검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 162

        81.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        In spite of simple and cheap cultivation method, water broadcast-seeded rice demonstrates uneven and unstable seedling establishment per unit land area and requires more herbicide and labor-input for weed control. Three experiments were conducted in a phytotron at 18~circC to evaluate the adaptability of seed-mat mulching cultivation technologies in water seeded rice for the uniform seedling establishment and the inhibition of weed occurrence without herbicide application. Five different kinds of mat with different mesh sizes and fabric properties were tested. The emergence of rice was the highest in Lawn-mat treatment, being comparable with the control, in which seeds were sown without mat. The Lawn-mat also exhibited the lowest mat tension. Mat tension may influence the emergence of rice. And once it was soaked in water, it didn't maintain its original shape any more. The emergence rate of rice was the lowest in Safer-mat treatment. In Lawn-mat treatment, which was the most effective for rice emergence in the first study, the differences of emergence and seedling establishment of rice depending on the seeding position (upper, beneath, and between mats) treatments were negligible, while they were higher in dry seeds than in pre-germinated seeds treatment. The emergence as affected by the kinds of mat also showed the same trend when tested using barnyard grass. Depending on the kinds of mat, the inhibition effect of weeds was the greatest in Safer-mat and the poorest in Lawn-mat. These results strongly suggest the possibility that the uniform seedling establishment and weed management without chemical could be achieved simultaneously by seed-mat mulching through the combination of effective mat for the emergence of rice and another efficient mat for the inhibition of weed occurrence. This possibility was also tested in the field.
        84.
        2001.09 KCI 등재 서비스 종료(열람 제한)
        Experiments were conducted to find out the optimum level of slow release N fertilizers when total amounts of nitrogen required throughout the growing season in paddy were applied in the soil of seedling box. To evaluate the emergence rate and growth of rice seedlings, five levels of Meister (MS) 10, MS S10, and latex coated urea (LCU) which are equivalent to 0, 40, 60, 80, and 100kg N h a-l were mixed in soil of the seedling box. Emergence rate differed depending on the fertilizers and N levels; in MS 10 plots the emergence rate was 40.8% at 40kg N h a-l and no seedlings were emerged at the higher levels, in MS S10 plots higher than 80% at all the N levels, and decreased with the N levels from 70.0% at 40 kg N h a-l to 59.5% at 100kg N h a-l of LCU. Seedling started to wilt at 40 kg N h a-l of MS 10 and 80 and 100 kg N h a-l N of LCU on the 8th day after sowing, while seedling growth was normal at all the levels of MS S10. Field performance of rice was evaluated at the 0, 30, 60, 90, 120kg N h a-l of MS S10 applied in the soil of seedling box and N was not applied in paddy. Grain yield at 90 and 120kg N h a-l of MS S10 was similar to conventional urea split application (120 kg N h a-l ), but significantly higher compared to 30 and 60kg N h a-l of MS S10. Fertilizer N recovery decreased with N levels and the N recovery at 90 kg N h a-l of MS S10 and conventional urea split application were 62.2 % and 44.2%, respectively, with similar grain yield. The optimum level of MS S10 to be applied in seedling box seems to be about 90 kg N h a-l considering grain yield, price of fertilizer, labor applying fertilizer, and fertilizer N recovery.d fertilizer N recovery
        87.
        2001.06 KCI 등재 서비스 종료(열람 제한)
        벼 어린모 육묘시 적기이앙을 못하여 육묘일수가 연장 될 경우 모소질과 본답초기 생육 및 수량에 미치는 영향을 검토하고자 화성벼를 공시하여 1997년 작물시험장 포장에서 8일모, 12일모, 16일모, 20일모를 이용하여 시험을 수행한 결과는 다음과 같다. 1. 성묘을은 8일모가 93.9%로 가장 높았으며, 12일모는 88.9%, 16일모는 82.0%, 20일모는 80.8%로 육묘일수가 길어질수록 성율이 낮아졌다. 2. 이앙당시 초장이 8일모가 7,6cm, 12일모가 13.0cm, 16일모가 15.1cm, 20일모가 16.9cm로 육묘 12일 이후는 육묘일수 지연에 따른 생육 차이가 적었다. 3. 종자내 배유양분 잔존율은 8일모가 52.5%로 가장 많았으며 12일모가 36.2%, 16일모 30.1%, 20일모가 27.4%였다. 4. 결주율은 8일모와 12일모는 5.1-5.2%로 비슷하였으나 16일모와 20일모는 6.7%, 7.8%로 결주 발생이 많았다. 5. 발근량은 8일모가 104.0로 가장 높았으며, 다음은 12일모로 59.5, 16일모는 41.4, 20일초는 27.9였다 6. ha당 쌀수량은 육묘일수가 길어질수록 수량감소가 현저하여, 8일모 대비(6.18톤) 12일모는 5%, 16일모는 11%, 20일 모는 16%가 감소하였다. 7. 현미의 완전미 비율은 8일모와 12일모는 92.1, 91.5%로 비슷하였으며, 16일모와 20일모는 88.8, 85.4%로 현저히 감소되었다.
