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  • Title/Summary/Keyword: Agricultural R and D

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Modeling Temperature-Dependent Development and Hatch of Overwintered Eggs of Pseudococcus comstodki (Homoptera:Pseudococcidae) (가루깍지벌레(Pseudococcus comstocki (Kuwana))월동알의 온도발육 및 부화시기예찰모형)

  • Jeon, Heung-Yong;Kim, Dong-Soon;Yiem, Myoung-Soon;Lee, Joon-Ho
    • Korean journal of applied entomology
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    • v.35 no.2
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    • pp.119-125
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    • 1996
  • Temperature-dependent development study for overwintered eggs of Pseudococcus comstocki (Kuwana) wasconducted to develop a forecasting model for egg hatch date. Hatch times of overwintered eggs were comparedat five constant temperatures (10, 15, 20, 25, 27C) and different collection dates. A nonlinear, four-parameterdevelopmental model with high temperature inhibition accurately described (R2=0.9948) mean developmentalrates of all temperatures. Variation in developmental times was modeled(~~=0.972w9)it h a cumulative Weibullfunction. Least-squares linear regression (rate=O.O06358[Temp.]-0.07566)d escribed development in the linearregion (15-25C) of the development curve. The low development threshold temperature was estimated 11.9"Cand 154.14 degree-days were required for complete development. The linear degree-day model (thermal summation)and rate summation model (Wagner et al. 1985) were validated using field phenology data. In degreedaymodels, mean-minus-base method, sine wave method, and rectangle method were used in estimation of dailythermal units. Mean-minus-base method was 18 to 28d late, sine wave method was 11 to 14d late, rectanglemethod was 3 to 5d late, and rate summation model was 2 to 3d late in predicting 50% hatch of overwinteredeggs. hatch of overwintered eggs.

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Improvement of Salt Accumulated Soil and Crop Growth using Coal Ash (석탄회를 이용한 염류집적 토양 개선과 작물 생육 증진)

  • Lee, Jong Cheol;Oh, Se Jin;Kang, Min Woo;Kim, Young Hyun;Kim, Dong Jin;Lee, Sang Soo
    • Korean Journal of Environmental Agriculture
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    • v.40 no.2
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    • pp.83-91
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    • 2021
  • BACKGROUND: Cultivation area using agricultural plastic film facilities in Korea is rapidly increasing every year; however, it accelerates the salt accumulation in soils due to repeated cultivation and excessive use of chemical fertilizers. Coal ash contains various trace elements and has high potential to be used in agricultural purposes. This research was aimed to improve the quality of salts-accumulated soils and crop growth grown in the plastic film facilities using the soil amendment derived from coal ash and zero-valent iron powder. METHODS AND RESULTS: Soil amendment used in the study was manufactured using coal ash with iron powder and subjected to a typical upland soil for soil quality enhancement and two salts-accumulated soils for crop growth. After one month incubation of the salts-accumulated soils treated with the soil amendment, soil pH increased significantly and soil EC decreased by approximately 50%, compared to the control or the treatment without the soil amendment. Since the soil salts' concentration is proportional to EC, the subjected soil amendment can be proposed as an effective way to overcome soil salts accumulation in agricultural plastic film facilities. For crop growth, the length of roots and stems increased by approximately 10% and the dry weight also increased by a maximum of 75%, compared to the control. CONCLUSION: The soil amendment made from waste resources such as coal ash and zero-valent iron was found to not only be effective in improving salt-accumulated soils and crop yield but also be safe against harmful heavy metals.

