or granular fertilizer application with the consideration of rainfall pattern. In all researches for nutritional explanation including potassium of crop yield reasonable and practicable nutritional indices will most easily be obtained through multifactor analysis.

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Studies on the Effects of Various Methods of Rotation Irrigation System Affecting on The Growth, Yield of Rice Plants and Its Optimum Facilities (수환관개방법의 차이가 수도생육 및 수량에 미치는 영향과 그 적정시설에 관한 연구)

  • 이창구
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.12 no.2
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    • pp.1937-1947
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    • 1970
  • This experiment was conducted, making use of the 'NONG-RIM No, 6' a recommended variety of rice plant for the year of 1969. Main purpose of the experiment are to explore possibilities of; a) ways and means of saving irrigation water and, b) overcoming drought at the same time so that an increaded yield in rice production could be resulted in Specifically, it was tried to determine the effects of the Rotation Irrigation method combined with differentiated thickess of Lining upon the growth and Yield of rice production. Some of the major finding are summarized in the follows. 1) The Different thicknesses show a significant relationship with the weight of 1000 grains. In the case of 3cm Lined plot, the grain weight is 39.0 Grams, the heaviest. Next in order is 6 cm lined plnt, 5 day control plot, 6 day control plot. 2) In rice yield, it is found that there is a considerably moderate signicant relationship with both the different thickness of lining and the number of irrgation, as shown in the table No,7. 3) There is little or no difference among different plot in terms of; a) physical and chemical properties of soil, b) quality of irrgation water, c) climatic condition, and rainfalls. 4) It is found that there is no significant relationship between differences in the method of rotation irrgation and the number of ears per hill because of too much rainydays and low temperature during irrigation season. 5) In uyny1-treated plots, it is shown that there is on difference among different plots, but the irrigation water requirement saved as much as 1/2 to actual irrigation water compare to uncontroled plot. 6) The irrigation water requirement for 48 days is saved as much 67% compared to uncontroled plot, the order are; the 9cm lined plot, the plot of vinyl with no hole, the plot with a hole of $1cm/m^2$ as shows in fig 15. 7) The rate of percolation of 40-30mm/day is decreased to 30-20/day. It is found that the decreasad rate of percolation due to vinyl-cutoff in footpath. 8) The growing condition was fine, and there was no found that decease and lageing as always submerged plot. 9) It is found that it must be constructed irrigation and drainage system, inlet and outlet perpect, respectly, of which could be irrigation water saved and would be inereased the irrigation water temperature.

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A Study on the Differences in Breeding Call of Cicadas in Urban and Forest Areas (도시와 산림지역 매미과 번식울음 차이 연구)

  • Kim, Yoon-Jae;Ki, Kyong-Seok
    • Korean Journal of Environment and Ecology
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    • v.32 no.6
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    • pp.698-708
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    • 2018
  • The purpose of this study was to investigate differences in the breeding call characteristics of cicada species found in urban and forest areas in the central region of Korea by examining the interspecific effects and environmental factors affecting the breeding calls and breeding call patterns. The selected research sites were Gyungnam Apartment in Bangbae-dong, Seoul for the urban area and Chiak Mountain National Park in Wonju for the forest area. The research method for both sites was to record cicada breeding calls for 24 hours with a recorder installed at the site and analyze the results. Data from the Korea Meteorological Administration were used for environmental factors. The research period was from June 19, 2017 to September 30, 2017. As a result of the study, there were differences in the emergence of species between the two research sites: while Platypleura kaempferi, Hyalessa fuscata, Meimuna opalifera, Graptopsaltria nigrofuscata, and Suisha coreana were observed at both sites, Cryptotympana atrata was observed in the urban area and Leptosemia takanonis in the forest area only. The emergence periods of cicadas at the two sites were also different. The activities of P. kaempferi and L. takanonis were noticeable in the forest area. In the urban area, however, L. takanonis was not observed and the duration of activity of P. kaempferi was short. In the urban area, C. atrata appeared and sang for a long period; H. fuscata, M. opalifera, and G. nigrofuscata appeared earlier than in the forest area. S. coreana appeared earlier in the forest area than in the urban area. According to the daily call cycle analysis, even cospecific cicada showed a wide variation in their daily cycle depending on the region and the interspecific effects between different cicadas, and the environmental differences between the urban and forest areas affected the calls of cicadas. The results of correlation analysis between each cicada breeding calls and environmental factors of each site showed positive correlation with average temperature of most cicadas except P. kaempferi and C. atrata. The same species of each site showed positive correlations with more diverse weather factors such as solar irradiance. Logistic regression analysis showed that cicadas with overlapping calling times had significant effects on each other's breeding calls. C. atrata, which appeared only in the urban area, had a positive effect on the calling frequency of H. fuscata, M. opalifera, and G. nigrofuscata, which called in the same period. Additionally, L. takanonis, which appeared only in the forest area, and P. kaempferi had a positive effect on each other, and M. opalifera had a positive effect on the calling frequency of H. fuscata and G. nigrofuscata in the forest area. For the environmental factors, the calling frequency of cicadas was affected by the average temperatures of the urban and forest areas, and cicadas that appeared in the forest area were also affected by the amount of solar radiation. According to the results of statistical analysis, urban cicadas with similar activity periods are influenced by species, especially with respect to urban dominant species, C. atrata. Forest cicadas were influenced by species, mainly M. opalifera, which is a forest dominant species. The results of the meteorological impact analysis were similar to those of the correlation analysis, and were influenced mainly by the temperature, and the influence of the insolation was more increased in the forests.