        88.
        2001.03 KCI 등재 서비스 종료(열람 제한)
        In order to develop more stable seedling stand method in wet direct rice seeding culture, the effect of making the drainage ditches was studied in both methods of broadcast seeding on floody paddy surface and puddled-soil drill seeding. In a broadcast seeding on floody paddy surface, the ditching after seeding using a tractor or small ditch maker improved the seedling stand, and reduced the floating seedling and herbicide injury by accelerating the drainage. Suitable ditching time was at 2 days after seeding (DAS) for the tractor and at 3 DAS for the ditch maker. In the puddled-soil drill rice seeding culture, the ditching before seeding with a ditch maker at 3 days after draining effectively improved the seedling stand due to quick draining through well formed the seeding furrows. In the puddled-soil drill seeding, seedling stand number showed higher in both ditching plots synchronized with seeding compared with both only draining treatment at 1 DAS without ditching and the flooding plot condition for 6 DAS. And the suitable ditching depth was 6 cm, as considered the ditching status and drained status. These results suggest that the ditching in wet direct rice seeding is an resonable practice for improving the seedling stand through the accelerating drainage of field.
        89.
        1999.12 KCI 등재 서비스 종료(열람 제한)
        Rice seedling test was conducted to check the loging tolerance at ripening stage through evaluating the root characters. Thirteen Korean and foreign rice cultivars with direct seeding adaptable or high quality characteristics were grown in a cell pot and under submerged paddy. The root characters and pushing resistance of rice hill were determined at seedling and ripening stage, respectively. The diameter of crown root at the 7th and 8th leaf stages was thicker in lodging tolerance cultivars than those of others and showed significant-positive correlation with both pushing resistance and crown root diameter of mature plants. Also, the tensile strength of crown root at the 7th and 8th leaf stage showed highly positive correlation with the tensile strength of crown root of mature plants. The number of crown root at 7th leaf stage was significant-positively correlated with that of mature plant. The diameter of seminal root was not significantly correlated with the diameter of crown root throughout the whole growth stage. These results indicate that the diameter, tensile strength and number of crown root associated with root lodging tolerance can be detected with the seedling at about 7th or 8th leaf stage, and the seedling test using the cell pot is an useful and practical method to select lodging tolerant cultivars or lines of rice based on root characters, especially diameter of crown root.
        90.
        1999.09 KCI 등재 서비스 종료(열람 제한)
        To examine the seedling stand and growth as affected by early seeding dates of dry direct seeded rice in the Honam plain area of Korea, Dongjinbyeo was seeded at six seeding dates from early March to late April in rice fields of silty loam soil(Jeonbuk series) at the National Honam Agricultural Experiment Station (NHAES) for two years, 1996 and 1998. Seedling stand decreased slightly. with an early seeding date, but it produced more than the optimum seedling number except for the seeding of 25 March in 1996. Days to emergence was significantly longer, as seeding date was earlier, and days to emergence by early seeding was shortened only by 8 days because the mean air temperature was lower in 1996 than average, while in 1998, the reduction effect was nine to twenty five days because the mean air temperature was higher than average. In early seeding, various weeds occurred at the emergence date of rice and dominant weeds were Alopecurus aequailis, Ludwigia prostata and Rorippa islandica. NH4 + -N content in the soil at the 5th leaf stage and maximum tillering stage were lower, as the seeding date was earlier when nitrogen was split applied as basal and top dressed in 1996, while it was not significantly different among seeding dates when nitrogen was intensively applied as a top dressing in 1998. Tiller number at the maximum tillering stage and panicle number/m2 were more, as seeding date was earlier in 1996, while it was not different in 1998. Filled grain rate and 1,000 grain weight was not different among the seeding dates. Milled rice yield was significantly decreased in the seeding before the middle of March, but in the seeding after late March, it was not varied when compared with the normal seeding date in 1996, while in 1998, there was no difference among seeding dates. From the above results, in consideration of seedling stand, weed occurance, rice growth and milled rice yield, the critical optimum early seeding time in the southern plain area may lie in early April. But it was suggested that when soil moisture is proper for seeding practices, seeding amount is increased and nitrogen is applied after plumule emergence of rice, milled rice yield may not be reduced in the seeding of middle or late March, compared with the seeding in April.l.