Fate of inorganic nitrogen by addition of silica materials on the fresh soil condition (규산자재(珪酸資材)의 첨가(添加)에 따른 답토양중(沓土壤中) 무기태질소(無機態窒素)의 동태(動態))

  • Lee, Sang Kyu;Yu, Jin Chang;Kohno, Michiyoshi
    • Korean Journal of Soil Science and Fertilizer
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    • v.8 no.2
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    • pp.61-68
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    • 1975
  • A laboratory study was conducted to determine the effect of nitrogen mineralization in accordance with addition of calcium silicate and wollastonite on the fresh soil condition. Results are summarized as follows. 1. Nitrogen mineralization due to application of silica materials was rapidly occured in Saweon sand soil than in Honam clay soil. Also wollastonite application more stimulated the nitrogen mineralization than calcium silicate. 2. Silica material application enhanced loss of applied nitrogen by denitrification due to accelerate the nitrification in Suweon sand soil. This tendency was more severe in calcium silicate applicated treatment than in wallasnonite applicated. 3. From these results, nitrogen should be applicated with organic matter to improve the supply of nitrogen nutrient to plant when silica materials were applied.

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Conformation and Reactivity of Herbicidal Benzenesulfonyl urea Compounds (제초성 Benzenesulfonyl urea계 화합물의 형태와 반응성)

  • Yu, Seong-Jae;Lee, Sang-Ho;Ko, Young-Kwan;Sung, Nak-Do
    • Applied Biological Chemistry
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    • v.39 no.3
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    • pp.235-240
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    • 1996
  • The most stable stereo conformer in non substituted benzenesulfonyl urea, 1 was the II-keto form, which the molecule was intramolecular associated(H-bond) coformer between imide group and N atom on the Pyrimidine ring. The hydrolytic degradation of 2 derivatives were proceeds by nucleophilic addition reaction(p<0) with orbital controlled intermolecular interaction between LUMO with electron donating(σ<0) groups of 2 and HOMO of water molecule. N-(4,6-disub. pyrimid ine-2-yl)aminocarbonyl-2-(1,1-dimethoxy-2-fluoro)ethylbenze nesulfonamides,3 and N-(4,6-disub. triazine-2-yl)aminocarbonyl-2-(1,1-d imethoxy-2-fluoro)ethylbenzenesulfonamides,4 we re synthesized and their herbicidal activities in vivo against bulrush (Scirpus juncoides.) were measured by the pot test under the paddy conditions And the structure activity relationships(SAR) were analyzed by the multiple regression technique. The results of the SAR suggested that the 3 and 4 derivatives indicated dependent on the hydrophobicity of the 4,6-disubstituents and the heterocyclo group, where the optimal value ((logP)opt.=0.89) of hydrophobicity was 0.89. The pyrimidine substituents, 3 showed higher herbicidal activity than the triazine substituents, 4. Among them, 4,6-dimethoxypyrimidine substituent, 3a showed the best herbicidal activity.

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Foliage Contact Herbicidal Activity of Dehydrocostus lactone Derived from Saussurea lappa (목향(Saussurea lappa) 유래 Dehydrocostus lactone의 경엽 접촉 살초 활성)

  • Cho, Kwang-Min;An, Xue-Hua;Chon, Jae-Kwan;Kim, Hyo-Sun;Chun, Jae-Chul
    • Korean Journal of Weed Science
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    • v.30 no.4
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    • pp.421-428
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    • 2010
  • A foliage contact herbicidal substance was separated from ethyl ether fraction in n-hexane extract of Saussurea lappa roots and identified as dehydrocostus lactone [(3aS,6aR,9aR,9bS)-3,6,9-trimethylidene-3a,4,5,6a,7,8,9a,9b-octahydroazuleno[5,4-d]furan-2-one](DHCL). When DHCL at 4,000 ppm was foliage-applied to two grasses and two broadleaf plants, greater than 85% necrotic injury was obtained from large crabgrass, maize and soybean, whereas only about 40% necrotic injury appeared in black nightshade, indicating that DHCL has no gross morphological selectivity, but shows difference in contact response among the plant species tested. Conductivity in incubation medium of the leaf disks treated with DHCL increased as the incubation time continued. Relatively low contact injury in black nightshade as compared with the other three plant species tested was attributed to decrease in absorption of DHCL due to relatively high amount of cuticle. DHCL did not require light in the herbicidal action and there were no inhibitory effects on seed germination and cell elongation. Acetyl-CoA carboxylase activity was inhibited by 30% and 58% at 100μM and 1000μM DHCL, respectively. These results suggested that the herbicidal action of DHCL was related with inhibition of fatty acid synthesis which in turn caused to weaken cell membrane integrity.