Factors Affecting the Formation of Iodo-Trihalomethanes during Chlorination in Drinking Water Treatment (정수처리에서 염소 처리시 요오드계 트리할로메탄류 생성에 영향을 미치는 인자들)

  • Son, Hee-Jong;Yoom, Hoon-Sik;Kim, Kyung-A;Song, Mi-Jeong;Choi, Jin-Taek
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.8
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    • pp.542-548
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    • 2014
  • Effects of bromide ($Br^-$) and iodide ($I^-$) concentrations, chlorine ($Cl_2$) doses, pH, temperature, ammonia nitrogen concentrations, reaction times and water characteristics on formation of iodinated trihalomethanes (I-THMs) during oxidation of iodide containing water with chlorine were investigated in this study. Results showed that the yields of I-THMs increased with the high bromide and iodide level during chlorination. The elevated pH significantly increased the yields of I-THMs during chlorination. The formation of I-THMs was higher at $20^{\circ}C$ than $4^{\circ}C$, $10^{\circ}C$ and $30^{\circ}C$. In chloramination study, addition of ammonium chloride ($NH_4Cl$) markedly increased the formation of I-THMs. Among the water samples collected from seven water sources including wastewater treatment plant (WWTP) effluent water (EfOM water), prepared humic containing water (HA water) and algal organic matter (AOM) containing water (AOM water), EfOM water generated the highest yields of I-THMs ($12.31{\mu}g/mg$ DOC), followed by HA water ($4.96{\mu}g/mg$ DOC), while AOM water produced the lowest yields of I-THMs ($0.99{\mu}g/mg$ DOC). $SUVA_{254}$ values of EfOM water, HA water and AOM water were $1.38L/mg{\cdot}m$, $4.96L/mg{\cdot}m$ and $0.97L/mg{\cdot}m$, respectively. The I-THMs yields had a low correlation with $SUVA_{254}$ values ($r^2$ = 0.002).

Evaluation of Environment-friendly Control Agents for the Management of Powdery Mildew Infection during Seedling Stage of Three Cucurbitaceae Vegetables (친환경 육묘시 세 가지 박과채소의 흰가루병에 대한 친환경 제제의 방제효과)

  • Yeo, Kyung-Hwan;Jang, Yoon Ah;Kim, Su;Um, Young Chul;Lee, Sang Gyu;Rhee, Han Cheol
    • Journal of Bio-Environment Control
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    • v.22 no.4
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    • pp.413-420
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    • 2013
  • The purpose of this study was to evaluate the control efficacy of major environment-friendly control agents against powdery mildew, as affected by the application condition such as disease-developing stage and microclimate, as compared with the efficacy of pesticides in plug seedling of three Cucurbitaceae vegetables, including cucumber, melon, and oriental melon. Single or combined application of major six environment-friendly control agents was used in the experiment: two biofungicide (Ampelomyces quisqualis 94013 and Bacillus subtilis Y1336), two plant extracts (neem oil and extracts of Rheum undulatum), and two mineral materials (wettable sulfur powder and lime bordeaux mixture). These control agents were treated to the plug seedlings for preventing powdery mildew and curative applications for managing powdery mildew. In all treatments, the disease incidence declined as daily average temperatures increased to $30^{\circ}C$ for consecutive 6~8 days with maximum temperature over $40^{\circ}C$. In preventative application, the control efficacy against powdery mildew was the highest in the treatment of wettable sulfur powder, and lowest in the B. subtilis Y1336, with values of 20~40%. In cucumber seedlings, the preventive single application of neem oil or wettable sulfur powder was more effective than curative application of fungicides, while the control efficacy of these agents was similar to those of fungicides in melon seedlings. The single application of R. undulatum extracts was also effective in preventing the disease for both cucumber and melon seedlings, showing a higher control efficacy than those of biofungicides during seedling stage. The treatment of water spray was not effective and showed a higher disease incidence than the untreated control plot in the oriental melon and melon seedlings. The curative application with environment friendly control agents, after powdery mildew was first detected, could not successfully controlled the disease at the middle stage (5~10% of disease incidence) of disease development. The curative combined application of [R. undulatum extracts (1st application) + wettable sulfur powder (2nd) + neem oil (3rd)] showed the highest control efficacy among the other treatments, with control value over 80% at the early stage (less than 1% of disease incidence) of disease development.