        91.
        1999.09 KCI 등재 서비스 종료(열람 제한)
        Unstable seedling stand establishment of wet direct seeding culture of rice is one of the major elements preventing the extension of its culture area. In order to develop methods of seedling stand improvement in direct seeded rice on flooded surfaces, three field experiments were conducted on silty loam soil using a cultivar 'Donjinbyeo' for three years, mainly focusing on water management after seeding and seed soaking with plant growth regulators (PGRs). Under the condition of shallow flooding after seeding, seedling stand rate increased and floating seedling rate decreased in both early and normal season seeding compared to deep flooding. With earlier draining time after seeding, there was a tendency towards preferential growth of the seminal root, increase of seedling stand and decrease of the floating seedling rate. Therefore the highest seedling numbers per unit area and the lowest floating seedling numbers were found upon drainage at 1 day after seeding (DAS), while a contrary tendency was shown upon conventional drainage at 7 DAS. Seed soaking with PGRs such as Metalaxyl or mixing of Metalaxyl with gibberellic acid (GA3 ) significantly increased the seedling stand. In addition the effects of PGR treatment on seedling stand and the early growth of plants were greater under flooded conditions than under drained conditions after seeding, although draining of water after seeding improved the seedling establishment rate more when compared with the PGR treatment. These results suggest that draining management after seeding or maintaining of shallow flooding for a week is the most effective method to improve the seedling stand rate in wet direct seeding.
        92.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        priming; rice seed; SEM; embryo; starch granule; α -amylase; sugar
        93.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        Three rice cultivars, Namweonbyeo (early maturing), Hwaseongbyeo (medium maturing) and Dongjinbyeo (medium-late maturing) were trans-planted with 3 different seedling ages to investigate their growth habits and to improve the cultural method in paddy fields in the southern plain area of the Honam region in 1993. The 10-day old seedlings had more vigorous elongation of plant height and higher tillering ability but lower effective tiller rate, when compared with 35-day or 40-day old seedlings. Leaf area index and top dry weight were lower in 10-day old seedlings up to 40 days after transplanting but thereafter, were not different among seedlings ages. CGR was later in 10-day old seedlings, up to 30 days after transplanting, but in 30 to 40 days after transplanting, it was reversed. RGR was the highest in infant seedlings to 40 days after trans-planting, while in 50 days after transplanting, it was reversed. Panicle number and spikelet number per square meter were the highest in 40-day old seedlings, next highest in 35-day old seedlings and the lowest and in adult seedlings up to 40 days after transplanting, while spikelet number per panicle was vice versa. Milled rice yield did not vary significantly by seedling ages, but among the varieties, it was less in Hwaseongbyeo compared with Naweonbyeo and Dongjnbyeo.
        94.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        본 실험은 볍씨에 염화망간의 농도를 2500, 3500 및 4,500ppm을 처리하여 벼의 초기생육에 대한 생육반응, 엽록소 함량, 유리 proline 및 SOD활성변화를 자포니카형인 일품벼를 실험재료로하여 실험한 결과를 요약하면 다음과 같다. 1. 근장은 무처리보다 망간농도 4,500ppm에서는 0.3cm로 망간농도가 증가할수록 뿌리 생장이 억제되었다. 2. 발아율은 망간농도 3,500ppm에서 68%였으나 망간농도 4,500ppm에서 는 43%로 가장 낮았다. 3, 엽록소 함량은 무처리보다 고농도인 4,500ppm 에서 1.16mg으로 가장 낮았다. 4. 유리 proline 함량은 무처리에서는 발아 후 3일과 8일에서 큰 차이를 보이지 않았고 발아 후 3일째 망간농도2,500ppm과 4,500ppm에서 각각 3,286μmole과 5,872μmole로 망간농도가 높아질수록 유리 proline 함량이 증가하였다. 5. SOD 활성은 발아 후 2일째 무처리가 762EU인 것에 비해 망간농도 4,500ppm에서는 1,693EU로 가장 높았다.
        95.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        The study was conducted to find the critical concentrations of zinc toxicity and to determine the changes of the contents of free proline and organic acids with treatment of different zinc chloride concentrations during rice germination and seedlings grown for seven days. The concentration of zinc chloride, 140 ppm, inhibited root elongation as much as 46 times compared with the control, and the germination rate was also decreased in all treatments of zinc chloride, showing that the germination rate decreased more with increasing concentrations of zinc chloride. Its rate was only 13% with treatment of 140 ppm zinc chloride. The content of free proline with treatment of zinc chloride, 140 ppm, was highest about 4,873 ~mu M at 3 days compared with the control. Malic acid concentration with treatment of zinc chloride, 140 ppm, increased to approximately 4 times compared to the control. Citric and succinic acid content were also slightly increased in all treatments of zinc chloride
        96.