The Study for Antioxidative Effects of Acanthopanax sessiliflorus Extract as a New Cosmetics Ingredients Using Electron Paramagnetic Resonance (전자상자성공명법을 이용한 오가피나무추출물의 항산화효과에 대한 연구)

  • Choi, Shin-Wook;Kim, Chang-Su;Choi, Myoung-Soo;Kim, Bo-Hyeon;Kim, Hack-Soo;Choi, Dae-Sung
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.31 no.1 s.49
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    • pp.73-78
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    • 2005
  • This work was carried out to investigate the antioxidative effects of Acanthopnax sessiliflorus from Jeongseon County for the purpose of development of a novel antioxidant from natural products. The antioxidant activity was determined by using electron paramagnetic resonance (EPR), not measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) which have bun used for antioxidant activity of natural sources. Although DPPH radical scavenging activity assay have been generally used for antioxidant activity, this assay is nut appropriated for determinating which radical is scavenged by extracts from natural products. Using EPR, we determinated whether A. sessiliflorus extracts from Jeongseon County scavenge specific radicals or not. On experiment of scavenging superoxide anion radical, hydroxyl radical, nitrogen dioxide and peroxinitrite. Extracts from A. sessiliflorus showed high antioxidant activities to reactive oxygen and nitrogen species. These result suggest that extracts from A. sessiliflorus act as an antioxidant by scavenging reactive oxygen and nitrogen species and used as new cosmetic ingredients for anti-oxidative stress in skin.

Preliminary Studies on Production of Porcine Leucocyte Interferon (돼지 Leucocyte Interferon 생산(生産)에 대한 기초연구(基礎硏究))

  • Jun, Moo Hyung;Chung, Un Ik;Park, Bong Kyun;Kim, Kyo Joon;Lee, Hun Jun
    • Korean Journal of Agricultural Science
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    • v.12 no.1
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    • pp.153-161
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    • 1985
  • As a preliminary step for production of large quantities of porcine leucocyte interferon(Por IFN-\alha), various factors such as the sources of leucocytes, inducers and culture conditions were investigated. In addition, an assay system for the potency of porcine interferon was developed in a micro-system by using porcine kidney cell line, PK-15, and vesicular stomatitis virus. By the experiments, it was found that the porcine leucocyte interferon was synthesized more effectively in the leucocyte suspension with the higher viability and the lesser erythrocyte contamination. Regarding cell sources, the peripheral leucocytes produced a consistently higher unit of interferon than the spleen cells. When the efficiency of inducers was compared, the Sendai virus at the concentration of 125 HA unit/ml was found to be more effective for porcine leucocyte interferon production than the Newcastle disease virus. Average potency of 9 batches of the crude interferon measured by the established assay system was 1,200 unit/ml.

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Immobilization of βgalactosidase with High Transgalactosylation Activity from Bacillus sp. A4442 Mutant (변이주 Bacillus sp. A4442가 생산하는 갈락토스 전이활성이 높은 βgalactosidase의 고정화)

  • Kim, Min-Hong;Jung, Jin;In, Man-Jin
    • Applied Biological Chemistry
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    • v.39 no.5
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    • pp.333-337
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    • 1996
  • For continuous production of galactooligosaccharides(GOS), βgalactosidase with h1gh transgalactosylation activity from Bacillus sp. A 4442 was Immobilized onto DiaionTM HPA 75(styrene-divinylbenzene resin). The parameters influencing enzyme immobilization were scrutinized in order to maximize immobilization yield while minimizing enzyme inactivation. The optimum conditions turned out to be: Tris buffer concentration 30 mM, pH 8.0, contact time at room temperature 3 hr, and enzyme loading 25 mg protein/g resin. Both the thermal stability and the operational stability of immobilized enzyme were markedly enchanced by the treatment with 0.5% glutaraldehyde as a cross-linker. Under the experimental conditions established, the yield of βgalactosidase immobilization was 40% or more and the activity of the immobilized enzyme ca. 200 U/g resin. When a packed-bed reactor was employed to continuously convert lactose to GOS, the specific production, which refers to as the amount of commercially valuable GOS produced by a unit amount of immobilized βgalactosidase, was found to be ca. 300 g GOS/g carrier.