Road-map for Environmental Friendly Integrated Pest Management(IPM) of Insect Pests on the Strawberry Vinyl-houses of Farmer's Field (딸기재배 하우스에서 발생하는 해충의 환경친화적 종합적방제를 위한 로드맵)

  • Lee, D.H.;Jo, C.W.;Park, C.R.;Lee, H.J.;Kang, E.J.;Seok, H.B.;Seo, M.J.;Kim, H.Y.;Kim, Y.H.;Yu, Y.M.;Youn, Y.N.
    • Korean journal of applied entomology
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    • v.47 no.3
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    • pp.273-286
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    • 2008
  • Road-map for the environmental friendly integrated pest management(IPM) of insect pests was drawn up on the strawberry vinyl-houses of farmer's field. Major insect pests were occurred Tetranychus urticae and Aphis gossypii during the strawberry plant seeding in the vinyl house and open field. Also, same insect pests were occurred in the vinyl house during harvesting season of strawberry. For the control of T. urticae and A. gossypii, Phytoseiulus persimilis and Aphidius colemani as natural enemies were input to the vinyl house, respectively. However, because these natural enemies could not control insect pest populations, acaricide and insecticide were sprayed. Then natural enemies were input again in the vinyl house. Natural enemies could not endure the intense cold and differences of temperature and relative humidity between day and night during strawberry harvesting season. So, their behavior and control activity of pests were more decrease than pests. Firstly, natural enemies are input in the vinyl house during the early breeding season of strawberry, secondly, acaricides and insecticide are sprayed for the control of mites and aphids, respectively, during the middle breeding season in the hard winter. Finally, natural enemies are re-input in the vinyl house during the middle and late breeding season.

Diaspore, seed dispersion and seed germination characteristics of two myrmecochrous spring ephemerals -Jeffersonia dubia and Corydalis remota- (개미가 종자를 산포하는 춘계단명식물 깽깽이풀과 현호색의 전파체, 종자산포 및 발아 특성)

  • Kim, Hoi-Jin;Kim, Gab-Tae
    • Korean Journal of Environment and Ecology
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    • v.31 no.6
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    • pp.485-491
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    • 2017
  • This study examined the germination characteristics by collecting fruits and pretreatment of the diaspore from April 2014 to June 2015 to investigate the diaspore characteristics, seed dispersion, and seed germination characteristics of two myrmecochorous spring ephemerals (MCSE): -Jeffersonia dubia (Jb) and Corydalis remota (Cr)-. The diaspore of Jb was about 5mm-long yellow-dark brown, oblong seeds with the attached amorphous white elaiosome. The mean weights of diaspore, seed, and elaiosome were 15.86mg, 13.46mg, and 2.40mg, respectively, and the elaiosome ratio was 15.13%. The diaspore of Cr was about 1.2mm diameter and glossy black ovoid seeds with the attached white spatula-shaped elaiosome. The mean weights of diaspore, seed, and elaisome were 2.58mg, 2.05mg, and 0.53mg, respectively, and the elaiosome ratio was 20.54%. Camponotus niponensis and Formica japonica transported the diaspore of Jb while Formica japonica and Lasius japonicus transported the diaspore of Cr. The germination percentage of Jb seeds was statistically significant and had the significance level of 1% with the pretreatment and date of sowing. However, it was independent of attachment of elaiosome. The mean germination percentages of Jb seeds was 65.0% during sowing on June 20, 17.5% during sowing on August 19, and 0% during sowing on October 20. The germination percentage of Cr was statistically significant and had the significance level of 5% and 1% with the attachment of elaisome and date of sowing, respectively. The mean germination rates were 54.17% and 35.0% in the non-treatment section and the treatment section with elaisome detached, respectively. The mean germination percentages of Cr seeds was 75.0% during sowing on June 20, 53.75% during sowing on August 19, and 5.0% during sowing on October 20. Considering the fact that the ants transported the diaspores to the ant house when the fruits of MCSE were ripened and dropped the seeds, the direct seeding right after collecting may be most suitable to the characteristics of the evolution of these plant species and may be the best method to obtain the highest germination percentages. Since the ants distribute their seeds, the MCSE produces and attaches the elaiosome to the seed to maintain the symbiotic relationship with ants. The ants then transport the seed to the ant house where the environment is controlled for suitable temperature and humidity, and then the MCSE succeeds in germination after the embryo grows sufficiently in the next spring.