        1998.12 KCI 등재 서비스 종료(열람 제한)
        These experiments were conducted to investigate water uptake, electrical conductivity, germination percentage, seedling growth, and seedling establishment rate in direct seeding cultivation of rice. The rice seeds of six japonica type varieties were coated with 12 kinds of polymers in a standard concentration of 0.2% using seed coating machine. The water absorption of the polymer-coated seeds under saturation conditions was not different among varieties, and was the highest in kulcel, maltrin, and waterlock on the polymer-coated seeds. The electrical conductivity with waterlock (55.0 ~mu scm-1g-1 ) was higher than the control plot (45.6 ~mu scm-1g-1 ) and other treatments. The germination of the polymer-coated seeds was 95.9% at control plot, 92.7% at low temperature and 35.7% at high temperature. The total dry weight of seed decreased in the order of low temperature, control plot, and high temperature, and was effective in pvp (polyvinyl pyrrolidone), opadry, and sacrust. The seedling establishment rate in direct seeding cultivation ranged from 74.9 to 81.0% in flooded paddy surface, and ranged from 64.7 to 76.6% in dry paddy. In both cases, it decreased in the order of early, medium and medium-late varieties, but was enhanced in daran 8600, sepirect, and sacrust. According to this study the recommended polymers for direct seeding cultivation of rice are daran 8600, sepirect, and sacrust
        97.
        1998.09 KCI 등재 서비스 종료(열람 제한)
        An experiment was carried out to find out the priming effects of rice seeds, Oryza sativa L. (cv. Ilpumbyeo) on. the seedling establishment and early emergence under excess soil moisture conditions. Seeds were primed by soaking in -0.6 MPa polyethylene glycol (PEG) solution at 25~circC for 4 days. The primed seeds were sown in soils with various soil moistures (60, 80, 100, 120, and 140% field capacity) at 17 and 25~circC , respectively. Germination and emergence rates, plumule height, and radicle length of primed seeds were higher than those of untreated seeds at any soil moisture and temperature examined. The time from planting to 50% germination (T50 ) of primed seeds was less than that of untreated seeds by 0.9~3.7 days. Germination rate, emergence rate, plumule height, and radicle length were highest at the soil moisture of 80% field capacity among the soil moistures. Priming effects of rice seeds on germination and emergence rates were more prominent under the unfavorable soil moistures (60, 100, 120, and 140% field capacity) than those under the optimum soil moisture condition (80% field capacity). However, priming effects on seedling growth were greater at near optimum soil moisture compared with too lower or higher soil moistures. Therefore, these findings suggest that priming of rice seeds may be a useful way for better seedling establishment under the adverse soil conditions.
        100.
        1997.08 KCI 등재 서비스 종료(열람 제한)
        벼 품종 안중벼를 공시하고 조류 기피제인 methiocarb을 여러 가지 제형으로 제조하고, 약량을 달리하여 최아 볍씨에 처리한 후 새 피해, 초기 생육 및 약해를 조사한 결과를 요약하면 다음과 같다. 1. <시험 1> Methiocarb 제형별 새 피해 경감 효과와 모의 생육 1) Methiocarb의 처리는 제형과 약량에 관계없이 새에 의한 피해가 없었으나 무처리구는 5일후에 30%, 10일 후에 85%, 15일 후에는 100%의 피해를 입었다. 2) 입모율은 처리간 유의한 차이가 없었으나, 파종 15일 후의 초장과 잎수는 methiocarb 15g 처리구에서는 methiocarb 10g 처리구에 비하여 유의하게 작아서 약해가 있었다. 3) 파종 35일 후 약해에 대한 회복 상태를 보면 methiocarb+thiram 15g 처리구는 초장이 유의하게 작았으나, methiocarb FS 15g처리구 초장은 무처리구와 큰 차이가 없었다. 2. <시험 2> Methiocarb 제형의 벼 종자 분의에 의한 본답 시험 1) Methiocarb 처리구는 무처리구에 비하여 새 피해가 유의하게 경감되는 것으로 나타났다. 2) 파종 25일 후의 초장과 잎수는 모든 처리구에서 유의한 차이를 보이지 않았다. 3) 파종 10일 후에는 약제 처리구는 경후한 약해가 발생하였으나 파종 20일 후에는 무처리구와 큰 차이가 없었다.
        1 2 3 4 5