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Effect of a microbial phytase on growth performance, plasma parameters and apparent ileal amino acid digestibility in Youxian Sheldrake fed a low-phosphorus corn-soybean diet

  • He, Shaoping;Medrano, R.F.;Yu, Qifang;Cai, Yixin;Dai, Qiuzhong;He, Jianhua
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.10
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    • pp.1442-1449
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    • 2017
  • Objective: This study investigated the effect of microbial phytase supplementation on growth performance, tibia ash, plasma parameters, apparent ileal digestibility (AID) of amino acid (AA) and apparent digestibility of nutrients in Youxian Sheldrakes fed with low-phosphorus (P) cornsoybean diets. Methods: A total of 350 Youxian Sheldrakes (7d old) were randomly divided into 5 treatment groups: positive control (PC) group has adequate available P diet (0.42% and 0.38%, starter and grower), negative control (NC) group were deficient in available P (0.32% and 0.28%, starter and grower) and NC diet was supplemented with 3 levels of microbial phytase (500, 750, and 1,000 U/kg). Results: Dietary supplementation of phytase in NC diet improved the average daily gain, increased the levels of serum calcium (Ca), tibia Ca and P, AID of AA and apparent digestibility of energy and Ca in starter stage (p<0.05). There was an increased (p<0.001) in the utilization of P from 17.3% to 23.9%. Phytase supplementation (1,000 U/kg) has shown that the AID of His, Thr, Val, indispensable AA, Glu, Pro, and dispensable AA was higher (p<0.05) than that of NC. Moreover, phytase supplementation improved (p<0.05) serum and tibia Ca and P, AID of AA and apparent digestibility of dry matter, crude protein, energy, P and Ca, and reduced (p<0.05) feed to gain ratio (F/G) and the levels of serum alkaline phosphatase in grower stage. Likewise, an increase (p<0.001) in the utilization of P was noticed from 12.6% to 17.2%. Supplement phytase at 750 U/kg improved the AID of His, Thr, Asp, Cys, Pro, and Ser (p<0.05). Conclusion: The microbial phytase supplement could improve growth performance, AID of some AA and apparent utilization of other nutrients in Youxian Sheldrakes, and reduce excreta P load to environment.

Linkage Between Brown Planthopper Resistance Gene and Salt Tolerance in Rice (벼멸구 저항성 유전자와 내염성과의 연관)

  • Yang Dae Hwa;Kim Jin-Hong;Wi Seung Gon;Baek Myung-Hwa;Lim Sang Yong;Lee In Sok;Lee Kyu-Seong;Lee Myung Chul;Lim Yong-Pyo;Chung Byung Yeoup;Kim Jae-Sung
    • Journal of Life Science
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    • v.15 no.1 s.68
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    • pp.61-65
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    • 2005
  • Using two japonica rice cultivars (Ilpumbyeo and Sanghaehyanghyella), which are distinguishable by the brown planthopper (BHP) resistance maker (R208), a relationship between the BPH resistance gene (Os-Bil) and salt-tolerance was investigated. To do this, changes in the expression level of Os-Bil by the salt stress were quantified by the real-time PCR in the two cultivars, and compared with those in other two indica rice cultivars (Pokkali and IR29). In Ilpumbyeo, the expression level of Os-Bil decreased by the treatments of 50 and 200 mM NaCl in a concentration-dependent manner, and in Sanghaehyanghyella it rather increased slightly at 50 mM but decreased drastically at 200 mM. Comparably, IR29, a salt-sensitive cultivar, showed a reduction of the Os-Bil gene expression after the treatment of 100 mM NaCl, but Pokkali, a salt-tolerance cultivar, rather increased about two times in the level of Os-Bil transcripts. These results suggest that the BPH resistance gene may involve in the difference in the salt-tolerance at least between the two indica rice cultivars.